The UCC1570 family of pulse width modulators is intended for application in isolated switching supplies using primary side control and a voltage mode feedback loop. Made with a BiCMOS process, these devices feature low startup current for efficient off-line starting with a bootstrapped low voltage supply. Operating current is also very low; yet these devices maintain the ability to drive a power MOSFET gate at frequencies above 500kHz. Voltage feedforward provides fast and accurate response to wide line voltage variation without the noise sensitivity of current mode control. Fast current limiting is included with the ability to latch off after a programmable number of repetitive faults has occurred. This allows the power supply to ride through a temporary overload, while still shutting down in the event of a permanent fault. Additional versatility is provided with a maximum duty cycle clamp programmable within a 20% to 80% range and line voltage sensing with a programmable window of allowable operation.
The UNITRODE UCC1570 family of pulse width modulators is intended for application in isolated switching supplies using primary side control and a voltage mode feedback loop. These devices feature a low power BiCMOS process with 1mA run current and the ability to drive a power MOSFET gate at frequencies above 500kHz.
| Run Current | 1mA |
|---|---|
| Peak Gate Drive Output | 1A |
| Operating Frequency | Above 500kHz |
| Oscillator Frequency | 100kHz |
| Temperature Range (UCC1570) | -55°C to +125°C |
The devices feature 1mA run current for efficient off-line starting.
These devices are intended for use in isolated switching supplies that use primary side control and a voltage mode feedback loop.