PIC16C55-HSE/SP - 8-Bit 16MHz OTP MCU 28-SPDIP | Microchip
MPN: PIC16C55-HSE/SP β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.95 | $6.95 |
| 10 | $6.21 | $62.10 |
| 100 | $5.48 | $548.00 |
| 500 | $4.92 | $2,460.00 |
| 1,000 | $4.36 | $4,360.00 |
PIC16C55-HSE/SP Overview
A PIC (Peripheral Interface Controller) microcontroller is a compact, low-cost embedded computing device built around a RISC (Reduced Instruction Set Computer) core, with program memory, data RAM, and peripherals integrated onto a single silicon die. Microcontrollers in the PIC16C5X baseline family sit within the hierarchy: MCU -> 8-bit microcontroller -> PIC16 baseline family -> PIC16C5X subgroup -> CMOS OTP -> industrial control IC. The baseline architecture is the original PIC core that launched Microchip's dominance in low-power embedded control, prized for deterministic execution, low quiescent current, and a tiny 33-instruction set that simplifies code generation in assembly or C.
Key features of the PIC16C55-HSE/SP include a single 8-bit timer/counter (Timer0), a watchdog timer with on-chip RC oscillator for reliable brown-out recovery, power-saving sleep mode, and a wide operating voltage range of 2.5 V to 6.25 V. The HSE suffix specifies the oscillator range (high-speed, 16 MHz crystal/resonator), while the CMOS process enables low power consumption suitable for battery-backed and always-on applications. The baseline architecture executes one instruction per instruction cycle (4 clock cycles), giving a 100 ns minimum instruction time at 40 MHz-equivalent performance.
Typical applications include low-cost industrial control loops, appliance control boards, sensor signal conditioning front-ends, automotive body and accessory controllers (in non-safety roles), and legacy embedded products where OTP one-time-programmability is acceptable. The 20 I/O pins can directly drive LEDs, keypads, and small relays, while internal pull-ups simplify matrix-scanned user interfaces.
Designers should note that the PIC16C55 lacks in-circuit serial programming (ICSP), in-circuit debugging, and any analog peripherals (no ADC, no comparators), so it is best suited for digital glue logic and simple control tasks where high-pin-count analog or field-updatable firmware is not required.
This page synthesizes real distributor stock and pricing, drop-in same-package alternatives from Microchip's own baseline PIC16C5X family, and practical design notes not found in the original manufacturer datasheet - giving procurement and firmware engineers a single source to evaluate, source, and design around the PIC16C55-HSE/SP.
For long-life industrial designs, consider the flash-based PIC16F54 or PIC16F57 as a drop-in firmware-compatible upgrade path; for ultra-low power, the PIC16LF series offers lower VDD operation at the cost of oscillator frequency.
Drop-in alternatives for PIC16C55-HSE/SP β 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-HSE/SP (same form factor and footprint) β differing in Maximum Clock Frequency, Package, RAM Size, Program Memory Size, Core.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16C55-HS/SP
β Drop-Inβ In Stock
$2.24 / Unit
View Datasheet βPIC16C55-10/SP
β Drop-Inβ In Stock
$2.45 / Unit
View Datasheet βPIC16F54-I/P
β Drop-Inπ Reference alternative (not in catalog)
PIC16F57-I/P
β Drop-Inπ Reference alternative (not in catalog)
PIC16C54-HS/P
β Drop-Inβ In Stock
$1.15 / Unit
View Datasheet βPIC16C54A-20I/SP
β Drop-Inπ Reference alternative (not in catalog)
PIC16C55-HSE/SP Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16C5X baseline (RISC, 12-bit instruction word) |
| Data Bus Width | 8 bit |
| Maximum Clock Frequency | 16 MHz |
| Program Memory Size | 768 B (512 x 12) OTP |
| RAM Size | 24 B (24 x 8) |
| Programmable I/O Pins | 20 |
| Supply Voltage Range | 2.5 V to 6.25 V |
| Package | 28-SPDIP (Skinny Plastic DIP, 0.300 in / 7.62 mm row spacing) |
| Mounting Type | Through-Hole |
| Oscillator Type | External HS (HSE = 16 MHz high-speed crystal/resonator) |
| Timer/Counters | 1 x 8-bit (Timer0) |
| Watchdog Timer | Yes (with on-chip RC oscillator) |
| Hardware Stack | 2 levels |
| Instruction Set Size | 33 instructions |
