MIC20XX Family
Fixed and Adjustable Current Limiting
Power Distribution Switches
Kickstart is a trademark of Micrel, Inc.
MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc.
CableCARD is a trademark of CableLabs.
Protected by U.S. Patent No. 7,170,732
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
General Description
MIC20XX family of switches are current limiting, high-side
power switches, designed for general purpose power
distribution and control in digital televisions (DTV), printers,
set top boxes (STB), PCs, PDAs, and other peripheral
devices (see Functionality Table and Pin Configuration
drawings)
MIC20XX family’s primary functions are current limiting
and power switching. They are thermally protected and will
shutdown should their internal temperature reach unsafe
levels, protecting both the device and the load, under high-
current or fault conditions
Features include fault reporting, fault blanking to eliminate
noise-induced false alarms, output slew rate limiting, under
voltage detection, automatic-on output, and enable pin
with choice of either active low or active high enable. The
FET is self-contained, with a fixed- or user-adjustable
current limit. The MIC20XX family is ideal for any system
where current limiting and power control are desired.
The MIC201X (3 x 9) and MIC2019A switches offer a
unique new patented feature: Kickstart™, which allows
momentary high-current surges up to the secondary
current limit (ILIMIT_2nd) without sacrificing overall system
safety.
The MIC20xx family is offered, depending on the desired
features, in a space-saving 5-pin SOT-23, 6-pin SOT-23,
and 2mm x 2mm MLF® packages.
Datasheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
Features
• MIC20X3 – MIC20X9
70mΩ typical on-resistance @ 5V
• MIC2005A/20X9A
170mΩ typical on-resistance @ 5V
• Enable active high or active low
• 2.5V – 5.5V operating range
• Pre-set current limit values of 0.5A, 0.8A, and 1.2A*
• Adjustable current limit 0.2A to 2.0A* (MIC20X7-
MIC20X9)
• Adjustable current limit 0.1A to 0.9A* (MIC20X9A)
• Undervoltage lock-out (UVLO)
• Variable UVLO allows adjustable UVLO thresholds*
• Automatic load discharge for capacitive loads*
• Soft-start prevents large current inrush
• Adjustable slew rate allows custom slew rates*
• Automatic-on output after fault
• Thermal protection
* Available on some family members
Applications
• Digital televisions (DTV)
• Set top boxes
• PDAs
• Printers
• USB / IEEE 1394 power distribution
• Desktop and laptop PCs
• Game consoles
• Docking stations
___________________________________________________________________________________________________________
Typical Application
VIN VOUT
MIC2005A
VBUS
USB
Port
GND
EN FAULT/
5V Supply
VIN
Logic
Controller
ON/OFF
OVERCURRENT/ 1µF
120µF
Figure 1. Typical Application Circuit
August 2011 M9999-080211-D
Micrel, Inc. MIC20xx Family
August 2011
2 M9999-080211-D
Ordering Information
MIC2003/2013
Part Number(1) Marking(2) Current Limit Kickstart™ Package
MIC2003-0.5YM5 FD05 0.5A
MIC2003-0.8YM5 FD08 0.8A
MIC2003-1.2YM5 FD12 1.2A
5-Pin SOT-23
MIC2003-0.5YML 50D 0.5A
MIC2003-0.8YML 80D 0.8A
MIC2003-1.2YML 21D 1.2A
No
6-Pin 2mm x 2mm MLF®
MIC2013-0.5YM5 FL05 0.5A
MIC2013-0.8YM5 FL08 0.8A
MIC2013-1.2YM5 FL12 1.2A
5-Pin SOT-23
MIC2013-0.5YML 50L 0.5A
MIC2013-0.8YML 90L 0.8A
MIC2013-1.2YML 21L 1.2A
Yes
6-Pin 2mm x 2mm MLF®
MIC2004/2014
Part Number(1) Marking(2) Current Limit Kickstart™ Package
MIC2004-0.5YM5 FE05 0.5A
MIC2004-0.8YM5 FE08 0.8A
MIC2004-1.2YM5 FE12 1.2A
5-Pin SOT-23
MIC2004-0.5YML 50E 0.5A
MIC2004-0.8YML 80E 0.8A
MIC2004-1.2YML 21E 1.2A
No
6-Pin 2mm x 2mm MLF®
MIC2014-0.5YM5 FM05 0.5A
MIC2014-0.8YM5 FM08 0.8A
MIC2014-1.2YM5 FM12 1.2A
5-Pin SOT-23
MIC2014-0.5YML 50M 0.5A
MIC2014-0.8YML 90M 0.8A
MIC2014-1.2YML 21M 1.2A
Yes
6-Pin 2mm x 2mm MLF®
Notes:
1. All MIC20XX Family parts are RoHS-compliant lead free.
2. Over/Under-bar symbol ( ¯ / _ ) may not be to scale. On the package the over/under symbol begins above/below the first character of the
marking.
Micrel, Inc. MIC20xx Family
August 2011
3 M9999-080211-D
Ordering Information (Continued)
MIC2005
Part Number(1) Marking(2) Current Limit Enable Kickstart™ Package
MIC2005-0.5YM6 FF05 0.5A Active High
MIC2005-0.8YM6 FF08 0.8A Active High
MIC2005-1.2YM6 FF12 1.2A Active High
6-Pin SOT-23
MIC2005-0.5YML 50F 0.5A Active High
MIC2005-0.8YML 80F 0.8A Active High
MIC2005-1.2YML 21F 1.2A Active High
No
6-Pin 2mm x 2mm MLF®
MIC2005L
Part Number(1) Marking(2) Current Limit Enable Kickstart™ Package
MIC2005-0.5LYM5 5LFF 0.5A Active Low
MIC2005-0.8LYM5 8LFF 0.8A Active Low
MIC2005-1.2LYM5 4LFF 1.2A Active Low
No 5-Pin SOT-23
MIC2005A
Part Number(1) Marking(2) Current Limit Enable Kickstart™ Package
MIC2005A-1YM5 FA51 0.5A Active High
MIC2005A-2YM5 FA52 0.5A Active Low 5-Pin SOT-23
MIC2005A-1YM6 FA53 0.5A Active High
MIC2005A-2YM6 FA54 0.5A Active Low
No
6-Pin SOT-23
MIC2015
Part Number(1) Marking(2) Current Limit Enable Kickstart™ Package
MIC2015-0.5YM6 FN05 0.5A Active High
MIC2015-0.8YM6 FN08 0.8A Active High
MIC2015-1.2YM6 FN12 1.2A Active High
6-Pin SOT-23
MIC2015-0.5YML 50N 0.5A Active High
MIC2015-0.8YML 80N 0.8A Active High
MIC2015-1.2YML 21N 1.2A Active High
Yes
6-Pin 2mm x 2mm MLF®
Notes:
1. All MIC20XX Family parts are RoHS-compliant lead free.
2. Over/Under-bar symbol ( ¯ / _ ) may not be to scale. On the package the over/under symbol begins above/below the first character of the
marking.
