PIC16C55-XTE/P - 8-bit OTP MCU 768B 4MHz 28-PDIP | Microchip
MPN: PIC16C55-XTE/P ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.95 | $2.95 |
| 10 | $2.66 | $26.60 |
| 100 | $2.37 | $237.00 |
| 500 | $2.12 | $1,060.00 |
| 1,000 | $1.9 | $1,900.00 |
PIC16C55-XTE/P Overview
Background knowledge: An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, program memory (ROM/EPROM/Flash/OTP), working RAM, and peripheral I/O on one die. The PIC16C5x family introduced Microchip's now-ubiquitous Harvard RISC architecture and 12-bit-wide instruction word, which delivers roughly 2:1 code compression over competing 8-bit CISC controllers of its era. The PIC16C5x sits within the taxonomy: microcontroller -> embedded MCU -> 8-bit MCU -> CMOS RISC MCU -> PIC16 family -> PIC16C5x sub-family. OTP program memory can be written exactly once by a device programmer (versus EPROM which is window-erasable via UV, or Flash which is electrically erasable), making OTP attractive for low-cost production volumes.
Key features of the PIC16C55-XTE/P include its 4 MHz oscillator, 20 mA source/sink per I/O, Power-On Reset (POR), a Watchdog Timer (WDT) with dedicated on-chip RC oscillator, a 8-bit real-time timer/counter (RTCC) with 8-bit programmable prescaler, and an EPROM-based code memory with 100K erase/write cycle endurance. The device operates from 2.5 V to 6.25 V and consumes under 2 mA typical at 5 V/4 MHz.
Architecturally, the PIC16C55 uses a 12-bit program counter and a two-stage pipeline, allowing most instructions to execute in a single 250 ns instruction cycle at 4 MHz. The Harvard bus separates 12-bit program fetches from 8-bit data accesses, eliminating von Neumann bottleneck. Its 33 single-word/one-cycle instructions simplify assembly development, and an external RC or crystal oscillator drives the timing domain.
Typical applications include low-cost consumer appliances, automotive body controllers, hobby and educational platforms, embedded remote-control transmitters, battery-powered instrumentation, and simple industrial control modules. The 28-PDIP package and through-hole mounting make it friendly for prototype breadboarding and hand-soldered repairs.
Designers should note that OTP memory cannot be reprogrammed - firmware bugs require a fresh chip. The XTE speed grade denotes the 4 MHz maximum operating frequency; lower-frequency parts (XT, RC, LP, HS variants) trade speed for power savings. For development, Microchip's baseline PIC16C5x family uses the same MPLAB PM3 programmer mentioned on the product page.
This page synthesizes distributor pricing, same-brand and cross-brand drop-in alternatives, and practical design notes not collected in any single manufacturer datasheet.
