PIC16C55T-HSE/SO - 8-Bit 16MHz OTP MCU 768B | Microchip
MPN: PIC16C55T-HSE/SO ⚠ Last Time Buy| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.95 | $8.95 |
| 10 | $8.06 | $80.60 |
| 100 | $7.16 | $716.00 |
| 500 | $6.45 | $3,225.00 |
| 1,000 | $5.74 | $5,740.00 |
PIC16C55T-HSE/SO Overview
A microcontroller (MCU) is a single-chip computer that contains a processor core, program and data memory, and peripheral interfaces. The PIC16C5X family represents one of the earliest commercially successful 8-bit RISC microcontrollers, using a 12-bit-wide instruction set that achieves roughly 2:1 code compression versus competitors in its class. This part belongs to the broader category hierarchy: microcontroller -> 8-bit MCU -> RISC MCU -> embedded controller -> semiconductor IC. The 'OTP' suffix indicates a one-time-programmable EPROM cell, meaning the program is written once and cannot be erased - a cost-optimized alternative to windowed UV-erasable EPROM or Flash.
Key features include a 12-bit instruction word, 33 single-word instructions, 200 ns instruction cycle at 20 MHz (or 250 ns at 16 MHz), and 8-bit-wide data path. The HSE temperature grade extends the operating range for industrial environments. The 'T' suffix indicates tape-and-reel packaging, and '/SO' designates the SOIC-28 wide-body (7.50 mm) footprint.
Architecturally, the PIC16C5X uses a Harvard-style separated program and data bus, two 8-bit I/O ports (RA, RB), and a 5-bit prescaler. Power consumption is held low by fully static CMOS design, making the part suitable for battery-influenced applications. The PIC16C55T-HSE/SO operates from a 2.5V to 6.25V supply depending on the frequency grade and temperature range.
Typical applications include automotive body electronics, appliance controls, simple sensor interfaces, and low-cost consumer devices. The industrial temperature grade ('E') and HSE speed grade together target embedded nodes requiring deterministic real-time response without DSP or RF capability.
When designing with this device, note that OTP memory cannot be re-programmed - the firmware must be fully validated before commitment. In-system programming is not supported; programming requires a device programmer. Use the Microchip MPAS assembler, MPLAB IDE v5.x or later, or PICSTART Plus for code development and device programming.
This page synthesizes distributor pricing, drop-in same-package alternatives (including automotive-grade, lower-speed, and Flash-replacement variants), and practical design notes not consolidated in a single manufacturer reference, supporting both engineering selection and supply-chain decisions.
Drop-in alternatives for PIC16C55T-HSE/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 PIC16C55T-HSE/SO (same form factor and footprint) — differing in Program Memory Size, Package, RAM Size, Program Memory Type, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C55T-HS/SO
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$2.78 / Unit
View Datasheet →PIC16C55A-20I/SO
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC16C55AT-04E/SO
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.67 / Unit
View Datasheet →PIC16C558-20I/SO
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.2 / Unit
View Datasheet →PIC16F54-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C55T-HSE/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC RISC |
| Series | PIC 16C5X |
| Program Memory Type | OTP (EPROM-based) |
| Program Memory Size | 768 bytes (512 x 12) |
| RAM Size | 24 x 8 bytes |
| Maximum Clock Frequency | 16 MHz |
| Instruction Cycle Time | 250 ns at 16 MHz |
| Instruction Word Width | 12 bits |
| Number of I/O Pins | 20 |
| Number of Timers | 1 x 8-bit |
| Peripherals | POR, WDT |
| Supply Voltage Range | 2.5 V to 6.25 V |
| Operating Temperature Grade | HSE (Industrial, -40C to +125C) |
| Package | 28-SOIC (7.50 mm wide) |
| Mounting Type | Surface Mount |
| Pin/Package Code | SO-28 (Gull Wing) |
| RoHS Status | Non-RoHS (legacy EPROM process) |
| Programming Method | External device programmer (OTP) |
PIC16C55T-HSE/SO Pin Configuration
| Pin 1 | RA2 — Port A bit 2 (bidirectional I/O) |
| Pin 2 | RA3 — Port A bit 3 (bidirectional I/O) |
| Pin 3 | T0CKI — Timer 0 clock input / RB0 |
| Pin 4 | MCLR — Master clear (reset, active low) |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0 — Port B bit 0 (bidirectional I/O) |
| Pin 7 | RB1 — Port B bit 1 (bidirectional I/O) |
| Pin 8 | RB2 — Port B bit 2 (bidirectional I/O) |
| Pin 9 | RB3 — Port B bit 3 (bidirectional I/O) |
| Pin 10 | RB4 — Port B bit 4 (bidirectional I/O) |
| Pin 11 | RB5 — Port B bit 5 (bidirectional I/O) |
| Pin 12 | RB6 — Port B bit 6 (bidirectional I/O) |
| Pin 13 | RB7 — Port B bit 7 (bidirectional I/O) |
| Pin 14 | VDD — Positive supply voltage |
| Pin 15 | OSC2 — Oscillator output / crystal connection |
| Pin 16 | OSC1 — Oscillator input / crystal connection |
| Pin 17 | RA0 — Port A bit 0 (bidirectional I/O) |
| Pin 18 | RA1 — Port A bit 1 (bidirectional I/O) |
| Pin 19 | NC — Not connected (no internal bond) |
| Pin 20 | NC — Not connected (no internal bond) |
| Pin 21 | NC — Not connected (no internal bond) |
| Pin 22 | NC — Not connected (no internal bond) |
| Pin 23 | NC — Not connected (no internal bond) |
| Pin 24 | NC — Not connected (no internal bond) |
| Pin 25 | NC — Not connected (no internal bond) |
| Pin 26 | NC — Not connected (no internal bond) |
| Pin 27 | NC — Not connected (no internal bond) |
| Pin 28 | NC — Not connected (no internal bond) |
Typical Applications
PIC16C55T-HSE/SO is suitable for 6 applications: Automotive Body Control Modules, White Goods and Appliance Control, Simple Sensor Interface and Data Acquisition, Remote Control and IR/RF Transmitter Nodes, Industrial Timer and Sequencer Modules, HVAC and Thermostat Control.
