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 MAX1614 drives high-side, n-channel power MOSFETs
to provide battery power-switching functions in portable
equipment. The n-channel power MOSFETs typically have
one-third the on-resistance of p-channel MOSFETs of simi-
lar size and cost. An internal micropower regulator and
charge pump generate the high-side drive output voltage,
while requiring no external components.
The MAX1614 also features a 1.5%-accurate low-battery
comparator that can be used to indicate a low-battery
condition, provide an early power-fail warning to the sys-
tem microprocessor, or disconnect the battery from the
load, preventing deep discharge and battery damage. An
internal latch allows for pushbutton on/off control with very
low current consumption. Off-mode current consumption
is only 6µA while normal operation requires less than
25µA. The MAX1614 is available in the space-saving
µMAX®package that occupies about 60% less space
than a standard 8-pin SO.
________________________Applications
Notebook Computers
Portable Equipment
Hand-Held Instruments
Battery Packs
____________________________Features
oInternal On/Off Latch
oHigh-Side, n-Channel Power MOSFET Drive
o25µA (max) Quiescent Current
o6µA (max) Off Current
oRequires No External Components
o1.5%-Accurate Low-Battery Detector
oSpace-Saving µMAX Package
o5V to 26V Input Voltage Range
oDrives Single or Back-to-Back MOSFETs
oControlled Turn-On for Low Inrush Current
High-Side, n-Channel MOSFET
Switch Driver
1+
2
3
4
8
7
6
5
BATT
SRC
GATE
GND
LBI
LBO
OFF
ON
MAX1614
µMAX
TOP VIEW
PART TEMP RANGE PIN-PACKAGE
MAX1614C/D 0°C to +70°C Dice*
MAX1614EUA+ -40°C to +85°C 8 µMAX
MAX1614EUA/V+ -40°C to +85°C 8 µMAX
__________________Pin Configuration
MAX1614 OFF
LBO
GND
LBI
BATT
SRCGATE
ON
NN
LOAD
OPTIONAL FOR
REVERSE CURRENT
PROTECTION
R1
R2
__________Typical Operating Circuit
______________Ordering Information
*
Contact factory for dice specifications.
+
Denotes a lead(Pb)-free/RoHS-compliant package.
/V denotes an automotive qualified part.
Devices are also available in a tape-and-reel package.
Specify tape-and-reel by adding “T” to the part number when
ordering.
µMAX is a registered trademark of Maxim Integrated Products, Inc.
19-1176; Rev 1; 6/11
MAX1614
µA
High-Side, n-Channel MOSFET
Switch Driver
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VBATT = 15V, TA= 0°C to +85°C, 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.
BATT, SRC to GND.................................................-0.3V to +30V
GATE to SRC ..........................................................-0.3V to +12V
GATE to GND .........................................................-0.3V to +36V
GATE + SRC Sink Current, Continuous .............................2.7mA
LBI, LBO, ON, OFF to GND....................................-0.3V to +12V
LBO Current ..........................................................................5mA
Continuous Power Dissipation (TA= +70°C)
µMAX (derate 4.10mV/°C above +70°C) .....................330mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow) .......................................+260°C
VBATT = 15V, ON = OFF = unconnected,
IGATE = 0A, device latched on, VLBI = 1.5V,
SRC = BATT
VBATT = 5V
VBATT = 26V, ON = OFF = unconnected,
IGATE = 0A, device latched off, VLBI = 1.5V
VBATT = 26V
VGATE - VSRC > 3V, SRC = BATT
VBATT = 5V
Tested at 0.6V
Tested at 2V
Tested at VLBI = VBATT / 4
VLBO = 11.5V
LBI input falling
Measured from GATE to SRC, VBATT = 15V,
IGATE = 0A
VGATE = VSRC = 15V
ISINK = 1mA
VGATE = 4V, device latched off
VLBI = 1.3V
CONDITIONS
µs0.5 1.0tPW
Minimum Input Pulse Width
V2.0VIH
Input High Voltage
V0.6VIL
Input Low Voltage
µA1.5 2Maximum Input Pullup Current
µA0.5Minimum Input Pullup Current
µA0.5VOH
LBO High Leakage
V0.4VOL
LBO Low Voltage
nA10ILBI
LBI Input Current
17 30
µA47ISHDN
V526BATT Operating Range
BATT Shutdown Current
V0.9 4
Minimum VBATT for Valid LBO
V0.02VTH
LBI Trip Hysteresis
V1.182 1.20 1.218VTH
LBI Trip Level
V
6.5 8 9.0
VGS
GATE Drive Voltage
µA15 60GATE Drive Output Current
mA0.5 2GATE Discharge Current
UNITSMIN TYP MAXSYMBOLPARAMETER
VBATT = 26V, ON = OFF = unconnected,
IGATE = 0A, device latched on, VLBI = 1.5V,
SRC = BATT
21 40
Measured from GATE to SRC, VBATT = VSRC = 5V,
IGATE = 1.5µA 3
µA
IBATT +
ISRC
Quiescent Current
INTERNAL CHARGE PUMP
LOW-BATTERY COMPARATOR
CONTROL INPUTS (OONN, OOFFFF)
MAX1614
2
High-Side, n-Channel MOSFET
Switch Driver
ELECTRICAL CHARACTERISTICS
(VBATT = 15V, TA= -40°C to +85°C, unless otherwise noted.) (Note 1)
__________________________________________Typical Operating Characteristics
(TA = +25°C, unless otherwise noted.)
