MIC2039
High-Accuracy, High-Side, Adjustable
Current Limit Powe r Switch
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • US A • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
November 14, 2013
Revision 1.2
General Description
The MIC2039 is a high-side MOSFET power distribution
switch providing increased system reliability by using 5%
current-limit accuracy.
The MIC2039 has an operating input voltage range from
2.5V to 5.5V, is internally current limited, and has thermal
shutdown to protect the device and system. The MIC2039
is offered with either active-high or active-low logic level
enable input controls. It has an open drain fault status
output flag with a built-in 32ms delay that asserts low
during overcurrent or thermal-shutdown conditions.
The MIC2039 switches feature an adjustable output
current limit that is resistor programmable from 0.2A to
2.5A. The MIC2039 switch also offers a unique, Kickstart
feature that allows momentary high-current surges up to
the secondary current limit (ILIMIT_2nd) during startup or
while operating in steady state. This is useful for charging
loads with high inrush currents, such as capacitors. After
an overcurrent condition is established, these switches
enter into a constant current-limit mode unless the die
temperature exceeds the thermal-shutdown specification.
The MIC2039 is available in 6-pin SOT-23 and 6-pin 2mm
× 2mm thin DFN packages. The MIC2039 has an
operating junction temperature range of 40°C to +125°C.
Data sheets and support documentation are available on
Micrel’s web site at: www.micrel.com.
Features
±5% current limit accuracy
Input supply range from 2.5V to 5.5V
Low quiescent current: 100µA typical (switch ON)
75mΩ typical RDS(ON) at 5.0 V
0.2A to 2.5A adjustable output current
Kickstart momentary secondary current-limit threshold
(120ms period)
Soft-start functionality
Undervoltage lockout (UVLO)
Fast 10µs short-circuit response time (non-Kickstart
options)
Fault status output flag
Logic-controlled enable (active-hi gh, ac ti ve-low)
Thermal shutdown
Pin compatible with the MIC2009/MIC2019
6-pin 2mm × 2mm thin DFN and 6-pin SOT -23
packages
Junction temperature range from 40°C to +12C
Applications
USB peripherals and USB 2.0/3.0 compatible
DTV/STB
Notebooks and consumer electronics
General-purpose power distribution
____________________________________________________________________________________________________________
Typical Appli cation
Micrel, Inc.
MIC2039
November 14, 2013
Revision 1.2
Ordering Information
Part Number Top Mark
(1)
Current Limit Enable Kickstart Package
MIC2039AYM6 39AA Adjustable Active High No SOT-23-6L
MIC2039BYM6 39BB Adjustable Active Low No SOT-23-6L
MIC2039AYMT 3A9 Adjustable Active High No 6-pin 2mm x 2mm Thin DFN
(2)
MIC2039BYMT B39 Adjustable Active Low No 6-pi n 2mm x 2mm Thin DFN
(2)
MIC2039EYM6 39AE Adjustable Active High Yes SOT-23-6L
MIC2039FYM6 39AF Adjustable Active Low Yes SOT-23-6L
MIC2039EYMT D39 Adjustable Active High Yes 6-pin 2mm x 2mm Thin DFN
(2)
MIC2039FYMT F39 Adjustable Active Low Yes 6-pin 2mm x 2mm Thin DFN
(2)
Notes:
1. Under-bar symbol ( _ ) may not be to scale.
2. Thin DF N is a GREE N RoHS-c ompliant package. Lead finish is NiPdAu. Mold compound is Halogen Free.
Pin Configuration
VIN
FAULT/
ILIMIT
VOUT
GND
4
5
6
1
2
3
EN
VIN
FAULT/
ILIMIT
VOUT
GND
EP
EN
6
1
2
3
5
4
SOT-23 6-Lead (M6)
Top View
2mm x 2mm 6-pin Thin DFN (MT)(3)
Top View
Notes:
3. Thin DFN ▲ = Pin 1 identifier.
Micrel, Inc.
