Renesas M37548G3FP#U0

Overview

M37548G3FP#U0 from Renesas Electronics is a single-chip 8-bit CMOS microcontroller based on the 740 family core, featuring 6 KB QzROM, 256 bytes RAM, integrated 10-bit 6-channel A/D converter, UART/clock-synchronous serial interface, and dual-speed on-chip oscillators (4 MHz high-speed, 250 kHz low-speed). It targets embedded control in home appliances and factory automation where LED direct drive, key-on wakeup, and low-voltage detection are required.

For engineers reviewing the M37548G3FP#U0 datasheet, M37548G3FP#U0 pinout, M37548G3FP#U0 application, or M37548G3FP#U0 equivalent, key selection factors include its 20-pin PLSP0020JB-A SSOP package, built-in power-on reset and low-voltage detection circuits, 0.25 µs minimum instruction execution time at 8 MHz (double-speed mode), and support for external ceramic resonator or 32 kHz crystal.

Technical Context

The M37548G3FP#U0 implements the standard 740-family CPU architecture with 71 basic instructions, including MUL/DIV and WIT support but excluding FST/SLW. Its memory map reserves addresses FFD8–FFDA for function set ROM configuration of peripheral modes (e.g., watchdog enable, LVD validity, oscillation mode selection).

Peripheral integration includes three 8-bit timer channels (two 8-bit + one 16-bit), one 16-bit input capture channel, three output compare channels, and an 8-bit serial interface configurable as UART or clock-synchronous mode. All I/O ports - P0 (8-bit LED-drive capable), P1 (6-bit), and P2 (2-bit) - support programmable direction, pull-up resistors, and CMOS 3-state outputs.

Key Specifications

Pinout & Package

Package: 20-pin plastic molded SSOP (PLSP0020JB-A), 0.65 mm pitch, surface-mount compatible.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit microcontroller applications.

Compared with M37548G2FP#U0 and M37548G1FP#U0, the M37548G3FP#U0 provides 6 KB of executable code space - enabling richer feature sets like multi-protocol UART handling, extended calibration tables in ROM, and larger state-machine buffers - while maintaining full hardware compatibility within the 7548 Group.

Availability

M37548G3FP#U0 is available at Aetrix Electronics and suitable for home appliance control, factory automation sensor nodes, and office equipment power management requiring stable component supply across long-lifecycle manufacturing programs.

Supply support for M37548G3FP#U0 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

Renesas Electronics Corporation is a global semiconductor leader specializing in microcontrollers, analog, power, and SoC solutions for industrial, automotive, and consumer markets.

The 7548 Group was designed for cost-sensitive, low-power embedded control applications in home appliances and industrial equipment - emphasizing integrated peripherals (A/D, LED drive, key-wakeup) to minimize external components.

FAQ

What is the maximum operating frequency of the M37548G3FP#U0?

The M37548G3FP#U0 supports a maximum external oscillation frequency of 8 MHz when using a ceramic resonator in double-speed mode. At this frequency, the minimum instruction execution time is 0.25 µs. The internal high-speed oscillator operates at a typical 4 MHz, and the low-speed oscillator at 250 kHz - both usable across the full 1.8–5.5 V supply range. These options allow dynamic clock scaling to balance performance and power consumption in the M37548G3FP#U0.

Does the M37548G3FP#U0 support in-circuit debugging or emulation?

The M37548G3FP#U0 does not integrate on-chip debug circuitry. However, Renesas offers the M37549RLSS emulator MCU in the same 7548 Group, which shares identical pinout and peripheral functionality but replaces QzROM with mask-ROM and adds emulation support. For development, engineers typically use the M37549RLSS with Renesas E8 emulator tools, then migrate final firmware to the production M37548G3FP#U0 device.

How is ROM code protection implemented on the M37548G3FP#U0?

ROM code protection on the M37548G3FP#U0 is controlled by the byte at address FFDB in QzROM. Writing "00" to this location disables serial programming read/write access to the entire ROM area. This setting is applied during final programming at Renesas or via serial programmer configuration. Once enabled, the M37548G3FP#U0 prevents firmware reverse engineering and unauthorized reprogramming - critical for protecting proprietary control algorithms.

Can the M37548G3FP#U0 operate from a 3.3 V supply?

Yes, the M37548G3FP#U0 supports 3.3 V operation when using the internal 250 kHz low-speed oscillator or external 1 MHz ceramic resonator in high-speed mode (1.8–5.5 V range). At 3.3 V, it delivers full functionality including 10-bit A/D conversion, UART communication, and LED drive - making it compatible with modern 3.3 V system rails without level-shifting. Always verify timing margins using the relevant voltage/frequency derating curves from the datasheet for the M37548G3FP#U0.

What peripheral functions are configured via the Function Set ROM in the M37548G3FP#U0?

The Function Set ROM (addresses FFD8–FFDA) in the M37548G3FP#U0 configures hardware behavior at reset: enabling/disabling the watchdog timer, selecting oscillation mode (external crystal vs. on-chip oscillator), enabling/disabling the low-voltage detection circuit, and disabling the STP instruction. These settings are latched at power-up and cannot be altered in runtime - ensuring deterministic startup behavior and eliminating boot-time configuration code overhead in the M37548G3FP#U0.