22
6
530
ON SUPPLY CURRENT
vs. VBATT
MAX1614-01
VBATT (V)
SUPPLY CURRENT (µA)
20
14
10
10 15
18
20
12
8
16
25
TA = +85°C
TA = +25°C
TA = -40°C
4.0
1.0
530
OFF SUPPLY CURRENT
vs. VBATT
MAX1614-02
VBATT (V)
SHUTDOWN CURRENT (µA)
20
3.0
2.0
10 15
2.5
1.5
3.5
25
TA = +25°C
TA = -40°C
TA = +85°C
Note 1: Specifications to TA= -40°C are guaranteed by design and not production tested.
LOW BATTERY COMPARATOR
INTERNAL CHARGE PUMP
3
Measured from GATE to SRC, VBATT = 5.25V,
IGATE = 1.5µA, VSRC = 5.25V
40
PARAMETER SYMBOL MIN TYP MAX UNITS
GATE Drive Output Current 15 60 µA
GATE Drive Voltage VGS
6.5 9.0
V
LBI Trip Level VTH 1.176 1.20 1.224 V
BATT Shutdown Current
BATT Operating Range 5.0 26 V
ISHDN 8µA
Quiescent Current IBATT +
ISAC µA
CONDITIONS
VGATE = VSRC = 15V
Measured from GATE to SRC, VBATT = 15V,
IGATE = 0A
LBI input falling
VGATE - VSRC > 3V, SRC = BATT
VBATT = 26V, ON = OFF = unconnected,
IGATE = 0A, device latched off, VLBI = 1.5V
VBATT = 26V, ON = OFF = unconnected,
IGATE = 0A, device latched on, VLBI = 1.5V
INTERNAL CHARGE PUMP
LOW-BATTERY COMPARATOR
1.30
1.16
-40 100
LOW-BATTERY THRESHOLD
vs. TEMPERATURE
MAX1614-05
TEMPERATURE (°C)
LBI THRESHOLD (V)
40
1.24
1.20
-20 0
1.22
1.18
1.26
1.28
80
20 60
VBATT = 15V
VLBI RISING
VLBI FALLING
3
MAX1614
High-Side, n-Channel MOSFET
Switch Driver
____________________________Typical Operating Characteristics (continued)
(TA = +25°C, unless otherwise noted.)
2.5
-0.5
020
GATE-DISCHARGE CURRENT
vs. GATE VOLTAGE
MAX1614-04
VGATE (V)
GATE-DISCHARGE CURRENT (mA)
12
1.5
0.5
48
1.0
0
2.0
16214610 18
TA = +85°C
TA = +25°C
TA = -40°C
30
22
530
GATE-CHARGING CURRENT
vs. BATT VOLTAGE
MAX1614-06
VBATT (V)
GATE-CHARGING CURRENT (µA)
25
27
25
10 15
26
24
28
29
23
20
TA = +85°C
TA = -40°C
5V/div
GATE AND SOURCE TRANSITIONS
FOR TYPICAL MOSFET LOAD
1ms/div
Si9936 MOSFETS
ILOAD = 1A
ON = GND
VGATE
VSRC
VOFF
MAX1614-07
5V/div
GATE TURN-ON TRANSITION
FOR TYPICAL MOSFET LOAD
100µs/div
Si9936 MOSFETS
ILOAD = 1A
Ciss = 400pF
ON = GND
VGATE
VSRC
VOFF
MAX1614-08
0V
0V
5V/div
GATE TURN-OFF TRANSITION
FOR TYPICAL MOSFET LOAD
20µs/div
Si9936 MOSFETS
ILOAD = 1A
Ciss = 400pF
ON = GND
VOFF
MAX1614-09
VGATE
VSRC
34
26
-40 0 80 100
GATE-CHARGING CURRENT
vs. TEMPERATURE
28
27
MAX1614--03
TEMPERATURE (°C)
GATE-CHARGING CURRENT (µA)
40-20 6020
32
30
33
31
29
VBATT = 15V
MAX1614
4
High-Side, n-Channel MOSFET
Switch Driver
_______________Detailed Description
The MAX1614 uses an internal, monolithic charge pump
and low-dropout linear regulator to supply the required
8V VGS voltage to fully enhance an n-channel MOSFET
high-side switch (Figure 1). The charge pump typically
supplies 30µA, charging 800pF of gate capacitance in
400µs (VBATT = 15V). For slower turn-on times, simply
add a small capacitor between the GATE and SRC
pins. When turned off, GATE and SRC pull low and typi-
cally discharge an 800pF gate capacitance in 80µs.
