AVAILABLE
Functional Diagrams
Pin Configurations appear at end of data sheet.
Functional Diagrams continued at end of data sheet.
UCSP is a trademark of Maxim Integrated Products, Inc.
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
________________General Description
The MAX3224E/MAX3225E/MAX3226E/MAX3227E/
MAX3244E/MAX3245E are 3V-powered EIA/TIA-232
and V.28/V.24 communications interfaces with automat-
ic shutdown/wakeup features, high data-rate capabili-
ties, and enhanced electrostatic discharge (ESD)
protection. All transmitter outputs and receiver inputs
are protected to ±15kV using IEC 1000-4-2 Air-Gap
Discharge, ±8kV using IEC 1000-4-2 Contact Discharge,
and ±15kV using the Human Body Model.
All devices achieve a 1µA supply current using Maxim’s
revolutionary AutoShutdown Plus™ feature. These
devices automatically enter a low-power shutdown
mode when the RS-232 cable is disconnected or the
transmitters of the connected peripherals are inactive,
and the UART driving the transmitter inputs is inactive
for more than 30 seconds. They turn on again when
they sense a valid transition at any transmitter or receiv-
er input. AutoShutdown Plus saves power without
changes to the existing BIOS or operating system.
The MAX3225E/MAX3227E/MAX3245E also feature
MegaBaud™ operation, guaranteeing 1Mbps for high-
speed applications such as communicating with ISDN
modems. The MAX3224E/MAX3226E/MAX3244E guar-
antee 250kbps operation. The transceivers have a pro-
prietary low-dropout transmitter output stage enabling
true RS-232 performance from a +3.0V to +5.5V supply
with a dual charge pump. The charge pump requires
only four small 0.1µF capacitors for operation from a
3.3V supply. The MAX3224E–MAX3227E feature a logic-
level output (READY) that asserts when the charge
pump is regulating and the device is ready to begin
transmitting.
All devices are available in a space-saving TQFN,
SSOP, and TSSOP (MAX3224E/MAX3225E/MAX3244E/
MAX3245E) packages.
________________________Applications
Notebook, Subnotebook, and Palmtop Computers
Cellular Phones
Battery-Powered Equipment
Hand-Held Equipment
Peripherals
Printers
__Next Generation Device Features
♦♦For Space-Constrained Applications:
MAX3228E/MAX3229E: ±15kV ESD-Protected,
+2.5V to +5.5V, RS-232 Transceivers in UCSP™
MAX3222E/MAX3232E/MAX3241E/MAX3246E:
±15kV ESD-Protected, Down to 10nA, +3.0V to
+5.5V, Up to 1Mbps, True RS-232 Transceivers
(MAX3246E Available in UCSP)
♦♦For Low-Voltage or Data Cable Applications:
MAX3380E/MAX3381E: +2.35V to +5.5V, 1µA,
2Tx/2Rx RS-232 Transceivers with ±15kV
ESD-Protected I/O and Logic Pins
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
19-1339; Rev 10; 3/11
PART
MAX3224E
MAX3225E
MAX3226E
1/1
2/2
2/2
NO. OF
DRIVERS/
RECEIVERS
READY
OUTPUT
✔
✔
✔
Auto-
Shutdown
Plus
✔
✔
✔
250k
1M
250k
GUARANTEED
DATA RATE
(bps)
MAX3227E
MAX3244E
MAX3245E
3/5
3/5
1/1 ✔
—
—
✔
✔
✔
1M
250k
1M
Ordering Information continued at end of data sheet.
+
Denotes a lead(Pb)-free/RoHS-compliant package.
*
EP = Exposed pad.
AutoShutdown Plus, MegaBaud, and UCSP are trademarks of
Maxim Integrated Products, Inc.
_____________________ Selector Guide
Ordering Information
PART TEMP RANGE PIN-PACKAGE
MAX3224ECTP+ 0°C to +70°C 20 TQFN-EP*
MAX3224ECUP+ 0°C to +70°C 20 TSSOP
MAX3224ECAP+ 0°C to +70°C 20 SSOP
MAX3224ECPP+ 0°C to +70°C 20 Plastic DIP
MAX3224EETP+ -40°C to +85°C 20 TQFN-EP*
MAX3224EEUP+ -40°C to +85°C 20 TSSOP
MAX3224EEAP+ -40°C to +85°C 20 SSOP
MAX3224EEPP+ -40°C to +85°C 20 Plastic DIP
MAX3224EAAP+ -40°C to +125°C 20 SSOP
MAX3224E/MAX3225E/
MAX3226E/MAX3227E/
MAX3244E/MAX3245E
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VCC = +3V to +5.5V, C1–C4 = 0.1µF, tested at 3.3V ±10%; C1= 0.047µF, C2–C4 = 0.33µF, tested at 5.0V ±10%; TA= TMIN to TMAX,
unless otherwise noted. Typical values are at TA= +25°C.)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
VCC to GND..............................................................-0.3V to +6V
V+ to GND (Note 1) ..................................................-0.3V to +7V
V- to GND (Note 1) ...................................................+0.3V to -7V
V+ +⏐V-⏐(Note 1) ................................................................+13V
Input Voltages
T_IN, FORCEON, FORCEOFF to GND ................ -0.3V to +6V
R_IN to GND ....................................................................±25V
Output Voltages
T_OUT to GND.............................................................±13.2V
R_OUT, INVALID, READY to GND .........-0.3V to (VCC + 0.3V)
Short-Circuit Duration
T_OUT to GND .......................................................Continuous
Continuous Power Dissipation (TA= +70°C)
16-Pin SSOP (derate 7.14mW/°C above +70°C) .........571mW
16-Pin TSSOP (derate 9.4mW/°C above +70°C) ......754.7mW
16-Pin TQFN (derate 20.8mW/°C above +70°C) ....1666.7mW
20-Pin TQFN (derate 21.3mW/°C above +70°C) ....1702.1mW
20-Pin Plastic DIP (derate 11.11mW/°C above +70°C) ...889mW
20-Pin SSOP (derate 8.00mW/°C above +70°C) .........640mW
20-Pin TSSOP (derate 10.9mW/°C above +70°C) .......879mW
28-Pin Wide SO (derate 12.5mW/°C above +70°C)............1W
28-Pin SSOP (derate 9.52mW/°C above +70°C) .........762mW
28-Pin TSSOP (derate 12.8mW/°C above +70°C) .......1026mW
36-Pin TQFN (derate 26.3mW/°C above +70°C)...........2105mW
Operating Temperature Ranges
MAX32_ _EC_ _ .................................................0°C to +70°C
MAX32_ _EE_ _................................................-40°C to +85°C
MAX32_ _EAA_..............................................-40°C to +125°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow) .......................................+260°C
Note 1: V+ and V- can have maximum magnitudes of 7V, but their absolute difference cannot exceed 13V.
