UCC38C4x family is a high-performance current- mode PWM controller. It is an enhanced BiCMOS version with pin-for-pin compatibility to the industry standard UC384xA family and UC384x family of PWM controllers. In addition, lower startup voltage versions of 7 V are offered as UCC38C40 and UCC38C41. Providing necessary features to control fixed frequency, peak current-mode power supplies, this family offers the following performance advantages. The device offers high-frequency operation up to 1 MHz with low start-up and operating currents, thus minimizing start-up loss and low operating power consumption for improved efficiency. The device also features a very fast current-mode output limiting function that can limit the output current in each cycle to prevent the output current from exceeding the maximum permissible value.
The UCC28C4x and UCC38C4x families are high-performance current-mode PWM controllers designed as enhanced replacements for the UC384xA family. They offer pin-to-pin compatibility with the industry-standard UC384xA and UC384x families, featuring high-frequency operation up to 1 MHz with low startup and operating currents to minimize power consumption. The devices include a fast 35-ns cycle-by-cycle overcurrent limiting feature and a +1-A peak output current capability with improved rise and fall times for driving large external MOSFETs directly.
| Maximum Operating Frequency | 1 MHz |
|---|---|
| Standby Current | 50-u.A |
| Maximum Operating Current | 100-u.A |
| Operating Current | 2.3 mA |
| Overcurrent Limiting Delay | 35 ns |
| Peak Output Current | +1-A |
| Output Rise Time | 25 ns |
| Output Fall Time | 20 ns |
| Error Amplifier Reference Accuracy | +1% |
| Input Voltage Range | 18 V |
| Operating Junction Temperature | -55°C to 150°C |
| Package Types | MSOP-8, SOIC-8, PDIP-8 |
The UCC28C4x family offers pin-for-pin compatibility to the industry standard UC384xA family and UC384x family of PWM controllers.
These controllers are intended for use in switch-mode power supplies, de-to-de converters, and board mount power modules.
The maximum duty cycle is 94% to 96% when the feedback voltage is less than 2.4V.