The UC1825B-SP PWM control device 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 1-V 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 undervoltage lockout
section with 800 mV of hysteresis assures low start up current. During undervoltage lockout,
the outputs are high impedance.
This device features 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 UC1825B-SP PWM control device 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 1-V 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 undervoltage lockout
section with 800 mV of hysteresis assures low start up current. During undervoltage lockout,
the outputs are high impedance.
This device features 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.