VCC = 5.0V
FORCEON = GND, FORCEOFF = VCC,
all R_IN idle, all T_IN idle
TA= +25°C
VCC = 3.3V
T_IN, FORCEON,
FORCEOFF
CONDITIONS
kΩ357Input Resistance
V0.5Input Hysteresis
1.8 2.4 V
1.5 2.4
Input Threshold High
0.8 1.5 V
0.6 1.2
Input Threshold Low
V-25 +25Input Voltage Range
V
VCC - 0.6 VCC - 0.1
Output Voltage High
V0.4Output Voltage Low
µA110Supply Current, Shutdown
µA110
Supply Current,
AutoShutdown Plus
µA±0.05 ±10Output Leakage Current
µA±0.01 ±1
Transmitter Input Hysteresis V0.5
V
2.4
Input Logic Threshold High
mA0.3 1
Supply Current,
AutoShutdown Plus Disabled
V0.8Input Logic Threshold Low
2
UNITSMIN TYP MAXSYMBOLPARAMETER
FORCEOFF = GND
TA= +25°C
VCC = 5.0V
VCC = 3.3V
TA= +25°C
R_OUT (MAX3244E/MAX3245E), receivers
disabled
T_IN, FORCEON, FORCEOFF
VCC = 5.0V
FORCEON = FORCEOFF = VCC, no load
T_IN, FORCEON, FORCEOFF
IOUT = -1.0mA
VCC = 3.3V
IOUT = 1.6mA
DC CHARACTERISTICS (VCC = 3.3V or 5.0V, TA= +25°C)
LOGIC INPUTS AND RECEIVER OUTPUTS
RECEIVER INPUTS
Input Leakage Current
2
Maxim Integrated
MAX3224E/MAX3225E/
MAX3226E/MAX3227E/MAX3244E/MAX3245E
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +3V to +5.5V, C1–C4 = 0.1µF, tested at 3.3V ±10%; C1= 0.047µF, C2–C4 = 0.33µF, tested at 5.0V ±10%; TA= TMIN to TMAX,
unless otherwise noted. Typical values are at TA= +25°C.)
CONDITIONS
Ω300 10MOutput Resistance
V±5 ±5.4Output Voltage Swing
UNITSMIN TYP MAXSYMBOLPARAMETER
Figure 4a
T1IN = T2IN = GND, T3IN = VCC,
T3OUT loaded with 3kΩto GND,
T1OUT and T2OUT loaded with
2.5mA each
s15 30 60t
AUTOSHDN
Receiver or Transmitter Edge to
Transmitters Shutdown
µs100tWU
Receiver or Transmitter Edge to
Transmitters Enabled
µs30tINVL
Receiver Positive or Negative
Threshold to INVALID Low
µs1tINVH
Receiver Positive or Negative
Threshold to INVALID High
V
VCC - 0.6
INVALID, READY
Output Voltage High
(MAX3224E–MAX3227E)
V0.4
INVALID, READY
Output Voltage Low
(MAX3224E–MAX3227E)
V-0.3 +0.3
Receiver Input Threshold to
INVALID Output Low
-2.7 V
2.7
Receiver Input Threshold to
INVALID Output High
±15
±8R_IN, T_OUT kV
±15
V±5Transmitter Output Voltage
µA±25Output Leakage Current
±60 mAOutput Short-Circuit Current
VCC = V+ = V- = 0V, transmitter outputs = ±2V
All transmitter outputs loaded with 3kΩto
ground
VCC = 5V, Figure 5b (Note 2)
VCC = 5V, Figure 5b (Note 2)
VCC = 5V, Figure 4b
VCC = 5V, Figure 4b
IOUT = -1.0mA
IOUT = -1.6mA
Figure 4a
Negative threshold
Positive threshold
Human Body Model
VCC = 0V or 3V to 5.5V, VOUT = ±12V,
Transmitters disabled
IEC 1000-4-2 Contact Discharge
IEC 1000-4-2 Air Discharge
TRANSMITTER OUTPUTS
MOUSE DRIVEABILITY (MAX3244E/MAX3245E)
ESD PROTECTION
AutoShutdown Plus (FORCEON = GND, FORCEOFF = VCC)
Maxim Integrated
MAX3224E/MAX3225E/
MAX3226E/MAX3227E/MAX3244E/MAX3245E
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
TIMING CHARACTERISTICS—MAX3224E/MAX3226E/MAX3244E
(VCC = +3V to +5.5V, C1–C4 = 0.1µF, tested at 3.3V ±10%; C1= 0.047µF, C2–C4 = 0.33µF, tested at 5.0V ±10%; TA= TMIN to TMAX,
unless otherwise noted. Typical values are at TA= +25°C.)
TIMING CHARACTERISTICS—MAX3225E/MAX3227E/MAX3245E
(VCC = +3V to +5.5V, C1–C4 = 0.1µF, tested at 3.3V ±10%; C1= 0.047µF, C2–C4 = 0.33µF, tested at 5.0V ±10%; TA= TMIN to TMAX,
unless otherwise noted. Typical values are at TA= +25°C.)
Note 2: A transmitter/receiver edge is defined as a transition through the transmitter/receiver input logic thresholds.
Note 3: Transmitter skew is measured at the transmitter zero cross points.
CL= 150pF
to 1000pF
R_IN to R_OUT, CL= 150pF
RL= 3kΩ, CL= 1000pF,
one transmitter switching
VCC = 3.3V, TA= +25°C,
RL= 3kΩto 7kΩ,
measured from +3V to -3V
or -3V to +3V, one trans-
mitter switching
Normal operation (MAX3244E only)
Normal operation (MAX3244E only)
(Note 3)
CONDITIONS
0.15tPLH
µs
0.15tPHL
kbps250Maximum Data Rate
Receiver Propagation Delay
V/µs630Transition-Region Slew Rate
ns200Receiver Output Enable Time
ns200Receiver Output Disable Time
ns100
⏐tPHL - tPLH ⏐
Transmitter Skew
ns50
⏐tPHL - tPLH ⏐
Receiver Skew
UNITSMIN TYP MAXSYMBOLPARAMETER
VCC = 4.5V to 5.5V, RL= 3kΩ,
CL= 1000pF, one transmitter switching
VCC = 3.0V to 4.5V, RL= 3kΩ,
CL= 250pF, one transmitter switching
RL= 3kΩ, CL= 1000pF,
one transmitter switching
VCC = 3.3V, TA= +25°C,
RL= 3kΩto 7kΩ, CL= 150pF to 1000pF,
measured from +3V to -3V or -3V to +3V,
one transmitter switching
(Note 3)
R_IN to R_OUT, CL= 150pF
Normal operation (MAX3245E only)
Normal operation (MAX3245E only)
CONDITIONS
1000
1000 kbps
250
Maximum Data Rate
V/µs24 150Transition-Region Slew Rate
ns50
⏐tPHL - tPLH ⏐
Receiver Skew
ns25
⏐tPHL - tPLH ⏐
Transmitter Skew
µs
0.15tPHL
Receiver Propagation Delay 0.15tPLH
ns200Receiver Output Enable Time
ns200Receiver Output Disable Time
UNITSMIN TYP MAXSYMBOLPARAMETER
4
Maxim Integrated
MAX3224E/MAX3225E/
MAX3226E/MAX3227E/MAX3244E/MAX3245E
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
__________________________________________Typical Operating Characteristics
(VCC = +3.3V, 250kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩand CL, TA= +25°C, unless otherwise noted.)
