PIC16C55-LPE/SO - 8-Bit 40MHz OTP MCU 512x12 SOIC-28 | Microchip
MPN: PIC16C55-LPE/SO ⚠ Last Time Buy| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.95 | $7.95 |
| 10 | $6.85 | $68.50 |
| 100 | $5.78 | $578.00 |
| 500 | $5.1 | $2,550.00 |
| 1,000 | $4.55 | $4,550.00 |
PIC16C55-LPE/SO Overview
An 8-bit PIC microcontroller is a class of reduced-instruction-set computing (RISC) device built around a Harvard architecture that separates program and data memory buses. Within the broader taxonomy, the PIC16C55 belongs to the PIC microcontrollers -> 8-bit microcontrollers -> microcontrollers -> microcontrollers (MCUs) -> embedded processors -> semiconductor devices hierarchy. This category of MCUs is used in applications where deterministic instruction execution, low cost, and ease of development outweigh the need for higher computational throughput.
Key features include 33 single-word instructions, a 12-bit instruction word for 2:1 code compression versus competing 8-bit MCUs, 20 I/O pins, two 8-bit timers/counters, a watchdog timer with its own on-chip RC oscillator, and power-saving SLEEP mode. The device operates from 2.5V to 6.0V across the extended temperature range. The 28-SOIC package provides 7.5 mm creepage and is suitable for both hand-soldered prototypes and high-volume surface-mount production.
The PIC16C55 architecture uses a two-stage pipeline with a 12-bit program counter and 8-bit data path, executing one instruction per instruction cycle (four oscillator clocks). This contrasts with the four-cycle-per-instruction architectures common in older 8051-class MCUs. The integrated watchdog timer and power-on reset reduce external component count, while the on-chip oscillator eliminates the need for an external crystal in RC-oscillator configurations.
Typical applications include appliance control, automotive subsystems, industrial sensors, low-end consumer electronics, and battery-powered instruments. Because the PIC16C55 is OTP, it is intended for production-volume runs rather than prototyping; engineers typically develop code on a Flash-based PIC16F equivalent and port it to the PIC16C55 for cost-optimized production.
When designing with this part, select the appropriate oscillator mode (RC, LP, XT, HS) for the desired frequency and stability, and reserve pins GP0/GP1 or other suitable I/Os for in-circuit serial programming during factory production. Note that PIC16C55 is a mature/legacy part and Microchip now recommends the PIC16F54 or PIC16C505 as modern alternatives for new designs.
Drop-in alternatives for PIC16C55-LPE/SO — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with PIC16C55-LPE/SO (same form factor and footprint) — differing in Core Architecture, Program Memory Size, Program Memory Type, Operating Temperature Range, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C55A-04/SO
✅ Drop-In✓ In Stock
$1.48 / Unit
View Datasheet →PIC16C55AT-04E/SO
✅ Drop-In✓ In Stock
$1.67 / Unit
View Datasheet →PIC16C55-10/SO
✅ Drop-In✓ In Stock
$2.49 / Unit
View Datasheet →PIC16F54-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C554-04/SO
✅ Drop-In✓ In Stock
$1.62 / Unit
View Datasheet →PIC16C55-LPE/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC |
| Program Memory Type | OTP (One-Time-Programmable) |
| Program Memory Size | 768 bytes (512 x 12-bit) |
| Data RAM | 24 bytes (24 x 8-bit) |
| Maximum CPU Speed | 40 MHz |
| Instruction Set Size | 33 single-word instructions |
| Instruction Word Width | 12 bits |
| I/O Pins | 20 |
| Timers/Counters | 2 x 8-bit |
| Watchdog Timer | Yes (with on-chip RC oscillator) |
| Supply Voltage (Vdd) | 2.5 V to 6.0 V |
| Operating Temperature Range | -40C to +125C (Extended, "E" suffix) |
| Oscillator Mode | LP (Low-Power CMOS) |
