UC3724

UC1724 UC2724 UC3724 Isolated Drive Transmitter 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 instantaneous 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 packages, as well as 16 pin SOIC package. BLOCK DIAGRAM Note: Pin numbers refer to DIL-8 packages. UDG-92037 04/99 UC1724 UC2724 UC3724 ABSOLUTE MAXIMUM RATINGS Supply Voltage VIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40V S...