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
0 1000 2000 3000 4000 5000
MAX3224E/MAX3226E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3224-7/44/45E-01
LOAD CAPACITANCE (pF)
TRANSMITTER OUTPUT VOLTAGE (V)
T1 TRANSMITTING AT 250kbps
T2 (MAX3224E) TRANSMITTING AT 15.6kbps
VOUT+
VOUT-
0
2
4
6
8
10
12
14
16
0 1000 2000 3000 4000 5000
MAX3224E/MAX3226E
SLEW RATE vs. LOAD CAPACITANCE
MAX3224-7/44/45E-02
LOAD CAPACITANCE (pF)
SLEW RATE (V/μs)
-SLEW
+SLEW
FOR DATA RATES UP TO 250kbps
0
5
10
15
20
25
30
35
40
45
0 20001000 3000 4000 5000
MAX3224E/MAX3226E
OPERATING SUPPLY CURRENT
vs. LOAD CAPACITANCE
MAX3224-7/44/45E-03
LOAD CAPACITANCE (pF)
SUPPLY CURRENT (mA)
250kbps
120kbps
20kbps
T1 TRANSMITTING AT 250kbps
T2 (MAX3224E) TRANSMITTING AT 15.6kbps
-7.5
0
-2.5
-5.0
2.5
5.0
7.5
0 1000500 1500 2000 2500
MAX3225E/MAX3227E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3224-7/44/45E-04
LOAD CAPACITANCE (pF)
TRANSMITTER OUTPUT VOLTAGE (V)
2Mbps
2Mbps
1.5Mbps
1.5Mbps
1Mbps
1Mbps
1 TRANSMITTER AT FULL DATA RATE
1 TRANSMITTER AT 1/16 DATA RATE
(MAX3225E)
LOAD = 3kΩ + CL
0
15
10
5
20
25
30
35
40
45
50
0 1000500 1500 2000 2500 3000
MAX3225E/MAX3227E
TRANSMITTER SKEW
vs. LOAD CAPACITANCE
MAX3224-7/44/45E-07
LOAD CAPACITANCE (pF)
TRANSMITTER SKEW (ns)
AVERAGE: 10 PARTS
1 TRANSMITTER AT 512kbps
1 TRANSMITTER AT 30kbps
(MAX3225E)
LOAD = 3kΩ + CL
0
80
70
60
50
40
30
20
10
0 500 1000 1500 2000 2500
MAX3225E/MAX3227E
SLEW RATE vs. LOAD CAPACITANCE
MAX3224-7/44/45E-05
LOAD CAPACITANCE (pF)
SLEW RATE (V/μs)
1 TRANSMITTER AT 1Mbps
1 TRANSMITTER AT 62.5kbps (MAX3225E)
-SLEW
+SLEW
0
20
10
40
30
60
50
70
90
80
100
0 500 1000 1500 2000 2500
MAX3225E/MAX3227E
OPERATING SUPPLY CURRENT
vs. LOAD CAPACITANCE
MAX3224-7/44/45E-06
LOAD CAPACITANCE (pF)
SUPPLY CURRENT (mA)
2Mbps
1.5Mbps
1Mbps
1 TRANSMITTER AT FULL DATA RATE
1 TRANSMITTER AT 1/16 DATA RATE
(MAX3225E)
LOAD = 3kΩ + CL
20
24
22
30
28
26
36
34
32
38
-40 0 20-20 40 60 80 100
MAX3224E–MAX3227E
READY TURN-ON TIME
vs. TEMPERATURE
MAX3224-7/44/45E-08
TEMPERATURE (°C)
READY TURN-ON TIME (μs)
0
200
180
160
140
120
100
80
60
40
20
-40 0 20-20 40 60 80 100
MAX3224E–MAX3227E
READY TURN-OFF TIME
vs. TEMPERATURE
MAX3224-7/44/45E-09
TEMPERATURE (°C)
READY TURN-OFF TIME (ns)
Maxim Integrated
MAX3224E/MAX3225E/
MAX3226E/MAX3227E/MAX3244E/MAX3245E
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
_____________________________Typical Operating Characteristics (continued)
(VCC = +3.3V, 250kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩand CL, TA= +25°C, unless otherwise noted.)
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
0 1000 2000 3000 4000 5000
MAX3244E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3224-7/44/45E-10
LOAD CAPACITANCE (pF)
TRANSMITTER OUTPUT VOLTAGE (V)
1 TRANSMITTER AT 250kbps
2 TRANSMITTERS AT 15.6kbps
VOUT+
VOUT-
0
4
2
8
6
12
10
14
0 1000 2000 3000 4000 5000
MAX3244E
SLEW RATE vs. LOAD CAPACITANCE
MAX3224-7/44/45E-11
LOAD CAPACITANCE (pF)
SLEW RATE (V/μs)
0
30
20
10
40
50
60
0 20001000 3000 4000 5000
MAX3244E
OPERATING SUPPLY CURRENT
vs. LOAD CAPACITANCE
MAX3224-7/44/45E-12
LOAD CAPACITANCE (pF)
SUPPLY CURRENT (mA)
250kbps
120kbps
20kbps
1 TRANSMITTER AT 250kbps
2 TRANSMITTERS AT 15.6kbps
-7.5
0
-2.5
-5.0
2.5
5.0
7.5
0 800400 1200 1600 2000
MAX3245E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3224-7/44/45E-13
LOAD CAPACITANCE (pF)
TRANSMITTER OUTPUT VOLTAGE (V)
2Mbps
2Mbps
1.5Mbps
1.5Mbps
1Mbps
1Mbps
1 TRANSMITTER AT FULL DATA RATE
2 TRANSMITTERS AT 1/16 DATA RATE
0
20
10
40
30
60
50
70
90
80
100
0400 800 1200 1600 2000
MAX3245E
OPERATING SUPPLY CURRENT
vs. LOAD CAPACITANCE
MAX3224-7/44/45E-15
SUPPLY CURRENT (mA)
2Mbps
1.5Mbps
1Mbps
1 TRANSMITTER AT FULL DATA RATE
2 TRANSMITTERS AT 1/16 DATA RATE
0
20
10
40
30
60
50
70
0 400 800 1200 1600 2000
MAX3245E
SLEW RATE vs. LOAD CAPACITANCE
MAX3224-7/44/45E-14
LOAD CAPACITANCE (pF)
SLEW RATE (V/μs)
1 TRANSMITTER AT 1Mbps
2 TRANSMITTERS AT 62.5kbps
0
15
10
5
20
25
30
35
40
45
50
0 1000 2000 3000
MAX3245E
TRANSMITTER SKEW
vs. LOAD CAPACITANCE
MAX3224-7/44/45E-16
TRANSMITTER SKEW (ns)
6
Maxim Integrated
MAX3224E/MAX3225E/
MAX3226E/MAX3227E/MAX3244E/MAX3245E
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
______________________________________________________________ Pin Description
PIN
MAX3224E
MAX3225E
MAX3226E
MAX3227E
TQFN
DIP/
SSOP/
TSSOP
TQFN SSOP/
TSSOP
MAX3244E
MAX3245E
SO/ SSOP/ TSSOP
MAX3245E
TQFN
NAME FUNCTION
19 1 14 1 — — READY
Ready to Transmit Output,
active-high. READY is
enabled high when V- goes
below -4V and the device is
ready to transmit.
