Delay Time vs Temperature

RDSON vs Supply Voltage

20112316

20112317

UVLO Thresholds and Hysteresis vs Temperature

20112318

Detailed Operating Description

LM5111 dual gate driver consists of two independent and

identical driver channels with TTL compatible logic inputs

and high current totem-pole outputs that source or sink

current to drive MOSFET gates. The driver output consist of

a compound structure with MOS and bipolar transistor oper-

ating in parallel to optimize current capability over a wide

output voltage and operating temperature range. The bipolar

device provides high peak current at the critical threshold

region of the MOSFET VGS while the MOS devices provide

rail-to-rail output swing. The totem pole output drives the

MOSFET gate between the gate drive supply voltage V

CC

and the power ground potential at the V

The control inputs of the drivers are high impedance CMOS

buffers with TTL compatible threshold voltages. The LM5111

pinout was designed for compatibility with industry standard

gate drivers in single supply gate driver applications.

The two driver channels of the LM5111 are designed as

identical cells. Transistor matching inherent to integrated

circuit manufacturing ensures that the AC and DC pe-

formance of the channels are nearly identical. Closely

matched propagation delays allow the dual driver to be

operated as a single with inputs and output pins connected.

The drive current capability in parallel operation is precisely

2X the drive of an individual channel. Small differences in

switching speed between the driver channels will produce a

transient current (shoot-through) in the output stage when

two output pins are connected to drive a single load. The

efficiency loss for parallel operation has been characterized

at various loads, supply voltages and operating frequencies.

The power dissipation in the LM5111 increases be less than

1% relative to the dual driver configuration when operated as

a single driver with inputs/ outputs connected.

An Under Voltage Lock Out (UVLO) circuit is included in the

LM5111 , which senses the voltage difference between V

CC

and the chip ground pin, V

difference falls below 2.8V both driver channels are disabled.

The UVLO hysteresis prevents chattering during brown-out

conditions and the driver will resume normal operation when

the V

3.0V.

The LM5111 is available in dual non-inverting (-1), dual

Inverting (-2) and the combination inverting plus non-

inverting (-3) configurations. All three configurations are of-

fered in the SOIC-8 plastic package.

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