MIC2039
November 14, 2013
Revision 1.2
Pin Description
Pin Number
Pin
Name Pin Function
SOT-23-6L 6-pin
2mmx2mm
Thin DFN
1 6 VIN Input: Power switch and logic supply input.
2 5 GND Ground: Input and output return pin.
3 4 EN Enable (Input): Logic compati b le, enabl e control input that allows switch turn-on/off.
Do not leave the EN pin floating.
4 3 FAULT/
Fault Status Flag (Output): Active-low, open-drain output. A logic low state
indicates an overcurrent or thermal shutdown condition. An overcurrent condition
must last longer than tFAULT/ to assert FAULT/. A pull-up resistor (10kΩ
recommended) to an external supply is required.
5 2 ILIMIT Current Limit Set: Current limit adjust setting. Connect a resistor from this pin to
GND to set the current limit, but do not leave the ILIMIT pin floating.
6 1 VOUT Switch Output: Power switch output.
EP ePad Exposed Pad: Exposed pad on bottom of package. Connect to electrical ground for
optimum thermal dissipation.
Micrel, Inc.
MIC2039
November 14, 2013
Revision 1.2
Absolute Maximum Ratings(4)
VIN to GND ....................................................... 0.3V to +6V
VOUT to GND .................................................... 0.3V to +6V
VILIMIT to GND .................................................. 0.3V to +6V
VENABLE to GND ................................................ 0.3V to +6V
VFAULT/ to GND ................................................. 0.3V to +6V
FAULT/ Current (IFAULT/) .............................................. 25mA
Maximum Power Dissipation (PD) ............. Internally Limited
Lead Temperature (soldering, 10s) ............................ 260°C
Storage Temperature (TS) ......................... 65°C to +150°C
ESD Rating(6)
HBM ......................................................................... 3kV
MM ......................................................................... 300V
Operating Ratings(5)
Supply Voltage (VIN) ..................................... +2.5V to +5.5V
VEN, VFAULT/ ................................................... 0.3V to +5.5V
VILIMIT, VOUT ........................................................ 0.3V to VIN
Junction Temperature (TJ) ........................ 40°C to +125°C
Package Thermal Resistance
SOT-23-6 (θJA) .............................................. 177.2°C/W
6-pin 2mm × 2mm DFN (θJA) ............................. 90°C/W
Electrical Characteristics(7)
VIN = VEN = 5V; CIN = 1µF; COUT = 1µF TJ = 25°C. Bold values indicate 40°C ≤ TJ ≤ +125°C, unless noted otherwise.
Symbol Parameter Condition Min. Typ. Max. Units
Power Supply Input
VIN Input Voltage Range 2.5 5.5 V
VUVLO Input Supply Undervoltage
Lockout Threshold VIN rising
2.0
2.25
2.5
V
VIN falling 1.9 2.15 2.4
VUVLOHYS Input Supply Undervoltage
Lockout Threshold Hysteresis VIN rising or VIN falling 100 mV
IDD Supply Current
Switch OFF
(IOUT = 0A)
Active-high Enable (A): VEN = 0V,
VIN = 5V 0.75 5
µA
Active-low Enable (B): VEN = VIN = 5V
Switch ON
(IOUT = 0A)
Active-high Enable (A): VEN = 1.5V,
VIN = 5V 100 300
Active-low Enable (B): VEN = 0V,
VIN = 5V
Power MOSFET
RDS(ON) Switch On Resistance
VIN = 2.5V, IOUT = 350mA 100 177
VIN = 3.3V, IOUT = 350mA 85 145
VIN = 5V, IOUT = 350mA 75 125
ILKG Output Leakage Current Switch Off, VOUT = 0V 0.22 15 µA
Notes:
4. Exceeding the absolute maximum rating may damage the device.
5. The device is not guaranteed to functi on properly outs i de its operating rating.
6. Devices are ESD sensitive. Handling precauti ons recommended. Human body model (HBM), 1.5k in series with 100pF.
7. Specific at i on for packaged product only.
Micrel, Inc.
