UCC28C45DR PWM Controller for Avalon A1346 Power Supply

UCC28C45DR PWM Controller | Fixed-Frequency Peak-Current-Mode IC for Avalon A1346 PSU3400-03 Repair

The UCC28C45DR is a high-performance PWM controller IC for fixed-frequency, peak-current-mode power supplies — the topology used on the Avalon A1346 PSU3400-03 power supply. Designed for lower power consumption and improved efficiency, with faster current sensing, precise oscillation frequency, and the essential functionalities for controlling switching power supplies at the 3400W class.

Headline specs: 1MHz maximum operating frequency, 50µA startup current (100µA max), 2.3mA operating current at 52kHz, 35ns cycle-by-cycle overcurrent response, ±1A peak driving current. ±1% accurate 2.5V error amplifier reference and trimmed oscillator discharge current keep the PSU regulation tight under load.

When to Replace the UCC28C45DR

• PSU stuck at startup — controller dead, no PWM output to the main switching stage.
• PSU repeatedly trips on over-current — controller's OC sense circuit drifted, false trip on normal load.
• Output voltage drift outside the ±1% reference tolerance — error amplifier degraded.
• Audible squealing or coil whine at the switching frequency — controller frequency drift.
• Visible damage on the IC package after a fault event.

UCC28C45DR Specifications

FAQ — UCC28C45DR PWM Controller

Q: UCC28C45 vs UCC28C42 / 43 / 44 — which one do I need?
A: Different dash numbers in the UCC28C4x family target different startup voltage thresholds and duty-cycle ranges. UCC28C45 is the one used on the Avalon PSU3400-03. Match the silk marking on your existing IC — substituting a different variant changes startup behaviour and can damage the PSU.

Q: How do I confirm the controller is the failed part?
A: Scope the IC's output pin (OUT) with the PSU trying to start. Healthy controller produces a clean PWM waveform at the configured frequency. Stuck high, stuck low, missing pulses, or wrong frequency = chip failed. Confirm the IC's VCC pin has the expected bias voltage before condemning the chip.

Q: Rework profile?
A: Standard SOIC-8 rework. Preheat to 100°C, hot air at 320°C with flux paste. Watch for warpage on the small body.

Q: Bulk pricing?
A: Yes — email contact@lys-sz.com for tape-and-reel quantities for Avalon PSU3400 repair benches.

Related products

• Avalon PSU3400-03 (A1346 / A1366)
• NCP1399AM Current Mode Controller (Avalon PSU)
• TEA2095T Synchronous Rectifier Controller
• MUR860F Ultrafast Recovery Diode (Avalon PSU3400)

Avalon A1346 PSU repair benches stocking UCC28C45DR in tape-and-reel volume? Email contact@lys-sz.com for bulk pricing. Worldwide shipping from our Shenzhen warehouse.