December 2001
LM2722
High Speed Synchronous/Asynchronous MOSFET Driver
average current. Input UVLO (Under-Voltage-Lock-Out)
forces both driver outputs low to ensure proper power-up
General Description
The LM2722, part of the LM2726 family, is designed to be
and power-down operation. The gate drive bias voltage
used with multi-phase controllers. This part differs from the
needed by the high side MOSFET is obtained through an
LM2726 by changing the functionality of the SYNC_EN pin
external bootstrap. Minimum pulse width is as low as 55ns.
from a whole chip enable to a low side MOSFET enable. As
a result, the SYNC_EN pin now provides control between
Synchronous and Asynchronous operations. Having this
Features
n Synchronous or Asynchronous Operation
n Adaptive shoot-through protection
n Input Under-Voltage-Lock-Out
n Typical 20ns internal delay
control can be advantageous in portable systems since
Asynchronous operations can be more efficient at very light
loads.
The LM2722 drives both top and bottom MOSFETs in a
push-pull structure simultaneously. It takes a logic level
PWM input and splits it into two complimentary signals with
n Plastic 8-pin SO package
a
typical 20ns dead time in between. The built-in
Applications
cross-conduction protection circuitry prevents the top and
bottom FETs from turning on simultaneously. The
cross-conduction protection circuitry detects both the driver
outputs and will not turn on a driver until the other driver
output is low. With a bias voltage of 5V, the peak sourcing
and sinking current for each driver of the LM2722 is typically
3A. In an SO-8 package, each driver is able to handle 50mA
n Driver for LM2723 Intel Mobile Northwood CPU core
power supply.
n High Current DC/DC Power Supplies
n High Input Voltage Switching Regulators
n Fast Transient Microprocessors
Typical Application
20028901
Note: National is an Intel Mobile Voltage Positioning (IMVP) licensee.
© 2001 National Semiconductor Corporation
DS200289
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