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4061A / SEM4061A / SEM3051 / S3051 SOP-8 Power Management IC — SMPS Repair (5-Pack)
The 4061A, SEM4061A, SEM3051, and S3051 are SOP-8 power management ICs used in switching power supply (SMPS) and LED driver circuits. These ICs integrate PWM control and protection functions for offline and DC-DC power conversion applications. They are commonly found in LED bulb drivers, charger power boards, and consumer electronics SMPS, making them essential repair stock for electronics technicians.
Key Specifications
| Parameter | Value |
|---|---|
| Package | SOP-8 (SMD) |
| Function | PWM controller / power management |
| Application | LED driver, offline SMPS, charger power board |
| Protection | OCP, OVP, thermal shutdown, soft-start |
| Quantity | 5 pieces |
Variant Overview
| Part Number | Primary Application | Notes |
|---|---|---|
| 4061A / SEM4061A | LED bulb driver SMPS | Most common in LED retrofit bulb power stages |
| SEM3051 | Offline flyback SMPS | Used in charger and adapter power boards |
| S3051 | Offline flyback SMPS | Compatible replacement for SEM3051 |
Why Choose This IC Pack?
- Multi-variant pack — covers the most common SOP-8 SMPS repair ICs in one listing
- LED driver repair — 4061A/SEM4061A are the most frequently failed IC in LED bulb power stages
- Full protection suite — OCP/OVP/thermal shutdown prevents repeat failures after repair
- SOP-8 package — direct replacement on existing PCB footprints
- 5-pack value — sufficient for multiple repair jobs
Compatible With / Common Repair Applications
- LED bulb repair: 4061A/SEM4061A failure causes LED bulb to flicker, dim, or not light — most common LED driver IC failure
- Charger power board repair: SEM3051/S3051 failure causes no-output or unstable output in phone chargers and adapters
- Consumer electronics SMPS: Auxiliary power supply repair in set-top boxes and routers
- LED driver design: Reference circuit for isolated LED driver using 4061A
Frequently Asked Questions
Q: What symptoms indicate a failed 4061A in an LED bulb?
A: Common symptoms: (1) LED bulb flickers rapidly, (2) bulb lights briefly then goes off, (3) bulb does not light at all despite correct input voltage. Before replacing the IC, check the electrolytic capacitors on the LED driver board — bulging or leaking caps are a more common cause of LED driver failure than IC failure.
Q: Can SEM3051 replace S3051 directly?
A: Yes — SEM3051 and S3051 are functionally equivalent with the same SOP-8 pinout. They are direct drop-in replacements for each other in offline flyback SMPS applications.
Q: What other components should I replace when repairing an LED driver with 4061A?
A: When replacing 4061A, also inspect: (1) electrolytic output capacitor (most common failure point), (2) the power MOSFET if shorted, (3) the current-sense resistor for open circuit. Replacing only the IC without checking these often results in the new IC failing again.
Package Contents
- 5× 4061A / SEM4061A / SEM3051 / S3051 Power Management IC (SOP-8) — variant as selected


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