Skip to main content
Log in
Texas Instruments UC2843N — Analog & Data Acquisition

UC2843N PWM Controller, 500kHz, 97% Duty Cycle, 8-PDIP

MPNUC2843N
End of Life

UC2843N, Texas Instruments, Current-Mode PWM Controller, Boost/Buck/Flyback/Forward, Up to 500kHz, 97% Duty Cycle, 12V-28V Supply, Through Hole 8-PDIP, -40°C to 85°C.

$1.74Ref. price · indicative, final on quote
Texas Instruments UC2843N datasheet (PDF)
Packaging8-DIP (0.300", 7.62mm)
RoHSROHS3 Compliant
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

UC2843N specifications
ParameterValue
Output typeTransistor Driver
MountingThrough Hole
Voltage - supply (Vcc (Vdd))12V ~ 28V
Frequency - switchingUp to 500kHz
I/O channels1
Output phases1
Duty cycle97%
Operating temperature-40°C ~ 85°C (TA)
PackageTube
FunctionStep-Up, Step-Down, Step-Up/Step-Down
TopologyBoost, Buck, Buck-Boost, Flyback, Forward
Clock syncNo
Case8-DIP (0.300\", 7.62mm)
Control featuresFrequency Control
Output configurationPositive, Isolation Capable
Synchronous rectifierNo

Product details

The Texas Instruments UC2843N is a current-mode PWM controller for off-line and DC-DC converters. It handles step-up, step-down, and step-up/step-down topologies including boost, buck, buck-boost, flyback, and forward.

The 97% maximum duty cycle is the headline figure for this controller family. It allows the part to maintain regulation with very low input-to-output voltage ratios — useful in boost converters where the output is only slightly above the input, or in flyback designs that need a long on-time to store energy in the transformer. The 12V to 28V supply range (Vcc) lines up with standard 24V industrial buses and off-line bias windings from a transformer auxiliary winding.

Frequently asked questions

What is the maximum duty cycle of UC2843N?

The maximum duty cycle is 97%, which allows near-continuous on-time for low dropout ratio designs in boost or flyback topologies.

What is the maximum switching frequency of UC2843N?

Switching frequency runs up to 500 kHz, enabling smaller transformer and filter component sizes compared to 100 kHz-class controllers.

Is UC2843N equivalent to UC3843?

The UC2843N is the industrial-temperature-range sibling of the UC3843 family. Both share the same pinout and functional behavior; the key difference is the UC2843N's -40°C to 85°C rating versus the UC3843's commercial 0°C to 70°C range.

What is UC2843N used for?

It is a current-mode PWM controller for DC-DC converters and off-line power supplies using boost, buck, buck-boost, flyback, or forward topologies. Typical applications include industrial power supplies, battery chargers, and auxiliary bias supplies.