PIC16C55AT-04/SS - 8-bit OTP MCU 768B 20 I/O 4MHz SSOP-28 | Microchip
MPN: PIC16C55AT-04/SS ✓ Hoạt độngPIC16C55AT-04/SS Tóm tắt
What is an 8-bit OTP microcontroller? An 8-bit OTP MCU is a small, fixed-instruction-set processor whose program memory can be written exactly once (One-Time-Programmable) using an EPROM-style bit cell. The "8-bit" designation refers to the width of the ALU and the data bus; the PIC16C5X family uses a 12-bit-wide instruction word to achieve 2:1 code compression over competing 8-bit MCUs. In the broader taxonomy, OTP microcontrollers sit between mask-ROM MCUs (cheapest at high volume) and Flash MCUs (re-programmable, higher cost per bit). They are favored for cost-sensitive, high-volume, stable-firmware applications.
Key features include a RISC architecture with only 33 single-word/single-cycle instructions, an 8-bit timer/counter, a watchdog timer for reliable operation, and a power-saving SLEEP mode. The device is built on a CMOS process that yields low power consumption and high noise immunity. It supports in-circuit serial programming through Microchip's standard tools and is compatible with the PICSTART Plus and MPLAB development environments, allowing the same firmware to migrate across the PIC16C5X family.
Typical applications for the PIC16C55AT-04/SS include low-end consumer appliances, automotive sub-systems (body controllers, lighting drivers), industrial control loops, sensor interfaces, and remote-control transmitters. The 20 I/O pins are well-suited to keypad scanning, LED matrix driving, and small-stepper or DC-motor control via external drivers. The industrial-grade temperature range and SSOP footprint also enable space-constrained designs.
When designing with this device, allocate I/O pins carefully because the PIC16C5X has a fixed 12-bit program word and limited RAM (24 bytes); high-volume data structures should be stored in program memory using RETLW lookup tables. Place a 0.1 microfarad decoupling capacitor within 5 mm of VDD and use the on-chip oscillator with a 4 MHz crystal or ceramic resonator; bypass the MCLR pin according to the datasheet to ensure a clean reset.
This page synthesizes distributor pricing, drop-in alternatives from the same PIC16C5X family, and practical design notes that complement the manufacturer datasheet.
Bộ thay thế dễ dàng lắp đặt cho PIC16C55AT-04/SS — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với PIC16C55AT-04/SS (cùng hình factor và footprint) — khác nhau ở Program Memory Size, Package, Program Memory Type, Core Architecture, RAM Size.
PIC16C55AT-04I/SS
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC16C55AT-04E/SS
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC16C55A-04E/P
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC16C554T-04/SS
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC16C558T-04/SS
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC16F54-I/SS
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC16C55AT-04/SS Tỷ lệ tối đa & tính chất điện
| Core Architecture | PIC 8-bit RISC |
| Family | PIC16C5X |
| Program Memory Size | 768 B (512 x 12) OTP |
| Data RAM | 24 B |
| Maximum Clock Speed | 4 MHz |
| Instruction Cycle | 250 ns (4 MHz / 4) |
| Supply Voltage (VDD) | 3 V to 6.25 V |
| Number of I/O Pins | 20 |
| Timers | 1 x 8-bit |
| Watchdog Timer | Yes (on-chip) |
| Hộp | 28-SSOP (5.30 mm / 0.209") |
| Kiểu lắp đặt | Surface Mount |
| Program Memory Type | OTP (One-Time-Programmable EPROM) |
| Nhiệt độ hoạt động | 0C to +70C (commercial) |
| Trạng thái RoHS | Compliant |
| Lead-Free | Yes |
Cấu hình chân PIC16C55AT-04/SS
| Chân 1 | RA0 — I/O port A bit 0 |
| Chân 2 | RA1 — I/O port A bit 1 |
| Chân 3 | RA2 — I/O port A bit 2 |
| Chân 4 | RA3 — I/O port A bit 3 |
| Chân 5 | GND — Ground reference |
| Chân 6 | RB0 — I/O port B bit 0 |
| Chân 7 | RB1 — I/O port B bit 1 |
| Chân 8 | RB2 — I/O port B bit 2 |
| Chân 9 | RB3 — I/O port B bit 3 |
| Chân 10 | RB4 — I/O port B bit 4 |
| Chân 11 | RB5 — I/O port B bit 5 |
| Chân 12 | RB6 — I/O port B bit 6 |
| Chân 13 | RB7 — I/O port B bit 7 |
| Chân 14 | VDD — Positive supply voltage |
| Chân 15 | RC0 — I/O port C bit 0 |
| Chân 16 | OSC1 — Oscillator input / external clock |
| Chân 17 | OSC2 — Oscillator output (crystal mode) |
| Chân 18 | RC1 — I/O port C bit 1 |
| Chân 19 | RC2 — I/O port C bit 2 |
| Chân 20 | RC3 — I/O port C bit 3 |
| Chân 21 | RC4 — I/O port C bit 4 |
| Chân 22 | RC5 — I/O port C bit 5 |
| Chân 23 | RC6 — I/O port C bit 6 |
| Chân 24 | RC7 — I/O port C bit 7 |
| Chân 25 | NC — Not connected (per datasheet) |
| Chân 26 | NC — Not connected (per datasheet) |
| Chân 27 | NC — Not connected (per datasheet) |
| Chân 28 | MCLR — Master clear (active-low reset) |
Ứng dụng tiêu biểu
PIC16C55AT-04/SS phù hợp cho 6 Áp dụngs: Low-End Consumer Appliance Control, Automotive Body and Lighting Modules, Industrial Sensor Interface Front-End, Remote Control and IR Transmitter, Small DC Motor and Stepper Control, Battery-Powered Wireless Sensor Tag.
