Diodes Incorporated AL1672-40CSP-13

Overview

AL1672-40CSP-13 from Diodes Incorporated is a single-stage, boundary-conduction-mode (BCM) buck LED driver IC integrating a 600V/4A high-voltage MOSFET, delivering constant-current output for dimmable LED lighting. It supports analog dimming (0.3–2.4V DC on APWM) and PWM dimming (1kHz, 3–100% duty), achieves >0.9 power factor, <10% THD, and features valley switching for low EMI and high efficiency in compact SO-8EP packages.

For engineers reviewing the AL1672-40CSP-13 datasheet, AL1672-40CSP-13 pinout, AL1672-40CSP-13 application, or AL1672-40CSP-13 equivalent, key selection criteria include integrated 600V/4A MOSFET capability, dual-dimming interface compatibility, thermal fold-back and latch-type OTP protection, tight ±3% LED current regulation, and SO-8EP package thermal performance with θJC = 22.4°C/W.

Technical Context

The AL1672 operates in quasi-resonant boundary conduction mode to minimize switching loss and EMI while maintaining high power factor via constant-on-time control. Its internal 600V/4A MOSFET eliminates external high-voltage switch requirements, reducing BOM count and layout complexity in offline LED drivers.

Dimming is implemented through dual-mode APWM pin logic: analog voltage level (0.3–2.4V) linearly scales output current from 18% to 100%, while digital PWM signals (≥2.4V high / ≤0.3V low) enable 3–100% duty-cycle control at 1kHz. Protection architecture includes cycle-by-cycle OCP (VCS_OCP = 1.2V), VCC/FB-based OVP, OSP, UVLO (17–20V startup), TFP (145°C activation), and latch-mode OTP (165°C).

Key Specifications

Pinout & Package

AL1672-40CSP-13 is housed in an SO-8EP (Exposed Pad) package with thermal pad connected internally to DRAIN pins (3, 4, 9). The exposed pad must be soldered to ≥3.6mm × 2.7mm PCB copper area for thermal compliance per datasheet layout guidelines.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LED buck driver applications.

Compared with AL1673-40CSP-13, AL1672-40CSP-13 omits X-cap discharge but delivers identical dimming flexibility and thermal performance; versus BP5609D, it integrates dimming control and offers higher current rating, reducing bill-of-materials and firmware complexity in standalone LED drivers.

Availability

AL1672-40CSP-13 is available at Aetrix Electronics and suitable for commercial downlights, smart bulbs, industrial indicator panels, and outdoor streetlight auxiliary drivers requiring stable component supply, long-lifecycle assurance, and RoHS-compliant manufacturing.

Supply support for AL1672-40CSP-13 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

Diodes Incorporated is a global semiconductor company specializing in discrete, analog, and mixed-signal devices, with leadership in power management, lighting control, and protection solutions.

The AL1672 belongs to Diodes' AL16xx family of highly integrated AC/DC LED drivers, designed specifically for cost-sensitive, high-efficiency, dimmable offline LED lighting applications requiring minimal external components and robust protection.

FAQ

What dimming protocols does AL1672-40CSP-13 natively support?

AL1672-40CSP-13 supports two native dimming modes via its APWM pin: analog dimming (0.3–2.4V DC input, 18–100% output current) and PWM dimming (1kHz frequency, 3–100% duty cycle). No external circuitry or configuration registers are needed-mode detection is automatic based on signal characteristics. It does not support DALI, 0–10V, or wireless protocols without external translation.

Can AL1672-40CSP-13 operate without an auxiliary winding?

No. The AL1672 requires an auxiliary winding to power the VCC pin after startup. During initial power-up, VCC is charged via a high-value resistor from the rectified AC bus; once the auxiliary winding generates sufficient voltage (>7.8V), it takes over VCC supply. Without the auxiliary winding, VCC drops below the minimum operating voltage (7.8V), causing shutdown and preventing continuous operation.

How is thermal protection implemented in AL1672-40CSP-13?

AL1672-40CSP-13 implements dual thermal protection: Thermal Fold-Back (TFP) activates at +145°C junction temperature, linearly reducing the internal current reference to limit power dissipation; Over Temperature Protection (OTP) triggers at +165°C, forcing a latch-off state that requires full power cycle recovery. Both functions are monitored internally-no external thermistor or feedback is needed.

What is the minimum recommended PCB copper area for the exposed pad (EP) in SO-8EP?

The datasheet specifies a minimum copper area of 3.600 mm × 2.700 mm (X1 × Y1) under the exposed pad for thermal compliance. This corresponds to ≥9.7 mm² of 2-oz copper, connected directly to internal ground or drain planes. Using less area increases θJA beyond 65°C/W, risking thermal derating of the 4A current rating above +60°C ambient.