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. Protected by U.S. Patent No. 7,170,732
CableCARD is a trademark of CableLabs.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
January 2009
M9999-012109-A
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 on page 6
and Pin Configuration Drawings on page 7.
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) subfamily offers 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.
Data sheets and support documentation can be found on
Micrel’s web site at www.micrel.com.
Features
• 70mΩ typical on-resistance @ 5V
• 170mΩ typical on-resistance @ 5V (MIC2005A)
• 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 *
• User adjustable current limit from 0.2A to 2.1A *
• Under voltage 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
MIC20X5
VBUS
USB
Port
GND (2,3)IADJ
EN (1,3)FAULT/
5V Suppl
y
VIN
Logic
Controller
ON/OFF
OVERCURRENT/ 1µF
120µF
Figure 1. Typical Application Circuit
Notes: (1) Depending on the family member this pin can function as FAULT/, IADJ, or VUVLO.
(2) Depending on the family member this pin can function as IADJ, or CSLEW.
(3) See Pin Configuration and Functional Diagram.
Micrel, Inc. MIC20XX Family
January 2009 2 M9999-012109-A
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 D05 0.5A
MIC2003-0.8YML D08 0.8A
MIC2003-1.2YML D12 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 L05 0.5A
MIC2013-0.8YML L09 0.8A
MIC2013-1.2YML L12 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 E05 0.5A
MIC2004-0.8YML E08 0.8A
MIC2004-1.2YML E12 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 M05 0.5A
MIC2014-0.8YML M09 0.8A
MIC2014-1.2YML M12 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
January 2009 3 M9999-012109-A
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 F05 0.5A Active High
MIC2005-0.8YML F08 0.8A Active High
MIC2005-1.2YML F12 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 N05 0.5A Active High
MIC2015-0.8YML N08 0.8A Active High
MIC2015-1.2YML N12 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
January 2009 4 M9999-012109-A
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 G05 0.5A
MIC2006-0.8YML G08 0.8A
MIC2006-1.2YML G12 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 P05 0.5A
MIC2016-0.8YML P09 0.8A
MIC2016-1.2YML P12 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
January 2009 5 M9999-012109-A
Ordering Information (continued)
MIC2007/2017
Part Number(1) Marking(2) Current Limit Kickstart Package
MIC2007YM6 FHAA 6-Pin SOT-23
MIC2007YML HAA No 6-Pin 2mm x 2mm MLF®
MIC2017YM6 FQAA 6-Pin SOT-23
MIC2017YML QAA
0.2A – 2.0A
Yes 6-Pin 2mm x 2mm MLF®
MIC2008/2018
Part Number(1) Marking(2) Current Limit Kickstart Package
MIC2008YM6 FJAA 6-Pin SOT-23
MIC2008YML JAA No 6-Pin 2mm x 2mm MLF®
MIC2018YM6 FRAA 6-Pin SOT-23
MIC2018YML RAA
0.2A – 2.0A
Yes 6-Pin 2mm x 2mm MLF®
MIC2009/2019
Part Number(1) Marking(2) Current Limit Kickstart Package
MIC2009YM6 FKAA 6-Pin SOT-23
MIC2009YML KAA No 6-Pin 2mm x 2mm MLF®
MIC2019YM6 FSAA 6-Pin SOT-23
MIC2019YML SAA
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
January 2009 6 M9999-012109-A
MIC20XX Family Member Functionality
Part Number Pin Function
Normal
Limiting Kickstart(1) I Limit ILIMIT
ENABLE
High ENABLE
Low CSLEW FAULT/ VUVLO(5) Load
Discharge
2003 2013
2004 2014
2005 2015
2005L (2)
Fixed (3)
(6)
2005A-1 (2) (6)
2005A-2 (2) (6)
2006 2016
2007 2017
2008 2018
2009 2019
Adj.(4)
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.