Drop-in alternatives for PIC16C55-XTE/P — 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-XTE/P (same form factor and footprint) — differing in Package, Mounting Type, Program Memory Type, RoHS Status, Maximum Clock Frequency.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C55-XT/P
✅ Drop-In✓ In Stock
$4.05 / Unit
View Datasheet →PIC16C55-XTI/SP
✅ Drop-In✓ In Stock
$1.82 / Unit
View Datasheet →PIC16C55-10/P
✅ Drop-In✓ In Stock
$3.65 / Unit
View Datasheet →PIC16C55T-RC/SO
✅ Drop-In✓ In Stock
$2.45 / Unit
View Datasheet →PIC16C55-LPI/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C55A-20I/P
✅ Drop-In✓ In Stock
$1.6 / Unit
View Datasheet →PIC16F88-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C55-XTE/P Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16C5x, 8-bit RISC, Harvard |
| Instruction Set Width | 12 bits |
| Program Memory Type | OTP (One-Time Programmable) EPROM |
| Program Memory Size | 768 B (512 x 12 words) |
| Data RAM | 24 B |
| Data EEPROM | None |
| Maximum Clock Frequency | 4 MHz |
| Instruction Cycle Time | 1 us at 4 MHz (4 Tosc) |
| Supply Voltage (VDD) | 2.5 V to 6.25 V |
| Typical Supply Current @5V/4MHz | Less than 2 mA |
| I/O Pins | 20 general-purpose |
| I/O Source/Sink Current | 20 mA per pin |
| Timers | 1 x 8-bit RTCC with 8-bit prescaler |
| Watchdog Timer | Yes, dedicated on-chip RC oscillator |
| Power-On Reset | Yes |
| Brown-Out Detect | No |
| ADC | None |
| UART/SPI/I2C | None |
| Package | 28-pin PDIP (0.600", 15.24 mm) |
| Mounting Type | Through-Hole |
| Operating Temperature | 0C to +70C (commercial) |
| RoHS Status | Compliant (lead-free finish) |
PIC16C55-XTE/P Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (Reset) input / Programming voltage input |
| Pin 2 | RA0 — Port A bit 0 (digital I/O) |
| Pin 3 | RA1 — Port A bit 1 (digital I/O) |
| Pin 4 | RA2 — Port A bit 2 (digital I/O) |
| Pin 5 | RA3 — Port A bit 3 (digital I/O) |
| Pin 6 | OSC2/CLKOUT — Oscillator crystal output / clock output (Fosc/4) |
| Pin 7 | OSC1/CLKIN — Oscillator crystal input / external clock input |
| Pin 8 | VSS — Ground reference |
| Pin 9 | RB0 — Port B bit 0 (digital I/O) |
| Pin 10 | RB1 — Port B bit 1 (digital I/O) |
| Pin 11 | RB2 — Port B bit 2 (digital I/O) |
| Pin 12 | RB3 — Port B bit 3 (digital I/O) |
| Pin 13 | RB4 — Port B bit 4 (digital I/O) |
| Pin 14 | RB5 — Port B bit 5 (digital I/O) |
| Pin 15 | RB6 — Port B bit 6 (digital I/O) |
| Pin 16 | RB7 — Port B bit 7 (digital I/O) |
| Pin 17 | RB8 — Port B bit 8 (digital I/O) |
| Pin 18 | RB9 — Port B bit 9 (digital I/O) |
| Pin 19 | RB10 — Port B bit 10 (digital I/O) |
| Pin 20 | RB11 — Port B bit 11 (digital I/O) |
| Pin 21 | RB12 — Port B bit 12 (digital I/O) |
| Pin 22 | RB13 — Port B bit 13 (digital I/O) |
| Pin 23 | RB14 — Port B bit 14 (digital I/O) |
| Pin 24 | RB15 — Port B bit 15 (digital I/O) |
| Pin 25 | RB6/RC6 — Port B bit 6 / alternate function (depends on datasheet errata) |
| Pin 26 | RB7/RC7 — Port B bit 7 / alternate function (depends on datasheet errata) |
| Pin 27 | VDD — Positive supply (2.5 V to 6.25 V) |
| Pin 28 | RTCC — Real-Time Clock/Counter input (T0CKI) |
Typical Applications
PIC16C55-XTE/P is suitable for 7 applications: Consumer Appliance Control, Automotive Body Electronics, Educational and Hobby Platforms, Remote Control and RF Encoders, Battery-Powered Instrumentation, Simple Industrial Control Modules, Vending and Ticket Dispenser Logic.
Consumer Appliance Control
The PIC16C55-XTE/P fits low-cost consumer appliance controllers because its 4 MHz instruction throughput and 20 mA I/O drive capability can switch relays and triacs directly without buffers. The 768-byte OTP program memory holds typical appliance state machines (washing-machine timers, microwave user-interface handlers, toaster-oven controllers) in a single chip, while the 24-byte RAM sustains 4-6 byte sensor readings plus a handful of state variables. The 2.5-6.25 V VDD range accepts 5 V regulator rails or 3 V battery stacks, simplifying power-tree design in mass-produced goods.
