NXP Semiconductors MCHC705JP7CDWE

Overview

MCHC705JP7CDWE from Freescale Semiconductor is a 8-bit HCMOS microcontroller featuring 4 KB on-chip EPROM, 192 bytes RAM, 28-pin SOIC package, and integrated analog subsystem including dual voltage comparators, 8-channel 8-bit ADC, and programmable current source. It operates at up to 4 MHz with 5 V supply and supports automotive and industrial control applications requiring low-power operation and mixed-signal integration.

For engineers reviewing the MCHC705JP7CDWE datasheet, MCHC705JP7CDWE pinout, MCHC705JP7CDWE application, or MCHC705JP7CDWE equivalent, key selection criteria include its 28-pin SOIC footprint, 4 KB EPROM/192 B RAM memory map, dual comparator + 8-bit ADC analog capability, COP watchdog reset, and SIOP serial interface compatibility with legacy HC05 systems.

Technical Context

The MCHC705JP7CDWE implements the MC68HC05 CPU core with accumulator-based architecture, 16-bit address space, and instruction set backward-compatible with MC6805. It integrates a 16-bit programmable timer with input capture and output compare functions, plus a dedicated core timer with real-time interrupt capability.

Analog functionality includes two independent voltage comparators (CMP1/CMP2), an 8-channel analog multiplexer, sample-and-hold circuitry, internal temperature sensing diode, and ratiometric/absolute voltage measurement modes-all controlled via dedicated analog registers (AMUXR, ACR, ASR) and accessible through Port B pins PB4–PB7.

Key Specifications

Pinout & Package

Package: 28-pin SOIC (Small Outline Integrated Circuit), 300 mil body width, gull-wing leads, RoHS-compliant lead finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68HC705JB8CP and MC68HC705P6M, the MCHC705JP7CDWE provides the largest on-chip EPROM (4 KB) in the 28-pin SOIC HC705 family, retains both voltage comparators, and uniquely supports SIOP-making it the most feature-complete option for new designs requiring analog integration and serial expandability.

Availability

MCHC705JP7CDWE is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor nodes, appliance motor controllers, and legacy PLC I/O modules requiring stable component supply and long-term obsolescence management.

Supply support for MCHC705JP7CDWE 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, analog, and power management ICs for automotive, industrial, and consumer markets.

The MC68HC705 family was engineered for cost-sensitive, low-power 8-bit control applications where analog integration, EEPROM/EPROM programmability, and robust reset architecture were essential-targeting automotive sub-systems and industrial equipment.

FAQ

What is the maximum operating frequency of the MCHC705JP7CDWE?

The MCHC705JP7CDWE supports a maximum external clock frequency of 4 MHz when using a crystal or ceramic resonator on OSC1/OSC2. This corresponds to an instruction execution rate of approximately 1 million instructions per second (MIPS), consistent with the MC68HC05 core architecture. The device does not include an internal RC oscillator, so timing accuracy depends entirely on the external timing source connected to the oscillator pins. MCHC705JP7CDWE must be operated within its specified 4.5–5.5 V supply range to guarantee timing compliance across the full temperature range.

Does the MCHC705JP7CDWE support in-circuit programming?

No, the MCHC705JP7CDWE does not support in-circuit programming. Its on-chip EPROM requires 12.5 V applied to the IRQ/VPP pin during programming, which necessitates a dedicated EPROM programmer with high-voltage capability. The device lacks ISP (In-System Programming) or bootloader functionality. Firmware updates require removal from the PCB and programming in a socketed programmer. MCHC705JP7CDWE programming is a one-time process unless erasure via UV light is performed-but the SOIC package is not windowed, making UV erasure impossible. Therefore, the EPROM content is effectively permanent after initial programming.

How many analog input channels does the MCHC705JP7CDWE support?

The MCHC705JP7CDWE supports eight analog input channels (AN0–AN7), mapped to Port B pins PB0–PB7. Channels AN0–AN3 are routed exclusively to PB0–PB3; AN4 is on PB4; AN5–AN7 are on PC0–PC2 (Port C). All channels feed into the same 8-bit successive-approximation ADC, with conversion time of 44 µs typical at 4 MHz. The analog subsystem also includes dual independent voltage comparators (CMP1/CMP2), each with configurable hysteresis and interrupt generation-functionally distinct from the ADC but sharing some analog routing resources. MCHC705JP7CDWE uses a single ADC module shared across all channels, not parallel converters.

What low-power modes are available on the MCHC705JP7CDWE?

The MCHC705JP7CDWE offers four hardware-supported low-power modes: Stop, Wait, Halt, and Data-Retention. In Stop mode, the oscillator halts, CPU and peripherals freeze, and current drops to ≤10 µA while retaining RAM and register contents. Wait mode stops the CPU but keeps the oscillator and selected peripherals (e.g., timer, SIOP) active. Halt mode disables the oscillator but maintains register state. Data-Retention mode powers down most circuitry except RAM and reset logic, drawing ~1 µA. All modes are entered via STOP, WAIT, or HALT instructions and exited by RESET, IRQ, or internal timer events. MCHC705JP7CDWE's low-power capability makes it suitable for battery-backed or energy-constrained industrial sensors.

Is the MCHC705JP7CDWE pin-compatible with other MC68HC705 variants?

The MCHC705JP7CDWE is pin-compatible with the MC68HC705JP7 and MC68HRC705JP7 in the 28-pin SOIC package, sharing identical pinout, electrical characteristics, and memory map. It is not pin-compatible with 20-pin (e.g., JB8) or 24-pin (e.g., JJ7) variants due to differing pin counts and Port C presence. Port C (PC0–PC7) is exclusive to 28-pin versions and absent in smaller packages. While functional overlap exists with MC68HC705SP7 (same package), differences in EPROM size (4 KB vs. 2 KB) and analog features (dual vs. single comparator) affect interchangeability. MCHC705JP7CDWE should be verified against target PCB layout before substitution-even within the JP7 family.