UC2825M Series

High Speed PWM Controller

Catalog

High Speed PWM Controller

Part	Duty Cycle (Max)	Package / Case	Package / Case	Control Features	Output Phases	Number of Outputs	Output Configuration	Mounting Type	Clock Sync	Operating Temperature [Max]	Operating Temperature [Min]	Supplier Device Package	Function	Frequency - Switching	Synchronous Rectifier	Output Type	Voltage - Supply (Vcc/Vdd) [Min]	Voltage - Supply (Vcc/Vdd) [Max]	Topology
Texas Instruments UC2825J	80 %	0.3 in 7.62 mm	16-CDIP	Current Limit Enable Frequency Control Ramp Soft Start	1	2	Positive	Through Hole		85 °C	-40 °C	16-CDIP	Step-Up Step-Up/Step-Down	1 MHz		Transistor Driver	8.4 V	30 V	Boost Flyback Forward Converter Full-Bridge Half-Bridge Push-Pull

Catalog

High Speed PWM Controller

Key Features

• Compatible with Voltage or Current Mode TopologiesPractical Operation Switching Frequencies to 1MHz50ns Propagation Delay to OutputHigh Current Dual Totem Pole Outputs (1.5A Peak)Wide Bandwidth Error AmplifierFully Latched Logic with Double Pulse SuppressionPulse-by-Pulse Current LimitingSoft Start / Max. Duty Cycle ControlUnder-Voltage Lockout with HysteresisLow Start Up Current (1.1mA)Compatible with Voltage or Current Mode TopologiesPractical Operation Switching Frequencies to 1MHz50ns Propagation Delay to OutputHigh Current Dual Totem Pole Outputs (1.5A Peak)Wide Bandwidth Error AmplifierFully Latched Logic with Double Pulse SuppressionPulse-by-Pulse Current LimitingSoft Start / Max. Duty Cycle ControlUnder-Voltage Lockout with HysteresisLow Start Up Current (1.1mA)

Description

The UC1825 family of PWM control ICs is optimized for high frequency switched mode power supply applications. Particular care was given to minimizing propagation delays through the comparators and logic circuitry while maximizing bandwidth and slew rate of the error amplifier. This controller is designed for use in either current-mode or voltage mode systems with the capability for input voltage feed-forward. Protection circuitry includes a current limit comparator with a 1V threshold, a TTL compatible shutdown port, and a soft start pin which will double as a maximum duty cycle clamp. The logic is fully latched to provide jitter free operation and prohibit multiple pulses at an output. An under-voltage lockout section with 800mV of hysteresis assures low start up current. During under-voltage lockout, the outputs are high impedance. These devices feature totem pole outputs designed to source and sink high peak currents from capacitive loads, such as the gate of a power MOSFET. The on state is designed as a high level. The UC1825 family of PWM control ICs is optimized for high frequency switched mode power supply applications. Particular care was given to minimizing propagation delays through the comparators and logic circuitry while maximizing bandwidth and slew rate of the error amplifier. This controller is designed for use in either current-mode or voltage mode systems with the capability for input voltage feed-forward. Protection circuitry includes a current limit comparator with a 1V threshold, a TTL compatible shutdown port, and a soft start pin which will double as a maximum duty cycle clamp. The logic is fully latched to provide jitter free operation and prohibit multiple pulses at an output. An under-voltage lockout section with 800mV of hysteresis assures low start up current. During under-voltage lockout, the outputs are high impedance. These devices feature totem pole outputs designed to source and sink high peak currents from capacitive loads, such as the gate of a power MOSFET. The on state is designed as a high level.