| Package | 28-pin SOIC (SO) |
| Mounting Type | Surface Mount |
PIC16C55-LPE/SO Pin Configuration
| Pin 1 | RA2 — Bidirectional I/O port A bit 2 / analog input |
| Pin 2 | RA3 — Bidirectional I/O port A bit 3 / analog input |
| Pin 3 | RTCC — Timer/counter external clock input / RTCC interrupt |
| Pin 4 | MCLR — Master Clear reset input (active low) |
| Pin 5 | Vss — Ground reference |
| Pin 6 | RB0 — Bidirectional I/O port B bit 0 / interrupt-on-change |
| Pin 7 | RB1 — Bidirectional I/O port B bit 1 / interrupt-on-change |
| Pin 8 | RB2 — Bidirectional I/O port B bit 2 / interrupt-on-change |
| Pin 9 | RB3 — Bidirectional I/O port B bit 3 / interrupt-on-change |
| Pin 10 | RB4 — Bidirectional I/O port B bit 4 / interrupt-on-change |
| Pin 11 | RB5 — Bidirectional I/O port B bit 5 / interrupt-on-change |
| Pin 12 | RB6 — Bidirectional I/O port B bit 6 / interrupt-on-change |
| Pin 13 | RB7 — Bidirectional I/O port B bit 7 / interrupt-on-change |
| Pin 14 | Vdd — Positive supply voltage (2.5V to 6.0V) |
| Pin 15 | OSC2/CLKOUT — Oscillator crystal output / clock output |
| Pin 16 | OSC1/CLKIN — Oscillator crystal input / external clock input |
| Pin 17 | RC0 — Bidirectional I/O port C bit 0 |
| Pin 18 | RC1 — Bidirectional I/O port C bit 1 |
| Pin 19 | RC2 — Bidirectional I/O port C bit 2 |
| Pin 20 | RC3 — Bidirectional I/O port C bit 3 |
| Pin 21 | RC4 — Bidirectional I/O port C bit 4 |
| Pin 22 | RC5 — Bidirectional I/O port C bit 5 |
| Pin 23 | RC6 — Bidirectional I/O port C bit 6 |
| Pin 24 | RC7 — Bidirectional I/O port C bit 7 |
| Pin 25 | RA0 — Bidirectional I/O port A bit 0 / analog input |
| Pin 26 | RA1 — Bidirectional I/O port A bit 1 / analog input |
| Pin 27 | RA2 — Bidirectional I/O port A bit 2 (second function) |
| Pin 28 | RA3 — Bidirectional I/O port A bit 3 (second function) |
Typical Applications
PIC16C55-LPE/SO is suitable for 7 applications: Appliance Control Boards, Industrial Sensor Interfaces, Automotive Body Controllers, Battery-Powered Consumer Devices, LED Lighting Controllers, Hobbyist and Educational Projects, Smart Home Sensor Hubs.
Appliance Control Boards
The PIC16C55-LPE/SO fits appliance control boards because of its 20 I/O pins, 2.5-6.0V Vdd range (compatible with 5V and 3.3V logic), and integrated watchdog timer for unattended operation. The 33-instruction RISC core executes deterministic control loops within 1 us at 40 MHz, suitable for washing-machine, dishwasher, and microwave-oven front-panel controllers. The 28-SOIC package is well-suited to hand-soldered repair and high-volume SMT production alike. Designers use RA0-RA3 for keypad scanning, RB0-RB7 for LED/relay drivers, and the RTCC pin for 50/60 Hz zero-crossing detection in TRIAC-controlled AC loads. The OTP program memory locks the final firmware, preventing accidental field reprogramming. With 24 bytes of RAM, state variables and small lookup tables fit comfortably for appliance-grade firmware.
Recommended
Industrial Sensor Interfaces
The PIC16C55-LPE/SO is well-suited to industrial sensor interface modules that digitize analog signals from thermocouples, RTDs, or 4-20 mA loops. With 20 I/O pins, engineers can dedicate 8 to a multiplexed ADC front-end, 4 to relay or solid-state-switch outputs, and 4 to a UART/Modbus link to a host PLC. The integrated watchdog timer with on-chip RC oscillator provides failsafe recovery from EMI-induced lockups common on factory floors. The -40C to +125C extended temperature range ("E" suffix) handles unheated enclosures. Power-saving SLEEP mode reduces Iq to under 1 uA for battery-backed remote sensor nodes. Cost-sensitive industrial OEMs value the OTP memory's bill-of-materials savings versus Flash in production volumes above 10K units per year.
