FAN3268_11 Datasheet, PDF (1/16 Pages) Fairchild Semiconductor – 2A Low-Voltage PMOS-NMOS Bridge Driver

January 2011
FAN3268
2A Low-Voltage PMOS-NMOS Bridge Driver
Features
 4.5V to 18V 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 100kΩ Resistor) when
V_DD is below UVLO Threshold
 TTL Input Thresholds
 2.4A Sink / 1.6A Source at V_OUT=6V
 Internal Resistors Turn Driver Off If No Inputs
 MillerDrive™ Technology
 8-Lead SOIC Package
 Rated from –40°C to +125°C Ambient
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
Description
The FAN3268 dual 2A 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 18V. 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 V_DD supply
voltage is below the operating level. Internal 100kΩ
resistors bias the non-inverting output low and the
inverting output to V_DD 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.
Figure 1. Typical Motor Drive Application
© 2009 Fairchild Semiconductor Corporation
FAN3268 • Rev. 1.0.1
1
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