1. Low-Voltage PMOS-NMOS Bridge Drivers FAN3268 and FAN3278 Sales Fighting Guide
With non-inverting and inverting logic channels, Fairchild Semiconductor’s FAN3268 and FAN3278 are a special low-voltage high-performance bridge drivers for fan/pump DC motor drive applications with PMOS/NMOS Half-Bridge configuration. The FAN3268 operating range is 4.5 to 18 V and it switches rail-to-rail. The FAN3278 includes a gate drive regulator to allow operation up to 27V.
PORTFOLIO SUMMARY
BENEFITS AND FEATURES
FAN3278
FAN3268
Operating voltage Range
Optimum operating range is 8 V to 27 V. Absolute maximum is 30 V.
4.5 V to 18 V; Absolute Maximum is 20 V.
Gate Drive Regulator
Yes, the gate voltage to the external MOSFETs is clamped to about 13V.
No gate drive regulator needed. The FAN3268 switches rail-to-rail.
Start-up
The outputs are held OFF before the IC starts operating.
The outputs held OFF before IC exceeds UVLO ON threshold.
Output Gate Drive Architecture
Standard MOS-based output structure with gate drive clamp feature.
Compound MillerDrive™ provides a more efficient gate drive current during the Miller plateau stage.
OUTB Gate Drive Current Strength
Optimized for PMOS. Turn-OFF (1.5 A) is stronger than turn-ON (1.0A).
P-channel turn-ON (2.4A) is stronger than turn-OFF (1.6A).
One non-inverting logic and one inverting logic channels
FAN3268: 4.5 V to 18 V Operating Range; 2.4 A / 1.6 A Sink/Source Gate Drive
FAN3278: 8 V to 27 V Operating Range; 1.5 A/ 1.0 A Gate Drive
TTL input thresholds provide buffer and level translation functions from logic inputs.
Internal circuitry provides an under-voltage lockout function that prevents the switching if the VDD supply voltage is below the operating level.
If input are left unconnected, internal resistors are biased to keep the external MOSFETs OFF.
Two independent enable pins, a key feature during medical device power-up. They default to ON if not connected.
Suitable with FDD8424H Dual MOSFETs (40 V, 20 A) in 4-lead DPAK
SOIC package
–40°C to +125°C ambient
APPLICATIONS
COMPETITION
Battery-Powered Compact Brushless-dc Motor Drives in Industrial, Medical and Automotive applications such as 12-V blower motors.
Other Motor Control Circuits 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
Interface between a sensitive PWM or DSP and the MOSFETs
Competitor
Product Name and Desc.
Why we are better?
No direct replacements but there are other standard drivers with inverting and non-inverting logics such as IR4428
IR4428S, Dual Low Side Driver
Higher operating voltage range of FAN3278 (27 V operating max vs. 20 V). Note: FAN3268 has 18 V.
Additional flexibility to control the driver with dual independent Enable pins
Stronger gate drives to minimize switching losses
2x (FAN3278) to 4x (FAN3268) faster propagation delays for higher frequency operations.