UC1724

UC2724

UC3724

04/99

FEATURES

• 500mA Output Drive, Source or Sink

• 8 to 35V Operation

• Transmits Logic Signal Instantly

• Programmable Operating Frequency

• Under-Voltage Lockout

• Able To Pass DC Information Across

Transformer

• Up To 600kHz Operation

DESCRIPTION

The UC1724 family of Isolated Drive Transmitters, along with the UC1725

Isolated Drivers, provide a unique solution to driving isolated power

MOSFET gates. They are particularly suited to drive the high-side devices

on a high-voltage H-bridge. The UC1724 devices transmit drive logic, and

drive power, to the isolated gate circuit using a low cost pulse transformer.

This drive system utilizes a duty-cycle modulation technique that gives in-

stantaneous response to the drive control transistions, and reliably passes

steady-state, or DC, conditions. High frequency operation, up to 600kHz,

allows the cost and size of the coupling transformer to be minimized.

These devices will operate over an 8 to 35 Volt supply range. The dual high

current totem pole outputs are disabled by an uder-voltage lockout circuit to

prevent spurious responses during startup or low voltage conditions.

These devices are available in 8 pin plastic or ceramic dual-inline pack-

ages, as well as 16 pin SOIC package.

Isolated Drive Transmitter

BLOCK DIAGRAM

UDG-92037

Note: Pin numbers refer to DIL-8 packages.