Microchip Technology AC320004-2

Overview

AC320004-2 from Microchip Technology is an Ethernet PHY daughter board built around the IC Plus IP101G 10/100BASE-TX physical layer transceiver, featuring RMII interface support, integrated 50 MHz clock input capability, and LED status indicators for link/activity. It enables plug-in Ethernet connectivity to Microchip MPLAB® starter kits including PIC32 and dsPIC33 platforms.

For engineers reviewing the AC320004-2 datasheet, AC320004-2 pinout, AC32004-2 application, or AC320004-2 equivalent, this board provides verified RMII-level PHY interfacing, pre-configured PHY address (00001b), and layout-optimized magnetics coupling for rapid evaluation of embedded Ethernet communication in microcontroller-based designs.

Technical Context

The AC320004-2 implements a complete 10/100 Mbps Ethernet PHY interface using the IP101G IC, supporting both MII and RMII modes with configurable LED behavior (LEDMODE = 0). It accepts either internal clocking via XTAL2 or external 50 MHz reference on TXCLK/50M_CLKI.

Signal integrity is maintained through matched-pair differential routing for MDI_TN/TP and MDI_RN/RP, onboard 75 Ω termination resistors, and dedicated EGND copper pour around the RJ-45 connector. The board uses fixed PHY address 00001b set by resistor network R1–R5.

Key Specifications

Availability

AC320004-2 is available at Aetrix Electronics and suitable for embedded Ethernet prototyping, microcontroller starter kit expansion, and industrial edge node development requiring stable component supply and quick-turn evaluation hardware.

Supply support for AC320004-2 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

Microchip Technology Inc. is a U.S.-based semiconductor company specializing in microcontrollers, analog devices, and development tools for embedded control applications.

The AC320004-2 belongs to Microchip's ecosystem of plug-in daughter boards designed to extend starter kit functionality with standardized interfaces-specifically enabling rapid Ethernet integration for PIC32 and dsPIC33-based evaluation platforms.

FAQ

What is the primary function of the AC320004-2?

The AC320004-2 is a daughter board that adds 10/100 Mbps Ethernet PHY capability to Microchip starter kits via RMII interface. It integrates the IP101G transceiver, RJ-45 connector with magnetics, and fixed PHY addressing, allowing immediate Ethernet connectivity without custom PCB design. The AC320004-2 requires no firmware configuration for basic link establishment due to its hardwired address and LED mode.

Which Microchip starter kits are compatible with the AC320004-2?

The AC320004-2 is explicitly validated for use with Microchip MPLAB® Starter Kits based on PIC32 and dsPIC33 microcontrollers, including the PIC32MX Starter Kit and dsPIC33EP Starter Kit. Compatibility relies on matching RMII pinout alignment and +3.3 V power delivery; mechanical fit and header spacing follow Microchip's standard daughter board footprint.

Does the AC320004-2 support MII mode in addition to RMII?

Yes, the AC320004-2 supports both RMII and MII modes via the underlying IP101G PHY, but the board is routed and configured for RMII by default-including 50 MHz clock routing and signal grouping. Switching to MII would require trace modifications and reconfiguration of PHY registers; no jumper or solder bridge enables mode switching on the AC320004-2.

How is the PHY address set on the AC320004-2?

The AC320004-2 uses a fixed PHY address of 00001b (decimal 1), established by resistor network R1–R5 tied to IP101G pins LED0/PHY_AD0 through LED3/PHY_AD3. This eliminates address conflict risk and removes the need for MDIO-based discovery during driver initialization. The AC320004-2 does not provide user-accessible jumpers or DIP switches to alter the address.

Is an external crystal required for the AC320004-2 to operate?

No - the AC320004-2 can operate using either the onboard 50 MHz oscillator circuit (via X1_INPUT/X2_OUTPUT) or an external 50 MHz clock applied to TXCLK/50M_CLKI. The schematic shows X1 as populated with a 50 MHz crystal, but the AC320004-2 functions identically with either source; no crystal is mandatory if the host system supplies a clean 50 MHz reference.