Micrel, Inc. MIC20xx Family
August 2011
4 M9999-080211-D
Ordering Information (Continued)
MIC2006/2016
Part Number(1) Marking(2) Current Limit Kickstart™ Package
MIC2006-0.5YM6 FG05 0.5A
MIC2006-0.8YM6 FG08 0.8A
MIC2006-1.2YM6 FG12 1.2A
6-Pin SOT-23
MIC2006-0.5YML 50G 0.5A
MIC2006-0.8YML 80G 0.8A
MIC2006-1.2YML 21G 1.2A
No
6-Pin 2mm x 2mm MLF®
MIC2016-0.5YM6 FP05 0.5A
MIC2016-0.8YM6 FP08 0.8A
MIC2016-1.2YM6 FP12 1.2A
6-Pin SOT-23
MIC2016-0.5YML 50P 0.5A
MIC2016-0.8YML 90P 0.8A
MIC2016-1.2YML 21P 1.2A
Yes
6-Pin 2mm x 2mm MLF®
MIC2007/2017
Part Number(1) Marking(2) Current Limit Kickstart™ Package
MIC2007YM6 FHAA 6-Pin SOT-23
MIC2007YML AHA No 6-Pin 2mm x 2mm MLF®
MIC2017YM6 FQAA 6-Pin SOT-23
MIC2017YML
0.2A – 2.0A
Yes 6-Pin 2mm x 2mm MLF®
AQA
MIC2008/2018
Part Number(1) Marking(2) Current Limit Kickstart™ Package
MIC2008YM6 FJAA 6-Pin SOT-23
MIC2008YML AJA No 6-Pin 2mm x 2mm MLF®
MIC2018YM6 FRAA 6-Pin SOT-23
MIC2018YML
0.2A – 2.0A
Yes 6-Pin 2mm x 2mm MLF®
ARA
MIC2009/2019
Part Number(1) Marking(2) Current Limit Kickstart™ Package
MIC2009YM6 FKAA 6-Pin SOT-23
MIC2009YML AKA No 6-Pin 2mm x 2mm MLF®
MIC2019YM6 FSAA 6-Pin SOT-23
MIC2019YML ASA
0.2A – 2.0A
Yes 6-Pin 2mm x 2mm MLF®
Notes:
1. All MIC20XX Family parts are RoHS-compliant lead free.
2. Over/Under-bar symbol ( ¯ / _ ) may not be to scale. On the package the over/under symbol begins above/below the first character of the
marking.
Micrel, Inc. MIC20xx Family
August 2011
5 M9999-080211-D
Ordering Information (Continued)
MIC2009A/2019A
Part Number(1) Marking(2) Current Limit Kickstart™ Enable Package
MIC2009A-1YM6 FK1 Active High
MIC2009A-2YM6 FK2 No Active Low
MIC2019A-1YM6 FS1 Active High
MIC2019A-2YM6 FS2
0.1 A – 0.9 A
Yes Active Low
6-pin SOT-23
Notes:
1. All MIC20XX Family parts are RoHS-compliant lead free.
2. Over/Under-bar symbol ( ¯ / _ ) may not be to scale. On the package the over/under symbol begins above/below the first character of the
marking.
MIC20XX Family Member Functionality
Part Number Pin Function
Normal
Limiting Kickstart™(1) I
LIMIT I
LIMIT ENABLE
High ENABLE
Low CSLEW FAULT/ VUVLO(5) Load
Discharge
2003 2013 – – – – – –
2004 2014
2005 2015
2005L (1)
2005A-1 (1) (6)
2005A-2 (1) (6)
2006 2016
Fixed (2)
2007 2017
2008 2018
2009 2019
2009A-1 2019A-1
2009A-2 2019A-2
Adj.(3)
Notes:
1. Kickstart™ provides an alternate start-up behavior; however, pin-outs are identical.
2. Kickstart™ not available.
3. Fixed = Factory-programmed current limit.
4. Adj. = User adjustable current limit.
5. VUVLO = Variable UVLO (Previously called DML).
6. CSLEW not available in 5-pin package.
Micrel, Inc. MIC20xx Family
August 2011
6 M9999-080211-D
MIC20XX Family Mem ber Pin Configuration Table, SOT Pa ck ages
Part Number Pin Number
Normal
Limiting Kickstart™ ILIMIT 1 2 3 4 5 6
2003 2013 VIN GND NC NC VOUT
2004 2014 VIN GND EN NC VOUT
2005 2015 VIN GND EN FAULT/ CSLEW VOUT
2005L (1) VIN GND EN FAULT/ VOUT
2005Axxx6 (1) VIN GND EN FAULT/ CSLEW VOUT
2005Axxx5 (1) VIN GND EN FAULT/ VOUT
2006 2016
Fixed(2)
VIN GND EN VUVLO(4) CSLEW VOUT
2007 2017 VIN GND EN ILIMIT CSLEW VOUT
2008 2018 VIN GND EN ILIMIT CSLEW VOUT
2009 2019 VIN GND EN FAULT/ ILIMIT VOUT
2009A 2019A
Adj.(3)
VIN GND EN FAULT/ ILIMIT VOUT
Notes:
1. Kickstart™ not available.
2. Fixed = Factory-programmed current limit.
3. ILIMIT = User adjustable current limit.
4. VUVLO = Variable UVLO (Previously called DLM).
MIC20XX Family Member Pin Configuration Table, MLF® Packages (5)
Part Number Pin Number
Normal Limiting Kickstart™ I Limit 6 5 4 3 2 1
2003 2013 VIN GND NC
NC NC VOUT
2004 2014 VIN GND EN
NC NC VOUT
2005 2015 VIN GND EN FAULT/ CSLEW VOUT
2006 2016
Fixed(2)
VIN GND EN
VUVLO(4) CSLEW VOUT
2007 2017 VIN GND EN ILIMIT CSLEW VOUT
2008 2018 VIN GND EN ILIMIT CSLEW VOUT
2009 2019
Adj.(3)
VIN GND EN FAULT/ ILIMIT VOUT
Notes:
