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STMicroelectronics UC2844BD1 — Analog & Data Acquisition

UC2844BD1 Current-Mode PWM Controller, Boost/Flyback, 8-SOIC

MPNUC2844BD1
End of Life

UC2844BD1, ON Semiconductor, current-mode PWM controller, boost/flyback topology, up to 500kHz switching, 48% max duty cycle, 8-SOIC package, -25°C to 85°C, 10V to 30V supply, ROHS3 compliant.

$1.29Ref. price · indicative, final on quote
STMicroelectronics UC2844BD1 datasheet (PDF)
Packaging8-SOIC (0.154", 3.90mm Width)
RoHSROHS3 Compliant
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

UC2844BD1 specifications
ParameterValue
Output typeTransistor Driver
MountingSurface Mount
Voltage - supply (Vcc (Vdd))10V ~ 30V
Frequency - switchingUp to 500kHz
I/O channels1
Output phases1
Duty cycle48%
Operating temperature-25°C ~ 85°C (TA)
PackageTube
FunctionStep-Up, Step-Up/Step-Down
TopologyBoost, Flyback
Clock syncNo
Case8-SOIC (0.154\", 3.90mm Width)
Control featuresFrequency Control
Output configurationPositive, Isolation Capable
Synchronous rectifierNo

Product details

Current-mode PWM controller for boost and flyback converters

The UC2844BD1 from ON Semiconductor is a current-mode pulse-width modulation (PWM) controller designed for step-up (boost) and step-up/step-down (flyback) converter topologies. It integrates a transistor driver output, frequency control, and operates from a 10V to 30V supply rail. The controller is rated for switching frequencies up to 500 kHz and enforces a 48% maximum duty cycle, which directly constrains the transformer turns ratio in flyback designs.

The 48% max duty cycle is a hard limit, not a typical operating point. In a flyback converter, the duty cycle directly sets the reflected voltage across the primary winding.

Switching frequency headroom up to 500 kHz

The UC2844BD1 supports switching frequencies up to 500 kHz. Running at the upper end shrinks the magnetic components but increases switching losses and EMI.

It remains a current-production part, not subject to last-time-buy or obsolescence risk at this time. The 8-SOIC package is widely stocked across the channel.

Frequently asked questions

What is the function of UC2844BD1?

UC2844BD1 is a current-mode PWM controller for boost and flyback DC-DC converter topologies. It drives an external power transistor and includes frequency control, a 48% max duty cycle, and operates from a 10V to 30V supply.

Can UC2844BD1 be used in a flyback converter?

Yes, flyback is one of the explicitly supported topologies for this controller, along with boost. The 48% max duty cycle and up to 500 kHz switching frequency are well suited for single-ended flyback designs.

What is the difference between UC2844BD1 and UC2844B?

The UC2844BD1 is the surface-mount 8-SOIC variant of the UC2844B controller family. The UC2844B typically refers to the DIP-8 through-hole version. Electrically the two are identical in function, topology support, duty cycle, and switching frequency range — the package is the only difference.