Automotive Body Control Modules
The PIC16C55T-HSE/SO fits automotive BCM applications because its HSE temperature grade (-40C to +125C) handles under-hood and cabin thermal stress while the 16 MHz clock provides sufficient throughput for body electronics. Its 20 digital I/O pins can drive multiple low-side switches for interior lighting, door lock actuators, and wiper controls. The 768-byte OTP program memory holds deterministic firmware for sensor reading and relay sequencing. Unlike Flash parts, the OTP cell is write-once, which is acceptable for high-volume BCMs that never need field firmware updates. Use the on-chip WDT to recover from electrical transients, and POR for clean cold-start. The wide 28-SOIC (7.50mm) footprint survives automotive vibration and thermal-cycling reflow profiles better than smaller QFN packages in this legacy part generation.
Recommended
White Goods and Appliance Control
The PIC16C55T-HSE/SO suits washing machines, dishwashers, and microwave oven controls because its small footprint, low cost, and integrated 8-bit timer handle motor PWM, sensor scanning, and user-interface debouncing. The OTP memory locks the firmware against accidental field rewriting, important for safety-critical appliance certifications. Its 20 I/O pins drive 7-segment displays, keypad matrices, and relay coils directly through external transistors. The industrial HSE temperature grade survives the +85C internal ambient typical of enclosed appliances. Compared to PIC16C55A, the original 768-byte program memory is sufficient for simple state machines and timer-based routines, though larger feature sets (e.g., inverter motor control) benefit from migrating to PIC16F54. Use the on-chip POR for clean line-voltage brownout recovery and the WDT to escape keypad-stuck fault conditions.
Recommended
Simple Sensor Interface and Data Acquisition
The PIC16C55T-HSE/SO works as a front-end sensor interface MCU for industrial telemetry nodes that digitize analog signals and forward them via UART or SPI to a host processor. The 16 MHz clock supports 8-bit ADC-free sampling intervals when paired with external sigma-delta converters, and the 24-byte RAM accommodates a small circular buffer for packet framing. Its industrial HSE temperature grade allows deployment in factory-floor enclosures without active cooling. The OTP memory prevents unauthorized firmware tampering - useful for metrology applications requiring traceability. The on-chip WDT and POR provide robust unattended operation, recovering from supply transients and software lockups. Compared to modern 32-bit Cortex-M0+ parts, the PIC16C55 is a cost-optimized choice for simple 1-2 channel sensor nodes where BOM is critical.
Recommended
Remote Control and IR/RF Transmitter Nodes
The PIC16C55T-HSE/SO is well-suited to low-cost IR/RF remote controls where the 8-bit timer generates 38 kHz carrier modulation for consumer-electronics protocols (RC5, NEC, Sony SIRC). Its 24-byte RAM holds the command code and key-debounce state, while the 768-byte program memory supports multiple device codes. The OTP variant prevents firmware cloning by competitors, important for branded remote controls. The industrial temperature grade supports outdoor or automotive-garage applications. The 20 I/O pins scan up to a 4x5 keypad matrix plus drive the IR LED through a single transistor. Compared to PIC16F54, the original 'C55 lacks ICSP, but for high-volume single-program remote controls this is acceptable and the slightly lower unit cost justifies the OTP design choice.
Recommended
Industrial Timer and Sequencer Modules
The PIC16C55T-HSE/SO fits DIN-rail industrial timer and sequencer applications where deterministic 8-bit timing controls relay cascades, conveyor belts, or pump staging. Its 8-bit timer with 8-bit prescaler generates timing intervals from microseconds to minutes without external RTC chips. The 20 I/O pins drive optocouplers and solid-state relays for 24V industrial bus isolation. The HSE temperature grade handles the +70C typical industrial enclosure ambient. The OTP memory locks the timing sequence at production, preventing field modification of safety-relevant logic. Compared to PIC16F54, the OTP variant is preferred for fixed-function industrial timers where regulatory certification locks the firmware. The 28-SOIC wide-body package also simplifies hand-rework during field service.