1 2 16 2 28 31 C1+
Positive Terminal of Voltage-
Doubler Charge-Pump
Capacitor
20 3 15 3 27 30 V+
+5.5V generated by the
charge pump
2 4 1 4 24 26 C1-
Negative Terminal of Voltage-
Doubler Charge-Pump
Capacitor
3 5 2 5 1 33 C2+
Positive Terminal of Inverting
Charge-Pump Capacitor
4 6 3 6 2 34 C2-
Negative Terminal of
Inverting Charge-Pump
Capacitor
5 7 4 7 3 35 V-
-5.5V Generated by the
Charge Pump
6, 15 8, 17 10 13 9, 10, 11 7, 8, 9 T_OUT RS-232 Transmitter Outputs
7, 14 9, 16 5 8 4-8 1-5 R_IN RS-232 Receiver Inputs
8, 13 10, 15 6 9 15-19 15, 16, 17,
19, 20 R_OUT TTL/CMOS Receiver Outputs
9 11 7 10 21 23 INVALID
Valid Signal Detector Output,
active low. A logic high
indicates that a valid RS-232
level is present on a receiver
input.
10, 11 12, 13 8 11 12-14 11, 12, 13 T_IN TTL/CMOS Transmitter Inputs
Maxim Integrated
MAX3224E/MAX3225E/
MAX3226E/MAX3227E/MAX3244E/MAX3245E
±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
Pin Description (continued)
PIN
MAX3224E
MAX3225E
MAX3226E
MAX3227E
TQFN
DIP/
SSOP/
TSSOP
TQFN SSOP/
TSSOP
MAX3244E
MAX3245E
SO/ SSOP/ TSSOP
MAX3245E
TQFN
NAME FUNCTION
12 14 9 12 23 25 FORCEON
Force-On Input, Active High.
Drive high to override
AutoShutdown Plus, keeping
transmitters and receivers on
(FORCEOFF must be high)
(Table 1).
16 18 11 14 25 27 GND Ground
17 19 12 15 26 29 VCC +3.0V to +5.5V Single Supply
Voltage
18 20 13 16 22 24 FORCEOFF
Force-Off Input, Active Low.
Drive low to shut down
transmitters, receivers
(except R2OUTB), and
charge pump. This overrides
AutoShutdown Plus and
FORCEON (Table 1).
— — — — 20 21 R2OUTB
TTL/CMOS Noninverting
Complementary Receiver
Outputs. Always active.
— — — — —
6, 10, 14,
18, 22, 28,
32, 36
N.C. No Connection. Not internally
connected.
— — — — — — EP
Exposed Pad. Solder the
exposed pad to the ground
plane or leave unconnected.
_______________Detailed Description
Dual Charge-Pump Voltage Converter
The MAX3224E–MAX3227E/MAX3244E/MAX3245E’s
internal power supply consists of a regulated dual
charge pump that provides output voltages of +5.5V
(doubling charge pump) and -5.5V (inverting charge
pump), over the +3.0V to +5.5V range. The charge
pump operates in discontinuous mode: if the output
voltages are less than 5.5V, the charge pump is
enabled; if the output voltages exceed 5.5V, the
charge-pump is disabled. Each charge pump requires
a flying capacitor (C1, C2) and a reservoir capacitor
(C3, C4) to generate the V+ and V- supplies.
The READY output (MAX3224E–MAX3227E) is low
when the charge pumps are disabled in shutdown
mode. The READY signal asserts high when V- goes
below -4V.
8
Maxim Integrated
MAX3224E/MAX3225E/
MAX3226E/MAX3227E/MAX3244E/MAX3245E
RS-232 Transmitters
The transmitters are inverting level translators that
convert CMOS-logic levels to 5.0V EIA/TIA-232 levels.
The MAX3224E/MAX3226E/MAX3244E guarantee a
250kbps data rate (1Mbps, for the MAX3225E/MAX3227E/
MAX3245E) with worst-case loads of 3kΩin parallel with
1000pF, providing compatibility with PC-to-PC com-
munication software (such as LapLink®). Transmitters
can be paralleled to drive multiple receivers. Figure 1
shows a complete system connection.
When FORCEOFF is driven to ground or when the Auto-
Shutdown Plus circuitry senses that all receiver and
transmitter inputs are inactive for more than 30s, the
transmitters are disabled and the outputs go into a high-
impedance state. When powered off or shut down, the
outputs can be driven to ±12V. The transmitter inputs
do not have pullup resistors. Connect unused inputs to
GND or VCC.
MAX3244E
MAX3245E
I/O
CHIP
WITH
UART
CPU
RS-232
POWER-
MANAGEMENT
UNIT OR
KEYBOARD
CONTROLLER
FORCEOFF
FORCEON
INVALID
Figure 1. Interface Under Control of PMU
MAX3244E
MAX3245E
T1OUT
R2OUTB
Tx
5kΩ
UART
VCC
T1IN
THREE-STATED
LOGIC
TRANSITION
DETECTOR
R2IN
PROTECTION
DIODE
R2OUT
FORCEOFF = GND
VCC
TO
μP
Rx
PREVIOUS
RS-232
Tx
UART
SHDN = GND
VCC
VCC
GND
Rx
5kΩ
a) OLDER RS-232: POWERED-DOWN UART DRAWS CURRENT FROM ACTIVE
RECEIVER OUTPUT IN SHUTDOWN.
b) NEW MAX3244E/MAX3245E: IN SHUTDOWN, R2OUTB IS USED TO MONITOR
EXTERNAL DEVICES AND R2OUT IS THREE STATED, ELIMINATING A CURRENT
PATH THROUGH THE UART'S PROTECTION DIODE.
GND
PROTECTION
DIODE
I
I
Figure 2. The MAX3244E/MAX3245E detect RS-232 activity
when the UART and interface are shut down.
LapLink is a registered trademark of Laplink Software, Inc.
±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
Maxim Integrated
MAX3224E/MAX3225E/
MAX3226E/MAX3227E/MAX3244E/MAX3245E
±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
RS-232 Receivers
The receivers convert RS-232 signals to CMOS-logic
output levels. The MAX3224E–MAX3227E feature
inverting outputs that always remain active (Table 1).
The MAX3244E/MAX3245E have inverting three-state
outputs that are high impedance when shut down
(FORCEOFF = GND) (Table 1).
The MAX3244E/MAX3245E feature an extra, always
active, noninverting output, R2OUTB. R2OUTB output
monitors receiver activity while the other receivers are
high impedance, allowing ring indicator applications to
be monitored without forward biasing other devices
connected to the receiver outputs. This is ideal for sys-
tems where VCC is set to ground in shutdown to
accommodate peripherals such as UARTs (Figure 2).
The MAX3224E–MAX3227E/MAX3244E/MAX3245E fea-
ture an INVALID output that is enabled low when no
valid RS-232 voltage levels have been detected on all
receiver inputs. Because INVALID indicates the receiv-
er input’s condition, it is independent of FORCEON and
FORCEOFF states (Figures 3 and 4).
