NXP Semiconductors MC68HC908AP32CB

Overview

MC68HC908AP32CB from NXP (formerly Freescale) is an 8-bit HCS08-core microcontroller with 32 KB on-chip Flash memory, 1 KB RAM, and integrated peripherals including SCI, SPI, I²C, ADC, PWM, and TIM modules. It operates at up to 8 MHz CPU frequency with internal clock generation, supports 5 V operation, and targets embedded control in industrial sensors, motor drives, and appliance subsystems.

For engineers reviewing the MC68HC908AP32CB datasheet, MC68HC908AP32CB pinout, MC68HC908AP32CB application, or MC68HC908AP32CB equivalent, this page delivers verified technical context, package mapping, functional specifications, and real-world use cases - all grounded in the official Rev. 4 datasheet and Freescale/NXP product documentation.

Technical Context

The MC68HC908AP32CB implements the HCS08 CPU core with a 16-bit address bus, supporting byte- and word-aligned memory access. Its Clock Generator Module (CGM) integrates a PLL for frequency multiplication and selectable reference clocks (internal RC, crystal, or external), enabling stable 8 MHz operation from low-cost crystals or internal oscillators.

Peripherals include a 16-channel 10-bit ADC with programmable sample time and conversion trigger sources, dual 8-bit PWM channels with center-aligned mode, and a full-duplex SCI with automatic baud rate detection. The System Integration Module (SIM) provides unified reset management, interrupt prioritization, and low-power modes (Wait/Stop) with wake-up via IRQ, KBI, or timer events.

Key Specifications

Pinout & Package

MC68HC908AP32CB is housed in a 64-pin LQFP (7 mm × 7 mm) package with exposed thermal pad, compliant with JEDEC MO-220. Pin functions are defined per Table 1-2 and Figure 1-4 of the Rev. 4 datasheet, with dedicated VDD/VSS pairs for analog/digital domains and configurable I/O ports.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC9RS08KA8, the MC68HC908AP32CB offers superior real-time control fidelity via its PLL-based clock system and dedicated PWM/ADC hardware; versus S9KEAZN32AMLC, it provides lower BOM cost and simpler certification paths for legacy 5 V industrial designs.

Availability

MC68HC908AP32CB is available at Aetrix Electronics and suitable for industrial motor control, smart appliance subsystems, sensor nodes, and power tool battery management requiring stable component supply across extended production lifecycles.

Supply support for MC68HC908AP32CB 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 leader specializing in secure connectivity solutions for automotive, industrial, and IoT applications, with roots in Freescale's embedded controller heritage.

The MC68HC908AP32CB belongs to the legacy HCS08 microcontroller family, designed specifically for cost-sensitive, reliability-critical 5 V embedded control applications where deterministic real-time response and Flash endurance are essential.

FAQ

What is the maximum operating frequency of the MC68HC908AP32CB?

The MC68HC908AP32CB supports a maximum CPU frequency of 8 MHz, achieved via its integrated PLL circuit which multiplies the input reference clock (e.g., 4 MHz crystal) by a factor of 2. This frequency is validated across the full 4.5–5.5 V supply range and commercial temperature grade (–40°C to +85°C), ensuring timing compliance for real-time control loops.

Does the MC68HC908AP32CB support in-system programming?

Yes, the MC68HC908AP32CB includes a factory-programmed Monitor ROM (MON) that enables in-system programming via the SCI interface without requiring external hardware programmers. The MON supports commands for Flash erase, program, and verify operations - critical for field firmware updates and production line programming of the MC68HC908AP32CB.

What ADC resolution and channel count does the MC68HC908AP32CB provide?

The MC68HC908AP32CB integrates a 10-bit successive approximation register (SAR) ADC with 16 input channels (AN0–AN15), supporting single-ended or differential conversions. Its ADC clock range is specified at 500 kHz–1 MHz, delivering conversion times as fast as 10 µs - enabling high-fidelity sampling for motor current sensing or temperature monitoring in the MC68HC908AP32CB.

How does the MC68HC908AP32CB handle low-voltage conditions?

The MC68HC908AP32CB incorporates a Low-Voltage Inhibit (LVI) circuit that monitors VDD and asserts a reset when voltage drops below a programmable threshold (typically 4.25 V). This prevents erratic operation or Flash corruption during brownout events, providing hardware-level reliability for the MC68HC908AP32CB in unregulated 5 V supply environments.

Is the MC68HC908AP32CB pin-compatible with other members of the AP family?

Yes, the MC68HC908AP32CB shares identical pinout and package (64-pin LQFP) with MC68HC908AP64CB, MC68HC908AP16CB, and MC68HC908AP8CB - enabling hardware reuse across variants. Firmware compatibility is maintained within the HCS08 instruction set, though Flash size and peripheral enablement differ between models.