The MAX1614 provides separate on/off control inputs
(ON and OFF). ON and OFF connect, respectively, to
the SET and RESET inputs of an internal flip-flop. When
ON is pulsed low (with OFF = high), the internal charge
pump turns on, and GATE is pumped to 8V above SRC,
turning on the external MOSFETs. The charge pump
maintains gate drive to the external MOSFETs until OFF
is pulsed low. When this happens, the internal charge
pump turns off, and GATE discharges to ground
through an internal switch. For slower turn-on times,
simply add a small capacitor.
__________ Applications Information
Connecting
ON
/
OFF
to 3V or 5V Logic
ON and OFF internally connect to 2µA max pullup
current sources (Figure 1). The open-circuit voltage
for ON and OFF ranges from 7V to 10.5V (nominally
8.5V). Since the current sources are relatively weak,
connecting ON and OFF directly to logic powered from
lower voltages (e.g., 3V or 5V) poses no problem if the
gate outputs driving these pins can sink at least 2µA
while high.
Although the MAX1614 shutdown function was designed
to operate with a single pushbutton on/off switch, it can
also be driven by a single gate. Connect ON to GND
and drive OFF directly (Figure 2).
Maximum Switching Rate
The MAX1614 is not intended for fast switching appli-
cations. In fact, it is specifically designed to limit the
rate of change of the load current, ∆I/∆t. The maximum
switching rate is limited by the turn-on time, which is a
function of the charge-pump output current and the
total capacitance on GATE (CGATE). Calculate the turn-
on time as a function of external MOSFET gate capaci-
tance using the Gate Charging Current vs. VBATT graph
in the
Typical Operating Characteristics
. Since turn-off
time is small compared to turn-on time, the maximum
switching rate is approximately 1/tON.
Adding Gate Capacitance
The charge pump uses an internal monolithic transfer
capacitor to charge the external MOSFET gates.
Normally, the external MOSFET’s gate capacitance is
sufficient to serve as a reservoir capacitor. If the
MOSFETs are located at a significant distance from the
MAX1614, place a local bypass capacitor (100pF typ)
across the GATE and SRC pins. For slower turn-on
times, simply add a small capacitor between GATE and
SRC.
______________________________________________________________Pin Description
System GroundGND5
Gate-Drive Output. Connect to the gates of external, n-channel MOSFETs. When the MAX1614 is off, GATE
actively pulls to GND.
GATE6
Source Input. Connect to the sources of external, n-channel MOSFETs. When the MAX1614 is off, SRC
actively pulls to GND.
SRC7
Battery Input. Connect to a battery voltage between 5V and 26V.BATT8
Low-Battery Comparator Input. LBO goes low when VLBI falls below 1.20V (typ). Connect a voltage divider
between BATT, LBI, and GND to set the battery undervoltage trip threshold (see
Typical Operating Circuit
).
LBI4
Open-Drain, Low-Battery Comparator Output. LBO is low when VLBI is below the trip point.LBO
3
PIN
RESET Input to the On/Off Latch. Pulse OFF low with ON high to turn off the external MOSFET switch. When
both ON and OFF are low, the part is off.
OFF
2
SET Input to the On/Off Latch. Pulse ON low with OFF high to turn on the external MOSFET switch. When
both ON and OFF are low, the part is off.