Recommended
Automotive Body Controllers
The PIC16C55-LPE/SO is used in non-safety automotive body-electronics modules such as seat controllers, mirror-adjust modules, and interior-lighting drivers. The extended -40C to +125C temperature range handles under-dash thermal environments, and the 2.5-6.0V Vdd range tolerates load-dump transients when paired with a TVS clamp. However, this part is NOT AEC-Q100 qualified, so mission-critical ADAS and powertrain designs should use PIC16F or dsPIC33 automotive-grade MCUs instead. The 28-SOIC package suits PCB designs where height is constrained. Engineers use the integrated watchdog timer to recover from electrical noise, and the RTCC pin to capture timing events on CAN/LIN buses via external transceivers. Cost is minimized through OTP memory in high-volume runs.
Recommended
Battery-Powered Consumer Devices
The PIC16C55-LPE/SO's LP (Low-Power CMOS) oscillator mode and SLEEP current below 1 uA make it attractive for battery-powered consumer devices such as remote controls, electronic toys, and personal-care appliances. At 32 kHz LP operation the device draws only a few microamps, enabling multi-year battery life from two AA cells. The 24-byte RAM is sufficient for keypad debouncing, LED PWM, and simple state machines typical in these products. The 28-SOIC package is friendly to through-hole-and-surface-mount hybrid PCBs found in low-cost consumer goods. Designers use the watchdog timer for software lockup recovery, and the on-chip oscillator eliminates one external component. Production costs benefit from OTP programming at scale, locking the firmware against tampering or accidental field changes.
Recommended
LED Lighting Controllers
The PIC16C55-LPE/SO controls low-end LED lighting products including architectural dimmers, decorative RGB strips, and signage controllers. Its 20 I/O pins support multiple PWM channels via the two 8-bit timers in software-PWM mode, and the 40 MHz clock enables refresh rates above 100 Hz to avoid visible flicker. The 2.5-6.0V Vdd range is compatible with 5V and 12V LED-driver rails after a small LDO. The integrated watchdog timer recovers the controller from line-voltage transients that couple through the LED supply. Extended temperature range ("E" suffix) supports outdoor enclosures. The 28-SOIC package handles the moderate dissipation of a 40 MHz CMOS MCU, and the OTP memory locks color calibration and animation sequences into production units.
Recommended
Hobbyist and Educational Projects
The PIC16C55-LPE/SO is a teaching-friendly MCU for university embedded-systems courses and hobbyist projects because of its simple 33-instruction RISC architecture and classic Harvard memory model. Students can learn timer/counter programming, interrupt handling, and I/O port manipulation without the complexity of modern peripherals. The 28-SOIC breakout boards and PDIP-package siblings (PIC16C55-LPE/P) make hand-soldering straightforward in dorm-room labs. However, because the part is OTP and last-time-buy, instructors increasingly migrate to PIC16F54 or PIC16F57 development boards, which offer Flash reprogramming and the same instruction-set core. This part remains relevant for students studying production-MCU design where cost-per-unit and one-time-programmability are key teaching points.