MIC2039
November 14, 2013
Revision 1.2
Electrical Characteristics(7) (Continued)
VIN = VEN = 5V; CIN = 1µF; COUT = 1µF TJ = 25°C. Bold values indicate –40°C ≤ TJ ≤ +125°C, unless noted otherwise.
Symbol
Parameter
Condition
Min.
Typ.
Max.
Units
Current Limit
ILIMIT Current Limit
(Resistor values are standard
0.1% values)
RLIMIT = 115Ω, VIN = 5V, VOUT = 0.8V × VIN 2.35 2.5 2.65
A
RLIMIT = 115Ω, VIN = 2.5V, VOUT = 0V × VIN 2.6 2.85 3.1
RLIMIT = 145Ω, VIN = 5V, VOUT = 0.8V × VIN 1.90 2.0 2.10
RLIMIT = 287Ω, VIN = 5V, VOUT = 0.8V × VIN 0.95 1.0 1.05
RLIMIT = 576Ω, VIN = 5V, VOUT = 0.8V × VIN 0.475 0.50 0.525
RLIMIT = 1.45kΩ, VIN = 5V, VOUT = 0.8V × VIN 0.19 0.20 0.21
ILIMIT_2nd Secondary Current Limit
(Kickstart parts only) VOUT = 0V 2.2 3.2 6 A
Symbol Parameter Condition Min. Typ. Max. Units
I/O
VEN Enable Voltage Logic Low 0.5 V
Logic High 1.5
IEN Enable Input Current 0V ≤ VEN 5V 1 µA
RFAULT/ FAULT/ Output Resistance IOUT = 10mA 25 Ω
IFAULT/_OFF FAULT/ Off Current VFAULT/ = VIN 10 µA
Thermal Protection
TSD Thermal-Shutdown Threshold TJ rising 157 °C
TSDHYS Thermal-Shutdown
Hysteresis 15 °C
Timing Specifications (AC Parameters)
tRISE Output Turn-on Rise Time
(8)
RLOAD = 10Ω; COUT = 1µF 700 µs
tFALL Output Turn-off Fall Time
(8)
VEN = OFF; RLOAD = 10Ω; COUT = 1µF 32 µs
tON_DLY Output Turn-on Delay
(8)
RLOAD = 10Ω; COUT = 1µF 700 µs
tOFF_DLY Output Turn-off Delay
(8)
RLOAD = 10Ω; COUT = 1µF 5 µs
tSC_RESP Short Circuit Response
Time(8) VOUT = 0V (short circuit) 10 µs
tFAULT/ Overcurrent Fault Response
Delay Time(8) Non-Kickstart parts 16 32 49 ms
tKICKSTART Overcurrent Fault Response
Delay During Kickstart (8) Kickstart parts only 64 120 200 ms
Note:
8. See Timing Di agrams(F igures 1 through 4).
Micrel, Inc.
MIC2039
November 14, 2013
Revision 1.2
Timing Diagrams
0
0
t
RISE
t
FALL
t
V
10% 10%
90% 90%
VOUT
EN
Figure 1. Output Rise/Fall Time
0
0
t
ON_DLY
t
OFF_DLY
t
V
10%
50% 50%
90%
VOUT
EN
Figure 2. Turn-On/Off Dela y
Micrel, Inc.
MIC2039
November 14, 2013
Revision 1.2
Timing Diagrams (Continued)
IOUT
FAULT/
0
0
tSC_RESP
tFAULT/
t
V
VOUT
0
ILIMIT
Figure 3. Short Circuit Response Time and Overcurrent Fault Flag Delay (Non-Kickstart)
IOUT
FAULT/
0
0
tKICKSTART
t
V
VOUT
0
ILIMIT
Figure 4. Overcurrent Fault Flag Delay (Kickstart)
Micrel, Inc.
