NXP Semiconductors MC68HC705P6ACDW

Overview

MC68HC705P6ACDW from Freescale Semiconductor is a 8-bit EPROM-based microcontroller in the M68HC05 family, featuring a 16-bit timer with input capture/output compare, 4-channel 8-bit ADC, SIOP serial interface, COP watchdog, 4672 bytes of user EPROM, 176 bytes RAM, and 21 I/O pins (20 bidirectional + 1 input-only) in a 28-pin SOIC package. It targets cost-sensitive embedded control applications such as appliance motor control and industrial sensor interfaces.

For engineers reviewing the MC68HC705P6ACDW datasheet, MC68HC705P6ACDW pinout, MC68HC705P6ACDW application, or MC68HC705P6ACDW equivalent, key selection considerations include its 5 V operation, bootloader ROM support, mask option register configurability (COP enable/disable, SIOP MSB/LSB order), static EPROM security options, and compatibility with legacy HC05 toolchains and development environments.

Technical Context

The MC68HC705P6ACDW implements the M68HC05 CPU core with 176 bytes of on-chip RAM and 4672 bytes of user EPROM, executing instructions at up to 2 MHz bus clock (f_op = f_osc/2). Its analog subsystem integrates a ratiometric 4-channel 8-bit ADC with VREFH reference input and configurable conversion timing.

It supports three low-power modes-STOP, HALT, and WAIT-with configurable wake-up sources including IRQ, timer overflow, and input capture events. The SIOP serial port operates with programmable clock dividers (OSC/8, /16, /32, /64) and supports both MSB-first and LSB-first data ordering via MOR configuration.

Key Specifications

Pinout & Package

MC68HC705P6ACDW is housed in a 28-pin Small Outline Integrated Circuit (SOIC) package (Case 751F), compliant with JEDEC MS-012 standards and suitable for automated PCB assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68HC705P6CDW and MC68HC705P6AMDW, the MC68HC705P6ACDW offers optimal cost and manufacturability for commercial-temperature SMT production, balancing thermal margin, package density, and supply chain availability.

Availability

MC68HC705P6ACDW is available at Aetrix Electronics and suitable for home appliance control, industrial sensor interface, and automotive body control applications requiring stable component supply across multi-year production cycles.

Supply support for MC68HC705P6ACDW 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) was a leading designer of embedded processors and analog/mixed-signal ICs, known for the 68HC05 and 68HC11 microcontroller families.

The MC68HC705P6ACDW belongs to the M68HC05 microcontroller product line, designed for cost-sensitive, low-pin-count embedded control applications where EPROM programmability, integrated peripherals, and toolchain maturity were critical.

FAQ

What is the maximum operating frequency of the MC68HC705P6ACDW?

The MC68HC705P6ACDW supports an oscillator frequency up to 4 MHz, yielding a 2 MHz internal bus clock (f_op = f_osc/2). This timing is specified in Chapter 14 Electrical Specifications and validated across the 0°C to +70°C commercial temperature range. The MC68HC705P6ACDW must be operated within these limits to ensure reliable instruction execution and peripheral timing compliance.

Does the MC68HC705P6ACDW include on-chip debug or programming capability?

The MC68HC705P6ACDW does not feature on-chip debug circuitry like BDM or JTAG. However, it includes 239 bytes of bootloader ROM that enables in-system EPROM programming via the SIOP serial interface using an external host. Programming requires applying 12.5 V to the IRQ/VPP pin and following the sequence defined in Chapter 10 EPROM.

How is the analog-to-digital converter configured on the MC68HC705P6ACDW?

The MC68HC705P6ACDW integrates a ratiometric 4-channel 8-bit ADC. Inputs are mapped to PC0–PC3 (AD0–AD3), with PC7 serving as the VREFH reference voltage input. Conversion is controlled by the A/D Status and Control Register (ADSC), and results are read from the A/D Conversion Data Register (ADC). Reference voltage accuracy directly impacts measurement linearity and full-scale range.

Can the MC68HC705P6ACDW operate from a 3.3 V supply?

No - the MC68HC705P6ACDW is specified only for 5.0 V ±10% operation (4.5 V to 5.5 V). Chapter 14 Electrical Specifications lists no 3.3 V DC characteristics. Attempting 3.3 V operation will result in undefined behavior, failed resets, or inability to program EPROM. For 3.3 V systems, consider later-generation HC08 or S08 devices.

What packaging options are available for the MC68HC705P6ACDW?

The MC68HC705P6ACDW is specifically offered in a 28-pin Small Outline Integrated Circuit (SOIC) package (Case 751F). Other variants exist - e.g., MC68HC705P6AMDW in PDIP and MC68HC705P6CDW in SOIC with extended temperature rating - but the "C" suffix in MC68HC705P6ACDW denotes commercial temperature and SOIC packaging per Freescale's ordering nomenclature.