The pulse-width modulator UCC35701/UCC35702 family is used to isolate switching power supplies using primary-side control supplies. They can be used both in offline applications and in the design of DC/DC converters, such as in distributed power system architectures, or as telecom power supplies.
These devices have low start-up current, high efficiency allowed on the off-field starting line, but there are enough output drivers in excess of 500kHz switching power MOSFETs.
Voltage feedforward compensation operates over a 5:1 input range and provides a fast and accurate response to input voltage changes over a 4:1 range. Accurate volt-second clamps and maximum duty cycle limits were also on display.
Fault protection provides pulse current limit for pulses and the ability to latch up programmable digits that occur repeatedly after a fault.
characteristic
- 700kHz operation
- Integrated oscillator/voltage feed-forward compensation
- Precise duty cycle limits
- Accurate volt-second clamping
- Optocoupler interface
- Count shutdown failures
- Fault lock off or automatic shutdown
- Soft-stop synchronous rectification optimization
- 1A peak gate drive output
- 130μA start-up current
- 750μA operating current
parameter
|
UCC25701 |
|
topology |
Boost, reverse, forward |
|
Control method |
Voltage mode |
|
Duty cycle (max.) (%) |
99 |
|
Frequency (max) (khertz) |
700 |
|
On/Off of Undervoltage Lockout Threshold (5) |
13 / 9 |
|
Pins/Packets |
14PDIP,14SOIC,14TSSOP |
|
(#) Regulated output |
One |
|
Operating temperature range(°C) |
-40 to 85 |
|