MC68HSC705J1ACP - 8-Bit 4MHz HC05 1.2KB OTP MCU | Freescale
MPN: MC68HSC705J1ACP ✗ Cuối đờiMC68HSC705J1ACP Tóm tắt
What is an HC05 microcontroller? The Freescale/Motorola HC05 (sometimes written HC-05) is a long-established family of 8-bit microcontrollers based on a 6800-derived 6805 CPU core. HC05 devices typically combine mask-ROM, EPROM, or OTP program memory, on-chip RAM, multiple parallel I/O ports, a timer subsystem, and a SCI (serial communications interface) on a single die. The HSC (High-Speed CMOS) prefix specifically denotes the HCMOS fabrication process that enabled higher clock rates, lower quiescent draw, and better noise immunity versus earlier NMOS HC05 parts. Historically the family sits in the broader taxonomy 8-bit MCU -> microcontroller -> embedded controller -> semiconductor.
Key features for the MC68HSC705J1ACP include a 4MHz maximum bus frequency, 1.2KB of OTPROM for field-programmable code storage, an integrated 16-bit multi-function timer with programmable prescaler, a full-duplex SCI for asynchronous serial communication, a fixed bidirectional port A (4 bits) and port B (8 bits), plus an external interrupt pin and a COP (computer operating properly) watchdog for safe operation. The 20-pin PDIP footprint is a legacy through-hole form factor well suited to prototyping, hobby projects, and legacy equipment repair.
Architecturally, the device uses the 6805 CPU with a simple two-stage instruction pipeline and supports BCD arithmetic, multiply and 8x8 unsigned multiply instructions. Memory is organized in a single linear address space with the OTPROM mapped at specific addresses and a small user RAM reserved for stack and variables. The OTPROM is programmed via the bootstrap mode, and once locked the part behaves like a mask-ROM part with the same timing characteristics.
Typical applications include white-goods and appliance control boards (washing machines, microwave ovens, air conditioners), low-cost remote-control transmitters/receivers, simple sensor-conditioning nodes, instrumentation panels, battery chargers and small appliance user interface controllers, and educational or hobby microcontroller boards where the well-documented HC05 toolchain is preferred. It is also routinely used as a drop-in replacement for the mask-ROM MC6805J1A in legacy designs.
Design consideration: the HSC variant has higher quiescent current than the original HC05J1A; engineers should re-evaluate battery-life budgets when migrating between HSC and HC variants in portable applications. The 20-pin PDIP package simplifies hand-soldered rework in legacy equipment but limits board density versus modern 20-pin SOIC MCU options, so it is rarely chosen for new high-density designs.
This page synthesizes distributor pricing, same-family drop-in alternatives, parametric comparison, and practical design notes drawn from the Freescale/NXP MC68HC705J1A datasheet in a way not found on any individual distributor page.
Bộ thay thế dễ dàng lắp đặt cho MC68HSC705J1ACP — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
MC68HC705J1ACP
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MC68HC705J1ACPE
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MC68HRC705J1ACP
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MC68HSR705J1ACP
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MC68HC705P6ACP
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MC68HSC705J1ACP Tỷ lệ tối đa & tính chất điện
| Manufacturer | Freescale Semiconductor (now NXP) |
| Series | MC68HC705J1A family |
| Core Processor | 6805 / HC05 (8-bit) |
| Core Size | 8-bit |
| Tần số xung maksimum | 4 MHz |
| Program Memory Size | 1.2 KB (1.2K x 8) OTPROM |
| Data EEPROM/ROM | None |
| Number of I/O Pins | 12 (Port A: 4-bit, Port B: 8-bit) |
| Hộp | 20-DIP / PDIP-20 (through-hole) |
| Kiểu lắp đặt | Through-Hole |
| Communication Interfaces | SCI (UART) |
| Timers | 16-bit multi-function timer (per datasheet) |
| Watchdog | COP (Computer Operating Properly) |
| Process Technology | HCMOS |
| Program Memory Type | OTP (One-Time Programmable) |
| Cấp MSL | Not applicable (through-hole) |
Cấu hình chân MC68HSC705J1ACP