MIC20XX Family Member Pin Configuration Table
Part Number Pin Number
Normal
Limiting Kickstart I Limit 1 2 3 4 5 6
2003 2013 VIN GND VOUT
2004 2014 VIN GND EN VOUT
2005 2015 VIN GND EN FAULT/ CSLEW VOUT
2005L (1) VIN GND EN FAULT/
CSLEW(5) VOUT
2005A (1) VIN GND EN FAULT/
CSLEW(5) VOUT
2006 2016
Fixed(2)
VIN GND EN VUVLO(4) CSLEW VOUT
2007 2017 VIN GND EN IADJ CSLEW VOUT
2008 2018 VIN GND EN IADJ CSLEW VOUT
2009 2019
Adj.(3)
VIN GND EN FAULT/ IADJ VOUT
Notes: 1. Kickstart not available.
2. Fixed = Factory programmed current limit.
3. Adj. = User adjustable current limit.
4. VUVLO = Variable UVLO (Previously called DLM).
5. CSLEW not available in 5-pin package.
Micrel, Inc. MIC20XX Family
January 2009 7 M9999-012109-A
MIC20XX Family Member Pin Configuration Drawings
Fixed Current Limit
VIN
3
15
2
4
GND
NC
VOUT
NC
1
V
OUT
NC
NC
6VIN
GND
NC
5
4
2
3
(Top View)
MIC20X3
VIN
3
15
2
4
GND
ENABLE
VOUT
NC
1
V
O
U
T
NC
NC
6VIN
GND
ENABLE
5
4
2
3
(Top View)
MIC20X4
VIN
3
15
2
4
GND
ENABLE
VOUT
FAULT/
VIN
3
1
5
2
GND
ENABLE
VOUT
FAULT/
6
4
CSLEW
1VOUT
CSLEW
FAULT/
6VIN
GND
ENABLE
5
4
2
3
(Top View)
MIC2005-X.XL / MIC2005A MIC20X5 MIC20X5
VIN
3
1
5
2
GND
ENABLE
VOUT
VUVLO
6
4
CSLEW
1VOUT
CSLEW
VUVLO
6VIN
GND
ENABLE
5
4
2
3
(Top View)
MIC20X6
Micrel, Inc. MIC20XX Family
January 2009 8 M9999-012109-A
MIC20XX Family Member Pin Configuration Drawings (continued)
Adjustable Current Limit
VIN
3
1
5
2
GND
ENABLE
VOUT
ILIMIT
6
4
CSLEW
1VOUT
CSLEW
ILIMIT
6VIN
GND
ENABLE
5
4
2
3
(Top View)
MIC20X7 / 20X8
VIN
3
1
5
2
GND
ENABLE
VOUT
FAULT/
6
4
ILIMIT
1VOUT
ILIMIT
FAULT/
6VIN
GND
ENABLE
5
4
2
3
(Top View)
MIC20X9
Micrel, Inc. MIC20XX Family
January 2009 9 M9999-012109-A
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.
ENABLE 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.
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
January 2009 10 M9999-012109-A
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...................................2.25A
Continuous Output Current (MIC2005A) ................0.9A
Maximum Junction Temperature (TJ) .................. 150°C
Storage Temperature (Ts)...................–65°C to +150°C
Operating Ratings(2)
Supply Voltage ..............................................2.5V to 5.5V
Continuous Output Current Range...................0A to 2.1A
Ambient Temperature Range (TA)............ –40°C to+85°C
Package Thermal Resistance(3)
SOT-23-5/6 (θJA) .......................................... 230ºC/W
2mm x 2mm MLF-6 (θJA)................................ 90ºC/W
2mm x 2mm MLF-6 (θJC) ............................... 45ºC/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
Switch = OFF
VEN = 0V 1 5 µA
Internal Supply Current
All except:
MIC2005-X.XLYM5
MIC2005A
Switch = ON, IOUT = 0A
VEN = 1.5V 80
330 µA
Switch = OFF
VEN = 1.5V 8
15 µA
Internal Supply Current
MIC2005-X.XLYM5 Switch = ON, IOUT = 0A