Low-End Consumer Appliance Control
The PIC16C55AT-04/SS fits cost-sensitive consumer appliances (coffee makers, toasters, microwave keypads, electric toothbrush chargers) where stable firmware and the lowest per-unit BOM cost are paramount. Its 20 I/O pins drive 7-segment displays, scan 4x4 keypads, and switch relays through transistors directly. The 768-byte OTP memory holds full state machines for appliance sequencing, while 24 bytes of RAM is sufficient for timers, debounce variables and mode flags. Unlike Flash MCUs, the OTP cell reduces silicon cost and prevents unauthorized firmware read-back, an advantage in consumer markets where IP protection matters. The 5 V tolerance and 0.70 mA typical active current also suit always-on mains-powered designs without expensive regulators.
Được đề xuất
Automotive Body and Lighting Modules
Within automotive body controllers (door locks, mirror adjusters, ambient lighting drivers, simple BCM sub-modules) the PIC16C55AT-04/SS offers 20 mA source/sink per pin capable of directly driving small LEDs and opto-isolators. The 4 MHz core handles PWM for LED dimming at audio frequencies without flicker, and the watchdog timer (WDT) recovers the module from load-dump transients on the 12 V battery rail. The E-suffix variant extends operation to -40C to +125C for under-dash or under-hood-near mounting. Where AEC-Q100 qualification is required, a Flash PIC16F-series equivalent with the same SSOP-28 footprint is preferred; the OTP part is widely used for non-safety sub-systems.
Được đề xuất
Industrial Sensor Interface Front-End
As a sensor-interface front-end, the PIC16C55AT-04/SS reads digital sensors over GPIO bit-banging (DHT11, simple one-wire devices) and converts the data into Modbus-friendly UART frames for a downstream PLC. The 24-byte RAM is enough for a small protocol buffer plus the sensor state machine, while the 4 MHz instruction rate polls sensors at 10 Hz with margin to spare for debouncing and CRC. The watchdog timer recovers from EMI-induced lockups in factory-floor cabinets. Pin-compatible PIC16C55x variants add hardware UART for cleaner protocol handling when the firmware grows beyond what bit-banging supports in 768 OTP bytes.
Được đề xuất
Remote Control and IR Transmitter
In handheld IR remote controls (TV, STB, AC) the PIC16C55AT-04/SS drives an IR LED through a single GPIO pin at 38 kHz carrier using timer interrupts, with the remaining I/O scanning a 5x4 keypad matrix. The 768-byte OTP holds complete code-sets for multiple protocols (RC5, NEC, SIRC) using RETLW lookup tables, and the 4 MHz oscillator supports accurate carrier generation with cycle-by-cycle control. The SLEEP mode drops active current below 1 microamp between key presses, extending battery life on coin cells. The OTP nature also prevents cloning of proprietary remote codes, an important anti-piracy feature.
Được đề xuất
Small DC Motor and Stepper Control
Driving small brushed DC motors or unipolar stepper motors via external MOSFET/IGBT drivers, the PIC16C55AT-04/SS uses 4 I/O pins for H-bridge direction/enable and 2 pins for Hall-sensor feedback. The 8-bit timer generates PWM at 1 kHz for smooth torque, and the 4 MHz instruction rate executes a software PID loop at 200 Hz with cycle margin. The 20 mA sink capability lets the MCU directly switch the gate-driver logic inputs, removing the need for buffer ICs. Where higher step-rates are needed, the PIC16C55A-20/SS (20 MHz) executes the same algorithm five times faster, but the standard -04 part covers typical small-fan, valve, and damper actuators.
