Diodes Incorporated AP1661P-E1

Overview

AP1661P-E1 from BCD Semiconductor Manufacturing Limited is a BiCMOS active power factor correction (PFC) controller IC designed for DCM boundary conduction mode operation in AC-DC adapters, off-line SMPS, and electronic ballasts. It integrates zero-current detection, a one-quadrant multiplier with 0.45–0.75 V⁻¹ gain, 2.5 V ±1% internal reference, and totem-pole gate driver capable of 600 mA source / 800 mA sink current.

For engineers reviewing the AP1661P-E1 datasheet, AP1661P-E1 pinout, AP1661P-E1 application, or AP1661P-E1 equivalent, key selection criteria include its 2.5 V reference precision, UVLO hysteresis of 2.5 V, 50 μA typical start-up current, and DIP-8 package compatibility with legacy through-hole PFC designs.

Technical Context

The AP1661P-E1 implements fixed-frequency DCM boundary-mode control using zero-current detection on Pin 5 (ZCD) to trigger MOSFET turn-on at inductor current zero-crossing. Its multiplier accepts AC line voltage (Pin 3) and error amplifier output (Pin 2) to generate a sinusoidal current reference, enabling >0.99 power factor with low THD.

Internal protection includes precise over-voltage protection triggered at 2.25 V static threshold or 40 μA dynamic current into COMP, under-voltage lockout with 12 V turn-on/9.5 V turn-off thresholds and 2.5 V hysteresis, and multiplier output clamping limiting peak current sense voltage to 1.7–1.8 V.

Key Specifications

Pinout & Package

DIP-8 package with 0.3 inch body width, through-hole mounting, and standard 2.54 mm lead pitch - compatible with legacy PCB layouts and wave-soldering processes.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PFC controller applications.

Compared with ICE2PCS01G and UCC28019DR, the AP1661P-E1 offers lower system cost for sub-100 W DCM applications due to its self-contained start-up timer, ZCD-based timing simplicity, and DIP-8 compatibility with existing through-hole manufacturing lines.

Availability

AP1661P-E1 is available at Aetrix Electronics and suitable for AC-DC adapters, electronic ballasts, and off-line SMPS requiring stable component supply, RoHS-compliant lead-free packaging, and long-term industrial lifecycle support.

Supply support for AP1661P-E1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

BCD Semiconductor Manufacturing Limited is a Shanghai-based analog and power IC designer specializing in high-voltage BiCMOS process technology for power management solutions.

The AP1661 belongs to BCD's active PFC controller product line, developed specifically for cost-sensitive, high-volume DCM boundary-mode applications in lighting and adapter markets.

FAQ

What is the function of the ZCD pin on AP1661P-E1?

The ZCD (Pin 5) detects zero current in the boost inductor's auxiliary winding. When voltage falls below 1.6 V, it triggers the gate driver to turn on the external MOSFET. It also serves as a disable input: pulling ZCD ≤150 mV halts operation and reduces supply current to 20–50 μA, enabling remote control of PFC stage activity.

How does the AP1661P-E1 achieve near-unity power factor?

It uses a one-quadrant multiplier that combines the rectified AC line voltage (applied to MULT, Pin 3) with the error amplifier output (COMP, Pin 2) to generate a time-varying current reference. This forces the average input current to track the sinusoidal input voltage waveform, achieving >0.99 PF in properly designed DCM boost converters.

Can AP1661P-E1 be used in continuous conduction mode (CCM)?

No - the AP1661P-E1 is explicitly designed for discontinuous conduction mode (DCM) boundary conduction only. Its zero-current detection architecture, fixed-frequency timing, and current-sense comparator behavior are optimized for DCM operation. Attempting CCM results in unstable regulation and potential overcurrent failure.

What is the maximum allowable VCC voltage for AP1661P-E1?

The absolute maximum VCC rating is 20 V. Operation above this risks permanent damage. The device enters UVLO shutdown below ~9.5 V and resumes operation above ~12 V, with 2.5 V hysteresis. Internal zener clamping at 22 V (typical) provides limited transient protection but is not a substitute for proper VCC regulation.