1. Kickstart™ not available.
2. Fixed = Factory-programmed current limit.
3. ILIMIT = User adjustable current limit.
4. VUVLO = Variable UVLO (Previously called DLM).
5. Connect EP to GND.
Micrel, Inc. MIC20xx Family
August 2011
7 M9999-080211-D
MIC20XX Family Mem ber Pin Configuration Drawings
Fixed Current Limit
MIC20X3
VIN
3
15
2
4
GND
NC
VOUT
NC
5-Pin SOT-23 (M5) 6-Pin MLF® (ML)
(Top View)
MIC20X4
VIN
3
15
2
4
GND
ENABLE
VOUT
NC
5-Pin SOT-23 (M5) 6-Pin MLF® (ML)
(Top View)
MIC20X5
VIN
3
15
2
4
GND
ENABLE
VOUT
FAULT/
VIN
3
1
5
2
GND
ENABLE
VOUT
FAULT/
6
4
CSLEW
5-Pin SOT-23 (M5)
MIC2005-X.XL 6-Pin SOT-23 (M6)
MIC20X5 6-Pin MLF® (ML)
(Top View)
MIC20X5
MIC20X6
VIN
3
1
5
2
GND
ENABLE
VOUT
VUVLO
6
4
CSLEW
6-Pin SOT-23 (M6) 6-Pin MLF® (ML)
(Top View)
Micrel, Inc. MIC20xx Family
August 2011
8 M9999-080211-D
MIC20XX Family Mem ber Pin Configuration Drawings (Continued)
Adjustable Current Limit
MIC20X7/20X8
VIN
3
1
5
2
GND
ENABLE
VOUT
ILIMIT
6
4
CSLEW
6-Pin SOT-23 (M6) 6-Pin MLF® (ML)
(Top View)
MIC20X9
VIN
3
1
5
2
GND
ENABLE
VOUT
FAULT/
6
4
ILIMIT
6-Pin SOT-23 (M6) 6-Pin MLF® (ML)
(Top View)
MIC2005A
VIN
3
15
2
4
GND
ENABLE
VOUT
FAULT/
VIN
3
1
5
2
GND
ENABLE
VOUT
FAULT/
6
4
CSLEW
5-Pin SOT-23 (M5) 6-Pin SOT-23 (M6)
MIC2009A
VIN
3
1
5
2
GND
ENABLE
VOUT
FAULT/
6
4
ILIMIT
6-Pin SOT-23 (M6)
Micrel, Inc. MIC20xx Family
August 2011
9 M9999-080211-D
Descriptions
These pin and signal descriptions aid in the
differentiation of a pin from electrical signals and
components connected to that pin. For example, VOUT
is the switch’s output pin, while VOUT is the electrical
signal output voltage present at the VOUT pin.
Pin Descriptions
Pin Name Type Description
VIN Input Supply input. This pin provides power to both the output switch and the switch’s internal control circuitry.
GND Ground.
EN Input Switch Enable (Input):
FAULT/ Output
Fault status. A logic LOW on this pin indicates the switch is in current limiting, or has been shut down by
the thermal protection circuit. This is an open-drain output allowing logical OR’ing of multiple switches.
CSLEW Input
Slew rate control. Adding a small value capacitor between this pin and VIN slows turn-ON of the power
FET.
VOUT Output Switch output. The load being driven by the switch is connected to this pin.
VUVLO Input
Variable Under Voltage Lockout (VUVLO): Monitors the input voltage through a resistor divider between
VIN and GND. Shuts the switch off if voltage falls below the threshold set by the resistor divider.
Previously called VUVLO.
ILIMIT Input Set current limit threshold via a resistor connected from ILIMIT to GND.
EP Thermal On MLF packages connect EP to GND.
Signal Descriptions
Signal Name Type Description
VIN Input Electrical signal input voltage present at the VIN pin.
GND Ground.
VEN Input Electrical signal input voltage present at the ENABLE pin.
VFAULT/ Output Electrical signal output voltage present at the FAULT/ pin.
CSLEW Component Capacitance value connected to the CSLEW pin.
VOUT Output Electrical signal output voltage present at the VOUT pin.
VVUVLO_TH Internal
VUVLO internal reference threshold voltage. This voltage is compared to the VUVLO pin input
voltage to determine if the switch should be disabled. Reference threshold voltage has a typical
value of 250mV.
CLOAD Component Capacitance value connected in parallel with the load. Load capacitance.
IOUT Output Electrical signal output current present at the VOUT pin.
ILIMIT Internal Switch’s current limit. Fixed at factory or user adjustable.
Micrel, Inc. MIC20xx Family
August 2011
10 M9999-080211-D
Absolute Maximum Ratings(1)
VIN, VOUT.....................................................–0.3V to 6V
All other pins...........................................–0.3V to 5.5V
Power Dissipation (PD) ..................... Internally Limited
Continuous Output Current
All except MIC2005A / MIC20X9A................. 2.25A
MIC2005A / 20X9A.......................................... 1.0A
Maximum Junction Temperature (TJ) ................ 150°C
Storage Temperature (Ts)................. –65°C to +150°C
Lead Temperature (Soldering 10 sec)............... 260°C
Operating Ratings(2)
Supply Voltage.............................................. 2.5V to 5.5V
Continuous Output Current
All except MIC2005A / MIC20X9A ........... 0A to 2.1A
MIC2005A/20X9A...................................... 0A to 0.9A
Ambient Temperature Range (TA) ............–40°C to+85°C
Package Thermal Resistance(3)
SOT-23-5/6 (JA) .........................................230°C /W
2mm × 2mm MLF® (JA) ................................90°C /W
2mm × 2mm MLF® (JC) ................................45°C /W
Electrical Characteristics(4)
VIN = 5V, TA = 25°C unless otherwise specified. Bold indicates –40°C to +85°C limits; CIN = 1µF.
Symbol Parameter Condition Min. Typ. Max. Units
VIN Switch Input Voltage 2.5
5.5 V
ILEAK Output Leakage Current(5)
Switch = OFF, VOUT = 0V
Active Low Enable, VEN = 1.5V
Active High Enable, VEN = 0V 12 100 µA
MIC2005A, MIC2009A, MIC2019 A
Switch = ON
Active Low Enable, VEN = 0V
Active High Enable, VEN = 1.5V
80 300
Switch = OFF
Active Low Enable, VEN = 1.5V 8 15
IIN Supply Current(5)
Switch = OFF
Active High Enable, VEN = 0V 1 5
µA
170 220
RDS(ON) Power Switch Resistance VIN = 5V, IOUT = 100mA 275 m
MIC2005A
ILIMIT Fixed Current Limit VOUT = 0.8 × VIN 0.5 0.7 0.9 A
MIC2009A, MIC2019A
IOUT = 0.9A, VOUT = 0.8 × VIN 172 211 263
IOUT = 0.5A, VOUT = 0.8 × VIN 152 206 263
IOUT = 0.2A, VOUT = 0.8 × VIN 138 200 263
CLF Variable Current Limit Factors
IOUT = 0.1A, VOUT = 0.8 × VIN 121 192 263
V
MIC2019A
ILIMIT_2nd Secondary Current Limit VIN = 2.5V, VOUT = 0V 1 2 3 A
Notes:
1. Exceeding the absolute maximum rating may damage the device.
2. The device is not guaranteed to function outside its operating rating.
3. Requires proper thermal mounting to achieve this performance
4. Specifications for packaged product only.
5. Check the Ordering Information section to determine which parts are Active High or Active Low.
Micrel, Inc. MIC20xx Family
August 2011
11 M9999-080211-D
Electrical Characteristics(4) (Continued)
VIN = 5V, TA = 25°C unless otherwise specified. Bold indicates –40°C to +85°C limits; CIN = 1µF.