VEN = 0V 80
300 µA
Switch = OFF
MIC2005A-1, VEN = 0V 1 5 µA
Switch = OFF
MIC2005A-2, VEN = 1.5V 8
15 µA
IIN
Internal Supply Current
MIC2005A Switch = ON
MIC2005A-1, VEN = 1.5V
MIC2005A-2, VEN = 0V
80
300 µA
ILEAK Output Leakage Current
Switch = OFF, VOUT = 0V
Active Low; ENABLE = 1.5V
Active High; ENABLE = 0V
12
100 µA
IEN Enable Input Current 0V VEN 5V 1 5 µA
ICSLEW C
SLEW Input Current 0V VOUT 0.8VIN 0.175 µA
70 100 Power Switch Resistance
All except MIC2005A VIN = 5V, IOUT = 100mA
125
170 220
RDS(ON) Power Switch Resistance
Only MIC2005A VIN = 5V, IOUT = 100mA
275
m
RDSCHG Load Discharge Resistance
MIC20X4 & MIC20X7 VIN = 5V, ISINK = 5mA 70 126 200
MIC20XX-0.5, VOUT = 0.8 * VIN 0.5 0.7 0.9
MIC20XX-0.8, VOUT = 0.8 * VIN 0.8 1.1 1.5
ILIMIT Fixed Current Limit
MIC20X3 – MIC20X6 MIC20XX-1.2, VOUT = 0.8 * VIN 1.2 1.6 2.1
A
Micrel, Inc. MIC20XX Family
January 2009 11 M9999-012109-A
Electrical Characteristics (continued)
Symbol Parameter Condition Min Typ Max Units
IOUT = 2A, VOUT = 0.8VIN 210 250 286
IOUT = 1A, VOUT = 0.8VIN 190 243 293
IOUT = 0.5A, VOUT = 0.8VIN 168 235 298
CLF
Variable Current Limit Factor
MIC20X7 – MIC20X9
RSET () = CLF (V)
IOUT (A) IOUT = 0.2A, VOUT = 0.8VIN 144 225 299
V
ILIMIT_2nd Secondary current limit
MIC201X (All Kickstart parts only) VIN = 2.5V 2.2 4 6 A
VIN Rising 2 2.25 2.5
UVLOTHRESHOLD Under Voltage Lock Out Threshold VIN Falling 1.9 2.15 2.4 V
UVLOHysteresis Undervoltage Lock Out
Hysteresis 0.1 V
VVUVLO_TH Variable UVLO Threshold
MIC20X6 225 250 275 mV
VIL (MAX)
0.5
VEN ENABLE Input Voltage(5) VIH (MIN) 1.5 V
VFAULT Fault status Output Voltage IOL = 10mA 0.25 0.4 V
TJ Increasing 145
OTTHRESHOLD Over-temperature Threshold TJ Decreasing 135 °C
AC Characteristics
Symbol Parameter Condition Min Typ Max Units
tRISE Output Turn-on rise time
RL = 10 , CLOAD = 1µF,
VOUT = 10% to 90%
*CSLEW = Open
500 1000 1500 µs
Delay before asserting or releasing
FAULT/
MIC200X
Time from current limiting to
FAULT/ state change 20 32 49
tD_FAULT Delay before asserting or releasing
FAULT/
MIC201X
Time from IOUT continuously
exceeding primary current
limit condition to FAULT/
state change
77 128 192
ms
tD_LIMIT Delay before current limiting
MIC201X 77 128 192 ms
tRESET
Delay before resetting Kickstart
current limit delay, tD_LIMIT
MIC201X
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
Note: * Whenever CSLEW is present.
Micrel, Inc. MIC20XX Family
January 2009 12 M9999-012109-A
Electrical Characteristics (continued)
ESD(6)
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:
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. VIL (MAX) = maximum positive voltage applied to the input which will be accepted by the device as a logic low.
VIH (MIN) = minimum positive voltage applied to the input which will be accepted by the device as a logic high.
6. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF.
