December 2013
© 2009 Fairchild Semiconductor Corporation www.fairchildsemi.com
FAN3268 • Rev. 1.0.3 1
FAN3268 —2 A Low-Volta g e PMOS -NMOS Bridge Dr iver
FAN3268
2 A Low-Voltage PMOS-NMOS Bridge Dri ver
Features
4.5 V to 18 V Operating Range
Drives High-Side PMOS and Low-Side NMOS in
Motor Control or Buck Step-Down Applications
Inverting Channel B Biases High-Side PMOS
Device Off (with internal 100 kΩ Resistor) when
VDD is below UVLO Threshold
TTL Input Thresholds
2.4 A Sink / 1.6 A Source at VOUT=6 V
Internal Resistors Turn Driver Off If No Inputs
MillerDrive™ Technology
8-Lead SOIC Package
Rated from –40°C to +125°C Ambient
Automotive Qualified to AEC-Q100 (F085 Version)
Applications
Motor Control with PMOS / NMOS Half-Bridge
Configuration
Buck Converters with High-Side PMOS Device;
100% Duty Cycle Operation Possible
Logic-Controlled Load Circuits with High-Side
PMOS Switch
Automotive-Qualified Systems (F085 version)
Description
The FAN3268 dual 2 A gate driver is optimized to drive
a high-side P-channel MOSFET and a low-side N-
channel MOSFET in motor control applications
operating from a voltage rail up to 18 V. The driver has
TTL input thresholds and provides buffer and level
translation functions from logic inputs. Internal circuitry
provides an under-voltage lockout function that
prevents the output switching devices from operating if
the VDD supply voltage is below the operating level.
Internal 100 kΩ resistors bias the non-inverting output
low and the inverting output to VDD to keep the external
MOSFETs off during startup intervals when logic control
signals may not be present.
The FAN3268 driver incorporates MillerDrive™
architecture for the final output stage. This bipolar-
MOSFET combination provides high current during the
Miller plateau stage of the MOSFET turn-on / turn-off
process to minimize switching loss, while providing rail-
to-rail voltage swing and reverse current capability.
The FAN3268 has two independent enable pins that
default to on if not connected. If the enable pin for non-
inverting channel A is pulled low, OUTA is forced low; if
the enable pin for inverting channel B is pulled low,
OUTB is forced high. If an input is left unconnected,
internal resistors bias the inputs such that the external
MOSFETs are off.
Related Resources
AN-6069 — Application Review and Comparative
Evaluation of Low-Side Gate Drivers
MOTOR
C
BYP
1
2
3
VDDGND
ENB
4
8
7
6
5
B
A
ENA
+VRAIL (4.5−18V)
Controller
FAN3268
Figure 1. Typical Motor Drive Application