Symbol Parameter Condition Min. Typ. Max. Units
MIC2003-MIC2009, MIC2013-MIC201 9, MIC2005-X.XL
Switch = ON
Active Low Enable, VEN = 0V
Active High Enable, VEN = 1.5V
80 330
Switch = OFF
Active Low Enable, VEN = 1.5V 8 15
IIN Supply Current(5)
Switch = OFF
Active High Enable, VEN = 0V 1 5
µA
70 100
RDS(ON) Power Switch Resistance VIN = 5V, IOUT = 100mA 125 m
MIC2003-X.X, MIC2004-X.X, MIC2005-X.X, MIC2006-X.X, MIC2013-X.X, MIC2014-X.X, MIC2015-X.X MIC2016-X.X, MIC2005-X.XL
−0.5, VOUT = 0.8 × VIN 0.5 0.7 0.9
−0.8, VOUT = 0.8 × VIN 0.8 1.1 1.5
ILIMIT Fixed Current Limit
−1.2, VOUT = 0.8 × VIN 1.2 1.6 2.1
A
MIC2005-0.5
ILIMIT Fixed Current Limit VOUT = 0.8 × VIN 0.5 0.7 0.9 A
MIC2007, MIC2008, MIC2009, MIC2017, MIC2018, MIC2019
IOUT = 2.0A, VOUT = 0.8 × VIN 210 250 286
IOUT = 1.0A, VOUT = 0.8 × VIN 190 243 293
IOUT = 0.5A, VOUT = 0.8 × VIN 168 235 298
CLF Variable Current Limit
Factors
IOUT = 0.2A, VOUT = 0.8 × VIN 144 225 299
V
MIC2013, MIC2014, MIC2015, MIC2016, MIC2017, MIC2018, MIC2019
ILIMIT_2nd Secondary Current Limit VIN = 2.5V, VOUT = 0V 2.2 4 6 A
MIC2006, MIC2016
VUVLO_TH Variable UVLO Threshold 225 250 275 mV
MIC20x4, MIC20x7
RDSCHG Load Discharge Resistance VIN = 5V, ISINK = 5mA 70 126 200
MIC20X5, MIC20X6, MIC20X7, MIC20X8
ICSLEW C
SLEW Input Current 0V ≤ VOUT ≤ 0.8VIN 0.175 µA
Micrel, Inc. MIC20xx Family
August 2011
12 M9999-080211-D
Electrical Characteristics(4) (Continued)
VIN = 5V, TA = 25°C unless otherwise specified. Bold indicates –40°C to +85°C limits; CIN = 1µF.
Symbol Parameter Condition Min. Typ. Max. Units
All P arts
VIL (MAX) 0.5
VEN ENABLE Input Voltage(6) VIH (MIN) 1.5 V
IEN ENABLE Input Current
0V ≤ VEN ≤ 5V 1 5 µA
VIN Rising 2 2.25 2.5
UVLOTHRESHOLD Undervoltage Lock-Out
Threshold VIN Falling 1.9 2.15 2.4 V
UVLOHYSTERESIS Undervoltage Lock-Out
Hysteresis 0.1 V
VFAULT Fault Status Output Voltage IOL = 10mA 0.25 0.4 V
TJ Increasing 145
OTTHRESHOLD Over-Temperature
Threshold TJ Decreasing 135 °C
Note:
6. VIL(MAX) = Maximum positive voltage applied to the input which will be accepted by the device as a logic low.
VIH(MAX) = Maximum positive voltage applied to the input which will be accepted by the device as a logic high.
Micrel, Inc. MIC20xx Family
August 2011
13 M9999-080211-D
AC Electrical Characteristics
Symbol Parameter Condition Min. Typ. Max. Units
tRISE Output Turn-on rise time
RL = 10, CLOAD = 1µF,
VOUT = 10% to 90%
CSLEW(7) = Open
500 1000 1500 µs
Delay before asserting or releasing
FAULT/
MIC2003 – MIC2009
MIC2009A, MIC2005A
Time from current limiting to FAULT/ state
change 20 32 49
tD_FAULT Delay before asserting or releasing
FAULT/
MIC2013 – MIC2019
MIC2019A
Time from IOUT continuously exceeding
primary current limit condition to FAULT/
state change 77 128 192
ms
tD_LIMIT
Delay before current limiting
MIC2013 – MIC2019
MIC2019A
77
128 192 ms
tRESET
Delay before resetting Kickstart™
current limit delay, tD_LIMIT
MIC2013 – MIC2019
MIC2019A
Out of current limit following a current limit
event. 77 128 192 ms
tON_DLY Output Turn-on Delay
RL = 43, CL = 120µF,
VEN = 50% to VOUT = 10%
*CSLEW = Open 1000 1500 µs
tOFF_DLY Output Turn-off Delay
RL = 43, CL = 120µF,
VEN = 50% to VOUT = 90%
*CSLEW = Open
700 µs
ESD(8)
Symbol Parameter Condition Min. Typ. Max. Units
VOUT and GND ±4
VESD_HB Electro Static Discharge Voltage:
Human Body Model All other pins ±2
kV
VESD_MCHN Electro Static Discharge Voltage;
Machine Model
All pins
Machine Model ±200 V
Notes:
7. Whenever CSLEW is present.
8. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF.