MIC2039
November 14, 2013
Revision 1.2
Typical Characteris tics
I nput Supply Current
vs. Temperature
0
25
50
75
100
125
150
175
200
-50 -25 025 50 75 100 125
TEM PERATURE ( °C)
SUPPL Y CURRENT ( µA)
VIN = 5V
IOUT = 0m A
VI N OFF Current
vs. Temperature
0.00
0.25
0.50
0.75
1.00
1.25
1.50
-50 -25 025 50 75 100 125
TEM PERATURE ( °C)
SUPPL Y OF F CURRENT (µ A)
V
IN
= 5V
V
EN
= OF F
I
OUT
= 0m A
Undervol tage Lockout
vs. Temperature
1.50
1.75
2.00
2.25
2.50
-50 -25 025 50 75 100 125
TEM PERATURE ( °C)
UVLO THRESHO L D ( V )
V
IN
Falling
V
IN
Rising
R
DS(ON)
vs. Temperature
0
25
50
75
100
125
-50 -25 025 50 75 100 125
TEM PERATURE ( °C)
RDS(ON)
(mΩ)
VIN = 5V
IOUT = 350m A
R
DS(ON)
vs. Output Current
0
25
50
75
100
125
0.0 0.5 1.0 1.5 2.0 2.5
O UT PUT CURRENT (A)
RDS(ON)
(mΩ)
VIN = 5V
TA = 25°C
R
DS(ON)
vs. Output Current
0
25
50
75
100
125
0.0 0.5 1.0 1.5 2.0 2.5
O UT PUT CURRENT (A)
RDS(ON)
(mΩ)
VIN = 3.3V
TA = 25°C
0
10
20
30
40
50
-50 -25 025 50 75 100 125
F AULT/ RESPONSE TIME (ms)
T EMPERAT URE (°C)
FAULT/ Respo nse Time
vs. Temperatu re
V
IN
= 5V
I
LIMIT
= 1A
NON-KICKSTART
0
50
100
150
200
250
-50 -25 025 50 75 100 125
F AULT/ RESPONSE TIME (ms)
T EMPERAT URE (°C)
FAULT/ Respo nse Time
vs. Temperatu re
V
IN
= 5V
I
LIMIT
= 1A
KICKSTART
0
50
100
150
200
250
0.0 0.5 1.0 1.5 2.0 2.5
F AULT/ RESPONSE TIME (ms)
OUTPUT CURRENT (A)
FAULT/ Respo nse Tim e
v s. O utp ut Cur re nt
V
IN
= 5V
T
A
= 25°C
KICKSTART
Micrel, Inc.
MIC2039
November 14, 2013
Revision 1.2
Typical Characteristics (Continued)
Output Leakage Current
vs. Temperature
0
1
2
3
4
5
-50 -25 025 50 75 100 125
TEM PERATURE ( °C)
O UT PUT LEAKAGE (µA)
V
IN
= 5V
V
EN
= OF F
I
OUT
= 0m A
VIN - VOUT
vs. Output Current
0
50
100
150
200
250
0.0 0.5 1.0 1.5 2.0 2.5
O UT PUT CURRENT (A)
VI N - VOUT ( mV)
VIN = 5V
TA = 25°C
Current Lim it Set Resistor
vs. Output Current
0
250
500
750
1000
1250
1500
0.0 0.5 1.0 1.5 2.0 2.5
O UT PUT CURRENT (A)
RSET )
VIN = 5V
TA = 25°C
Micrel, Inc.
MIC2039
November 14, 2013
Revision 1.2
Functional Characteristics
Micrel, Inc.
MIC2039
November 14, 2013
Revision 1.2
Functional Characteristics (Continued)
Micrel, Inc.
MIC2039
November 14, 2013
Revision 1.2
Functional Characteristics (Continued)
Micrel, Inc.
MIC2039
November 14, 2013
Revision 1.2
Functional Diagram
Thermal
Sensor
EN
GND
VOUTVIN
Control
Reference
Current
Limit Delay
UVLO
ILIMIT
Sense FET
Power FET
FAULT/
Figure 5. MIC2039 Block Diagram
Micrel, Inc.
