Diodes Incorporated AP3608EMTR-G1

Overview

AP3608EMTR-G1 from BCD Semiconductor is an eight-channel constant-current LED sink driver in SOIC-20 package, designed for precise current matching (±1.5%) across all channels with external resistor-set current ranging 10–100 mA per channel. It supports PWM dimming (0.1–25 kHz), open-LED fault tolerance, UVLO (3.6–4.0 V), and overtemperature shutdown (160 °C). Used in LCD TV backlight systems requiring stable multi-string current control.

For engineers reviewing the AP3608EMTR-G1 datasheet, AP3608EMTR-G1 pinout, AP3608EMTR-G1 application, or AP3608EMTR-G1 equivalent, key selection criteria include per-channel current accuracy, parallel operation capability via FBX/SDBX pins, thermal resistance (87 °C/W), PWM synchronization behavior, and compatibility with boost DC/DC controllers such as AP3039.

Technical Context

The AP3608EMTR-G1 implements eight matched current-sink channels using a bandgap-referenced ISET input (1.194 V typical) and internal 400× current mirror gain. Each channel's saturation voltage is specified at 0.45 V (20 mA), 0.8 V (60 mA), and 1.2 V (100 mA), enabling efficient operation with low forward-voltage LEDs.

Its interface architecture includes FB (min-voltage feedback to DC/DC controller), SDB (logic-level shutdown signal synchronized to PWM), and parallel-capable FBX/SDBX terminals. Open-LED detection triggers at 3.0 V total string voltage, initiating automatic channel isolation without disabling the IC.

Key Specifications

Pinout & Package

AP3608EMTR-G1 uses SOIC-20 (G/M package) with exposed pad for thermal enhancement. Pin 1 is top-left corner, marked by notch or dot. AGND and PGND must be connected directly to CIN ground plane; exposed pad improves thermal performance when soldered to PCB copper.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar eight-channel LED sink driver applications.

Compared with AL8862T-13 and MPQ3326GR-A, AP3608EMTR-G1 delivers true 8-channel integration with guaranteed ±1.5% matching, autonomous open-LED handling at 3.0 V, and native parallel expansion-reducing BOM count by ≥3 parts and eliminating external fault logic in display backlight systems.

Availability

AP3608EMTR-G1 is available at Aetrix Electronics and suitable for LCD TV backlight systems, industrial monitor designs, notebook display modules, and medical LCD display applications requiring stable component supply and long-term manufacturability.

Supply support for AP3608EMTR-G1 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 IC designer specializing in power management, LED drivers, and mixed-signal solutions for consumer, industrial, and automotive markets.

The AP3608E product line targets high-precision LED backlighting with emphasis on current matching, fault resilience, and seamless DC/DC controller interoperability-enabling compact, reliable displays without external calibration or supervision.

FAQ

What is the maximum recommended PCB copper area for thermal management of AP3608EMTR-G1 in SOIC-20?

The SOIC-20 package has θJA = 87 °C/W. For continuous 100 mA per channel (800 mA total), ambient temperature ≤50 °C, and junction limit of 125 °C, ≥200 mm² of 1-oz copper connected to PGND/AGND/exposed pad is required. Thermal vias (8×0.5 mm) to inner layers further reduce θJA by ~15 °C/W.

Can AP3608EMTR-G1 drive LEDs with forward voltage above 20 V per string?

No. Absolute maximum voltage per channel is 40 V, but functional operation is limited by the external DC/DC boost converter's output capability-not the AP3608E itself. The IC sinks current only; string voltage is supplied by the boost stage. Designers must ensure the boost controller (e.g., AP3039) supports the required V_OUT and that CHX pins remain within −0.3 V to 40 V.

How does the AP3608EMTR-G1 respond when two or more LED strings open simultaneously?

It detects each open string independently at the 3.0 V threshold and isolates them sequentially. FB continues reporting the lowest remaining active string voltage, and SDB remains asserted low only if all channels are inactive or EN = low. No latch-up occurs-the device stays operational with diminished string count.

Is the ISET pin internally biased, and what happens if left floating?

Yes-ISET has an internal 1.194 V reference. If left floating, leakage paths may cause unpredictable current setting and thermal instability. The datasheet mandates connection of R_ISET to AGND; floating ISET violates absolute maximum ratings and risks overcurrent in one or more channels.