Micrel, Inc. MIC20xx Family
August 2011
14 M9999-080211-D
Timing Diagrams
90%
10%
90%
10%
tFALL
tRISE
Rise and Fall Times
ENABLE
VOUT
50%
90%
10%
tON_DLY tOFF_DLY
50%
Switching Delay Times
Micrel, Inc. MIC20xx Family
August 2011
15 M9999-080211-D
Typical Characteristics
0
20
40
60
80
100
2.5 3.0 3.5 4.0 4.5 5.0 5.5
SUPPLY CURRENT (µA)
VIN (V)
Supply Current Output Enabled
MIC20XX
-40°C
85°C
25°C
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0.10
2.5 3.0 3.5 4.0 4.5 5.0 5.5
SUPPLY CURRENT (µA)
VIN (V)
Supply Current Output
Disabled (MIC20XX)
-40°C
85°C
25°C
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0.10
-40 -15 10 35 60 85
LEAKAGE CURRENT (µA)
TEMPERATURE (°C)
Switch Leakage Current
(MIC20XX)
5V
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
-40 -15 10 35 60 85
ILIMIT (A)
TEMPERATURE (°C)
ILIMIT vs. Temperature
(MIC20XX - 0.5)
5V
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
-40 -15 10 35 60 85
ILIMIT (A)
TEMPERATURE (°C)
ILIMIT vs. Temperature
(MIC20XX - 0.8)
5V
1.00
1.10
1.20
1.30
1.40
1.50
1.60
1.70
1.80
1.90
2.00
-40 -15 10 35 60 85
ILIMIT (A)
TEMPERATURE (°C)
ILIMIT vs. Temperature
(MIC20XX - 1.2)
5V
0
20
40
60
80
100
120
140
160
180
200
22.533.544.555.5
RDS(ON) (mOhm)
VIN (V)
RDS(ON) vs. VIN
(MIC20XX)
-40°C
25°C 85°C
0
20
40
60
80
100
120
140
160
180
200
-40 -15 10 35 60 85
RDS(ON) (mOhm)
TEMPERATURE (°C)
RDS(ON) vs. Temperature
(MIC20XX)
2.5V 3.3V
5.0V
0
200
400
600
800
1000
1200
-40 -15 10 35 60 85
CURRENT-LIMIT THRESHOLD (mA)
TEMPERATURE (°C)
ILIMIT vs. Temperature
(MIC20X9 - 0.9A)
RSET = 267Ohms
0
20
40
60
80
100
120
140
160
0 0.2 0.4 0.6 0.8 1 1.2
VIN – VOUT (mV)
IOUT (A)
VDROP vs. Temperature
(MIC20XX-1.2)
-40°C
25°C
85°C
VIN = 5.0V
0
20
40
60
80
100
120
140
160
00.20.40.60.811.2
VIN – VOUT (mV)
IOUT (A)
VDROP vs. Temperature
(MIC20XX-1.2)
-40°C
25°C
85°C
VIN = 3.3V
0
200
400
600
800
1000
1200
0 0.2 0.4 0.6 0.8 1 1.2 1.4
RSET (Ohms)
ILIMIT (A)
RSET vs. ILIMIT
(MIC20X9)
RSET = 242.62
ILIMIT
0.9538
Micrel, Inc. MIC20xx Family
August 2011
16 M9999-080211-D
Typical Characteristics (Continued)
0
10
20
30
40
50
60
70
80
90
100
2.533.544.555.5
SUPPLY CURRENT (µA)
VIN (V)
Supply Current Output Enabled
(MIC20XXA)
-40°C
25°C 85°C
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0.10
2.533.544.555.5
SUPPLY CURRENT (µA)
VIN (V)
Supply Current Output
Disabled (MIC20XXA)
-40°C 25°C 85°C
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0.10
-40 -15 10 35 60 85
LEAKAGE CURRENT (µA)
TEMPERATURE (°C)
Switch Leakage Current
(MIC20XXA)
5V
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
-40 -15 10 35 60 85
ILIMIT (A)
TEMPERATURE (°C)
ILIMIT vs. Temperature
(MIC20X5A)
5V
0
100
200
300
400
500
600
700
800
900
1000
-40 -15 10 35 60 85
ILIMIT (A)
TEMPERATURE (°C)
ILIMIT vs. Temperature
(MIC20X9A (0.8A))
RSET = 267Ohms
0
500
1000
1500
2000
2500
00.20.40.60.81
RSET (Ohms)
ILIMIT (A)
RSET vs. ILIMIT
(MIC20X9A)
RSET = 212.23
ILIMIT
0.9587
0
50
100
150
200
250
2.533.544.555.5
RDS(ON) (mOhms)
VIN (V)
RDS(ON) vs. VIN
(MIC20XXA)
-40°C
25°C 85°C
0
50
100
150
200
250
-40 -15 10 35 60 85
RDS(ON) (mOhms)
TEMPERATURE (°C)
RDS(ON) vs. Temperature
(MIC20XXA)
5.0V
2.5V 3.3V
0
5
10
15
20
25
30
35
40
-40 -15 10 35 60 85
FLAG DELAY (ms)
TEMPERATURE (°C)
Flag Delay
vs. Temperature
2.5V
3.3V
5.0V
0
20
40
60
80
100
120
140
160
0 0.1 0.2 0.3 0.4 0.5 0.6
VIN - VOUT (mV)
IOUT (A)
VDROP vs. Temperature
(MIC20XXA)
-40°C
25°C 85°C
VIN = 5.0V
0
20
40
60
80
100
120
140
160
0 0.1 0.2 0.3 0.4 0.5 0.6
VIN - VOUT (mV)
IOUT (A)
VDROP vs. Temperature
(MIC20XXA)
-40°C
25°C 85°C
VIN = 3.3V
2.05
2.1
2.15
2.2
2.25
2.3
-50 0 50 100 150
THRESHOLD (V)
TEMPERATURE (°C)
UVLO Threshold
vs. Temperature
V RISING
V FALLING
Micrel, Inc. MIC20xx Family
August 2011
17 M9999-080211-D
Functional Characteristics
Micrel, Inc. MIC20xx Family
August 2011
18 M9999-080211-D
Functional Characteristics (Continued)
Micrel, Inc. MIC20xx Family
August 2011
19 M9999-080211-D
Functional Characteristics (Continued)
Micrel, Inc. MIC20xx Family
August 2011
20 M9999-080211-D
Functional Diagram
Figure 2. MIC20XX Family Functional Diagram
Micrel, Inc. MIC20xx Family
August 2011
21 M9999-080211-D
Functional Description
VIN and VOUT
VIN is both the power supply connection for the internal
circuitry driving the switch and the input (Source
connection) of the power MOSFET switch. VOUT is the
Drain connection of the power MOSFET and supplies
power to the load. In a typical circuit, current flows from
VIN to VOUT toward the load. Since the switch is bi-
directional when enabled, if VOUT is greater than VIN,
current will flow from VOUT to VIN.
When the switch is disabled, current will not flow to the
load, except for a small unavoidable leakage current of
a few microamps. However, should VOUT exceed VIN by
more than a diode drop (~0.6 V), while the switch is
disabled, current will flow from output to input via the
power MOSFET’s body diode.
If discharging CLOAD is required by your application,
consider using MIC20X4 or MIC20X7; these MIC20XX
family members are equipped with a discharge FET to
insure complete discharge of CLOAD.
Current Sensing and Limiting
MIC20XX protects the system power supply and load
from damage by continuously monitoring current
through the on-chip power MOSFET. Load current is
monitored by means of a current mirror in parallel with
the power MOSFET switch. Current limiting is invoked
when the load exceeds the set over-current threshold.
When current limiting is activated the output current is
constrained to the limit value, and remains at this level
until either the load/fault is removed, the load’s current
requirement drops below the limiting value, or the
switch goes into thermal shutdown.
Kickstart™
2003 2004 2005X 2006 2007 2008 2009X
2013 2014 2015 2016 2017 2018 2019X
Only parts in bold have Kickstart™.
(Not available in 5-pin SOT-23 packages)
The MIC201X is designed to allow momentary current
surges (Kickstart™) before the onset of current limiting,
which permits dynamic loads, such as small disk drives
or portable printers to draw the energy needed to
overcome inertial loads without sacrificing system
safety. In this respect, the Kickstart™ parts (MIC201X)
differs markedly from the non-Kickstart™ parts
(MIC200X) which immediately limit load current,
potentially starving the motor and causing the appliance
to stall or stutter.
During this delay period, typically 128ms, a secondary
current limit is in effect. If the load demands a current in
excess the secondary limit, MIC201X acts immediately
to restrict output current to the secondary limit for the
duration of the Kickstart™ period. After this time the
MIC201X reverts to its normal current limit. An example
of Kickstart™ operation is shown in Figure 3.
Figure 3. Kickstart™ Operation
Figure 3 Label Key:
A. MIC201X is enabled into an excessive load (slew
rate limiting not visible at this time scale) The initial
current surge is limited by either the overall circuit
resistance and power supply compliance, or the
secondary current limit, whichever is less.