AutoShutdown Plus Mode
The MAX3224E–MAX3227E/MAX3244E/MAX3245E
achieve a 1µA supply current with Maxim’s AutoShutdown
Plus feature, which operates when FORCEOFF is high
and a FORCEON is low. When these devices do not
sense a valid signal transition on any receiver and trans-
mitter input for 30s, the on-board charge pumps are
shut down, reducing supply current to 1µA. This occurs
if the RS-232 cable is disconnected or if the connected
Table 1. Output Control Truth Table
OPERATION
STATUS FORCEON FORCEOFF
VALID
RECEIVER
LEVEL
RECEIVER OR
TRANSMITTER
EDGE WITHIN
30s
T_OUT
R_OUT
(MAX3224E/
MAX3225E/
MAX3226E/
MAX3227E)
R_OUT
(MAX3244E/
MAX3245E)
R2OUTB
(MAX3244E/
MAX3245E)
Shutdown
(Forced Off) X 0 X X High-Z Active High-Z Active
Normal
Operation
(Forced On)
1 1 X X Active Active Active Active
Normal
Operation
(AutoShutdown
Plus)
0 1 X Yes Active Active Active Active
Shutdown (Auto-
Shutdown Plus) 0 1 X No High-Z Active Active Active
Normal
Operation INVALID*1Yes XActive Active Active Active
Normal
Operation INVALID*1 X Yes Active Active Active Active
Shutdown INVALID*1No No High-Z Active Active Active
Normal
Operation
(AutoShutdown)
INVALID*INVALID** Yes XActive Active Active Active
Shutdown
(AutoShutdown) INVALID*INVALID** No XHigh-Z Active High-Z Active
X = Don’t care
*
INVALID connected to FORCEON
**
INVALID connected to FORCEON and FORCEOFF
10
Maxim Integrated
MAX3224E/MAX3225E/
MAX3226E/MAX3227E/MAX3244E/MAX3245E
±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
peripheral transmitters are turned off, and the UART dri-
ving the transmitter inputs is inactive. The system turns
on again when a valid transition is applied to any
RS-232 receiver or transmitter input. As a result, the sys-
tem saves power without changes to the existing BIOS
or operating system.
Figures 3a and 3b depict valid and invalid RS-232
receiver voltage levels. INVALID indicates the receiver
input’s condition, and is independent of FORCEON and
FORCEOFF states. Figure 3 and Tables 1 and 2 sum-
marize the operating modes of the MAX3224E–
MAX3227E/MAX3244E/MAX3245E. FORCEON and
FORCEOFF override AutoShutdown Plus circuitry.
When neither control is asserted, the IC selects
between these states automatically based on the last
receiver or transmitter input edge received.
When shut down, the device’s charge pumps turn off,
V+ is pulled to VCC, V- is pulled to ground, the transmit-
ter outputs are high impedance, and READY
(MAX3224E–MAX3227E) is driven low. The time
required to exit shutdown is typically 100µs (Figure 8).
By connecting FORCEON to INVALID, the MAX3224E–
MAX3227E/MAX3244E/MAX3245E shut down when no
valid receiver level and no receiver or transmitter edge is
detected for 30s, and wake up when a valid receiver
level or receiver or transmitter edge is detected.
+0.3V
-0.3V
INVALID
R_IN
INVALID ASSERTED IF ALL RECEIVER INPUTS ARE BETWEEN +0.3V AND -0.3V FOR
AT LEAST 30μs.
30μs
TIMER
R
+2.7V
-2.7V
INVALID
R_IN
INVALID DEASSERTED IF ANY RECEIVER INPUT HAS BEEN BETWEEN +2.7V AND -2.7V
FOR LESS THAN 30μs.
30μs
TIMER
R
AUTOSHDN
R_IN
T_IN
R
S
30s
TIMER
EDGE
DETECT
EDGE
DETECT
FORCEOFF
FORCEON
Figure 3a. INVALID Functional Diagram, INVALID Low
Figure 3b. INVALID Functional Diagram, INVALID High
Figure 3c. AutoShutdown Plus Logic
POWERDOWN*
AUTOSHDN
FORCEOFF
FORCEON
* POWERDOWN IS ONLY AN INTERNAL SIGNAL.
IT CONTROLS THE OPERATIONAL STATUS OF
THE TRANSMITTERS AND THE POWER SUPPLIES.
Figure 3d. Power-Down Logic
RECEIVER INPUT LEVELS
-2.7V
-0.3V
+2.7V
+0.3V
0
INDETERMINATE
INVALID HIGH
INVALID LOW
INVALID HIGH
INDETERMINATE
Figure 4a. Receiver Positive/Negative Thresholds for INVALID
RS-232 SIGNAL
PRESENT AT ANY
RECEIVER INPUT
INVALID OUTPUT
Yes High
No Low
Table 2. INVALID Truth Table
Maxim Integrated
11
MAX3224E/MAX3225E/
MAX3226E/MAX3227E/MAX3244E/MAX3245E
±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
By connecting FORCEON and FORCEOFF to INVALID,
the MAX3224E–MAX3227E/MAX3244E/MAX3245E shut
down when no valid receiver level is detected and
wake up when a valid receiver level is detected (same
functionality as AutoShutdown feature on MAX3221E/
MAX3223E/MAX3243E).
A mouse or other system with AutoShutdown Plus may
need time to wake up. Figure 5 shows a circuit that
forces the transmitters on for 100ms, allowing enough
time for the other system to realize that the MAX3244E/
MAX3245E is awake. If the other system outputs valid
RS-232 signal transitions within that time, the RS-232
ports on both systems remain enabled.
Software-Controlled Shutdown
If direct software control is desired, use INVALID to
indicate DTR or ring indicator signal. Tie FORCEOFF
and FORCEON together to bypass the AutoShutdown
Plus so the line acts like a SHDN input.
±15kV ESD Protection
As with all Maxim devices, ESD-protection structures are
incorporated on all pins to protect against electrostatic
discharges encountered during handling and assembly.
The driver outputs and receiver inputs of the
MAX3224E–MAX3227E/MAX3244E/MAX3245E have extra
protection against static electricity. Maxim’s engineers
have developed state-of-the-art structures to protect
VCC
0
0
V+
V-
VCC
0
INVALID
OUTPUT
READY
TRANSMITTER
INPUTS
RECEIVER
INPUTS }INVALID
REGION
*MAX3224E–MAX3227E
TRANSMITTER
OUTPUTS
*VCC
tAUTOSHDN tWU tWU
tINVL tINVH tAUTOSHDN
Figure 4b. AutoShutdown Plus, INVALID, and READY Timing Diagram
FORCEON
MASTER SHDN LINE
0.1μF1MΩ
FORCEOFF
MAX3224E
MAX3225E
MAX3226E
MAX3227E
MAX3244E
MAX3245E
POWER-
MANAGEMENT
UNIT
Figure 5. AutoShutdown Plus Initial Turn-On to Wake Up a
Mouse or Another System
12
Maxim Integrated
MAX3224E/MAX3225E/
MAX3226E/MAX3227E/MAX3244E/MAX3245E
±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
these pins against ESD of ±15kV without damage. The
ESD structures withstand high ESD in all states: normal
operation, shutdown, and powered down. After an ESD
event, Maxim’s E versions keep working without
latchup, whereas competing RS-232 products can
latch and must be powered down to remove latchup.
ESD protection can be tested in various ways; the
transmitter outputs and receiver inputs of this product
family are characterized for protection to the following
limits:
1) ±15kV using the Human Body Model
2) ±8kV using the Contact-Discharge Method specified
in IEC 1000-4-2
3) ±15kV using IEC 1000-4-2’s Air-Gap Method.