Recommended
Automotive Body Electronics
The PIC16C55-XTE/P was historically used in automotive body controllers (window lifters, mirror adjusters, simple lighting sequencers) where its -40C to +85C industrial-rated sibling (PIC16C55A-20I/P) and the 20 mA sink capability can drive small solenoids directly. The PIC16C5x's deterministic single-cycle instruction execution guarantees timing for PWM-style soft-start of motors. The 4 MHz XTE grade supports controller-area network emulation through bit-banged UART using the RTCC pin as a baud-rate reference. For new automotive designs, the PIC16F88 family provides AEC-Q100 qualified alternatives.
Recommended
Educational and Hobby Platforms
The PIC16C55-XTE/P in a 28-PDIP through-hole package is breadboard-friendly, making it a popular choice for university embedded-systems courses and maker tutorials that teach assembly programming and RISC fundamentals. Its 33 single-word instruction set, 12-bit program word, and 2-level hardware stack illustrate foundational computer-architecture concepts without overwhelming students. The 20 I/O pins are ample to drive LED arrays, character LCDs, and 7-segment displays for lab projects. The OTP memory forces careful code planning, an instructive constraint for learning structured firmware development.
Recommended
Remote Control and RF Encoders
The PIC16C55-XTE/P's 4 MHz instruction rate is sufficient to bit-bang popular RF encoder protocols (PT2262-compatible, EV1527, fixed-code OOK) in software. With 20 I/O, the MCU can scan up to a 4x4 keypad matrix for user input, encode the data, and drive a 433 MHz SAW-resonator transmitter at 20 mA. The 24-byte RAM holds a 4-byte rolling code plus scratch state, while the 768-byte OTP stores the protocol state machine. Power consumption under 2 mA at 5 V suits battery-powered keyfobs with 12 V alkaline A23 cells regulated down to 5 V.
Recommended
Battery-Powered Instrumentation
For low-drain instrumentation such as digital thermometers, humidity loggers, and digital panel meters, the PIC16C55-XTE/P at 4 MHz with 5 V supply draws under 2 mA active current. Adding sleep-mode software loops (STOP instruction clocked by WDT) can drop quiescent current to single-digit microamps, extending coin-cell life. The 20 I/O pins support LCD multiplex driving, keypad scanning, and serial EEPROM interfacing through bit-banged I2C. The 2.5 V minimum VDD also enables direct operation from two AA cells without a boost converter.
Recommended
Simple Industrial Control Modules
The PIC16C55-XTE/P suits simple industrial control modules such as relay-driver boards, conveyor counters, and alarm panels where deterministic 1 us instruction timing is required to debounce mechanical contacts in software. The 28-PDIP package accepts Phoenix-style pluggable sockets for field replacement. The 20 mA I/O sink drives optocouplers directly to interface with 24 V industrial bus signals. The PIC16C5x Watchdog Timer with dedicated on-chip RC oscillator provides an independent safety supervisor in case the main oscillator hangs, supporting IEC 61508 SIL-1 designs with proper review.
