NXP Semiconductors MC68HC908QY4MDTE

Overview

MC68HC908QY4MDTE from NXP (formerly Freescale) is an 8-bit HCS08-core microcontroller with 4 KB on-chip FLASH, 192 B RAM, and integrated 8-channel 8-bit ADC. It features internal RC oscillator (4 MHz nominal), low-voltage inhibit (LVI), computer operating properly (COP) watchdog, and keyboard interrupt (KBI) module. Designed for cost-sensitive embedded control in appliance panels, industrial sensors, and battery-powered instrumentation.

For engineers reviewing the MC68HC908QY4MDTE datasheet, MC68HC908QY4MDTE pinout, MC68HC908QY4MDTE application, or MC68HC908QY4MDTE equivalent, key selection criteria include its 8-pin SOIC package, 4 MHz internal clock accuracy (±2% over temperature), 8-bit ADC resolution with 10 µs conversion time, KBI wake-on-keypress capability, and COP timeout programmability (1.5–32 ms).

Technical Context

The MC68HC908QY4MDTE implements the M68HC08 CPU core with 16-bit address bus and Harvard architecture. Its oscillator module supports internal RC, external crystal (up to 8 MHz), or external clock input, with automatic failover and trimming via OSCTRIM register at $FFC0. The SIM integrates reset generation, IRQ handling, and clock distribution with BUSCLKX2/BUSCLKX4 outputs.

Memory organization includes 4 KB FLASH (with block protection), 192 B RAM, and dedicated I/O register space ($0000–$00FF). Peripheral modules include TIM (16-bit timer with input capture/output compare), AWU (programmable wake interval from 16 ms to 4 s), and LVI with selectable trip points (3.8 V/4.2 V/4.6 V).

Key Specifications

Pinout & Package

MC68HC908QY4MDTE is housed in an 8-pin SOIC package (case 751BD-02) with 1.27 mm pitch and 3.9 mm body width. Pin functions are shared across PORTA and system control signals, requiring configuration via DDRA and CONFIG registers.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68HC908QY4MDTE, MC9RS08KA2CFD offers reduced BOM cost and power but sacrifices KBI hardware offload, while STM8S003F3P6 provides greater memory and ADC resolution at the expense of added firmware development for keypad management.

Availability

MC68HC908QY4MDTE is available at Aetrix Electronics and suitable for appliance control panels, industrial sensor nodes, and smart power outlets requiring stable component supply and long-term industrial temperature support (–40°C to +85°C).

Supply support for MC68HC908QY4MDTE 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

NXP Semiconductors is a global semiconductor company formed from the spin-off of Philips' semiconductor division, specializing in secure connectivity solutions for automotive, industrial, and IoT markets.

The MC68HC908QY/QT family was designed for ultra-low-cost, low-pin-count embedded control-emphasizing integrated peripherals (KBI, AWU, LVI) to minimize external components in space-constrained applications.

FAQ

What is the maximum operating frequency of the MC68HC908QY4MDTE?

The MC68HC908QY4MDTE operates with a maximum bus clock frequency of 4 MHz using its internal RC oscillator, which is factory-trimmed to ±2% over the full industrial temperature range. When using an external crystal or clock source, the device supports up to 8 MHz input, yielding a 4 MHz bus clock after internal division. The MC68HC908QY4MDTE does not support PLL multiplication or higher-frequency modes beyond this specification.

Does the MC68HC908QY4MDTE support in-circuit programming?

Yes, the MC68HC908QY4MDTE supports in-circuit programming via the MON (Monitor) module using a single-wire background debug interface. Programming requires the MC68HC908QY4MDTE to be held in monitor mode using the BKGD pin and a compatible programmer such as the P&E Micro USB-ML-12. FLASH memory can be reprogrammed multiple times with standard erase/program algorithms defined in the datasheet.

How many ADC channels does the MC68HC908QY4MDTE have, and what is their resolution?

The MC68HC908QY4MDTE integrates an 8-bit successive-approximation ADC with eight input channels (AD0–AD7), though only AD0–AD2 are routed to physical pins (PTA1–PTA3) on the 8-pin SOIC package. The ADC provides ±1 LSB integral nonlinearity and completes conversions in 10 µs per sample, with configurable clock prescaling and single/differential input modes.

Can the MC68HC908QY4MDTE wake from Stop mode using a keyboard interrupt?

Yes, the MC68HC908QY4MDTE can wake from Stop mode using the Keyboard Interrupt (KBI) module. Pins PTA0–PTA3 are configurable as KBI inputs, and the KBI module generates a wake event upon valid edge detection without CPU involvement. This feature enables sub-10 µA standby current in battery-operated systems, with wake latency under 4 µs after key press detection.

What is the purpose of the OSCTRIM register in the MC68HC908QY4MDTE?

The OSCTRIM register (located at address $FFC0) allows fine adjustment of the internal RC oscillator frequency by modifying the oscillator's bias current. Factory trimming sets the default value for ±2% accuracy; users may re-trim during production calibration or field compensation. Writing to OSCTRIM dynamically adjusts INTCLK frequency without requiring a reset, enabling real-time clock accuracy optimization in the MC68HC908QY4MDTE.