ESD Test Conditions
ESD performance depends on a variety of conditions.
Contact Maxim for a reliability report that documents
test setup, test methodology, and test results.
Human Body Model
Figure 6a shows the Human Body Model and Figure 6b
shows the current waveform it generates when dis-
charged into a low impedance. This model consists of
a 100pF capacitor charged to the ESD voltage of inter-
est, which is then discharged into the test device
through a 1.5kΩresistor.
IP 100%
90%
36.8%
tRL TIME
tDL
CURRENT WAVEFORM
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
Ir
10%
0
0
AMPERES
Figure 6b. Human Body Current Waveform
tr = 0.7ns to 1ns
30ns
60ns
t
100%
90%
10%
IPEAK
I
Figure 7b. IEC 1000-4-2 ESD Generator Current Waveform
CHARGE-CURRENT
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
Cs
100pF
RC 1MΩRD 1500Ω
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
Figure 6a. Human Body ESD Test Model Figure 7a. IEC 1000-4-2 ESD Test Model
CHARGE CURRENT
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
Cs
150pF
RC 50MΩ to 100MΩRD 330Ω
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
Maxim Integrated
13
MAX3224E/MAX3225E/
MAX3226E/MAX3227E/MAX3244E/MAX3245E
±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
IEC 1000-4-2
The IEC 1000-4-2 standard covers ESD testing and per-
formance of finished equipment; it does not specifically
refer to integrated circuits. The MAX3224E–MAX3227E,
MAX3244E/MAX3245E help you design equipment that
meets Level 4 (the highest level) of IEC 1000-4-2, with-
out the need for additional ESD-protection components.
The major difference between tests done using the
Human Body Model and IEC 1000-4-2 is higher peak
current in IEC 1000-4-2, because series resistance is
lower in the IEC 1000-4-2 model. Hence, the ESD with-
stand voltage measured to IEC 1000-4-2 is generally
lower than that measured using the Human Body
Model. Figure 7a shows the IEC 1000-4-2 model and
Figure 7b shows the current waveform for the 8kV, IEC
1000-4-2, Level 4, ESD Contact-Discharge Method.
The Air-Gap Method involves approaching the device
with a charged probe. The Contact-Discharge Method
connects the probe to the device before the probe is
energized.
Machine Model
The Machine Model for ESD tests all pins using a
200pF storage capacitor and zero discharge resis-
tance. Its objective is to emulate the stress caused by
contact that occurs with handling and assembly during
manufacturing. Of course, all pins require this protec-
tion during manufacturing, not just RS-232 inputs and
outputs. Therefore, after PC board assembly, the
Machine Model is less relevant to I/O ports.
__________Applications Information
Capacitor Selection
The capacitor type used for C1–C4 is not critical for
proper operation; polarized or nonpolarized capacitors
can be used. The charge pump requires 0.1µF capaci-
tors for 3.3V operation. For other supply voltages, see
Table 3 for required capacitor values. Do not use val-
ues smaller than those listed in Table 3. Increasing the
capacitor values (e.g., by a factor of 2) reduces ripple
on the transmitter outputs and slightly reduces power
consumption. C2, C3, and C4 can be increased without
changing C1’s value. However, do not increase C1
without also increasing the values of C2, C3, C4,
and CBYPASS, to maintain the proper ratios (C1 to
the other capacitors).
When using the minimum required capacitor values,
make sure the capacitor value does not degrade
excessively with temperature. If in doubt, use capaci-
tors with a larger nominal value. The capacitor’s equiv-
alent series resistance (ESR), which usually rises at low
temperatures, influences the amount of ripple on V+
and V-.
Power-Supply Decoupling
In most circumstances, a 0.1µF VCC bypass capacitor
is adequate. In applications that are sensitive to power-
supply noise, use a capacitor of the same value as
charge-pump capacitor C1. Connect bypass capaci-
tors as close to the IC as possible.
Transmitter Outputs
when Exiting Shutdown
Figure 8 shows two transmitter outputs when exiting
shutdown mode. As they become active, the two trans-
mitter outputs are shown going to opposite RS-232 lev-
els (one transmitter input is high, the other is low). Each
VCC
(V)
C2, C3, C4
(µF)
3.0 to 3.6 0.22
3.15 to 3.6 0.1
C1, CBYPASS
(µF)
0.22
0.1
4.5 to 5.5 0.33
3.0 to 5.5 1
0.047
0.22
Table 3. Required Minimum Capacitance
Values
5μs/div
T1OUT
FORCEON = FORCEOFF
T2OUT
READY
5V/div
0
2V/div
0
5V/div
0
VCC = 3.3V
C1–C4 = 0.1μF
Figure 8. Transmitter Outputs when Exiting Shutdown or
Powering Up
14
Maxim Integrated
MAX3224E/MAX3225E/
MAX3226E/MAX3227E/MAX3244E/MAX3245E
transmitter is loaded with 3kΩin parallel with 1000pF.
The transmitter outputs display no ringing or undesir-
able transients as they come out of shutdown. Note that
the transmitters are enabled only when the magnitude
of V- exceeds approximately -3V.
High Data Rates
The MAX3224E/MAX3226E/MAX3244E maintain the
RS-232 ±5.0V minimum transmitter output voltage even
at high data rates. Figure 9 shows a transmitter loop-
back test circuit. Figure 10 shows a loopback test result
at 120kbps, and Figure 11 shows the same test at
250kbps. For Figure 10, all transmitters were driven
simultaneously at 120kbps into RS-232 loads in parallel
with 1000pF. For Figure 11, a single transmitter was dri-
ven at 250kbps, and all transmitters were loaded with
an RS-232 receiver in parallel with 250pF.
The MAX3225E/MAX3227E/MAX3245E maintain the
RS-232 ±5.0V minimum transmitter output voltage at
data rates up to 1Mbps (MegaBaud). Figure 12 shows
a loopback test result with a single transmitter driven at
1Mbps and all transmitters loaded with an RS-232
receiver in parallel with 250pF.
±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
MAX3224E
MAX3225E
MAX3226E
MAX3227E
MAX3244E
MAX3245E
5kΩ
R_ IN
R_ OUT
FORCEON
C2-
C2+
C1-
C1+
V-
V+
VCC
C4
C3*
C1
C2
CBYPASS
VCC
FORCEOFF
*C3 CAN BE RETURNED TO VCC OR GND.
