MIC4421/4422 Micrel, Inc.
August 2005 1 M9999-081005
MIC4421/4422
9A-Peak Low-Side MOSFET Driver
Bipolar/CMOS/DMOS Process
General Description
MIC4421 and MIC4422 MOSFET drivers are rugged, ef-
ficient, 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 networks.
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
freedom from latch-up. The rail-to-rail swing capability of
CMOS/DMOS insures adequate gate voltage to the MOS-
FET during 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
• 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
IN
OUT
MIC4421
IN V ER T I NG
MIC4422
NONINVERTING
0.1mA
0.3m
A
2k
Ω
V
S
GND
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com