Diodes Incorporated AP1661MTR-E1

Overview

AP1661MTR-E1 from BCD Semiconductor 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 a one-quadrant multiplier, zero-current detector (ZCD), totem-pole gate driver (600mA source / 800mA sink), 2.5V ±1% internal reference, and UVLO with 2.5V hysteresis. Its SOIC-8 package supports compact pre-converter designs requiring near-unity PF and THD compliance.

For engineers reviewing the AP1661MTR-E1 datasheet, AP1661MTR-E1 pinout, AP1661MTR-E1 application, or AP1661MTR-E1 equivalent, key selection criteria include ZCD threshold (2.1V rising edge), OVP trigger current (40μA), start-up current (50μA typ), COMP output clamp (2.25V/5.8V), and DCM-mode timing control via ZCD hysteresis (0.5V typ).

Technical Context

The AP1661 operates exclusively in discontinuous conduction mode (DCM) boundary control, using zero-current detection to initiate MOSFET turn-on at inductor current zero-crossing. Its multiplier accepts a scaled AC line voltage (0–3.5V) on MULT and error amplifier output (2.0–5.8V) on COMP to generate a dynamic current-sense threshold that shapes input current sinusoidally.

Internal protection includes precise over-voltage protection triggered by ≥40μA current into COMP (dynamic OVP), static OVP activation when COMP falls below 2.25V, UVLO with 12V turn-on/9.5V turn-off thresholds, and multiplier output clamping to limit peak current sense reference to 1.8V.

Key Specifications

Pinout & Package

AP1661MTR-E1 is housed in a RoHS-compliant, lead-free SOIC-8 package (5.0mm × 6.2mm, 1.27mm pitch), optimized for surface-mount assembly in space-constrained PFC pre-regulators.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ICE2PCS01 and UCC28019, AP1661MTR-E1 offers integrated DCM timing control, self-contained 2.5V reference, and simpler board layout-ideal for cost-sensitive, mid-power (<120W) PFC stages where EMI reduction and design simplicity are prioritized over programmability or CCM efficiency.

Availability

AP1661MTR-E1 is available at Aetrix Electronics and suitable for AC-DC adapters, off-line SMPS, and electronic ballasts requiring stable component supply, RoHS-compliant packaging, and proven DCM PFC performance.

Supply support for AP1661MTR-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 processes for power management, LED drivers, and PFC controllers.

The AP1661 belongs to BCD's active PFC controller product line, engineered specifically for cost-effective, high-PF pre-converter solutions in universal-input consumer and industrial power supplies.

FAQ

What is the recommended minimum ZCD signal amplitude for reliable DCM operation?

The ZCD pin requires a clean, monotonic falling edge reaching ≤1.6V to trigger MOSFET turn-on. A minimum amplitude of 3V peak-to-peak (with ≥2.1V high-state margin) is recommended to ensure noise immunity and avoid false triggering due to ringing or coupling. Layout best practices include short traces, local RC filtering (e.g., 10kΩ + 100pF), and separation from high-dV/dt nodes.

How does the AP1661 implement over-voltage protection without an external pin?

OVP is implemented internally by monitoring current flow into the COMP pin. When output overvoltage causes excess current (>40μA) to discharge through the feedback compensation capacitor into COMP, the IC triggers dynamic OVP and halts GD output. If COMP voltage drops below 2.25V, static OVP engages-both mechanisms require no external components beyond the standard feedback divider and compensation network.

Can the AP1661 operate with a non-isolated auxiliary winding for VCC supply?

Yes-the AP1661 supports direct connection of an auxiliary winding to VCC, provided the winding delivers ≥12V after rectification and filtering, and includes a series current-limiting resistor or zener clamp to prevent VCC exceeding 20V absolute maximum. The internal 22V zener (V_Z) provides secondary overvoltage protection, but primary clamping remains essential for reliability.

What is the impact of the 1% internal reference tolerance on output voltage regulation accuracy?

The 2.5V ±1% reference contributes ±1% error to the regulated DC bus voltage, assuming ideal resistors in the INV feedback divider. With standard 1% metal-film resistors, total output regulation error remains within ±2.5% over temperature and line/load-sufficient for most SMPS and ballast applications where 385V ±10V is acceptable. Tighter regulation requires precision resistors or post-PFC voltage trimming.