NXP Semiconductors MC68HC908JK1ECDW

Overview

MC68HC908JK1ECDW from NXP (formerly Freescale) is an 8-bit HCS08-core microcontroller with 1 KB on-chip FLASH, 64 bytes RAM, and integrated peripherals including a 6-channel 8-bit ADC, TIM module with PWM and input capture, KBI, COP watchdog, and LVI voltage monitor. It operates at up to 8 MHz bus frequency and targets low-cost embedded control in appliance motor drives and industrial sensor interfaces.

For engineers reviewing the MC68HC908JK1ECDW datasheet, MC68HC908JK1ECDW pinout, MC68HC908JK1ECDW application, or MC68HC908JK1ECDW equivalent, key selection criteria include its 20-pin SOIC package, 5 V operation, FLASH programmability in-system, single-supply ADC reference, and support for wait/stop low-power modes - all critical for cost-sensitive, battery-aware, or thermally constrained designs.

Technical Context

The MC68HC908JK1ECDW implements the HCS08 CPU core with 16-bit address space, indexed addressing, and 72-instruction set optimized for compact code size. Its System Integration Module (SIM) provides clock generation from internal RC or external crystal oscillator, reset supervision, and interrupt vectoring with priority-based hardware arbitration across IRQ, KBI, TIM, and ADC sources.

Peripheral integration includes a 6-channel analog-to-digital converter with 8-bit resolution and software-selectable conversion time (16–64 µs), a Timer Interface Module supporting unbuffered/buffered output compare, input capture, and PWM with configurable period and duty cycle, plus dedicated Keyboard Interrupt logic for matrix scanning with automatic debouncing and wake-on-key detection.

Key Specifications

Pinout & Package

MC68HC908JK1ECDW is housed in a 20-pin Small Outline Integrated Circuit (SOIC) package with 0.300-inch body width and standard 0.050-inch pitch, suitable for automated PCB assembly and space-constrained applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68HC908JK3ECDW and MC9RS08KA2CSCR, the MC68HC908JK1ECDW offers lowest BOM cost and proven reliability in legacy 5 V control systems, while trading off memory headroom and mixed-voltage flexibility for simplicity and long-term supply stability.

Availability

MC68HC908JK1ECDW is available at Aetrix Electronics and suitable for appliance motor control, industrial sensor interface, consumer remote keypad, and power supply monitoring requiring stable component supply and long-lifecycle support.

Supply support for MC68HC908JK1ECDW 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 focused on secure connectivity solutions for automotive, industrial, and IoT applications, with deep heritage in 8-bit microcontroller innovation.

The MC68HC908JK1ECDW belongs to the HCS08 family designed specifically for cost-optimized, low-power embedded control in white goods, power tools, and building automation systems.

FAQ

What is the maximum operating frequency of the MC68HC908JK1ECDW?

The MC68HC908JK1ECDW supports a maximum bus frequency of 8 MHz, achieved using either the internal RC oscillator (±2% accuracy) or an external crystal up to 8 MHz. This frequency determines instruction execution speed and peripheral timing resolution, enabling sub-125 µs interrupt latency and precise PWM generation for motor control applications. The actual core clock is derived from the bus clock via internal divider logic.

Does the MC68HC908JK1ECDW support in-system programming (ISP)?

Yes, the MC68HC908JK1ECDW supports in-system programming via its on-chip Monitor ROM, accessible through the single-wire background debug interface using the BKGD pin. Firmware updates can be performed without removing the device from the PCB, using standard UART-level signals and Freescale's BDM protocol. This capability is fully implemented in the MC68HC908JK1ECDW and requires no external programming hardware beyond a level-shifter.

How many analog input channels does the MC68HC908JK1ECDW ADC support?

The MC68HC908JK1ECDW integrates a 6-channel 8-bit analog-to-digital converter, with input channels mapped directly to Port A pins PTA0 through PTA5. Each channel supports single-ended measurement referenced to the internal 2.5 V bandgap or external VREFH/VREFL pins. Conversion time is software-selectable between 16 µs and 64 µs, allowing trade-offs between speed and noise immunity in the MC68HC908JK1ECDW design.

What low-power modes are available on the MC68HC908JK1ECDW?

The MC68HC908JK1ECDW provides two hardware-supported low-power states: Wait mode (CPU halted, peripherals active, ~100 µA typical) and Stop mode (all clocks stopped except LVI and IRQ wake sources, ~0.5 µA typical). Both modes retain RAM contents and allow wake-up via IRQ, KBI, or TIM overflow. These modes are fully documented for the MC68HC908JK1ECDW and require no external components to achieve specified current draw.

Is the MC68HC908JK1ECDW pin-compatible with other HCS08 family members?

The MC68HC908JK1ECDW uses a 20-pin SOIC package with a defined pinout shared across the JK1/JK3/JL3 variants, making it pin-compatible with MC68HC908JK3ECDW and MC68HC908JL3ECDW. However, differences in FLASH size, ADC channel count, and peripheral enable bits mean firmware is not interchangeable without modification. Pin compatibility applies strictly to the MC68HC908JK1ECDW physical layout and electrical I/O mapping.