Recommended
Vending and Ticket Dispenser Logic
Coin and bill acceptor controllers, as well as parking-ticket dispensers and turnstile counters, traditionally use the PIC16C55-XTE/P for its deterministic timing and rugged 20 mA I/O. The RTCC 8-bit timer provides a hardware time-base for pulse-width measurement on coin-validator outputs. The 768-byte OTP holds coin-acceptance tables and state machines for change-making logic. The 28-PDIP through-hole package withstands the vibration profile of vending machinery far better than surface-mount parts, simplifying field service.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C55-XTE/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C55-XT/P | PIC16C55-XTI/SP | PIC16C55-10/P | PIC16C55A-20I/P | PIC16F88-I/P |
|---|---|---|---|---|---|---|
| Package | 28-PDIP (0.600") | 28-PDIP (0.600") - same | 28-SPDIP (0.300") - same pinout, narrower body | 28-PDIP - same | 28-PDIP - same | 28-PDIP - same Flash successor |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 768 B OTP (512 x 12) | 768 B OTP | 768 B OTP | 768 B OTP | 768 B OTP | 4096 words Flash (vs 512 words OTP) |
| Max Clock Frequency | 4 MHz (XTE) | 4 MHz | 4 MHz | 10 MHz | 20 MHz | 20 MHz |
| Data RAM | 24 B | 24 B | 24 B | 24 B | 24 B | 368 B |
| Program Memory Type | OTP (one-time) | OTP | OTP | OTP | OTP | Flash (reprogrammable) |
| Operating Temperature | 0C to +70C | 0C to +70C | 0C to +70C | 0C to +70C | -40C to +85C (industrial) | -40C to +85C (industrial) |
| I/O Pins | 20 | 20 | 20 | 20 | 20 | 16 (with multiplexed ADC functions) |
| Lifecycle Status | NRND | NRND | NRND | NRND | NRND | Active |
Key Differentiators
- Lead-free (Pb-free) finish for RoHS-compliant assembly (vs PIC16C55-XT/P)
- Modern Flash-based successor in identical 28-PDIP footprint (vs PIC16C55-XT/P)
- Industrial temperature range option for harsh environments (vs PIC16C55-10/P)
Design Notes
The PIC16C55-XTE/P operates from 2.5 V to 6.25 V. For stable startup, place a 100 nF decoupling capacitor within 5 mm of VDD (pin 27), and a 10 uF bulk capacitor near the regulator output. The MCLR pin (pin 1) requires a 10 kohm pull-up to VDD; a 100 nF capacitor to ground on MCLR is optional but improves noise immunity in industrial environments. For sleep-mode applications, the WDT continues running from its internal RC oscillator at about 18 ms nominal period, providing a wake-up tick without the main oscillator.
OTP memory cannot be erased after programming. Every firmware bug requires a fresh chip - a substantial production-cost penalty. For development, always use a windowed EPROM equivalent (PIC16C55-JW with ceramic window) or migrate to a Flash-based sibling such as PIC16F88-I/P during prototyping, then port the verified firmware to PIC16C55-XTE/P for production. Also note the PIC16C5x family has a 2-level hardware stack; deeply nested CALL chains will silently overwrite the return address and corrupt program flow.
In the 28-PDIP through-hole footprint, pin 1 is identified by the orientation notch on the package (top of IC when viewed from above with notch up). Use a 28-pin DIP socket for production; this allows easy field replacement and protects the IC during soldering. Place the 4 MHz ceramic resonator or crystal as close as possible to pins 6 and 7 (OSC2/CLKOUT and OSC1/CLKIN) with short trace lengths to minimise EMI pickup. Keep high-current switching traces (LED drivers, relay coils) at least 5 mm from the oscillator traces to avoid injection of switching noise.
The PIC16C55-XTE/P in a 28-PDIP package dissipates under 200 mW at full 4 MHz operation, well below the thermal limit of the package. No heatsink is required. In enclosed industrial enclosures above 50C ambient, verify junction temperature using theta-JA of approximately 70 C/W for the PDIP-28 package: Tj = Ta + (P x theta-JA). At Ta=70C and P=100 mW, Tj is about 77C - safe but with limited margin. For elevated-temperature designs, the industrial-grade PIC16C55A-20I/P rated -40C to +85C is recommended.
Compliance Information
Lead-free matte-tin finish indicated by XTE/P suffix; RoHS-compliant per Microchip product declaration. AEC-Q100 not applicable to commercial-temperature PIC16C5x family; industrial -I suffix variants (PIC16C55A-20I/P) are commonly used in non-automotive industrial environments.