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
January 2009 13 M9999-012109-A
Typical Characteris t ics
0
20
40
60
80
100
23456
SUPPLY CURRENT (µA)
VIN (V)
Supply Curre nt
Output Enabled
-40°C
85°C
25°C
0
2
4
6
8
10
12
14
16
23456
SUPPLY CURRENT (µA)
VIN (V)
Supply Curre nt
Output Disabled
-40°C
85°C
25°C
Switch Leakage Curren t
OFF
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
2.00
-50-30-101030507090
LEAKAGE CURRENT (µA)
TEMPERATURE (°C)
0.94
0.96
0.98
1.00
1.02
1.04
1.06
1.08
1.10
-50-30-101030507090
ILIMIT (A)
TEMPERATURE (°C)
5V
3V
2.5V
ILIMIT vs. Temperature
(MIC20xx - 1.2)
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
-50 -30 -10 10 30 50 70 90
ILIMIT (A)
TEMPERATURE (°C)
5V
3V
2.5V
ILIMIT vs. Temperature
(MIC20xx - 0.8)
Note:
Please note that the 3
plots overlay each
0.96
0.98
1.00
1.02
1.04
1.06
1.08
1.10
-50-30-101030507090
ILIMIT (A)
TEMPERATURE (°C)
5V
2.5V
ILIMIT vs. Temperature
(MIC20xx - 0.5)
2.05
2.1
2.15
2.2
2.25
2.3
-50 0 50 100 150
THRESHOLD (V)
TEMPERATURE (°C)
UVLO Threshol d
vs. Temperature
V RISING
V FALLING
0
20
40
60
80
100
22.533.544.555.5
RON (mOhm)
VIN (V)
RON vs.
Suppl y Voltage
0
20
40
60
80
100
120
-50 -30 -10 10 30 50 70 90
RON (mOhm)
TEMPERATURE (°C)
RON vs.
Temperature
2.5V
3.3V
5V
Micrel, Inc. MIC20XX Family
January 2009 14 M9999-012109-A
Functional Characteristics
Micrel, Inc. MIC20XX Family
January 2009 15 M9999-012109-A
Functional Characteristics (continued)
Micrel, Inc. MIC20XX Family
January 2009 16 M9999-012109-A
Functional Diagram
CSLEW
MIC20X5 - MIC20X8
FAULT/
MIC20X5 & MIC20X9
ENABLE
MIC20X4 - MIC20X9
VIN
VOUT
Slew Rate
Control
Thermal
Sensor
Under
Voltage
Detector
Gate Control
VREF
Current Limit
Control Loop
Current
Mirror FET Power FET
GND
Control Logic
and
Delay Timer
VUVLO
VUVLO
MIC20X6
ILIM Factory Adjusted
MIC20X3 - MIC20X6
ILIM
User Adjustable
MIC20X7 - MIC20X9
Load Discharge
MIC20X4 & MIC20X7
Figure 2 MIC20XX Family Functional Diagram
Micrel, Inc. MIC20XX Family
January 2009 17 M9999-012109-A
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 2005 2006 2007 2008 2009
2013 2014 2015 2016 2017 2018 2019
Only parts in white boxes 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 below.
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.
Under Voltage Lock Out
Under voltage 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
January 2009 18 M9999-012109-A
Variable Under Voltage Lock Out (VUVLO)
2003 2004 2005 2006 2007 2008 2009
2013 2014 2015 2016 2017 2018 2019
Only parts in white boxes 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 2005 2006 2007 2008 2009
2013 2014 2015 2016 2017 2018 2019
Only parts in white boxes 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 1.8V.
ENABLE may be driven higher than VIN, but no higher
than 5.5V and not less than –0.3V.
FAULT/
2003 2004 2005 2006 2007 2008 2009
2013 2014 2015 2016 2017 2018 2019
Only parts in white boxes 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 2005 2006 2007 2008 2009
2013 2014 2015 2016 2017 2018 2019
Only parts in white boxes 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
January 2009 19 M9999-012109-A
Application Information
Setting ILIMIT
The MIC2009/2019’s current limit is user programmable
and controlled by a resistor connected between the ILIMIT
pin and Ground. The value of this resistor is determined
by the following equation:
SET
LIMIT R
LF)itFactor(CCurrentLim
I=
or
(A)I
)itFactor(VCurrentLim
R
LIMIT
SET =
For example: Set ILIMIT = 1.25 A
Looking in the Electrical specifications we will find CLF
at ILIMIT = 1 A.