B. RON of the power FET increases due to internal
heating (effect exaggerated for emphasis).
C. Kickstart™ period.
D. Current limiting initiated. FAULT/ goes LOW.
E. VOUT is non-zero (load is heavy, but not a dead short
where VOUT = 0V. Limiting response will be the same
for dead shorts).
F. Thermal shutdown followed by thermal cycling.
G. Excessive load released, normal load remains.
MIC201X drops out of current limiting.
H. FAULT/ delay period followed by FAULT/ going
HIGH.
Undervoltage Lock -Out
Undervoltage lock-out insures no anomalous operation
occurs before the device’s minimum input voltage of
UVLOTHRESHOLD which is 2V minimum, 2.25V typical,
and 2.5V maximum had been achieved. Prior to
reaching this voltage, the output switch (power
MOSFET) is OFF and no circuit functions, such as
FAULT/ or ENABLE, are considered to be valid or
operative.
Micrel, Inc. MIC20xx Family
August 2011
22 M9999-080211-D
Variable Undervoltage Lock Out (VUVLO)
2003 2004 2005X
2006 2007 2008 2009X
2013 2014 2015 2016 2017 2018 2019X
Only parts in bold have VUVLO.
VUVLO functions as an input voltage monitor when the
switch in enabled. The VIN pin is monitored for a drop in
voltage, indicating excessive loading of the VIN supply.
When VIN is less than the VULVO threshold voltage
(VVUVLO_TH) for 32ms or more, the MIC20XX disables
the switch to protect the supply and allow VIN to
recover. After 128ms has elapsed, the MIC20X6
enables switch. This disable and enable cycling will
continue as long as VIN deceases below the VUVLO
threshold voltage (VVUVLO_TH) which has a typical value
of 250mV. The VUVLO voltage is commonly established
by a voltage divider from VIN-to-GND.
ENABLE
2003 2004 2005X 2006 2007 2008 2009X
2013 2014 2015 2016 2017 2018 2019X
Only parts in bold have ENABLE pin.
ENABLE pin is a logic compatible input which activates
the main MOSFET switch thereby providing power to
the VOUT pin. ENABLE is either an active HIGH or active
LOW control signal. The MIC20XX can operate with
logic running from supply voltages as low as 1.5 V.
ENABLE may be driven higher than VIN, but no higher
than 5.5V and not less than –0.3V.
FAULT/
2003 2004
2005X 2006 2007 2008
2009X
2013 2014 2015 2016 2017 2018
2019X
Only parts in bold have FAULT/ pin.
FAULT/ is an N-channel open-drain output, which is
asserted (LOW true) when switch either begins current
limiting or enters thermal shutdown.
FAULT/ asserts after a brief delay when events occur
that may be considered possible faults. This delay
insures that FAULT/ is asserted only upon valid,
enduring, over-current conditions and that transitory
event error reports are filtered out.
In MIC200X FAULT/ asserts after a brief delay period,
of 32ms typical. After a fault clears, FAULT/ remains
asserted for the delay period of 32ms
MIC201X’s FAULT/ asserts at the end of the Kickstart™
period which is 128ms typical. This masks initial current
surges, such as would be seen by a motor load starting
up. If the load current remains above the current limit
threshold after the Kickstart™ has timed out, then the
FAULT/ will be asserted. After a fault clears, FAULT/
remains asserted for the delay of 128ms.
Because FAULT/ is an open-drain it must be pulled
HIGH with an external resistor and it may be wire-OR’d
with other similar outputs, sharing a single pull-up
resistor. FAULT/ may be tied to a pull-up voltage source
which is higher than VIN, but no greater than 5.5V.
Soft-Start Control
Large capacitive loads can create significant inrush
current surges when charged through the switch. For
this reason, the MIC20XX family of switches provides a
built-in soft-start control to limit the initial inrush
currents.
Soft-start is accomplished by controlling the power
MOSFET when the ENABLE pin enables the switch.
CSLEW
2003 2004
2005X 2006 2007 2008
2009X
2013 2014 2015 2016 2017 2018
2019X
Only parts in bold have CSLEW pin.
(Not available in 5-pin SOT-23 packages)
The CSLEW pin is provided to increase control of the
output voltage ramp at turn-on. This input allows
designers the option of decreasing the output’s slew
rate (slowing the voltage rise) by adding an external
capacitance between the CSLEW and VIN pins.
Thermal Shutdown
Thermal shutdown is employed to protect the MIC20XX
family of switches from damage should the die
temperature exceed safe operating levels. Thermal
shutdown shuts off the output MOSFET and asserts the
FAULT/ output if the die temperature reaches 145°C.
The switch will automatically resume operation when the
die temperature cools down to 135°C. If resumed
operation results in reheating of the die, another
shutdown cycle will occur and the switch will continue
cycling between ON and OFF states until the overcurrent
condition has been resolved.
Depending on PCB layout, package type, ambient
temperature, etc., hundreds of milliseconds may elapse
from the incidence of a fault to the output MOSFET
being shut off. This delay is due to thermal time
constants within the system itself. In no event will the
device be damaged due to thermal overload because die
temperature is monitored continuously by on-chip
circuitry.
Micrel, Inc. MIC20xx Family
August 2011
23 M9999-080211-D
Application Information
Setting ILIMIT
The MIC2009/2019’s current limit is user programmable
and controlled by a resistor connected between the
ILIMIT pin and GND. The value of this resistor is
determined by the following equation:
SET
LIMIT R
LF)itFactor(CCurrentLim
I=
or
(A)I
LF)itFactor(CCurrentLim
R
LIMIT
SET =
For example: Set ILIMIT = 1.25A
Looking in the Electrical specifications we will find CLF
at ILIMIT = 1A.
Min Typ Max Units
190 243 293 V
Table 1. CLF at ILIMIT = 1A
For the sake of this example, we will say the typical
value of CLF at an IOUT of 1A is 243V. Applying the
equation above:
Ω==Ω 4.194
1.25A
243V
)(RSET
RSET = 196
(the closest standard 1% value)
Designers should be aware that variations in the
measured ILIMIT for a given RSET resistor, will occur
because of small differences between individual ICs
(inherent in silicon processing) resulting in a spread of
ILIMIT values. In the example above we used the typical
value of CLF to calculate RSET. We can determine
ILIMIT’s spread by using the minimum and maximum
values of CLF and the calculated value of RSET.
