Isolated Drive Transmitter
UC1724
UC2724
UC3724
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.
BLOCK DIAGRAM
Note: Pin numbers refer to DIL-8 packages.
04/99
UDG-92037