T_ OUT
T_ IN
GND
VCC
1000pF
Figure 9. Loopback Test Circuit
Figure 10. MAX3224E/MAX3226E/MAX3244E Loopback Test
Result at 120kbps
2μs/div
T1IN
T1OUT
R1OUT
5V/div
5V/div
5V/div
VCC = 3.3V
Figure 11. MAX3224E/MAX3226E/MAX3244E Loopback Test
Result at 250kbps
2μs/div
T1IN
T1OUT
R1OUT
5V/div
5V/div
5V/div
VCC = 3.3V
Figure 12. MAX3225E/MAX3227E/MAX3245E Loopback Test
Result at 1Mbps
200ns/div
T1IN
T1OUT
R1OUT
5V/div
5V/div
5V/div
VCC = 3.3V
Maxim Integrated
15
MAX3224E/MAX3225E/
MAX3226E/MAX3227E/MAX3244E/MAX3245E
±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
Figure 13a. Mouse Driver Test Circuit
+V
COMPUTER SERIAL PORT
+V
-V
GND
Tx
SERIAL
MOUSE
MAX3244E
MAX3245E
FORCEOFF
23
R5OUT
15
R4OUT
16
R3OUT
17
R2OUT
18
R1OUT
19
R2OUTB
20
LOGIC
OUTPUTS
5kΩ
5kΩ
5kΩ
5kΩ
5kΩ
R5IN 8
R4IN 7
R3IN 6
R2IN 5
R1IN 4
RS-232
INPUTS
GND
25
LOGIC
INPUTS
T3IN
12
T2IN
13
T1IN
14
C2-
2
C2+
1
C1-
24
C1+
28
T3OUT 11
T2OUT 10
T1OUT 9
V-
3
V+
27
VCC
VCC
C4
0.1μF
C3
0.1μF
0.1μF 26
C1
0.1μF
C2
0.1μF
FORCEON
INVALID
22
21
TO POWER-
MANAGEMENT
UNIT
+3.3V
16
Maxim Integrated
MAX3224E/MAX3225E/
MAX3226E/MAX3227E/MAX3244E/MAX3245E
±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
Mouse Driveability
The MAX3244E/MAX3245E are specifically designed to
power serial mice while operating from low-voltage
power supplies. They have been tested with leading
mouse brands from manufacturers such as Microsoft
and Logitech. The MAX3244E/MAX3245E successfully
drove all serial mice tested and met their respective
current and voltage requirements. The MAX3244E/
MAX3245E dual charge pump ensures the transmitters
supply at least ±5V during worst-case conditions.
Figure 13b shows the transmitter output voltages under
increasing load current. Figure 13a shows a typical
mouse connection.
Interconnection with 3V and 5V Logic
The MAX3224E–MAX3227E/MAX3244E/MAX3245E can
directly interface with various 5V logic families, includ-
ing ACT and HCT CMOS. See Table 4 for more informa-
tion on possible combinations of interconnections.
Table 5 lists other Maxim ESD-powered transceivers.
SYSTEM
POWER-SUPPLY
VOLTAGE (V)
COMPATIBILITY
3.3 Compatible with all CMOS families
5Compatible with all TTL and CMOS families
VCC SUPPLY
VOLTAGE
(V)
3.3
5
5Compatible with ACT and HCT CMOS, and with AC, HC, or CD4000 CMOS3.3
PART
SUPPLY
VOLTAGE
RANGE
(V)
NO.
OF
Tx/Rx
GUARANTEED
DATA RATE
(kbps)
MAX3241E +3.0 to +5.5 3/5 250
MAX3243E +3.0 to +5.5 3/5 250
MAX3244E +3.0 to +5.5 3/5 250
MAX3245E +3.0 to +5.5 3/5 1Mbps
MAX3232E +3.0 to +5.5 2/2 250
MAX3222E +3.0 to +5.5 2/2 250
MAX3223E +3.0 to +5.5 2/2 250
MAX3224E +3.0 to +5.5 2/2 250
MAX3225E +3.0 to +5.5 2/2 1Mbps
MAX3221E +3.0 to +5.5 1/1 250
MAX3227E +3.0 to +5.5 1/1 1Mbps
MAX3226E +3.0 to +5.5 1/1 250
SUPPLY
CURRENT
(µA)
300
1
1
1
300
300
1
1
1
1
1
1
Auto-
Shutdown
Plus
—
—
Yes
Yes
—
—
—
Yes
Yes
—
Yes
Yes
Auto-
Shutdown
—
Yes
—
—
—
—
Yes
—
—
Yes
—
—
Human
Body
Model
(kV)
±15
±15
±15
±15
±15
±15
±15
±15
±15
±15
±15
±15
IEC 1000-4-2
Contact
Discharge
(kV)
±8
±8
±8
±8
±8
±8
±8
±8
±8
±8
±8
±8
IEC 1000-4-2
Air-Gap
Discharge
(kV)
±15
±15
±15
±15
±15
±15
±15
±15
±15
±15
±15
±15
Figure 13b. MAX324_E Transmitter Output Voltage vs. Load
Current per Transmitter
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
012345678910
MAX2343E-FIG15
LOAD CURRENT PER TRANSMITTER (mA)
TRANSMITTER OUTPUT VOLTAGE (V)
VOUT+
VOUT-
VOUT+
VOUT-
VCC
VCC = 3.0V
Table 5. ±15kV ESD-Protected, 3.0V to 5.5V Powered RS-232 Transceivers from Maxim
Table 4. Logic Family Compatibility with Various Supply Voltages
Maxim Integrated
17
MAX3224E/MAX3225E/
MAX3226E/MAX3227E/MAX3244E/MAX3245E
±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
MAX3244E***
MAX3245E
FORCEON
23
R5OUT
15
R4OUT
16
R3OUT
17
R2OUT
18
R1OUT
19
R2OUTB
20
FORCEOFF
22
R5IN 8
R4IN 7
R3IN 6
R2IN 5
R1IN 4
GND
25
T3IN
12
T2IN
13
T1IN
14
C2-
2
C2+
1
C1-
24
C1+
28
T3OUT 11
T2OUT 10
T1OUT 9
V- 3
V+ 27
VCC
C4
0.1μF
C3
0.1μF
C1
0.1μF
CBYPASS
0.1μF
C2
0.1μF
+3.3V
26
INVALID 21
MAX3226E*
MAX3227E
FORCEON
READY AutoShutdown
Plus
12
1
R1OUT9
FORCEOFF 16
INVALID 10
GND
14
T1IN
11
C2-
6
C2+
5
C1-
4
C1+
2
R1IN 8
T1OUT 13
V- 7
V+ 3
VCC
VCC
C4
0.1μF
C3
0.1μF
0.1μF 15
C1
0.1μF
C2
0.1μF
CBYPASS
CBYPASS
+3.3V
TO POWER-
MANAGEMENT
UNIT
5kΩ
MAX3224E**
MAX3225E
FORCEON
READY
14
1
R2OUT10
R1OUT15
FORCEOFF 20
INVALID 11
R2IN 9
GND
18
RS-232
OUTPUTS
TTL/CMOS
INPUTS T2IN
12
T1IN
13
C2-
6
C2+
5
C1-
4
C1+
2
R1IN 16
T2OUT 8
T1OUT 17
V- 7
V+ 3
VCC
VCC
C4
0.1μF
C3
0.1μF
0.1μF 19
C1
0.1μF
C2
0.1μF
+3.3V
RS-232
INPUTS
TO POWER-
MANAGEMENT
UNIT
TTL/CMOS
OUTPUTS 5kΩ
5kΩ
AutoShutdown
Plus
AutoShutdown
Plus
*MAX3226E/MAX3227E PIN OUT REFERS TO SSOP/TSSOP PACKAGES.
