MIC5020 Datasheet, PDF (1/7 Pages) Micrel Semiconductor – Current-Sensing Low-Side MOSFET Driver

MIC5020
Micrel
MIC5020
Current-Sensing Low-Side MOSFET Driver
General Description
The MIC5020 low-side MOSFET driver is designed to oper-
ate at frequencies greater than 100kHz (5kHz PWM for 2% to
100% duty cycle) and is an ideal choice for high-speed
applications 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 and plastic DIP
packages.
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
MIC5020BM
MIC5020BN
Temperature Range
–40°C to +85°C
–40°C to +85°C
Package
8-pin SOIC
8-pin Plastic DIP
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
5-162
October 1998