| ICSP / Debug | Not supported (OTP part) |
| ADC / Comparators | None (digital-only peripheral set) |
| RoHS Status | Compliant (per Microchip product page) |
PIC16C55-HSE/SP Pin Configuration
| Pin 1 | RA0 β Port A bit 0 (digital I/O) |
| Pin 2 | RA1 β Port A bit 1 (digital I/O) |
| Pin 3 | RA2 β Port A bit 2 (digital I/O) |
| Pin 4 | RA3 β Port A bit 3 (digital I/O) |
| Pin 5 | RA4/T0CKI β Port A bit 4 / Timer0 clock input |
| Pin 6 | /MCLR β Master Clear (active-low reset) |
| Pin 7 | RB0 β Port B bit 0 (digital I/O, interrupt-on-change) |
| Pin 8 | RB1 β Port B bit 1 (digital I/O) |
| Pin 9 | RB2 β Port B bit 2 (digital I/O) |
| Pin 10 | RB3 β Port B bit 3 (digital I/O) |
| Pin 11 | RB4 β Port B bit 4 (digital I/O) |
| Pin 12 | GND β Ground reference |
| Pin 13 | RB5 β Port B bit 5 (digital I/O) |
| Pin 14 | RB6 β Port B bit 6 (digital I/O) |
| Pin 15 | RB7 β Port B bit 7 (digital I/O) |
| Pin 16 | RC0 β Port C bit 0 (digital I/O) |
| Pin 17 | RC1 β Port C bit 1 (digital I/O) |
| Pin 18 | RC2 β Port C bit 2 (digital I/O) |
| Pin 19 | RC3 β Port C bit 3 (digital I/O) |
| Pin 20 | RC4 β Port C bit 4 (digital I/O) |
| Pin 21 | RC5 β Port C bit 5 (digital I/O) |
| Pin 22 | RC6 β Port C bit 6 (digital I/O) |
| Pin 23 | RC7 β Port C bit 7 (digital I/O) |
| Pin 24 | OSC2 β Oscillator output (crystal/resonator) |
| Pin 25 | OSC1 β Oscillator input (crystal/resonator) |
| Pin 26 | VDD β Positive supply voltage |
| Pin 27 | NC β Not connected (per datasheet) |
| Pin 28 | NC β Not connected (per datasheet) |
Typical Applications
PIC16C55-HSE/SP is suitable for 6 applications: Appliance Control Boards, Industrial Sensor Signal Conditioning, Automotive Body and Accessory Modules, Low-Cost Consumer Electronics, LED Display and Sign Drivers, Legacy Embedded Maintenance Boards.
Appliance Control Boards
The PIC16C55-HSE/SP fits appliance control boards (washing machines, dishwashers, microwave user interfaces) because its 20 programmable I/O pins can directly scan 4x4 keypads and drive LED or seven-segment displays without external glue logic. At 16 MHz it executes 10 MIPS, sufficient for state-machine control of motor start sequences and timeout handling. The 768 B OTP program memory holds compact sequencer firmware while the watchdog timer recovers from brown-out events common in relay-driven loads. Operates from 2.5 V to 6.25 V covering both 3.3 V and 5 V rail designs.
Recommended
Industrial Sensor Signal Conditioning
The PIC16C55-HSE/SP suits sensor signal conditioning front-ends where it acts as a digital pre-processor - debouncing limit switches, counting pulses from optical encoders, or sequencing multiplexer channels before a downstream ADC. Its single 8-bit Timer0 captures pulse widths up to 655 us at 16 MHz with 100 ns resolution, and the 33-instruction RISC set keeps interrupt latency deterministic at 4 clock cycles. The 2.5-6.25 V supply range accepts industrial 24 V bus systems stepped down to 5 V or 3.3 V rails.
Recommended
Automotive Body and Accessory Modules
The PIC16C55-HSE/SP is used in non-safety automotive body modules - window lift controllers, mirror adjusters, seat position memories, and interior lighting sequencers - where its 20 I/O pins drive relays and H-bridges directly and its 16 MHz performance handles debounce and timing tasks. The HSE oscillator tolerates the electrical noise of automotive 12 V buses when properly bypassed. Designers should add external TVS protection and follow Automotive EMC best practices. Note that this OTP part is not field-updatable - production firmware revisions require chip replacement.
Recommended
Low-Cost Consumer Electronics
The PIC16C55-HSE/SP powers low-cost consumer products - remote controls, toy controllers, novelty gadgets, and simple user interfaces - because its 768 B OTP cost-effectively holds fixed behavior code. The 16 MHz execution gives responsive button-press latency under 1 ms, and the wide 2.5-6.25 V VDD range enables direct battery operation from two AA cells. The 28-SPDIP through-hole package simplifies hand-soldering and prototyping for hobbyist and educational markets. For shipping consumer volumes, switch to PIC16F54-I/P to gain flash reprogrammability for late-stage firmware fixes.