A97.0
196
190V
ILIMIT_MIN =
Ω
=
1.5A
196
293V
ILIMIT_MAX ==
Giving us a maximum ILIMIT variation over temperature
of:
ILIMIT_MIN ILIMIT_TYP ILIMIT_MAX
0.97A (-22%) 1.25A 1.5A (+20%)
IOUT R
SET I
LIMIT_MIN I
LIMIT_MAX
0.1A 1928 0.063A 0.136A
0.2A 993 0.137A 0.265A
0.3A 673 0.216A 0.391A
0.4A 511 0.296A 0.515A
0.5A 413 0.379A 0.637A
0.6A 346 0.463A 0.759A
0.7A 299 0.548A 0.880A
0.8A 263 0.634A 1.001A
0.9A 235 0.722A 1.121A
Table 2. MIC20x9A RSET Table
IOUT R
SET I
LIMIT_MIN I
LIMIT_MAX
0.2A 1125 0.127A 0.267A
0.3A 765 0.202A 0.390A
0.4A 582 0.281A 0.510A
0.5A 470 0.361A 0.629A
0.6A 395 0.443A 0.746A
0.7A 341 0.526A 0.861A
0.8A 300 0.610A 0.976A
0.9A 268 0.695A 1.089A
1A 243 0.781A 1.202A
1.1A 222 0.868A 1.314A
1.2A 204 0.956A 1.426A
1.3A 189 1.044A 1.537A
1.4A 176 1.133A 1.647A
1.5A 165 1.222A 1.757A
Table 3. MIC20x9 RSET Table
Micrel, Inc. MIC20xx Family
August 2011
24 M9999-080211-D
ILIMIT vs. IOUT Measured
The MIC20XX’s current-limiting circuitry, during current
limiting, is designed to act as a constant current source
to the load. As the load tries to pull more than the
allotted current, VOUT drops and the input to output
voltage differential increases. When VIN - VOUT exceeds
1V, IOUT drops below ILIMIT to reduce the drain of fault
current on the system’s power supply and to limit
internal heating of the switch.
When measuring IOUT it is important to bear this voltage
dependence in mind, otherwise the measurement data
may appear to indicate a problem when none really
exists. This voltage dependence is illustrated in Figures
4 and 5.
In Figure 4, output current is measured as VOUT is
pulled below VIN, with the test terminating when VOUT is
1V below VIN. Observe that once ILIMIT is reached IOUT
remains constant throughout the remainder of the test.
In Figure 5 this test is repeated but with VIN - VOUT
exceeding 1V.
When VIN - VOUT > 1V, switch’s current limiting circuitry
responds by decreasing IOUT, as can be seen in Figure
5. In this demonstration, VOUT is being controlled and
IOUT is the measured quantity. In real life applications
VOUT is determined in accordance with ’s law by the
load and the limiting current.
Figure 4. IOUT in Current Limiting for VIN - VOUT < 1V
Figure 5. IOUT in Current Limiting for VIN - VOUT > 1V
This folding back of ILIMIT can be generalized by plotting
ILIMIT as a function of VOUT, as shown below in Figures 6
and 7. The slope of VOUT between IOUT = 0V and IOUT =
ILIMIT (where ILIMIT = 1A) is determined by RON of the
switch and ILIMIT.
0
0.2
0.4
0.6
0.8
1.0
1.2
0123456
NORMALIZED OUTPUT CURRENT (A)
OUTPUT VOLTAGE (V)
Normalized Output Current
vs. Output Voltage (5V)
Figure 6. Normalized Output Current vs. Output Voltage
Micrel, Inc. MIC20xx Family
August 2011
25 M9999-080211-D
0
0.2
0.4
0.6
0.8
1.0
1.2
0 0.5 1.0 1.5 2.0 2.5 3.0
NORMALIZED OUTPUT CURRENT (A)
OUTPUT VOLTAGE (V)
Normalized Output Current
vs. Outpu t Voltage (2.5V)
Figure 7. Normalized Output Current vs. Output Voltage
CSLEW
2003 2004
2005X 2006 2007 2008
2009X
2013 2014 2015 2016 2017 2018
2019X
Only parts in bold have CSLEW pin.
(Not available in 5-pin SOT-23 packages).
The CSLEW pin is provided to increase control of the
output voltage ramp at turn-on. This input allows
designers the option of decreasing the output’s slew
rate (slowing the voltage rise) by adding an external
capacitance between the CSLEW and VIN pins. This
capacitance slows the rate at which the pass FET gate
voltage increases and thus, slows both the response to
an Enable command as well as VOUT’s ascent to its final
value.
Figure 8 illustrates effect of CSLEW on turn-on delay and
output rise time.
0
0.002
0.004
0.006
0.008
0.01
0.012
0.014
0000000000
TIME (mS)
CSLEW (nF)
Typical Turn-on Times
vs. External CSLEW Capacitance
2
4
6
8
10
12
14
000.5 11.5 22.5 33.5 44.5
TRISE
TDELAY
TON
Figure 8. CSLEW vs. Turn-On, Delay and Rise Times
CSLEW’s Effect on ILIMIT
An unavoidable consequence of adding CSLEW
capacitance is a reduction in the MIC20X5 – 20X8’s
ability to quickly limit current transients or surges. A
sufficiently large capacitance can prevent both the
primary and secondary current limits from acting in time
to prevent damage to the MIC20X5 – 20X8 or the
system from a short circuit fault. For this reason, the
upper limit on the value of CSLEW is 4nF.
Variable Undervoltage Lock Out (VUVLO)
2003 2004 2005X
2006 2007 2008 2009X
2013 2014 2015 2016 2017 2018 2019X
Only parts in bold have VUVLO pin and functionality.
Power-conscious systems, such as those implementing
ACPI, will remain active even in their low-power states
and may require the support of external devices
through both phases of operation. Under these
conditions, the current allowed these external devices
may vary according to the system’s operating state and
as such require dual current limits on their peripheral
ports. The MIC20X6 is designed for systems
demanding two primary current limiting levels but
without the use of a control signal to select between
current limits.
To better understand how the MIC20X6 provides this,
imagine a system whose main power supply supports
heavy loads during normal operation, but in sleep mode
is reduced to only few hundred milliamps of output
current. In addition, this system has several USB ports
which must remain active during sleep. During normal
operation, each port can support a 500mA peripheral,
but in sleep mode their combined output current is
limited to what the power supply can deliver minus
whatever the system itself is drawing.
If a peripheral device is plugged in which demands
more current than is available, the system power supply
will sag, or crash. The MIC20X6 prevents this by
monitoring both the load current and VIN. During normal
operation, when the power supply can source plenty of
current, the MIC20X6 will support any load up to its
factory programmed current limit. When the weaker,
standby supply is in operation, the MIC20X6 monitors
VIN and will shut off its output should VIN dip below a
predetermined value. This predetermined voltage is
user programmable and set by the selection of the
resistor divider driving the VUVLO pin.
Micrel, Inc. MIC20xx Family
August 2011
26 M9999-080211-D
To prevent false triggering of the VUVLO feature, the
MIC20X6 includes a delay timer to blank out
momentary excursions below the VUVLO trip point. If
VIN stays below the VUVLO trip point for longer than
32ms (typical), then the load is disengaged and the
MIC20X6 will wait 128ms before reapplying power to
the load. If VIN remains below the VUVLO trip point,
then the load will be powered for the 32ms blanking
period and then again disengaged. This is illustrated in
the scope plot below. If VIN remains above the VUVLO
trip point MIC20X6 resumes normal operation.
