FAN3121 Datasheet, PDF (1/21 Pages) Fairchild Semiconductor – Single 9A High-Speed, Low-Side Gate Driver

September 2008
FAN3121 / FAN3122
Single 9A High-Speed, Low-Side Gate Driver
Features
ƒ Industry-Standard Pin-out with Enable Input
ƒ 4.5 to 18V Operating Range
ƒ 11.4A Peak Sink at VDD = 12V
ƒ 9.7A Sink / 7.1A Source at VOUT = 6V
ƒ Inverting Configuration (FAN3121) and
Non-Inverting Configuration (FAN3122)
ƒ Internal Resistors Turn Driver Off If No Inputs
ƒ 23ns/19ns Typical Rise/Fall Times with 10nF Load
ƒ 20ns Typical Propagation Delay Time
ƒ Choice of TTL or CMOS Input Thresholds
ƒ MillerDrive™ Technology
ƒ Available in Thermally Enhanced 3x3mm 8-Lead
MLP or 8-Lead SOIC Package (Pb-Free Finish)
ƒ Rated from –40°C to +125°C
Applications
ƒ Synchronous Rectifier Circuits
ƒ High-Efficiency MOSFET Switching
ƒ Switch-Mode Power Supplies
ƒ DC-to-DC Converters
ƒ Motor Control
Description
The FAN3121 and FAN3122 MOSFET drivers are
designed to drive N-channel enhancement MOSFETs in
low-side switching applications by providing high peak
current pulses. The drivers are available with either TTL
(FAN312xT) or CMOS (FAN312xC) input thresholds.
Internal circuitry provides an under-voltage lockout
function by holding the output low until the supply
voltage is within the operating range.
FAN312x drivers incorporate the MillerDrive™
architecture for the final output stage. This bipolar /
MOSFET combination provides the highest peak
current during the Miller plateau stage of the MOSFET
turn-on / turn-off process.
The FAN3121 and FAN3122 drivers implement an
enable function on pin 3 (EN), previously unused in the
industry-standard pin-out. The pin is internally pulled up
to VDD for active HIGH logic and can be left open for
standard operation.
The FAN3121/22 is available in a 3x3mm 8-lead thermally-
enhanced MLP package or an 8-lead SOIC package.
VDD 1
IN 2
EN 3
GND 4
8 VDD
7 OUT
6 _OUT
5 GND
Figure 1. FAN3121 Pin Configuration
VDD 1
IN 2
EN 3
GND 4
8 VDD
7 OUT
6 OUT
5 GND
Figure 2. FAN3122 Pin Configuration
© 2008 Fairchild Semiconductor Corporation
FAN3121 / FAN3122 • Rev. 1.0.0
www.fairchildsemi.com