HIGH-SPEED PWM CONTROLLER
SLUS781 – SEPTEMBER 2007
• Qualified for Automotive Applications
• Improved Version of the UC3825 PWM
• Compatible With Voltage-Mode or
Current-Mode Control Methods
• Practical Operation at Switching Frequencies
to 1 MHz
• 50-ns Propagation Delay to Output
• High-Current Dual Totem-Pole Outputs:
2 A (Peak)
• Trimmed Oscillator Discharge Current
• Low 100-μA Startup Current
• Pulse-by-Pulse Current-Limiting Comparator
• Latched Overcurrent Comparator With
The UC2825A pulse-width modulation (PWM)
controller is an improved versions of the standard
UC3825. Performance enhancements have been
made to several of the circuit blocks. Error amplifier
gain bandwidth product is 12 MHz, while input offset
voltage is 2 mV. Current limit threshold is specified to
a tolerance of 5%. Oscillator discharge current is
specified at 10 mA for accurate dead-time control.
Frequency accuracy is improved to 6%. Startup
supply current, typically 100 μA, is ideal for off-line
applications. The output drivers are redesigned to
actively sink current during undervoltage lockout
(UVLO) at no expense to the startup current
specification. In addition, each output is capable of
2-A peak currents during transitions.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2007, Texas Instruments Incorporated