Được đề xuất
Battery-Powered Wireless Sensor Tag
In simple wireless sensor tags that wake periodically to read a sensor and transmit a beacon, the PIC16C55AT-04/SS spends most of its life in SLEEP mode (current below 1 microamp) and wakes via watchdog timer overflow to take a reading and burst-transmit. The 24-byte RAM holds a packet frame and the 768-byte OTP stores the protocol stack and the sensor calibration table. Two GPIO pins bit-bang a UHF or sub-GHz transmitter enable/data line, while one pin powers the sensor through a MOSFET to minimize quiescent draw. Replacing the PIC16C55AT with a Flash PIC16F54-I/SS enables OTA-style firmware updates at the cost of slightly higher silicon price.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho PIC16C55AT-04/SS — 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 | PIC16C55AT-04I/SS | PIC16C55AT-04E/SS | PIC16C55A-04E/P | PIC16C554T-04/SS | PIC16F54-I/SS |
|---|---|---|---|---|---|---|
| Package | 28-SSOP (5.30 mm) | 28-SSOP (5.30 mm) - same | 28-SSOP (5.30 mm) - same | 28-SSOP (5.30 mm) - same | 28-SSOP (5.30 mm) - same | 28-SSOP (5.30 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 768 B OTP (512 x 12) | 768 B OTP (512 x 12) - same | 768 B OTP (512 x 12) - same | 768 B OTP (512 x 12) - same | 768 B OTP (512 x 12) - same | 512 B Flash (256 x 12) |
| Data RAM | 24 B | 24 B - same | 24 B - same | 24 B - same | 24 B - same | 25 B (+1 B) |
| Maximum Clock | 4 MHz | 4 MHz - same | 4 MHz - same | 4 MHz - same | 4 MHz - same | 20 MHz |
| I/O Pins | 20 | 20 - same | 20 - same | 20 - same | 20 - same | 12 |
| Memory Type | OTP (One-Time-Programmable) | OTP | OTP | OTP | OTP | Flash (re-programmable) |
| Operating Temperature | 0C to +70C (commercial) | -40C to +85C (industrial) | -40C to +125C (extended) | -40C to +125C (extended) | 0C to +70C (commercial) | -40C to +85C (industrial) |
Bảo phân biệt quan trọng
- Commercial temperature grade at the lowest OTP BOM cost (vsPIC16C55AT-04I/SS)
- Wide 3 V to 6.25 V supply range supports both 3.3 V and 5 V rails (vsPIC16F54-I/SS)
- 768-byte OTP holds 33% more code than the older PIC16C54A (vsPIC16C54A-04/SS)
- 20 mA source/sink on every GPIO removes external drivers for low-current loads (vsPIC16C554T-04/SS)
Ghi chú thiết kế
Place a 0.1 microfarad decoupling capacitor (X7R ceramic) within 5 mm of the VDD pin (pin 14) and a bulk 1 to 10 microfarad electrolytic at the board's supply input. The PIC16C55AT-04/SS draws roughly 0.7 mA active at 4 MHz and below 1 microamp in SLEEP, so the supply rail can be shared with low-power analog circuitry if decoupled locally. The MCLR pin (pin 28) requires a 10 kohm pull-up to VDD and a 100 nF capacitor to ground if the internal reset is not used; otherwise a clean reset is not guaranteed.
Use a 28-SSOP land pattern per IPC-7351 (0.65 mm pitch, 5.30 mm body width) with NSMD pads for reliable solder joint inspection. Keep the 4 MHz crystal or resonator within 5 mm of OSC1 (pin 16) and OSC2 (pin 17) with a ground guard ring on the PCB layer beneath to reduce EMI coupling into adjacent traces. Route MCLR and VDD traces first and avoid running long parallel tracks under the oscillator to minimise cross-talk and reset glitches.
Do not rely on the OTP device for prototype firmware iteration; the cell can be written only once, so a code bug requires a new part. Migrate development to the pin-compatible PIC16F54-I/SS Flash variant, then transfer the validated hex to the PIC16C55AT-04/SS for production. Also note that the PIC16C5X core has only one 8-bit file register for arithmetic; larger math operations need careful carry management, and the PCLATH register must be set correctly before computed GOTOs or table reads.
The PIC16C55AT-04/SS GPIO pins sink up to 20 mA but the combined source current is limited to 150 mA across the whole package; if you drive many LEDs simultaneously, use a low-side MOSFET array and PWM the gates instead of driving each LED from a GPIO. This keeps the die within its thermal envelope and prevents logic-level degradation on neighbouring pins due to internal bond-wire resistance.
Thông tin tuân thủ
RoHS and lead-free confirmed by Microchip product page. AEC-Q100 not qualified at the PIC16C55AT-04/SS grade; choose the E-suffix extended-temperature variant for automotive enclosures.