| Chân 1 | IRQ — External interrupt request input |
| Chân 2 | VSS — Ground |
| Chân 3 | OSC1 — Crystal/oscillator input |
| Chân 4 | OSC2 — Crystal/oscillator output |
| Chân 5 | TCAP — Timer capture / programming voltage |
| Chân 6 | PA0 — Port A bit 0 (4-bit bidirectional I/O) |
| Chân 7 | PA1 — Port A bit 1 (4-bit bidirectional I/O) |
| Chân 8 | PA2 — Port A bit 2 (4-bit bidirectional I/O) |
| Chân 9 | PA3 — Port A bit 3 (4-bit bidirectional I/O) |
| Chân 10 | PB0 — Port B bit 0 (8-bit bidirectional I/O) |
| Chân 11 | PB1 — Port B bit 1 (8-bit bidirectional I/O) |
| Chân 12 | PB2 — Port B bit 2 (8-bit bidirectional I/O) |
| Chân 13 | PB3 — Port B bit 3 (8-bit bidirectional I/O) |
| Chân 14 | PB4 — Port B bit 4 (8-bit bidirectional I/O) |
| Chân 15 | PB5 — Port B bit 5 (8-bit bidirectional I/O) |
| Chân 16 | PB6 — Port B bit 6 (8-bit bidirectional I/O) |
| Chân 17 | PB7 — Port B bit 7 (8-bit bidirectional I/O) |
| Chân 18 | RxD — SCI receive data |
| Chân 19 | TxD — SCI transmit data |
| Chân 20 | VDD — Positive supply voltage |
Ứng dụng tiêu biểu
MC68HSC705J1ACP phù hợp cho 6 Áp dụngs: White Goods and Appliance Control, Remote Control Transmitters and Receivers, Battery Chargers and Power Management Front-Ends, Industrial Sensor Conditioning Nodes, Hobby and Educational Microcontroller Boards, Legacy Industrial Control Replacement.
White Goods and Appliance Control
The MC68HSC705J1ACP's 4MHz 6805 core, 12 GPIO lines, SCI and OTPROM make it a natural fit for cost-sensitive white-goods control boards including washing machines, microwave ovens, dishwashers, and air-conditioner indoor units. Engineers typically use the on-chip 16-bit timer to drive TRIAC-based motor phase control at 100Hz AC line frequency, while the SCI talks to a remote-control receiver or human-machine interface keypad. The 1.2KB OTPROM is sufficient for simple state-machine firmware, and the through-hole PDIP-20 simplifies hand-soldered repair and field replacement on older appliances that the HSC variant was designed to serve. Compared to modern Cortex-M0 parts, the MC68HSC705J1ACP wins on cost-per-unit for very high volume control loops and where the existing HC05 toolchain is already deployed.
Được đề xuất
Remote Control Transmitters and Receivers
The MC68HSC705J1ACP's low component count, SCI and timer-based PWM capability suit low-cost RF/IR remote control transmitters where a small MCU handles button scanning, encryption, and infrared LED modulation. With 4MHz of CPU bandwidth and the SCI block, the part can easily manage Manchester-coded UHF links at rates up to a few kilobaud, while the OTPROM lets OEMs ship end-user-replaceable transmitters without an external EEPROM. The 20-pin PDIP-20 package also makes sense for hand-built hobby projects, garage-door openers and consumer remote-control kits where through-hole soldering remains desirable.
Được đề xuất
Battery Chargers and Power Management Front-Ends
Chargers for power tools, e-bikes, and small consumer electronics depend on the deterministic behavior of the 6805 core in the MC68HSC705J1ACP, which drives a current-loop ADC-free charger using the 16-bit timer for PWM and the SCI for status reporting. With 12 GPIO lines, the part can directly control enable signals for a flyback converter, monitor temperature via a thermistor on a comparator input, and drive indicator LEDs without external logic. The OTPROM is well-matched to cost-down chargers because the firmware is committed at the factory and does not require field updates, while the through-hole PDIP-20 simplifies EMI debugging on the power board.
Được đề xuất
Industrial Sensor Conditioning Nodes
The MC68HSC705J1ACP can act as a local controller for industrial sensor-conditioning nodes, communicating over the SCI with a higher-level PLC or with another MCU. The 6805 core's BCD arithmetic is well suited to engineering-unit conversions on sensor data, while 4MHz of compute horsepower covers basic linearization and averaging without external DSP. The 20-pin PDIP package lets engineers prototype sensor boards quickly and the HCMOS HSC process offers better noise immunity than the original HC05 process for low-noise analog signal acquisition.
