UC3825DWTRG4 ,High Speed PWM ControllerapplicationUC1825INFOUC2825availableUC3825High Speed PWM Controller
UC3825J , High Speed PWM Controller
UC3825N ,High Speed PWM ControllerapplicationUC1825INFOUC2825availableUC3825High Speed PWM Controller
UC3825NG4 ,High Speed PWM Controller 16-PDIP 0 to 70applicationUC1825INFOUC2825availableUC3825High Speed PWM Controller
UC3825Q ,High Speed PWM ControllerapplicationUC1825INFOUC2825availableUC3825High Speed PWM Controller
UC3825Q ,High Speed PWM ControllerapplicationUC1825INFOUC2825availableUC3825High Speed PWM Controller
UMH2N , NPN 100mA 50V Complex Digital Transistors (Bias Resistor Built-in Transistors)
UMH3N , General purpose (dual digital transistors)
UMH4N , General purpose (dual digital transistors)
UMH6N , General purpose (dual digital transistors)
UMH7N , General purpose (dual digital transistors)
UMH9 N TN , NPN 100mA 50V Complex Digital Transistors
UC3825-UC3825DW-UC3825DWTR-UC3825DWTRG4-UC3825N-UC3825NG4-UC3825Q
High Speed PWM Controller
UC1825
UC2825
UC3825
BLOCK DIAGRAM Compatible with Voltage or Current Mode
Topologies Practical Operation Switching Frequencies
to 1MHz 50ns Propagation Delay to Output High Current Dual Totem Pole Outputs
(1.5A Peak) Wide Bandwidth Error Amplifier Fully Latched Logic with Double Pulse
Suppression Pulse-by-Pulse Current Limiting Soft Start / Max. Duty Cycle Control Under-Voltage Lockout with Hysteresis Low Start Up Current (1.1mA)
The UC1825 familyof PWM control ICsis optimized for high fre-
quency switched mode power supply applications. Particular care
was givento minimizing propagation delays through the comparators
and logic circuitry while maximizing bandwidth and slew rateof the
error amplifier. This controlleris designed for usein either cur-
rent-modeor voltage mode systems with the capability for input volt-
age feed-forward.
Protection circuitry includesa current limit comparator witha 1V
threshold,a TTL compatible shutdown port, anda soft start pin
which will doubleasa maximum duty cycle clamp. The logicis fully
latchedto provide jitter free operation and prohibit multiple pulsesat output.An under-voltage lockout section with 800mVof hysteresis
assures low start up current. During under-voltage lockout, the out-
puts are high impedance.
These devices feature totem pole outputs designedto source and
sink high peak currents from capacitive loads, suchas the gateofa
power MOSFET. The on state is designed as a high level.
High Speed PWM Controller
FEATURES DESCRIPTION