MIC2039
November 14, 2013
Revision 1.2
Functional Description
The MIC2039 is a high-side MOSF ET power-distribution
switch that provid es increa sed s ystem reliabi lity by using
5% current limit accuracy. The MIC2039 is internally
current limited and has thermal shutdown, which
protects the device and system.
The MIC2039 has a soft-start circuit that minimizes in-
rush current by slowing the turn-on time. Additionally, the
MIC2039 has an optional Kickstart feature, which
momentarily overrides the normal current-limiting
function to allow higher inrush and/or transient currents.
Soft-Start
Soft-start reduces the power-supply input surge current
at startup b y control ling the outpu t voltage ris e tim e. The
input surge appears while the output capacitor is
charged up. A slower output rise time draws a lower
input surge current.
KICKSTART Inrush Overcurrent Filter
The MIC20 39 E Yxx an d MIC203 9F Yxx are equ ipped with
a secondary current limit that allows high inrush current
transients to pass for a set period before the primary
current-limit circuitry becomes ac ti ve. T he FAULT/ status
flag does n ot assert dur ing the Kickstart period ( typica lly
120ms), which elim inates an y false (FAULT/) assertions.
The Kickstart function is active during initial startup or
while operating in steady state.
Input Capacitor
Micrel recommends a F to 10µF ceramic input
capacitor for most applications.
Place the input capacitor on the same side of the board
and next to the MIC20 39 to minimize the voltage ringing
during transient and short-circuit conditions. Using two
vias for each end of the capacitor to connect to the
power and ground plane is also recommended.
Micrel recommends X7R or X5R dielectric ceramic
capacitors because of their temperature performance.
X7R-type capacitors change capacitance by 15% over
their operating temperature range and are the most
stable type of ceramic capacitors. Z5U and Y5V
dielectric capacitors change value by as much as 50%
and 60%, respectively, over their operating temperature
ranges. To use a ceramic chip capacitor with Y5V
dielectric, the value must be much higher than an X7R
ceramic or a tantalum capacitor to ensure the same
capacitance value over the operating temperature range.
Output Capacitor
The outp ut capacitor t ype and pl acement cr iteria are the
same as for the input capacitor. See the Input
Capacitorsection for a detailed description.
Enable
The MIC2039 offers either an active-high or active-low
enable input (EN) that allows ON/OFF control of the
switch outp ut. The cur rent through the de vice reduces to
near “zero” when the device is shut down, with only
microamperes of leakage current. The EN input can be
directly tied to VIN or driven by a voltage that is equal to
or less than VIN; do not leave this pin floating.
Adjustable Current Limit
The MIC2039 current limit is adjustable from 0.2A to
2.5A by connecting a resistor from the ILIMIT pin to
GND. The following equation determines the resistor:
LIMIT
I/289
LIMIT
R
Eq. 1
where ILIMIT is the typical current limit from the electrical
table. If the output current exceeds the set current limit,
the MIC2039 switch enters constant current limit mode.
The maximum allowable current limit can be less than
the full s pecified an d/or expected current if the MIC2039
is not mounted on a circuit board with sufficiently low
thermal resistance. Table 1 shows resistor values (1%)
for select current limit settings.
ILIMIT 0.2A 0.5A 1.0A 2A 2.5A
RLIMIT 1.45 576Ω 287Ω 145Ω 115Ω
Table 1. Resistor Selection for Adjustable Current Limit
Micrel, Inc.
MIC2039
November 14, 2013
Revision 1.2
Thermal Design
To help reduce the thermal resistance, the ePad
(underneath the IC) should be soldered to the PCB
ground. The placement of thermal vias either underneath
or near the ePad is highly recommended. Thermal
design requires the following application-specific
parameters:
Maximum ambient temperature (TA)
Output current (IOUT)
Input voltage (VIN)
Current limit (ILIMIT)
When the MIC2039 is in constant current limit mode, it
may exceed the overtemperature threshold. If this
occurs , the overtem peratur e condition will shut do wn the
MIC2039 switch and the fault status flag will go active
(asser t low). Af ter the s witc h cools down, it automatically
turns on again. The user can maximize the MIC2039
power dissipation by either lowering the thermal
resistance on the exposed pad (only the DFN package
has an exposed pad) on the printed circuit board, or by
limiting the maximum allowable ambient temperature.
