MIC5020_05 Datasheet, PDF (1/8 Pages) Micrel Semiconductor – Current-Sensing Low-Side MOSFET Driver

MIC5020
MIC5020
Micrel, Inc.
Current-Sensing Low-Side MOSFET Driver
General Description
The MIC5020 low-side MOSFET driver is designed to operate
at frequencies greater than 100kHz (5kHz PWM for 2% to
100% duty cycle) and is an ideal choice for high-speed ap-
plications such as motor control, SMPS (switch mode power
supplies), and applications using IGBTs. The MIC5020 can
also operate as a circuit breaker with or without automatic
retry. The MIC5020’s maximum supply voltage lends itself
to control applications using up to 50V. The MIC5020 can
control MOSFETs that switch voltages greater than 50V.
A rising or falling edge on the input results in a current source
or sink pulse on the gate output. This output current pulse
can turn on or off a 2000pF MOSFET in approximately 175ns.
The MIC5020 then supplies a limited current (< 2mA), if
necessary, to maintain the output state.
An overcurrent comparator with a trip voltage of 50mV makes
the MIC5020 ideal for use with a current sensing MOSFET.
An external low value resistor may be used instead of a
sensing MOSFET for more precise overcurrent control. An
optional external capacitor connected to the C_T pin may be
used to control the current shutdown duty cycle from 20%
to < 1%. A duty cycle from 20% to about 75% is possible
with an optional pull-up resistor from C_T to V_DD. An open
collector output provides a fault indication when the sense
inputs are tripped.
The MIC5020 is available in 8-pin SOIC package.
Other members of the MIC502x series include the MIC5021
high-side driver and the MIC5022 half-bridge driver with a
cross-conduction interlock.
Features
• 11V to 50V operation
• 175ns rise/fall time driving 2000pF
• TTL compatible input with internal pull-down resistor
• Overcurrent limit
• Fault output indication
• Gate to source protection
• Compatible with current sensing MOSFETs
Applications
• Lamp control
• Heater control
• Motor control
• Solenoid switching
• Switch-mode power supplies
• Circuit breaker
Ordering Information
Part Number
Standard
Pb-Free
MIC5020BM MIC5020YM
Temperature
Range
Package
–40ºC to +85ºC 8-pin SOIC
Typical Application
V+
+11V to +50V
10µF
150kHz max.
optional*
MIC5020
1
8
V_DD
Gate
2
7
Input Sense-
3
6
Fault Sense+
4
C_T
5
Gnd
N-Channel
Power MOSFET
R_SENSE
R_SENSE=
50mV
I_TRIP
* increases time before retry
Low-Side Driver with Overcurrent Trip and Retry
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 [phone] • fax + 1 [phone] • http://www.micrel.com
July 2005
1
MIC5020