Diodes Incorporated AL1771T16E-13

Overview

AL1771T16E-13 from Diodes Incorporated is a monolithic, 2-stage Smart Connected Lighting (SCL) controller integrating an offline Quasi-Resonant (QR) PFC controller and a single-channel dimmable linear LED driver in one TSSOP-16EP package. It delivers up to 1500mA regulated LED current, supports deep PWM dimming down to 0.1% at 1kHz with E-flicker-free operation, and enables primary-side regulation without optocoupler for <100mW standby power compliance. It targets 1-channel dimmable smart bulbs and panel lights operating from 85–265Vac input.

For engineers reviewing the AL1771T16E-13 datasheet, AL1771T16E-13 pinout, AL1771T16E-13 application, or AL1771T16E-13 equivalent, key selection considerations include its integrated PFC+LED driver topology, valley-switching QR control for high efficiency (>90% typical), adaptive thermal management (ATM), ±4% LED current accuracy, and support for Energy Star-compliant low-power mode during no-PWM conditions.

Technical Context

The AL1771T16E-13 implements a tightly coupled 2-stage architecture: Stage 1 uses QR valley detection on the FB pin for constant-voltage PFC output regulation (1.15–1.25V CV threshold), while Stage 2 employs independent PWM-controlled current regulation per channel via REF1 and PWM1 inputs. Its PFC section operates with constant-on-time control and internal COMP loop compensation, enabling stable output under wide load transients.

It features dual-protection coordination: PFC OVP triggers at FB >1.35V or AVCC >30V, forcing max-off-time recovery; LED driver UVLO activates at DVCC <6V with 300mV hysteresis, and fault reporting occurs via open-drain FAULTB asserted low for UVLO, OTP, or LED open/short events. Thermal shutdown initiates at +160°C with +30°C hysteresis.

Key Specifications

Pinout & Package

TSSOP-16EP (Type DX) package with exposed thermal pad (EP) requiring solder connection to PCB ground plane for optimal thermal performance (θJC = 15°C/W). Pin numbering follows standard top-view orientation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PFC + linear LED driver applications.

Compared with AL1772T16E-13, AL1771T16E-13 offers higher per-channel current capacity and simpler layout for single-white systems, while AL1782T16E-13 trades integrated PFC for expanded color control-making AL1771 the most cost- and space-efficient choice for 1-channel smart lighting.

Availability

AL1771T16E-13 is available at Aetrix Electronics and suitable for smart bulb manufacturing, commercial panel light production, and IoT-connected ceiling fixture development requiring stable component supply and long-term lifecycle assurance.

Supply support for AL1771T16E-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 solutions for power management, signal integrity, and connectivity applications.

The AL1771 belongs to Diodes' Smart Connected Lighting (SCL) product line, engineered specifically to consolidate PFC and linear LED driver functions into single-chip solutions for energy-efficient, standards-compliant, and firmware-light smart lighting systems.

FAQ

What is the maximum allowable LED string voltage when using AL1771T16E-13?

The AL1771T16E-13 supports up to 33V at the LED1 pin, verified per absolute maximum ratings. This allows driving typical 10–12-LED white strings (3.0–3.3V per LED) in series at full current. Exceeding 33V risks permanent damage to the internal pass transistor and voids protection coverage.

Does AL1771T16E-13 require an external compensation network for the PFC loop?

Yes-the COMP pin (Pin 13) must be connected to an RC network (typically 10kΩ + 1nF) between COMP and AGND to stabilize the PFC voltage regulation loop. Omitting this causes output voltage oscillation, poor load transient response, and potential FAULTB assertion due to FB OVP triggering.

How does the Adaptive Thermal Management (ATM) function interact with PWM dimming?

ATM continuously monitors die temperature via on-die sensor and scales LED1 current downward when junction temperature exceeds safe thresholds-regardless of PWM duty cycle. During dimming, ATM remains active, preventing thermal runaway even at 100% duty if ambient conditions exceed design limits.

Can AL1771T16E-13 operate without a PWM signal applied to PWM1?

Yes-when PWM1 is left floating or held low, the device automatically enters low-power mode with DVCC current dropping to ≤300µA. This satisfies Energy Star standby requirements and maintains system readiness for wake-up via external MCU or RF event without manual reset.