Diodes Incorporated AP3586AMPTR-G1

Overview

AP3586AMPTR-G1 from BCD Semiconductor is a fixed-frequency voltage-mode synchronous buck PWM controller in PSOP-8 package, designed for 5V/12V input systems delivering regulated output down to 0.6V with ±1% reference accuracy, 300kHz switching, and integrated 12V bootstrap drivers for N-channel MOSFETs - used in DDR memory termination and graphics card subsystem supplies.

For engineers reviewing the AP3586AMPTR-G1 datasheet, AP3586AMPTR-G1 pinout, AP3586AMPTR-G1 application, or AP3586AMPTR-G1 equivalent, this controller's fast 10MHz error amplifier, lossless R_DS(ON)-based overcurrent protection, soft-start timing, and adaptive shoot-through prevention are critical selection criteria in high-density DC-DC designs.

Technical Context

The AP3586AMPTR-G1 implements voltage-mode control with a single feedback loop referenced to an internal 0.6V bandgap (AP3586A variant), fixed 300kHz oscillator, and dual gate drivers capable of ±1.5A peak sink/source. Its adaptive shoot-through protection monitors UGATE and PHASE transitions to prevent cross-conduction.

It integrates a built-in bootstrap diode, 120µA COMP/EN current source for soft-start ramping, and lossless overcurrent detection using the low-side MOSFET's R_DS(ON), with programmable threshold via external ROCSET resistor. Thermal shutdown activates at 160°C with 20°C hysteresis.

Key Specifications

Pinout & Package

AP3586AMPTR-G1 is housed in a thermally enhanced PSOP-8 package with exposed pad soldered to PCB ground for improved power dissipation (θ_JA = 50°C/W). The exposed pad serves as additional GND connection and must be electrically tied to the main ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2238DJ-LF-Z and RT8205AZQW, AP3586AMPTR-G1 uniquely combines fixed 300kHz operation, integrated bootstrap diode, R_DS(ON)-based OCP, and pre-biased start-up - making it optimal for cost-sensitive, thermally constrained DDR and graphics subsystems where layout simplicity and robustness are prioritized over ultra-high frequency.

Availability

AP3586AMPTR-G1 is available at Aetrix Electronics and suitable for DDR memory termination, graphics card subsystems, cable modem power rails, and industrial FPGA I/O bank supplies requiring stable component supply, RoHS-compliant packaging, and long-term lifecycle continuity.

Supply support for AP3586AMPTR-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 China-based fabless analog and power management IC supplier focused on high-efficiency DC-DC solutions for consumer, computing, and industrial markets.

The AP3586 series belongs to BCD's synchronous buck controller product line, engineered specifically for compact, cost-effective, and thermally robust point-of-load regulation in graphics, memory, and broadband communication equipment.

FAQ

What is the purpose of the COMP/EN pin?

The COMP/EN pin serves dual functions: it is the output node of the internal error amplifier for loop compensation, and acts as the chip enable input. Pulling it below 0.25V disables the controller; releasing it allows a 120µA internal current source to ramp the voltage, initiating soft-start when it exceeds 0.3V. During normal operation, it holds the compensation network voltage and shuts down if driven low.

How does the AP3586AMPTR-G1 implement overcurrent protection without a sense resistor?

It uses lossless R_DS(ON) sensing on the low-side MOSFET. An internal 21.5µA current source flows through an external ROCSET resistor connected to LGATE/OCSET, generating a voltage threshold. When the voltage drop across the low-side MOSFET's R_DS(ON) exceeds this threshold during conduction, overcurrent is detected and both gates are disabled in hiccup mode.

Can the AP3586AMPTR-G1 start up into a pre-biased output?

Yes - it supports pre-biased load start-up. During soft-start, the controller monitors the PHASE node voltage before enabling UGATE. If VIN is absent or insufficient, it pauses soft-start and retries after a ~1ms hiccup delay. Once valid input is confirmed, it ramps the output from zero without forcing reverse current into the pre-charged rail.

What is the role of the exposed pad in the PSOP-8 package?

The exposed pad is electrically connected to GND and serves as the primary thermal path for heat dissipation. It must be soldered to a large PCB copper area tied to the system ground plane. This reduces θ_JA to 50°C/W and prevents thermal shutdown under sustained 1.5A+ load conditions typical in graphics and DDR applications.