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Texas Instruments UC3843ADTR — Power Management (PMIC / Gate Driver)

UC3843ADTR PWM Controller, Boost/Buck/Flyback, Up to 500 kHz

MPNUC3843ADTR
Active

Texas Instruments UC3843ADTR, current-mode PWM controller, Boost/Buck/Flyback/Forward topologies, up to 500 kHz switching, 96% max duty cycle, 7.6 V to 30 V supply, 0°C to 70°C, 14-SOIC.

$1.1200Ref. price · indicative, final on quote
Texas Instruments UC3843ADTR datasheet (PDF)
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

UC3843ADTR specifications
ParameterValue
Output typeTransistor Driver
MountingSurface Mount
Voltage - supply (Vcc (Vdd))7.6V ~ 30V
Frequency - switchingUp to 500kHz
I/O channels1
Output phases1
Duty cycle96%
Operating temperature0°C~70°C(TA)
PackageTape & Reel (TR); Cut Tape (CT)
FunctionStep-Up, Step-Down, Step-Up/Step-Down
TopologyBoost, Buck, Flyback, Forward
Clock syncNo
Case14-SOIC (0.154\", 3.90mm Width)
Control featuresFrequency Control
Output configurationPositive, Isolation Capable
Synchronous rectifierNo

Product details

Current-mode controller for isolated and non-isolated supplies

The Texas Instruments UC3843ADTR is a current-mode PWM controller designed for off-line and DC-DC converters. It supports step-up, step-down, and step-up/step-down topologies including boost, buck, flyback, and forward converters. A single transistor-driver output delivers up to 96% duty cycle, with switching frequency programmable to 500 kHz. The 7.6 V to 30 V supply range covers standard 12 V and 24 V industrial rails directly.

The 500 kHz ceiling lets you shrink the magnetic component — a flyback transformer at 300 kHz is roughly half the core volume of one at 100 kHz. The 96% max duty cycle gives headroom for boost converters that need a wide input-to-output ratio, such as a 5 V input to 24 V output.

Vcc from 7.6 V to 30 V means the controller can run off a 12 V bias winding or a 24 V industrial bus without a pre-regulator.

Frequently asked questions

Is UC3843ADTR compatible with the standard UC3843?

Yes, the UC3843ADTR is pin-compatible with the standard UC3843. The 'A' suffix typically denotes tighter tolerance on the reference voltage and oscillator frequency; the 'DTR' suffix indicates tape-and-reel packaging in a 14-SOIC body.

What is the maximum switching frequency of UC3843ADTR?

The controller can be programmed up to 500 kHz. Practical frequency selection depends on the transformer core loss and MOSFET gate charge; above 300 kHz, layout parasitics become the limiting factor.

Is UC3843ADTR RoHS compliant?

The UC3843ADTR is listed as a current-production part from Texas Instruments and is supplied in a lead-free (RoHS-compliant) finish per TI's standard green packaging. No separate RoHS certificate is required for this order code.