Min Typ Max Units
190 243 293 V
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
R
SET = 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
=
A5.1
196
260V
ILIMIT_MIN =
Ω
=
Giving us a maximum ILIMIT variation over temperature
of:
I
LIMIT_MIN ILIMIT_TYP I
LIMIT_MAX
0.97 A 1.25 A 1.5 A
or 1.25 A – 22% and 1.25 A + 20%
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 Ohm’s law by the
load and the limiting current.
Figure 4. IOUT in Current Limiting for VIN - VOUT < 1V
Micrel, Inc. MIC20XX Family
January 2009 20 M9999-012109-A
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 Volta ge (5 V)
Figure 6.
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)
Normaliz e d Ou tpu t Current
vs. Out put Volt age (2. 5 V)
Figure 7.
CSLEW
2003 2004 2005 2006 2007 2008 2009
2013 2014 2015 2016 2017 2018 2019
Only parts in white boxes 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’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 Under Voltage Lock Out (VUVLO)
2003 2004 2005 2006 2007 2008 2009
2013 2014 2015 2016 2017 2018 2019
Only parts in white boxes 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
Micrel, Inc. MIC20XX Family
January 2009 21 M9999-012109-A
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. In 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.
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 VOUT
VUVLO
Input
Supply
R1
R2
++
IIN_LOAD
Calculating VUVLO resistor divider values
Selection of R1 and R2 is driven by the input voltage at
which VUVLO should go into effect and the allowed
loading of the input supply. The VUVLO pin input
voltage is the result of the voltage division of VIN by the
voltage divider comprised of R1 and R2. We know
VVUVLO_TH = 250 mV, then by choosing a VIN trip voltage
(VTRIP) we know the voltage divider ratio formed by R1
and Then an R2.is chosen such that the series
resistance R1 + R2 results in a small IIN_LOAD.
And then the VUVLO trip voltage as it relates to the
comparator threshold and the resistor divider:
()
X=
+
=
12
2
TRIP
VUVLO_TH
RR
R
V
V
Rearranging these:
()
21 R*
1
RX
X
−
=
Choose an R2 that minimizes the IIN_LOAD current yet at
the same time is less than input impedance of the
VUVLO pin. The VUVLO pin internally is connected to a
comparator with an extremely high input impedance. It is
recommended that R2 not exceed 1 M. R2 can then be
calculated from the equation above.
For example:
V
TRIP = 4.75V for a 5V supply
V
VUVLO_TH = 250mV
R
2 = 750k
Substituting these values into the equation above:
05263.0
V0.25
V4.75
V
V
TRIP
VUVLO_TH ===X
()
Ω=Ω
−
=k667,41k 750 *
05263.01
05263.0
R1
R1 = 41,667k
Micrel, Inc. MIC20XX Family
January 2009 22 M9999-012109-A
In this example we have used the nominal value of
VVUVLO_TH. By substituting in the min and max values of
VVUVLO_TH, R1 and R2 the VUVLO trip point window can
be established.
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 2005 2006 2007 2008 2009
2013 2014 2015 2016 2017 2018 2019
Only parts in white boxes 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 10. Kickstart
Automatic Load Discharge
2003 2004 2005 2006 2007 2008 2009
2013 2014 2015 2016 2017 2018 2019
Only parts in white boxes 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
January 2009 23 M9999-012109-A
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
OUTDS(ON)D IRP ×=
To relate this to junction temperature, the following
equation can be used:
AA)-(JDJ TRPT +×=
θ
Where: TJ = junction temperature,
T
A = 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.
In Figure 11 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 switch s
for any design intending to supply continuous currents of
1A or more.
0
20
40
60
80
100
120
140
160
0.2
OUTPUT CURRENT (A)
Die Te mp eratur e vs .
Output Current (TCASE=85°C)
SOT-23
0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
MLF
Figure 11. Die Temperature vs. IOUT
Micrel, Inc. MIC20XX Family
January 2009 24 M9999-012109-A
Package Information
5-Pin SOT-23 (M5)
6-Pin SOT-23 (M6)
Micrel, Inc. MIC20XX Family
January 2009 25 M9999-012109-A
6 Pin 2mm x 2mm MLF® (ML)
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 US
A
TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com
The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its
use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product
can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implan
t
into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A
Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully
indemnify Micrel for any damages resulting from such use or sale.
© 2008 Micrel, Incorporated.
