MIC4421/4422
Micrel, Inc.
MIC4421/4422
9A-Peak Low-Side MOSFET Driver
Bipolar/CMOS/DMOS Process
General Description
Features
• BiCMOS/DMOS Construction
• Latch-Up Proof: Fully Isolated Process is Inherently
Immune to Any Latch-up.
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.
• 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 VS
• 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 VS
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
VS 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.
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
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.
Functional Diagram
VS
MIC4421
INVERTING
0.3mA
0.1mA
OUT
IN
2kΩ
MIC4422
NONINVERTING
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
M9999-081005
August 2005
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