NXP Semiconductors MC908JK3ECDWE

Overview

MC908JK3ECDWE from Freescale Semiconductor is an 8-bit HCS08-core microcontroller with 4 KB flash memory, 192 B RAM, and integrated 8-channel 8-bit ADC. It operates at up to 8 MHz bus frequency, supports on-chip COP watchdog and low-power wait/stop modes, and targets embedded control in automotive body electronics and industrial sensor interfaces.

For engineers reviewing the MC908JK3ECDWE datasheet, MC908JK3ECDWE pinout, MC908JK3ECDWE application, or MC908JK3ECDWE equivalent, key selection criteria include its 20-pin SOIC-W package, internal RC oscillator option (±2% accuracy), 5 V operation, and compatibility with Freescale's MON monitor ROM for in-system programming and debug.

Technical Context

The MC908JK3ECDWE implements the HCS08 CPU core with a 16-bit address bus, supporting indexed, extended, and relative addressing. Its System Integration Module (SIM) provides clock generation, reset control, interrupt management, and low-power mode coordination across all peripherals.

It integrates a Timer Interface Module (TIM) with two input-capture/output-compare channels and PWM capability, plus a Keyboard Interrupt Module (KBI) for matrix scanning. The ADC features programmable conversion speed (10–32 µs), software-triggered acquisition, and dedicated interrupt flag per channel.

Key Specifications

Pinout & Package

MC908JK3ECDWE is housed in a 20-pin SOIC-W (Small Outline Integrated Circuit – Wide) package with 0.600-inch body width and 0.050-inch lead pitch. Pin layout follows Freescale's standard J-series 20-pin assignment for HCS08 derivatives.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC908JK3ECDWE, the JK1E offers lower memory and no ADC for cost-driven digital-only use cases, while the JL3E provides expanded analog and I/O resources for more demanding sensing applications - both share identical 20-pin SOIC-W packaging and HCS08 core compatibility.

Availability

MC908JK3ECDWE is available at Aetrix Electronics and suitable for automotive body electronics, industrial temperature controllers, and smart appliance control boards requiring stable component supply and long-term manufacturing continuity.

Supply support for MC908JK3ECDWE 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

Freescale Semiconductor (now part of NXP Semiconductors) is a global leader in embedded processing, delivering scalable MCU, MPU, and analog solutions for automotive, industrial, and consumer markets.

The MC908JK3ECDWE belongs to the HCS08-based 908JKx family, designed specifically for cost-sensitive, low-power embedded control applications where integration of ADC, KBI, and MON debug simplifies system architecture.

FAQ

What is the maximum operating frequency of the MC908JK3ECDWE?

The MC908JK3ECDWE supports a maximum bus frequency of 8 MHz, derived from its internal oscillator or external crystal. This yields approximately 4 million instructions per second (MIPS), sufficient for real-time control of motors, sensors, and user interfaces without external acceleration. The actual achievable frequency depends on VDD stability and ambient temperature, with full specification guaranteed across the 4.5–5.5 V and –40°C to +85°C range.

Does the MC908JK3ECDWE include an analog-to-digital converter?

Yes, the MC908JK3ECDWE integrates an 8-channel, 8-bit successive-approximation ADC with programmable conversion time (10–32 µs). Channels map to PTD2–PTD3 and PTB0–PTB3, enabling direct connection to thermistors, potentiometers, or voltage dividers. Conversion can be triggered by software, timer overflow, or external event - making it suitable for synchronized sensor acquisition in control loops.

Can the MC908JK3ECDWE operate without an external crystal?

Yes, the MC908JK3ECDWE supports an internal factory-trimmed RC oscillator running at 4.2 MHz with ±2% accuracy over temperature and voltage. This eliminates the need for an external crystal in applications where precise timing is not required - such as basic I/O control or non-critical PWM generation - reducing BOM cost and PCB area.

What debug and programming interface does the MC908JK3ECDWE provide?

The MC908JK3ECDWE includes an on-chip Monitor ROM (MON) that enables UART-based in-system programming and debugging using only three pins: TXD, RXD, and RESET. No external programmer is needed - firmware updates and register inspection can be performed directly through a standard serial interface, significantly accelerating development and field maintenance cycles for the MC908JK3ECDWE.

Is the MC908JK3ECDWE pin-compatible with other members of the 908Jx family?

Yes, the MC908JK3ECDWE shares identical 20-pin SOIC-W packaging and pin assignments with MC908JK1ECDWE and MC908JL3ECDWE. This allows direct substitution within the same footprint for memory or feature scaling - for example, upgrading from JK1E (2 KB flash, no ADC) to MC908JK3ECDWE (4 KB flash, 8-channel ADC) without PCB redesign.