MIC4421/4422
Micrel
MIC4421/4422
9A-Peak Low-Side MOSFET Driver
Bipolar/CMOS/DMOS
Process
General Description
MIC4421 and MIC4422 MOSFET drivers are rugged, effi-
cient, and easy to use. The MIC4421 is an inverting driver,
while the MIC4422 is a non-inverting driver.
Both versions are capable of 9A (peak) output and can drive
the largest MOSFETs with an improved safe operating mar-
gin. The MIC4421/4422 accepts any logic input from 2.4V to
V
S
without external speed-up capacitors or resistor net-
works. Proprietary circuits allow the input to swing negative
by as much as 5V without damaging the part. Additional
circuits protect against damage from electrostatic discharge.
MIC4421/4422 drivers can replace three or more discrete
components, reducing PCB area requirements, simplifying
product design, and reducing assembly cost.
Modern Bipolar/CMOS/DMOS construction guarantees free-
dom from latch-up. The rail-to-rail swing capability of CMOS/
DMOS insures adequate gate voltage to the MOSFET dur-
ing power up/down sequencing. Since these devices are
fabricated on a self-aligned process, they have very low
crossover current, run cool, use little power, and are easy to
drive.
Features
• BiCMOS/DMOS Construction
• Latch-Up Proof: Fully Isolated Process is Inherently
Immune to Any Latch-up.
• Input Will Withstand Negative Swing of Up to 5V
• Matched Rise and Fall Times ............................... 25ns
• High Peak Output Current .............................. 9A Peak
• Wide Operating Range .............................. 4.5V to 18V
• High Capacitive Load Drive ........................... 47,000pF
• Low Delay Time ........................................... 30ns Typ.
• Logic High Input for Any Voltage from 2.4V to V
S
• Low Equivalent Input Capacitance (typ) ................. 7pF
• Low Supply Current .............. 450µA With Logic 1 Input
• Low Output Impedance ........................................ 1.5Ω
• Output Voltage Swing to Within 25mV of GND or V
S
Applications
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Switch Mode Power Supplies
Motor Controls
Pulse Transformer Driver
Class-D Switching Amplifiers
Line Drivers
Driving MOSFET or IGBT Parallel Chip Modules
Local Power ON/OFF Switch
Pulse Generators
Functional Diagram
V
S
0.3mA
0.1mA
MIC4421
INVERTING
OUT
IN
2kΩ
MIC4422
NON-INVERTING
GND
5-42
April 1998
MICREL [ MICREL SEMICONDUCTOR ]
