UCC28C44

Features:

 Enhanced Replacement for UC3842A Family With Pin-to-Pin Compatibility
 1-MHz Operation
 50-A Standby Current, 100-A Maximum
 Low Operating Current of 2.3 mA at 52 kHz
 Fast 35-ns Cycle-by-Cycle Overcurrent Limiting
 ±1-A Peak Output Current
 Rail-to-Rail Output Swings with 25-ns Rise and 20-ns Fall Times
 ±1% Initial Trimmed 2.5-V Error Amplifier Reference
 Trimmed Oscillator Discharge Current
 New Under Voltage Lockout Versions
 MSOP-8 Package Minimizes Board Space


Application

Switch-Mode Power Supplies
dc-to-dc Converters
Board Mount Power Modules


Pinout




Specifications

Supply voltage (V_DD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 V
                         (MAX ICC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 mA
Output current, I_OUT peak . . . . .  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±1 A
Output energy, capacitive load . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 J
Voltage rating (COMP, CS, FB). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to 6.3 V
                       (OUT) . .  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to 20 V
                       (RT/CT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to 6.3 V
                       (VREF) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
Error amplifier output sink current  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 mA
Total Power Dissipation at T_A = 25°C: D package (_jc = 22 °C/W, _ja = 40 − 70 °C/W)  . 650 mW
DGK package (_jc = 41 °C/W, _ja = 238 − 269 °C/W . . . . . .  . . . . . . . . . . . . . . . . . . . . . . .350 mW
P package (_jc = 50 °C/W, _ja = 110 °C/W  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 850 mW
Operating junction temperature range, T_J . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −55°C to 150°C
Storage temperature range T_stg . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . −65°C to 150°C
Lead Temperature (Soldering, 10 seconds) . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300°C 


Description

UCC38C4x family is a high-performance currentmode 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-sense-to-output delay time of 35 ns and a ±1 A peak output current capability with improved rise and fall times for driving large external MOSFETs directly.