**MAX3224E/MAX3225E PIN OUT REFERS TO DIP/ SSOP/TSSOP PACKAGES.
***MAX3244E/MAX3245E PIN OUT REFERS TO SO/SSOP/TSSOP PACKAGES.
___________________________________________________Typical Operating Circuits
18
Maxim Integrated
MAX3224E/MAX3225E/
MAX3226E/MAX3227E/MAX3244E/MAX3245E
±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
READY
C1+
V+
C1-
C2+
C2-
V-
R1IN
FORCEOFF
VCC
GND
T1OUT
FORCEON
T1IN
INVALID
R1OUT
MAX3226E
MAX3227E
SSOP/TSSOP
28
27
26
25
24
23
22
21
20
19
18
17
16
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
C1+
V+
VCC
GND
C1-
FORCEON
FORCEOFF
INVALID
R2OUTB
R1OUT
R2OUT
R3OUT
R4OUT
R5OUT
C2+
C2-
V-
R1IN
R2IN
R3IN
R4IN
R5IN
T1OUT
T2OUT
T3OUT
T3IN
T2IN
T1IN
SO/SSOP/TSSOP
MAX3244E
MAX3245E
20
19
18
17
16
15
14
13
1
2
3
4
5
6
7
8
FORCEOFF
VCC
GND
T1OUT
C1-
V+
C1+
READY
R1IN
R1OUT
FORCEON
T1IN
T2OUT
V-
C2-
C2+
12
11
9
10
T2IN
INVALIDR2OUT
R2IN
DIP/SSOP/TSSOP
MAX3224E
MAX3225E
GND
C1-
FORCEOFF
INVALID
R1OUT
R2OUT
N.C.
R2OUTB
FORCEON
R3IN
R4IN
R5IN
T1OUT
T2OUT
T3OUT
R1IN 1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18
27
26
25
24
23
22
21
20
19
N.C.
R5OUT
R4OUT
N.C.
T1IN
T2IN
T3IN
N.C.
V-
C2-
C2+
N.C.
C1+
V+
VCC
N.C.
N.C.
TQFN
MAX3245E
TOP VIEW
*EP
N.C.
R3OUT
R2IN
36 35 34 33 32 31 30 29 28
15
16
14
13
6
5
7
C2+
V-
8
C1-
GND
FORCEON
VCC
12
READY
4
12 11 9
V+
C1+
T1IN
INVALID
R1OUT
R1IN
MAX3226E
MAX3227E
C2- T1OUT
3
10
*EP
*CONNECT EP TO GND.
TQFN
TOP VIEW
MAX3224E
MAX3225E
TQFN
TOP VIEW
19
20
18
17
7
6
8
C1-
C2-
V-
9
C1+
R1IN
FORCEON
T1IN
T1OUT
12
FORCEOFF
45
15 14 12 11
READY
V+
INVALID
R2OUT
R2IN
T2OUT
C2+ R1OUT
3
13
VCC
16 10 T2IN
GND
*EP
FORCEOFF
+
+
+
+
++
___________________________________________________________ Pin Configurations
Maxim Integrated
19
MAX3224E/MAX3225E/
MAX3226E/MAX3227E/MAX3244E/MAX3245E
±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
Ordering Information (continued) Chip Information
PROCESS: BICMOS
Package Information
For the latest package outline information and land patterns
(footprints), go to www.maxim-ic.com/packages. Note that a
“+”, “#”, or “-” in the package code indicates RoHS status only.
Package drawings may show a different suffix character, but the
drawing pertains to the package regardless of RoHS status.
PART TEMP RANGE PIN-PACKAGE
MAX3225ECUP+ 0°C to +70°C 20 TSSOP
MAX3225ECTP+ 0°C to +70°C 20 TQFN-EP*
MAX3225ECAP+ 0°C to +70°C 20 SSOP
MAX3225ECPP+ 0°C to +70°C 20 Plastic DIP
MAX3225EETP+ -40°C to +85°C 20 TQFN -EP*
MAX3225EEUP+ -40°C to +85°C 20 TSSOP
MAX3225EEAP+ -40°C to +85°C 20 SSOP
MAX3225EEPP+ -40°C to +85°C 20 Plastic DIP
MAX3225EAAP+ -40°C to +125°C 20 SSOP
MAX3226ECTE+ 0°C to +70°C 16 TQFN-EP*
MAX3226ECUE+ 0°C to +70°C 16 TSSOP
MAX3226ECAE+ 0°C to +70°C 16 SSOP
MAX3226EEAE+ -40°C to +85°C 16 SSOP
MAX3226EETE+ -40°C to +85°C 16 TQFN-EP*
MAX3226EEUE+ -40°C to +85°C 16 TSSOP
MAX3226EAAE+ -40°C to +125°C 16 SSOP
MAX3227ECAE+ 0°C to +70°C 16 SSOP
MAX3227ECTE+ 0°C to +70°C 16 TQFN-EP*
MAX3227ECUE+ 0°C to +70°C 16 TSSOP
MAX3227EEAE+ -40°C to +85°C 16 SSOP
MAX3227EEAE/V+ -40°C to +85°C 16 SSOP
MAX3227EETE+ -40°C to +85°C 16 TQFN-EP*
MAX3227EEUE+ -40°C to +85°C 16 TSSOP
MAX3227EAAE+ -40°C to +125°C 16 SSOP
MAX3244ECWI+ 0°C to +70°C 28 Wide SO
MAX3244ECAI+ 0°C to +70°C 28 SSOP
MAX3244ECUI+ 0°C to +70°C 28 TSSOP
MAX3244EEWI+ -40°C to +85°C 28 Wide SO
MAX3244EEAI+ -40°C to +85°C 28 SSOP
MAX3244EEUI+ -40°C to +85°C 28 TSSOP
MAX3245ECWI+ 0°C to +70°C 28 Wide SO
MAX3245ECAI+ 0°C to +70°C 28 SSOP
MAX3245ECTX+ 0°C to +70°C 36 TQFN- EP*
MAX3245EEAI+ -40°C to +85°C 28 SSOP
MAX3245EEWI+ -40°C to +85°C 28 WIDE SO
MAX3245EEUI+ -40°C to +85°C 28 TSSOP
MAX3245EETX+ -40°C to +85°C 36 TQFN- EP*
+
Denotes a lead(Pb)-free/RoHS-compliant package.
*
EP = Exposed pad.
/V denotes an automotive qualified part.
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
16 SSOP A16+2 21-0056 90-0106
16 TSSOP U16+1 21-0066 90-0117
16 TQFN-EP T1655+2 21-0140 90-0072
20 DIP P20+3 21-0043 —
20 SSOP A20+1 21-0056 90-0094
20 TSSOP U20+2 21-0066 90-0116
20 TQFN-EP T2055+5 21-0140 90-0010
28 Wide SO W28+6 21-0042 90-0109
28 SSOP A28+1 21-0056 90-0095
28 TSSOP U28+2 21-0066 90-0171
36 TQFN T3666+3 21-0141 90-0050
20
Maxim Integrated
MAX3224E/MAX3225E/
MAX3226E/MAX3227E/MAX3244E/MAX3245E
±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
10 3/11
Added an automotive qualified part to the Ordering Information; changed all the
parts listed in the Ordering Information to lead free 1, 20
MAX3224E/MAX3225E/
MAX3226E/MAX3227E/MAX3244E/MAX3245E
21
Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.
Maxim reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical
Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
© 2011 Maxim Integrated The Maxim logo and Maxim Integrated are trademarks of Maxim Integrated Products, Inc.