Thermal Measurements
It is always wise to measure the IC’s case temperature
to mak e s ure t hat it is with i n its oper a tin g l imits. Althou gh
this might seem like an elementary task, it is very easy
to get false results. The most common m istake is to use
the standar d therm al coupl e that com es with t he ther mal
voltage meter. This thermal couple wire gauge is large,
typically 22 gauge, and behaves like a heatsink,
resulting in a lower case measurement.
There are two suggested methods for measuring the IC
case temperature: a thermal couple or an infrared
thermometer. If a thermal couple is used, it must be
constructed of 36 gauge wire or higher to minimize the
wire heatsinking effect. In addition, the thermal couple tip
must be c overe d in e it her therm al greas e or thermal glue
to make sure that the thermal couple junction is making
good contact to the case of the IC. Thermal couple
5SC-TT-K-36-36 from Omega is adequate for most
applications.
To avoid using m ess y ther m al couple grease or gl ue, an
infrared thermometer is recommended. Most infrared
thermometers’ spot size is too large for an accurate
reading on small form factor ICs. However, an IR
thermometer from Optris has a 1mm spot size, which
makes it ideal for the 2mm × 2mm thin DFN package.
Also, get the optional stand. The stand mak es it easy to
hold the beam on the IC for long periods of time.
Micrel, Inc.
MIC2039
November 14, 2013
Revision 1.2
Evaluation Board Schematic
Bill of Materials
Item Part Number Manufacturer Description Qty.
C1, C2 C1608X5R0J105K TDK
(9)
1µF/6.3V ceramic capacitor, X5R, 0603 2
06036D105KAT2A AVX
(10)
R1, R2 CRCW060310K0FKEA Vishay/Dale
(11)
10kΩ, film resistor, 0603, 1% 2
R3 CRCW06032870FKEA Vishay/Dale 287Ω film resistor, 0603, 1% 1
U1 MIC2039xYMT Micrel
(12)
High-accuracy, high-side, adjustable current-limit pow er sw itch 1
Notes:
9. TDK: www.tdk.com.
10. AVX.: www.avx.com.
11. Vishay: www.vishay.com.
12. Micrel, Inc.: www.micrel.com
Micrel, Inc.
MIC2039
November 14, 2013
Revision 1.2
PCB Layout (MIC2039xYMT Evaluation Board)
MIC2039xYMT Evaluation Board Top Layer
MIC2039xYMT Evaluation Board Bottom Layer
Micrel, Inc.
MIC2039
November 14, 2013
Revision 1.2
PCB Layout (MIC2039xYM6 Evaluation Board)
MIC2039xYM6 Evaluation Board Top Layer
MIC2039xYM6 Evaluation Board Bottom Layer
Micrel, Inc.
MIC2039
November 14, 2013
Revision 1.2
Package Information(13)
6-Pin 2mm x 2mm Thin DFN (MT)
Note:
13. Package information is correct as of the publication date. For updates and most current information, go to www.micrel.com.
Micrel, Inc.
MIC2039
November 14, 2013
Revision 1.2
Package Information(13) (Continued)
SOT23-6L (M6)
Micrel, Inc.
MIC2039
November 14, 2013
Revision 1.2
MICREL, INC. 2180 FORTUNE DRIVE SA N JOSE, CA 95131 USA
TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com
Micrel m akes no representati ons or warranties with respect t o the accuracy or completeness of the information furnis hed in this data sheet. This
informat i on is not intended as a warranty and Micrel does not assume responsibilit y for its use. Micrel reserves the right to change circuitry,
specificat i ons and descript i ons at any time without notice. No license, whether express , im plied, arisi ng by estoppel or otherwise, t o any intellectual
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relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intel l ect ual property right
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