NXP Semiconductors MC68HC705JP7CDW

Overview

MC68HC705JP7CDW from Freescale Semiconductor is a 8-bit HCMOS microcontroller featuring 4 KB on-chip EPROM, 128 bytes RAM, a 16-bit programmable timer, analog subsystem with dual voltage comparators and 8-channel 8-bit ADC, and SIOP serial interface. It operates at up to 4 MHz with internal oscillator options and supports low-power wait/stop modes. Used in embedded control systems such as appliance motor controllers and industrial sensor interfaces.

For engineers reviewing the MC68HC705JP7CDW datasheet, MC68HC705JP7CDW pinout, MC68HC705JP7CDW application, or MC68HC705JP7CDW equivalent, key selection criteria include its 28-pin SOIC-W package, PB0–PB7 and PC0–PC7 I/O mapping, COP watchdog reset capability, analog input multiplexing, and EPROM-based firmware retention without external memory.

Technical Context

This device belongs to the M68HC05 family and implements a Harvard architecture CPU with accumulator/index register design, supporting 59 instructions and multiple addressing modes including indexed and relative. Its analog subsystem integrates two independent voltage comparators (CMP1/CMP2), an 8-channel analog multiplexer, and sample-and-hold circuitry for precise A/D conversion.

The SIOP synchronous serial interface uses PB5 (SDO), PB6 (SDI), and PB7 (SCK) pins for master/slave communication with configurable clock polarity and phase. The 16-bit programmable timer supports input capture, output compare, and overflow interrupts, while the core timer provides real-time interrupt and COP watchdog functionality.

Key Specifications

Pinout & Package

MC68HC705JP7CDW is housed in a 28-pin SOIC-W (Wide) package with 1.27 mm pitch, designed for surface-mount assembly and thermal reliability in industrial environments.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68HC705P6CDW and MC68HC705C8CDW, the MC68HC705JP7CDW offers balanced memory size, full 28-pin I/O expansion including port C, and integrated SIOP - making it optimal for mid-complexity embedded systems needing analog sensing, serial reporting, and firmware persistence without external memory.

Availability

MC68HC705JP7CDW is available at Aetrix Electronics and suitable for appliance motor control, industrial sensor interfacing, smart power metering, and consumer electronics remote control requiring stable component supply across extended production lifecycles.

Supply support for MC68HC705JP7CDW 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) pioneered 8-bit microcontroller architectures for cost-sensitive embedded applications with robust industrial qualification.

The MC68HC705JP7CDW belongs to the M68HC05 family, designed specifically for resource-constrained control systems requiring integrated analog peripherals, low-power operation, and field-programmable EPROM in compact packages.

FAQ

What is the maximum operating frequency of the MC68HC705JP7CDW?

The MC68HC705JP7CDW supports a maximum internal bus frequency of 4 MHz when driven by an external crystal or resonator. This corresponds to a 2 MHz core clock in the M68HC05 architecture due to its two-phase clocking scheme. Operation above this frequency risks timing violations in instruction fetch and peripheral access cycles, and is not supported per Freescale's Advance Information Data Sheet Rev. 4.1.

Does the MC68HC705JP7CDW support in-circuit programming?

No, the MC68HC705JP7CDW does not support in-circuit programming. EPROM programming requires applying 12.5 V to the IRQ/VPP pin using a dedicated programmer, with VDD at 5.0 V and specific timing sequences defined in Chapter 13 of the datasheet. The device lacks ISP (in-system programming) capability and must be programmed before soldering or removed for reprogramming.

How many analog input channels does the MC68HC705JP7CDW support?

The MC68HC705JP7CDW supports eight analog input channels via its integrated 8-bit successive-approximation ADC. These are selected using the Analog Multiplex Register (AMUX) and mapped to pins PB0–PB3 and PB4/AN4, plus internal references. Channel selection is software-controlled, enabling flexible routing of external signals or internal diagnostics like temperature sensing.

What low-power modes are available on the MC68HC705JP7CDW?

The MC68HC705JP7CDW provides four low-power modes: Wait (CPU halted, peripherals active), Stop (all clocks stopped except real-time interrupt source), Halt (deep sleep with RAM retention), and Data-Retention (VDD ≥ 2.0 V, RAM preserved, minimal current). In Stop mode, typical current consumption drops below 10 µA, making it suitable for battery-backed applications where periodic wake-up is required.

Is the MC68HC705JP7CDW pin-compatible with other members of the M68HC05 family?

The MC68HC705JP7CDW is pin-compatible with other 28-pin SOIC-W variants in the M68HC05 family, including MC68HC705SP7 and MC68HC705SJ7, sharing identical port pinouts and power/ground locations. However, functional differences exist - e.g., MC68HC705SJ7 lacks port C and has reduced analog features - so firmware and peripheral initialization must be validated per device variant.