ON
1
FUNCTIONNAME
5
MAX1614
High-Side, n-Channel MOSFET
Switch Driver
8.5V
LDO
50kHz
OSC
SOFT
START
ON
0
0
1
1
OFF
0
1
0
1
STATE
OFF
ON
OFF
LAST VALID
STATE
P
BATT
POWER-ON
RESET (BATT < 2V)
1.21V
LBI
ON
N
N
GND
N
P
1µA1µA
GATE
SRC
CPUMP
LBO
OFF
ON
MAX1614
Figure 1. Functional Diagram
MAX1614
6
High-Side, n-Channel MOSFET
Switch Driver
On/Off Control with a
Single Pushbutton Switch
The MAX1614’s separate on and off inputs allow maxi-
mum flexibility in controlling the external MOSFETs.
Connect a pushbutton switch to the ON pin and micro-
controller (µC) I/O for single-button control. Connect the
OFF pin to another µC I/O pin. On the first button
depression, the MAX1614 turns on automatically; the
signal is also detected by the µC. When the button is
depressed a second time, the µC wraps around and
turns off the MAX1614 by pulling low on the OFF pin
(Figure 3).
Simple Low-Battery Disconnect/Fresh
Battery Reconnect Circuit
A simple undervoltage disconnect circuit is often desir-
able to prevent damage to secondary batteries due to
repeated deep discharge or cell reversal. The
Typical
Operating Circuit
turns off the MAX1614, disconnecting
the battery from the load when the battery voltage
falls below the minimum battery voltage required,
(VLOW BATT). VLOW BATT = (R1 + R2)/R2 x VTH where
VTH is the LBI input threshold (1.20V typ). When fresh
cells are installed or the batteries are recharged, a µC
or pushbutton reconnects the load.
Using
LBO
to Generate Early
Power-Fail Interrupt
Many applications require an early warning indicating
that power is failing so that the microprocessor (µP)
can take care of any “housekeeping” functions (storing
current settings in memory, etc.) before the power fails.
Connect LBI through a resistor divider across the bat-
tery, and connect LBO to the µP nonmaskable interrupt
(NMI). Set the threshold so that LBO goes low when the
battery decays to a point where regulation begins to
degrade (Figure 4). VLOW BATT = (R1 + R2)/R2 x VTH,
where VTH is the LBI input threshold (1.20V typ). Once
housekeeping is complete, the µP can turn off the load
by pulling OFF low.
MAX1614
SHUTDOWN
(CMOS OR TTL LOGIC)
GND ON
OFF
Figure 2. Single-Line Shutdown Control
MAX1614 OFF
LBO
GND
LBI
BATT
SRCGATE
ON
NN
LOAD
TO µC
R1
R2
Figure 3. Single-Pushbutton On/Off Control
MAX1614 OFF
LBO
GND
LBI
BATT
SRCGATE
ON
NN
LOAD
TO µC
PORT PINS
TO µC
NONMASKABLE
INTERRUPT
R1
R2
Figure 4. Using LBO to Generate Early Power-Fail Interrupt
7
MAX1614
High-Side, n-Channel MOSFET
Switch Driver
Increasing Low-Battery
Comparator Hysteresis
The MAX1614 contains an on-chip comparator with 2%
hysteresis for low-battery detection. If more than 2%
hysteresis is needed on the low-battery comparator and
LBO is connected to OFF, use the circuit in Figure 5 to
add hysteresis. The circuit of Figure 5 shows LBO con-
trolling an n-channel MOSFET that shorts R2 to add pos-
itive feedback to the trip point. This is necessary to
prevent loading down the 1µA pullup at OFF (Figure 1).
___________________Chip Information
SUBSTRATE CONNECTED TO GND
MAX1614 OFF
LBO
GND
LBI
SRCGATE
N
ON
BATT
LOAD
R2N
2N7002
(SOT23)
R1
R3
R1 = 909kΩ
R2, R3 = 150kΩ
VL = 8.5V
VH = 9.8V
HYSTERESIS = 6%
FALLING TRIP POINT VL
VL = VTH
( )
RISING TRIP POINT VH
VH = VTH
( )
R1 + R2 + R3
R3
R1 + R3
R3
Figure 5. Increasing Hysteresis of the Battery Disconnect
Circuit
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.
PACKAGE
TYPE
PACKAGE
CODE OUTLINE NO. LAND
PATTERN NO.
8 µMAX U8+1 21-0036 90-0092
MAX1614
8
High-Side, n-Channel MOSFET
Switch Driver
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 12/96 Initial release —
1 6/11 Added automotive-qualified part to the Ordering Information, added soldering
temperature to the Absolute Maximum Ratings. 1, 2
9
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.
MAX1614