Diodes Incorporated AP8800EV2

Overview

AP8800 from Diodes Incorporated is a 350mA constant-current step-down DC/DC LED driver IC designed for series-connected LED strings in 8V–28V input systems. It integrates a 1.7Ω internal MOSFET switch, operates up to 500kHz (typ.), supports analog and PWM dimming via the CTRL pin, and delivers up to 92% efficiency in commercial lighting and LCD backlight applications.

For engineers reviewing the AP8800 datasheet, AP8800 pinout, AP8800 application, or AP8800 equivalent, key selection considerations include its hysteretic control architecture, external R_SET-programmed current (e.g., 350mA @ 0.33Ω), 0.2V shutdown threshold at CTRL, SO-8/MSOP-8/U-DFN3030-10 package options, and open-circuit LED protection - all critical for reliable, compact LED power design.

Technical Context

The AP8800 employs a hysteretic (constant-on-time) control architecture that regulates LED current by sensing voltage across an external R_SET resistor and comparing it to an internal 100mV threshold. Its switching frequency varies dynamically with input voltage, LED string voltage, and inductor value - ranging from ~100kHz to 500kHz - enabling stable operation without external compensation.

It features dual-mode dimming: analog control (0.3V–2.5V at CTRL yields 24–200% I_LED) and PWM dimming (open-drain compatible, up to 8-bit resolution). The device includes built-in soft-start (via CTRL-to-GND capacitor), output open-circuit protection, and thermal derating curves validated for SO-8 (92°C/W), MSOP-8 (120°C/W), and U-DFN3030-10 (46°C/W) packages.

Key Specifications

Pinout & Package

AP8800 is available in three RoHS-compliant, lead-free packages: SO-8 (92°C/W θ_JA), MSOP-8 (120°C/W), and U-DFN3030-10 (46°C/W). Thermal performance is optimized with recommended pad layouts including thermal vias for the DFN variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AP8800, AL8860 and AL8861 offer higher switching frequencies and newer protection features but require redesign of inductor, layout, and control interface - making them unsuitable as drop-in replacements despite functional overlap in basic LED driving.

Availability

AP8800 is available at Aetrix Electronics and suitable for commercial lighting, LCD backlight, architectural detail lighting, and appliance interior lighting requiring stable component supply and long-term industrial availability.

Supply support for AP8800 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 manufacturer of discrete semiconductors and ICs, specializing in power management, signal integrity, and LED lighting solutions with broad distribution and automotive-grade quality systems.

The AP8800 belongs to Diodes' LED driver product line, engineered specifically for cost-sensitive, high-reliability constant-current LED applications in industrial and commercial lighting where simplicity, efficiency, and robust fault handling are prioritized.

FAQ

What is the maximum number of LEDs the AP8800 can drive?

The AP8800 can drive up to seven LEDs in series, depending on their forward voltage and the input supply voltage (8V–28V). For example, with 3.2V LEDs and a 24V input, up to seven LEDs (22.4V total VF) fit within the headroom, leaving ~1.6V for regulation margin and switch/diode losses.

How is LED current set and adjusted on the AP8800?

LED current is set by an external resistor (R_SET) between VIN and SET pins, where I_LED ≈ 0.1V / R_SET. It is adjusted via the CTRL pin: applying 0.3–2.5V gives 24–200% of nominal current (analog dimming), while a PWM signal enables precise duty-cycle-based current scaling down to near-zero.

Does the AP8800 require external compensation components?

No - the AP8800 uses a hysteretic (constant-on-time) control architecture that does not require external compensation capacitors or resistors. Stability is inherent to the topology, simplifying design and reducing component count compared to voltage-mode or current-mode controllers.

Is the AP8800 suitable for new designs?

No - Diodes Incorporated explicitly marks AP8800 as "NOT RECOMMENDED FOR NEW DESIGN" in its datasheet, citing newer alternatives (AL8860/AL8861) with improved features. It remains viable for legacy support, cost-sensitive replacements, or applications where its specific hysteretic behavior and proven field reliability are advantageous.