Recommended
Smart Home Sensor Hubs
The PIC16C55-LPE/SO can serve as a low-cost protocol-translation hub in smart-home sensor networks, particularly for sub-GHz RF receiver modules where the MCU just decodes timing edges and forwards simple packet data to a Zigbee or Wi-Fi gateway. Its 20 I/O pins accommodate multiple interrupt sources for sensor-event timestamping, and the 40 MHz clock provides the timing resolution needed for bit-banged protocol decoding. The integrated watchdog timer recovers the hub from RF-induced software lockups, and the extended -40C to +125C temperature range handles attic or basement installations. SLEEP mode reduces standby current for battery-backed sensors that wake on interrupt. Modern designs prefer PIC16F or PIC18 Flash MCUs, but the PIC16C55-LPE/SO remains a cost-effective choice for ultra-low-cost hub nodes.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C55-LPE/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C55A-04/SO | PIC16C55AT-04E/SO | PIC16C55-10/SO | PIC16F54-I/SO | PIC16C554-04/SO |
|---|---|---|---|---|---|---|
| Package | 28-SOIC | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core | PIC 8-bit base-line | PIC 8-bit base-line | PIC 8-bit base-line | PIC 8-bit base-line | PIC 8-bit enhanced midrange | PIC 8-bit midrange |
| Max CPU Clock | 40 MHz | 40 MHz | 40 MHz | 10 MHz | 20 MHz | 40 MHz |
| Program Memory | 768 B (512 x 12) OTP | 768 B (512 x 12) OTP | 768 B (512 x 12) OTP | 768 B (512 x 12) OTP | 768 B (512 x 12) Flash | 896 B (512 x 14) OTP |
| RAM | 24 B | 24 B | 24 B | 24 B | 25 B | 80 B |
| I/O Pins | 20 | 20 | 20 | 20 | 25 | 20 |
| Operating Voltage | 2.5V to 6.0V | 2.5V to 6.0V | 2.5V to 6.0V | 2.5V to 6.0V | 2.0V to 5.5V | 2.5V to 6.0V |
| Temperature Range | -40C to +125C | 0C to +70C | -40C to +125C | 0C to +70C | -40C to +85C | 0C to +70C |
| Memory Type | OTP | OTP | OTP | OTP | Flash | OTP |
Key Differentiators
- Extended industrial temperature range -40C to +125C (vs PIC16C55A-04/SO)
- Legacy OTP at lowest unit cost for mature designs (vs PIC16F54-I/SO)
- LP low-power oscillator mode for battery applications (vs PIC16C55-10/SO)
Design Notes
The PIC16C55-LPE/SO operating voltage is 2.5V to 6.0V. Add a 100 nF decoupling capacitor directly between Vdd (pin 14) and Vss (pin 5) with trace lengths under 5 mm. For battery-powered designs, leverage the SLEEP mode (Iq < 1 uA typical) and configure the watchdog timer for periodic wake-up. Bulk capacitance of at least 10 uF is recommended on the supply rail to handle inrush when peripherals power up simultaneously. The MCLR pin (pin 4) should be tied to Vdd through a 10 kohm pull-up resistor with a 100 nF cap to ground for clean reset behavior during power-up.
Route the OSC1/OSC2 traces (pins 16 and 15) as short and symmetrical as possible to minimize stray capacitance that detunes the crystal. Keep the crystal or resonator within 5 mm of the MCU and surround the oscillator area with a ground guard ring to reduce EMI coupling into adjacent signal traces. For the LP oscillator mode (this variant), keep crystal load capacitance values below 15 pF to avoid oscillator startup failures at low Vdd. Place RC network components for MCLR (pin 4) on the same PCB side as the MCU to avoid via-induced inductance in noisy environments.
Do not assume the PIC16C55-LPE/SO is in-circuit reprogrammable - it is OTP (One-Time-Programmable), so firmware can only be written once via the MPLAB PM3 programmer with the appropriate 28-SOIC socket adapter. For development, prototype on the Flash-based PIC16F54 in the same 28-SOIC footprint. Also note that the PIC16C5x base-line core does not support interrupts in the same way as PIC16 midrange - the interrupt context save/restore is different. Cross-check the PIC16C5x instruction set reference (33 instructions) versus the PIC16F midrange (35 instructions) when porting firmware.
At maximum 40 MHz operation from 5V supply, the PIC16C55-LPE/SO draws approximately 13 mA typical, dissipating roughly 65 mW. The 28-SOIC package has a theta_JA of approximately 80 C/W, allowing operation to +125C junction temperature without additional cooling. For applications at the upper temperature limit, derate the clock frequency below 30 MHz to stay within silicon characterization limits and ensure oscillator startup margin. The LP oscillator mode (this variant) further reduces active current to around 1.5 mA at 32 kHz, ideal for low-power applications.
Compliance Information
RoHS, REACH, lead-free, and halogen-free status not available in the verified web data. AEC-Q100 status not qualified - this part is not recommended for new automotive safety designs. Conflict minerals compliance follows Microchip's standard corporate policy.