Figure 9. VUVLO Operation
VUVLO and Kickstart™ operate independently in the
MIC2016. If the high-current surge allowed by
Kickstart™ causes VIN to dip below the VUVLO trip
point for more than 32ms, VUVLO will disengage the
load, even though the Kickstart™ timer has not timed
out.
VIN
MIC20X6
VOUT
VUVLO
Input
Supply
R1
R2
++
IIN_LOAD
Figure 10. VUVLO Application Circuit
Calculating VUVLO Resistor Divider Values
The VUVLO feature is designed to keep the internal
switch off until the voltage on the VUVLO pin is greater
than 0.25V. A resistor divider network connected to the
VUVLO and VIN pins is used to set the input trip
voltage VTRIP (see Figure 10). The value of R2 is
chosen to minimize the load on the input supply IDIV and
the value of R1 sets the trip voltage VTRIP.
The value of R2 is calculated using:
DIV
VUVLO
I
V
2R =
The vale of R1 is calculated using:
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛−×= 1
V
V
R2R1
VUVLO
TRIP
Where for both equations:
VVUVLO = 0.25V
When working with large value resistors, a small
amount of leakage current from the VUVLO terminal
can cause voltage offsets that degrade system
accuracy. Therefore, the maximum recommended
resistor value for R2 is 100k.
Using the divider loading current IDIV of 100µA, the
value of R2 can be estimated by:
Ω== k5.2
µA100
V25.0
2R
Now the value of R1 can be calculated by:
k451
V25.0
V75.4
k5.21R =
⎟
⎠
⎞
⎜
⎝
⎛−×Ω=
where:
VTRIP = 4.75V (for a 5V supply)
VVUVLO = 0.25V
Micrel, Inc. MIC20xx Family
August 2011
27 M9999-080211-D
The VUVLO comparator uses no hysteresis. This is
because the VUVLO blanking timer prevents any
chattering that might otherwise occur if VIN varies about
the trigger point. The timer is reset by upward crossings
of the trip point such that VIN must remain below the trip
point for the full 32ms period for load disengagement to
occur.
In selecting a VTRIP voltage, the designer is cautioned to
not make this value less than 2.5V. A minimum of 2.5V
is required for the MIC20X6’s internal circuitry to
operate properly. VUVLO trip points below 2.5V will
result in erratic or unpredictable operation.
Kickstart™
2003 2004 2005X 2006 2007 2008 2009X
2013 2014 2015 2016 2017 2018 2019X
Only parts in bold have Kickstart™.
(Not available in 5-pin SOT-23 packages).
Kickstart™ allows brief current surges to pass to the
load before the onset of normal current limiting, which
permits dynamic loads to draw bursts of energy without
sacrificing system safety.
Functionally, Kickstart™ is a forced override of the
normal current limiting function provided by the switch.
The Kickstart™ period is governed by an internal timer
which allows current to pass up to the secondary
current limit (ILIMIT_2nd) to the load for 128ms and then
normal (primary) current limiting goes into action.
During Kickstart™, a secondary current-limiting circuit
is monitoring output current to prevent damage to the
switch, as a hard short combined with a robust power
supply can result in currents of many tens of amperes.
This secondary current limit is nominally set at 4A and
reacts immediately and independently of the Kickstart™
period. Once the Kickstart™ timer has finished its count
the primary current limiting circuit takes over and holds
IOUT to its programmed limit for as long as the excessive
load persists.
Once the switch drops out of current limiting the
Kickstart™ timer initiates a lock-out period of 128ms
such that no further bursts of current above the primary
current limit, will be allowed until the lock-out period has
expired.
Kickstart™ may be over-ridden by the thermal
protection circuit and if sufficient internal heating
occurs, Kickstart™ will be terminated and IOUT Æ 0A.
Upon cooling, if the load is still present IOUT Æ ILIMIT, not
ILIMIT_2nd.
Figure 11. Kickstart™
Automatic Load Discharge
2003 2004 2005X 2006 2007 2008 2009X
2013 2014 2015 2016 2017 2018 2019X
Only parts in bold have automatic load discharge.
Automatic discharge is a valuable feature when it is
desirable to quickly remove charge from the VOUT pin.
This allows for a quicker power-down of the load. This
also prevents any charge from being presented to a
device being connected to the VOUT pin, for example,
USB, 1394, PCMCIA, and CableCARD™.
Automatic discharge is performed by a shunt MOSFET
from VOUT pin to GND. When the switch is disabled, a
break before make action is performed turning off the
main power MOSFET and then enabling the shunt
MOSFET. The total resistance of the MOSFET and
internal resistances is typically 126.
Supply Filtering
A minimum 1F bypass capacitor positioned close to
the VIN and GND pins of the switch is both good design
practice and required for proper operation of the switch.
This will control supply transients and ringing. Without a
bypass capacitor, large current surges or a short may
cause sufficient ringing on VIN (from supply lead
inductance) to cause erratic operation of the switch’s
control circuitry. For best-performance good quality,
low-ESR capacitors are recommended, preferably
ceramic.
When bypassing with capacitors of 10F and up, it is
good practice to place a smaller value capacitor in
parallel with the larger to handle the high frequency
components of any line transients. Values in the range
of 0.01F to 0.1F are recommended. Again, good
quality, low-ESR capacitors should be chosen.
Micrel, Inc. MIC20xx Family
August 2011
28 M9999-080211-D
In Figure 12, die temperature is plotted against IOUT
assuming a constant case temperature of 85°C. The
plots also assume a worst case RON of 140m at a die
temperature of 135°C. Under these conditions it is clear
that an SOT-23 packaged device will be on the verge of
thermal shutdown, typically 140°C die temperature,
when operating at a load current of 1.25A. For this
reason we recommend using MLF® packaged switches
for any design intending to supply continuous currents
of 1A or more.
Power Dissipation
Power dissipation depends on several factors such as
the load, PCB layout, ambient temperature, and supply
voltage. Calculation of power dissipation can be
accomplished by the following equation:
2
)I(RP OUT)ON(DSD ×
=
To relate this to junction temperature, the following
equation can be used:
0
20
40
60
80
100
120
140
160
0.2
OUTPUT CURRENT (A)
Die Temperature vs.
Output Current (T CASE=85°C)
SOT-23
0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
MLF
A
)AJ(
DJ TRPT +×= −
θ
where:
TJ = junction temperature
TA = ambient temperature
Rθ(J-A) is the thermal resistance of the package
In normal operation the switch’s RON is low enough that
no significant I2R heating occurs. Device heating is
most often caused by a short circuit, or very-heavy
load, when a significant portion of the input supply
voltage appears across the switch’s power MOSFET.
Under these conditions the heat generated will exceed
the package and PCB’s ability to cool the device and
thermal limiting will be invoked.
Figure 12. Die Temperature vs. IOUT
Micrel, Inc. MIC20xx Family
August 2011
29 M9999-080211-D
Package Information
5-Pin SOT-23 (M5)
6-Pin SOT-23 (M6)
Micrel, Inc. MIC20xx Family
August 2011
30 M9999-080211-D
Package Information (Continued)
6 Pin 2mm x 2mm MLF® (ML)
Section 1.01 MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
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