Được đề xuất
Hobby and Educational Microcontroller Boards
The MC68HSC705J1ACP is widely reused in hobby and educational kits because the HC05 toolchain (ImageCraft ICC05, Cosmic HC05, Byte Craft HC05) is well documented and supported on Windows, Linux and DOS-era IDEs. The 20-pin PDIP-20 package fits on DIP-compatible trainer boards and breadboards, and the 6805 instruction set provides a simpler teaching platform than Cortex-M parts while still requiring careful consideration of registers, ports and timers. Educators appreciate that the OTPROM is reusable for class projects and that students can experiment with the bootstrap programming protocol without worrying about flash wear.
Được đề xuất
Legacy Industrial Control Replacement
The MC68HSC705J1ACP is routinely deployed as a maintenance-replacement for end-of-life MC6805J1A mask-ROM parts in industrial control panels, elevators and other long-lifecycle equipment. The 6805 core and memory map are compatible with the original 6805J1A firmware, so vendors can move existing code onto modern OTP silicon while keeping the PCB unchanged. The 20-pin PDIP footprint is critical in this role because industrial boards typically use DIP sockets for fast field replacement, and the HSC variant's industrial temperature grade makes it suitable for cabinet installations.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho MC68HSC705J1ACP — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | MC68HC705J1ACP | MC68HC705J1ACPE | MC68HRC705J1ACP | MC68HSR705J1ACP | MC68HC705P6ACP |
|---|---|---|---|---|---|---|
| Brand | Freescale / NXP | Freescale / NXP | Freescale / NXP | Freescale / NXP | Freescale / NXP | Freescale / NXP |
| Package | PDIP-20 | PDIP-20 (same) | PDIP-20 (same) | PDIP-20 (same) | PDIP-20 (same) | PDIP-20 (same) |
| Core | HC05 / 6805 (8-bit) | HC05 / 6805 (same) | HC05 / 6805 (same) | HC05 / 6805 (same) | HC05 / 6805 (same) | HC05 / 6805 (same) |
| Maximum Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 5 MHz |
| Program Memory Size | 1.2 KB OTP | 1.2 KB OTP | 1.2 KB OTP | 1.2 KB OTP | 1.2 KB OTP | 4.6 KB EPROM |
| Number of I/O Pins | 12 (PA0-PA3 + PB0-PB7) | 12 | 12 | 12 | 12 | 21 |
| SCI/UART | Yes | Yes | Yes | Yes | Yes | Yes (SCI + SPI) |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete |
Bảo phân biệt quan trọng
- Pin-compatible with the entire HC05J1A family (vsMC68HC705J1ACPE)
- Larger program memory than original mask-ROM MC6805J1A (vsMC6805J1A (mask-ROM legacy part))
- More I/O than typical competitors in the same package (vsMC68HC705P6ACP)
Ghi chú thiết kế
Place two 100nF ceramic bypass capacitors as close as possible to pins 2 (VSS) and 20 (VDD) of the MC68HSC705J1ACP, with a 10uF aluminum or tantalum bulk bypass cap at the board entry point per the NXP MC68HC705J1A datasheet. Very fast signal transitions occur on the MCU pins, placing high short-duration current demands on the power supply, so the bulk bypass is critical when port pins source or sink high current. For battery-powered designs, additionally route a resistor-isolated decoupling network to keep deep-sleep current below the desired budget; HSC variants draw more quiescent current than HC variants, so re-validate any battery-life calculations.
Keep the 4MHz crystal traces between OSC1 (pin 3) and OSC2 (pin 4) short and symmetric, surrounded by a ground ring to minimize pickup on the SCI and timer pins. Route the SCI signals RxD (pin 18) and TxD (pin 19) as short, single-ended traces, and provide a guard ground trace on either side if the board is densely packed. Place the TCAP pin (pin 5) routing so it does not couple onto the IRQ pin (pin 1); this matters during OTPROM bootstrap-mode programming because TCAP carries the high-voltage programming waveform.
Estimated: A common mistake with the MC68HSC705J1ACP is to assume the HCMOS HSC variant draws the same quiescent current as the standard HCMOS HC05J1A variant, but per the same datasheet family the HSC process typically shows 30-50% higher quiescent numbers - re-validate any battery-life target. Another pitfall is substituting J1A firmware onto the J1ACP without re-checking the bootstrap mode jumper, since the OTPROM lock bit must be set after programming to behave as mask-ROM silicon.
Thông tin tuân thủ
RoHS, lead-free and halogen-free status not captured in verified web data; full compliance info requires the specific reel code or NXP product page flag. AEC-Q100 is not applicable - this is a legacy consumer/industrial MCU, not an automotive qualified part (HC705J1ACD versions historically carried automotive grades, not the J1ACP).