Recommended
LED Display and Sign Drivers
The PIC16C55-HSE/SP drives multiplexed LED matrices and scrolling sign controllers using its 20 I/O pins to scan rows and columns with software PWM for brightness control. At 10 MIPS, the baseline core refreshes 8x8 to 16x16 matrices without flicker, and the watchdog timer recovers from ESD-induced lockups common in sign installations. The 2.5-6.25 V supply range matches both 3.3 V logic-level and 5 V high-brightness LED chain designs. OTP code locks in the message sequence to prevent unauthorized modifications in commercial signage.
Recommended
Legacy Embedded Maintenance Boards
The PIC16C55-HSE/SP is used to maintain and service legacy embedded boards in industrial automation, HVAC controllers, and older test equipment where firmware is finalized and OTP is acceptable for long-life spares. Its 28-SPDIP through-hole package is well-suited for field-replacement scenarios where technicians hand-solder replacements on existing PCBs. The PIC16C5X 33-instruction RISC core ensures original assembly source code remains compilable across decades of revisions. For new designs targeting this same use case, switch to PIC16F54-I/P flash part to enable ICSP-based firmware updates without chip replacement.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C55-HSE/SP β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C55-HS/SP | PIC16C55-10/SP | PIC16F54-I/P | PIC16F57-I/P | PIC16C54A-20I/SP |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SPDIP | 28-SPDIP - same | 28-SPDIP - same | 28-SPDIP - same | 28-SPDIP - same | 28-SPDIP - same |
| Core Architecture | PIC16C5X baseline | PIC16C5X baseline | PIC16C5X baseline | PIC16C5X baseline (flash) | PIC16C5X baseline (flash) | PIC16C5X enhanced baseline |
| Max Clock Frequency | 16 MHz | 16 MHz | 10 MHz | 20 MHz | 20 MHz | 20 MHz |
| Program Memory | 768 B OTP | 768 B OTP | 768 B OTP | 768 B flash | 3 KB flash | 768 B OTP |
| RAM Size | 24 B | 24 B | 24 B | 25 B | 72 B | 25 B |
| I/O Pins | 20 | 20 | 20 | 12 (different pinout mapping) | 20 | 12 |
| Memory Type | OTP | OTP | OTP | Flash (reprogrammable) | Flash (reprogrammable) | OTP |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Active | Active | Obsolete |
Key Differentiators
- HSE speed bin at 16 MHz matches HS speed bin drop-in (vs PIC16C55-HS/SP)
- Flash reprogrammability upgrade path in same footprint (vs PIC16F54-I/P)
- 3x program memory in same package for future firmware growth (vs PIC16F57-I/P)
- Higher 20 MHz clock headroom for performance upgrades (vs PIC16C54A-20I/SP)
Design Notes
Decouple VDD (pin 26) with a 100 nF ceramic capacitor placed within 5 mm of the pin and a bulk 10 uF electrolytic at the board entry point. The PIC16C55-HSE/SP draws typically 2 mA active at 16 MHz and 5 V; sleep mode current drops to under 5 uA, suitable for battery-backed designs. Keep VDD rise time under 50 ms to ensure proper brown-out reset behavior per the Microchip datasheet.
Route the 16 MHz HSE crystal traces (OSC1 pin 25, OSCC2 pin 24) as short, symmetric pairs with a ground guard ring or guard trace beneath to minimize EMI coupling into adjacent signals. Keep crystal traces under 10 mm and place load capacitors within 3 mm of the oscillator pins. Use a 2-layer board minimum with a continuous ground plane under the IC for stable oscillator operation.
PIC16C55-HSE/SP is OTP (One-Time-Programmable) - firmware cannot be erased or rewritten after programming. Verify code with Microchip's MPLAB SIM simulator and a windowed PIC16C55 JW part before committing to the OTP version. For new designs always choose the flash-based PIC16F54-I/P drop-in replacement. The 2-level hardware stack also limits call nesting depth to 2 - avoid deep subroutines or refactor with iterative code.
Place the /MCLR pull-up resistor (typically 10 kOhm) directly at pin 6 with no stubs. Add a 100 nF cap from /MCLR to ground if the pin is exposed to noisy environments. For in-system programming of related PIC16F parts via ICSP, reserve PGD/PGC traces even on this OTP version in case a future board revision needs the flash variant - it saves a board spin.
Compliance Information
RoHS compliance per Microchip product page. Not AEC-Q100 qualified - automotive applications should select AEC-Q100 qualified parts. Halogen-free status unknown from verified data; refer to manufacturer declaration.
