Diodes Incorporated AP64500QSP-EVM

Overview

AP64500QSP-EVM from Diodes Incorporated is an evaluation board for the AP64500Q 40V, 5A synchronous buck converter featuring programmable switching frequency (100kHz–2.2MHz), 25µA quiescent current in PFM mode, and integrated 45mΩ/20mΩ MOSFETs in SO-8EP package. It supports automotive-grade input (3.8V–40V) and delivers precise 5.0V ±1% output at full 5A load for point-of-load testing.

For engineers reviewing the AP64500QSP-EVM datasheet, AP64500QSP-EVM pinout, AP64500QSP-EVM application, or AP64500QSP-EVM equivalent, this board enables rapid validation of EMI-reduction features-including Frequency Spread Spectrum (±6% jitter) and proprietary gate driver design-under real-world load transients, efficiency, and thermal conditions across 5V/12V/24V distributed power bus designs.

Technical Context

The AP64500QSP-EVM implements peak current mode control with external RT/CLK synchronization capability (100kHz–2.2MHz), enabling precise timing alignment in multi-rail systems. Its layout integrates low-ESR ceramic capacitors (C1/C2: 10µF ×2, C5/C6/C13: 22µF ×3) and a 4.7µH shielded inductor (L1, DCR = 10.2mΩ) to support stable 5A continuous operation with <20mVpp output ripple at full load.

Board-level protection includes undervoltage lockout (UVLO) via precision enable threshold, cycle-by-cycle current limiting, and thermal shutdown monitoring. The SO-8EP footprint for U1 (AP64500QSP) ensures direct correlation between evaluation results and production PCB thermal performance and EMI behavior.

Key Specifications

Availability

AP64500QSP-EVM is available at Aetrix Electronics and suitable for automotive infotainment power rails, industrial network switch PoL conversion, and cordless power tool battery management systems requiring stable component supply and fast-turn evaluation capability.

Supply support for AP64500QSP-EVM 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 analog ICs, specializing in high-efficiency power management solutions for automotive, industrial, and consumer applications.

The AP64500Q product line targets high-reliability DC/DC conversion in harsh environments, with emphasis on low IQ, wide VIN range, and EMI-compliant operation for ASIL-B–compatible systems.

FAQ

What input voltage range is supported during evaluation?

The AP64500QSP-EVM accepts 3.8V to 40V DC input, validated per datasheet absolute maximum ratings. For quick-start testing, 12V is recommended; operation up to 40V requires verification of capacitor voltage derating (C1/C2 rated 50V, C5/C6/C13 rated 16V) and thermal margin under full 5A load.

How is output voltage set, and what tolerance is achievable?

Output voltage is set using an external resistor divider (R1/R2) referenced to the 0.8V ±1% internal feedback node. At 5.0V output, R1 = 52.3kΩ and R2 = 10kΩ yield ±1% accuracy under 5A load, confirmed by oscilloscope measurement at VOUT test points with proper probing technique.

Does the board support external clock synchronization?

Yes - the RT/CLK pin (U1 Pin 6) accepts external clock signals from 100kHz to 2.2MHz. Jumper JP1 configures the pin for RT resistor programming or CLK input; when using external sync, R7 (15.8kΩ) must be removed and CLK source coupled through AC-coupling capacitor per Figure 3 schematic.

What protections are implemented and how are they verified?

The board demonstrates UVLO (via EN pin threshold), cycle-by-cycle current limit (observed as duty-cycle foldback during short-circuit), and thermal shutdown (triggered above TJ ≈ 150°C, indicated by output dropout). These are verified using load-step transients, output short tests (Figure 9), and IR thermography on U1's exposed pad during sustained 5A operation.