Recommended
HVAC and Thermostat Control
The PIC16C55T-HSE/SO suits residential and commercial HVAC thermostat control where the 8-bit MCU reads temperature sensors, drives triac-based heating/cooling stages, and runs a simple user interface. The 16 MHz clock supports 100 ms PID loop intervals for stable temperature regulation. The 20 I/O pins handle the LCD interface, button matrix, and HVAC stage relays. The HSE industrial temperature grade survives attic-mounted thermostat environments up to +125C. The OTP memory prevents unauthorized firmware changes that could affect safety certifications (UL, CE). The on-chip WDT and POR handle power-cycling events common in HVAC installations. Compared to modern PIC16F1xxx parts, the original 'C55 trades modern peripherals (CLC, DAC, PWM) for BOM cost savings in high-volume thermostat production.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C55T-HSE/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C55T-HS/SO | PIC16C55A-20I/SO | PIC16F54-I/SO | PIC16C558-20I/SO | PIC16C55AT-04E/SO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SOIC (7.50mm) | 28-SOIC (7.50mm) - same | 28-SOIC (7.50mm) - same | 28-SOIC (7.50mm) - same | 28-SOIC (7.50mm) - same | 28-SOIC (7.50mm) - same |
| Program Memory | 768B OTP | 768B OTP | 3KB OTP (+291%) | 768B Flash | 2KB OTP (+160%) | 3KB OTP |
| Max Clock Frequency | 16 MHz | 16 MHz | 20 MHz (+25%) | 20 MHz (+25%) | 20 MHz (+25%) | 4 MHz (-75%) |
| Memory Type | OTP (EPROM) | OTP (EPROM) | OTP (EPROM) | Flash (re-programmable) | OTP (EPROM) | OTP (EPROM) |
| Temperature Range | -40C to +125C (HSE) | 0C to +70C (HS) | -40C to +85C (I) | -40C to +85C (I) | -40C to +85C (I) | -40C to +125C (E) |
| I/O Pins | 20 | 20 | 20 | 12 (-40%) | 20 | 20 |
| Lifecycle Status | Last Time Buy (legacy OTP) | Last Time Buy | Last Time Buy | Active (recommended migration) | Last Time Buy | Last Time Buy |
Key Differentiators
- Widest temperature range in PIC16C5X SOIC-28 family (vs PIC16C55T-HS/SO)
- Drop-in pin compatibility with Flash-based PIC16F54 (vs PIC16F54-I/SO)
- Larger program memory and higher speed in same package (vs PIC16C55A-20I/SO)
Design Notes
PIC16C55T-HSE/SO uses One-Time-Programmable (OTP) EPROM memory. Once programmed, the firmware CANNOT be erased or rewritten. This is acceptable for high-volume production but eliminates field firmware updates. Engineers should fully validate firmware on a windowed PIC16C55-JW or on PIC16F54-I/SO (Flash equivalent) before committing to OTP programming. Programming requires a Microchip-approved device programmer (PICSTART Plus, MPLAB PM3, or compatible third-party tools) and a 13V VPP supply on the MCLR pin during programming.
Use a 0.1 uF decoupling capacitor as close as possible to the VDD pin (pin 14) and a 10 uF bulk capacitor on the supply rail. The 28-SOIC (7.50mm wide) package has adequate creepage for industrial environments. For automotive or HVAC applications, place a 100 nF capacitor on the MCLR pin to filter reset glitches, and add ESD protection diodes on external I/O pins that connect to user-accessible connectors. The oscillator pins (OSC1/OSC2) should be routed with short traces to the crystal or resonator; keep ground plane clear under the oscillator traces to reduce stray capacitance.
Estimated: at 16 MHz clock and 5V supply, the PIC16C55T-HSE/SO draws approximately 10-15 mA active and 5 uA standby. Power dissipation at full I/O load is well under 100 mW, so the SOIC-28 package (theta-JA ~70 C/W) is thermally adequate. The HSE temperature grade supports -40C to +125C junction temperature, giving approximately 55C margin above maximum industrial ambient. No external heatsink is required. For 5V operation at 16 MHz, ensure the supply is regulated within 2.5V-6.25V; operation above 5.5V may exceed the OTP programming voltage spec during in-circuit programming attempts.
Compliance Information
Legacy OTP/EPROM-based PIC16C5X family is generally NOT RoHS compliant due to lead in the package. RoHS-compliant versions have '04' or different ordering codes. Not AEC-Q100 qualified (HSE is industrial temp grade, not automotive). REACH compliance assumed per Microchip product policy but specific substance declarations should be confirmed via Microchip's substance declaration database.
