NXP Semiconductors MC68HC908QT1VPE

Overview

MC68HC908QT1VPE from NXP (formerly Freescale) is an 8-bit HCS08-core microcontroller with 1 KB FLASH, 64 bytes RAM, and integrated 8-channel 8-bit ADC, designed for cost-sensitive embedded control in appliance motor drives and industrial sensor interfaces. It operates at up to 8 MHz bus frequency, supports internal RC oscillator with ±2% accuracy after trimming, and features low-voltage inhibit (LVI), COP watchdog, and keyboard interrupt module.

For engineers reviewing the MC68HC908QT1VPE datasheet, MC68HC908QT1VPE pinout, MC68HC908QT1VPE application, or MC68HC908QT1VPE equivalent, key selection criteria include its 8-pin SOIC package, single-supply 2.7–5.5 V operation, on-chip oscillator trim register (OSCTRIM), and support for WAIT/STOP low-power modes with wake-up via IRQ, KBI, or AWU.

Technical Context

The MC68HC908QT1VPE implements the M68HC08 CPU core with 16-bit address space, 8-bit data path, and Harvard architecture memory map. Its oscillator module supports internal RC, external crystal (XTAL), or external clock input, with automatic switching between internal and external sources upon reset or configuration change.

System integration includes a 16-bit Timer Interface Module (TIM) with input capture/output compare, an Auto Wakeup Module (AWU) with programmable 1–1024 ms intervals, and a Low-Voltage Inhibit (LVI) circuit with selectable trip points (4.0 V or 3.0 V) and hysteresis.

Key Specifications

Pinout & Package

MC68HC908QT1VPE is housed in an 8-pin SOIC (Small Outline Integrated Circuit) package with 1.27 mm pitch, compliant with JEDEC MS-012AC, suitable for automated PCB assembly and space-constrained designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC9RS08KA2CP and STM8S003F3P6, the MC68HC908QT1VPE offers unique oscillator trimming and keyboard interrupt support in an 8-pin SOIC footprint, making it optimal for legacy-compatible, ultra-low-cost sensor and appliance control where minimal external components are critical.

Availability

MC68HC908QT1VPE is available at Aetrix Electronics and suitable for home appliance control, industrial sensor interface, motor drive feedback, and smart power outlet applications requiring stable component supply across long product lifecycles.

Supply support for MC68HC908QT1VPE 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, now specializing in secure connectivity solutions for automotive, industrial, and IoT markets.

The MC68HC908QT1VPE belongs to the legacy HCS08 microcontroller family, designed for cost-optimized, low-pin-count embedded control in appliances, power tools, and industrial subsystems where reliability and long-term availability are essential.

FAQ

What is the maximum operating frequency of the MC68HC908QT1VPE?

The MC68HC908QT1VPE supports a maximum bus frequency of 8 MHz when powered at VDD ≥ 4.5 V. At lower supply voltages (2.7–4.4 V), the maximum bus frequency is reduced to 4 MHz per electrical specifications. This frequency determines instruction execution speed and peripheral timing - for example, a 8 MHz bus yields a 125 ns minimum instruction cycle time for real-time control tasks. The actual clock source may be the internal RC oscillator, external crystal, or external clock signal, selected via CONFIG1 register bits.

Does the MC68HC908QT1VPE support in-circuit programming?

Yes, the MC68HC908QT1VPE supports in-system programming (ISP) via its single-wire background debug interface (BDM). Using a compatible BDM pod or debugger, users can erase, program, and verify the 1 KB FLASH memory without removing the device from the target PCB. Programming requires VDD = 4.5–5.5 V and adherence to timing requirements specified in Chapter 15 of the datasheet. The FLBPR register allows selective protection of FLASH blocks to prevent accidental overwrite during field updates.

How does the oscillator trimming function work on the MC68HC908QT1VPE?

The MC68HC908QT1VPE includes an 8-bit Oscillator Trim Register (OSCTRIM) located at memory address $FFC0. During manufacturing, this register is pre-programmed with a value that adjusts the internal RC oscillator's frequency to ±2% accuracy at 25°C. Users can re-trim the oscillator in-system by writing new values to OSCTRIM and measuring resulting bus clock deviation - for example, using a timer capture input or external frequency counter. The trim value affects only the internal RC oscillator; crystal-based operation remains unaffected.

Can the MC68HC908QT1VPE wake up from STOP mode using analog input events?

No, the MC68HC908QT1VPE cannot wake up directly from STOP mode based on ADC conversion completion or analog threshold crossing. Wake-up sources from STOP mode are limited to external IRQ, keyboard interrupt (KBI0/KBI1), auto wakeup timer (AWU), or reset. However, the ADC can be configured to trigger an interrupt upon conversion completion in WAIT mode, and the device can then enter STOP mode after processing - but analog event detection itself does not initiate wake-up from full STOP.

What packaging and temperature grade does the MC68HC908QT1VPE carry?

The MC68HC908QT1VPE is supplied in an 8-pin SOIC (Small Outline Integrated Circuit) package with 1.27 mm lead pitch, per JEDEC standard MS-012AC. Its "VPE" suffix denotes the commercial temperature grade (0°C to +70°C) and Pb-free (RoHS-compliant) finish. This package is compatible with standard surface-mount reflow processes and supports hand-soldering with appropriate thermal profiling. No industrial (–40°C to +85°C) or extended temperature variants exist for this specific part number.