Datasheet Texas Instruments UCC3884D — 数据表

UCC2884
UCC3884
www.ti.com. SLUS160C – AUGUST 1999 – REVISED NOVEMBER 2008 Frequency Foldback Current Mode PWM Controller
FEATURES 1 Frequency Foldback Reduces Operating
Frequency Under Fault Conditions
Accurate Programmable Volt-Second Clamp
Programmable Maximum Duty Cycle Clamp
Oscillator Synchronization
Overcurrent Protection
Shutdown With Full Soft Start
Wide Gain Bandwidth Amplifier (GBW > 2.5
MHz)
Current Mode Operation
Precision 5-V Reference DESCRIPTION
The UCC3884 is a high performance current mode
PWM controller intended for single ended switch
mode power supplies. The chip implements a
frequency foldback scheme that decreases the
oscillator frequency as the output voltage falls below
a programmed value. This technique decreases the
average output current sourced into a low impedance
load which can occur during an output short circuit or
overload condition. Excessive short circuit current is …