PIC16C56A-04E/P - 1.5KB OTP 8-bit MCU, 4MHz, Ext Temp | Microchip
MPN: PIC16C56A-04E/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.9 | $1.90 |
| 10 | $1.71 | $17.10 |
| 100 | $1.52 | $152.00 |
| 500 | $1.36 | $680.00 |
| 1,000 | $1.21 | $1,210.00 |
PIC16C56A-04E/P Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, working RAM and peripheral I/O. The PIC16C5X series belongs to the original baseline PIC architecture using 12-bit wide instructions and a RISC instruction set of only 33 single-word, single-cycle opcodes. Within the broader taxonomy, this part is a 8-bit MCU -> microcontroller -> embedded processor -> semiconductor IC. Its baseline RISC architecture makes it well suited to deterministic, low-cost control loops rather than to high-throughput digital signal processing.
Key features of the PIC16C56A-04E/P include 1.5KB OTP program memory (one-time field-programmable, ideal for mature/production code), 25 bytes of RAM, a 4MHz maximum operating frequency giving 1us instruction cycle, 12 bidirectional I/O pins, an 8-bit timer/counter (TMR0) with an 8-bit programmable prescaler, watchdog timer with on-chip RC oscillator, Power-on Reset, and brown-out detection. The device is built on a fully static CMOS process, allowing clock frequencies down to DC. Power-saving SLEEP mode and a wide 2.5V-5.5V operating range simplify battery and industrial 5V designs.
Typical applications include automotive body controllers, HVAC damper control, appliance front panels, simple sensor interfaces, white-goods motor control, security alarm keypads, and low-cost replacement of 555-timer-based discrete logic. The extended temperature grade (-40C to +125C) allows under-hood deployment.
When designing with this device, remember that OTP parts cannot be reprogrammed in-circuit; an EPROM windowed version (PIC16C56A-04/JW) is required for prototype development. For higher-volume or flash-based designs consider the pin-compatible PIC16F54 family.
Drop-in alternatives for PIC16C56A-04E/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 PIC16C56A-04E/P (same form factor and footprint) — differing in Package, Timers, Program Memory Size, Program Memory Type, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C55A-04E/P
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$3.15 / Unit
View Datasheet →PIC16C57C-04E/P
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC16C558-04E/P
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.55 / Unit
View Datasheet →PIC16F54-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C56A-04E/P Maximum Ratings & Electrical Characteristics
| Family | PIC16C5X (PIC16C56A) |
| Core | 8-bit RISC (12-bit instructions, 33 opcodes) |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 1.5 KB (1K x 12) |
| RAM | 25 bytes |
| Maximum CPU Frequency | 4 MHz |
| Instruction Cycle | 1 us @ 4 MHz |
| I/O Pins | 12 |
| Timers | 1 x 8-bit (TMR0) with 8-bit programmable prescaler |
| Watchdog Timer | Yes (on-chip RC oscillator) |
| Brown-out Reset | Yes |
| Power-on Reset | Yes |
| Supply Voltage | 2.5 V to 5.5 V |
| Operating Temperature | -40C to +125C (Extended, "E" grade) |
| Package | 18-pin PDIP (0.300", 7.62 mm) |
| Mounting Type | Through-Hole |
| RoHS Status | Compliant |
PIC16C56A-04E/P Pin Configuration
| Pin 1 | RA2 — Bidirectional I/O, Port A bit 2 |
| Pin 2 | RA3 — Bidirectional I/O, Port A bit 3 |
| Pin 3 | RA4/T0CKI — Bidirectional I/O / Timer0 clock input |
| Pin 4 | MCLR/Vpp — Master Clear (Reset) / Programming voltage input |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0/INT — Bidirectional I/O, Port B bit 0 / External interrupt |
| Pin 7 | RB1 — Bidirectional I/O, Port B bit 1 |
| Pin 8 | RB2 — Bidirectional I/O, Port B bit 2 |
| Pin 9 | RB3 — Bidirectional I/O, Port B bit 3 |
| Pin 10 | RB4 — Bidirectional I/O, Port B bit 4 |
| Pin 11 | RB5 — Bidirectional I/O, Port B bit 5 |
| Pin 12 | RB6 — Bidirectional I/O, Port B bit 6 |
| Pin 13 | RB7 — Bidirectional I/O, Port B bit 7 |
| Pin 14 | VDD — Positive supply (2.5V to 5.5V) |
| Pin 15 | OSC2/CLKOUT — Oscillator crystal output / Clock out (Fosc/4) |
| Pin 16 | OSC1/CLKIN — Oscillator crystal input / External clock input |
| Pin 17 | RA0 — Bidirectional I/O, Port A bit 0 |
| Pin 18 | RA1 — Bidirectional I/O, Port A bit 1 |
Typical Applications
PIC16C56A-04E/P is suitable for 6 applications: Automotive Body Controller, Appliance Front-Panel Controller, Security Alarm Keypad, Low-Cost Sensor Interface, Replacement of 555-Timer Discrete Logic, Industrial Timer and Counter Modules.
Automotive Body Controller
The PIC16C56A-04E/P's -40C to +125C extended temperature grade and OTP memory make it a natural fit for automotive body electronics such as mirror adjusters, seat controllers and HVAC mode selectors. Its 12 bidirectional I/O pins directly drive relay coils, LED indicators and switch inputs while the on-chip 8-bit TMR0 with prescaler handles debounce and PWM for motor speed control. With 1.5KB of OTP code space, designers can comfortably implement state machines for position memory, soft-start routines and fault diagnostics. The brown-out reset and watchdog timer provide the resilience demanded by under-hood electrical environments with cranking transients and load-dump spikes. The 18-pin PDIP package supports through-hole assembly for serviceable modules.
Recommended
Appliance Front-Panel Controller
In washing machines, microwave ovens and induction cooktops, the PIC16C56A-04E/P serves as the front-panel MCU scanning 4x3 key matrices, driving 7-segment LED displays and toggling triac outputs. The 12 I/O pins are sufficient for an 8-key matrix plus 4 digit/segment strobes, while the 1us instruction cycle at 4 MHz lets the chip execute full panel scans inside the human-perceptible debounce window. OTP memory guarantees the firmware cannot be field-tampered with, important for safety-certified white goods. The 25-byte RAM is adequate for digit buffers and last-key latches. Power-on reset and brown-out detection protect against brown-outs during compressor inrush.
Recommended
Security Alarm Keypad
The PIC16C56A-04E/P powers traditional wired security keypads where 4x4 matrix scanning, LED annunciation and a piezo buzzer driver must run from a single 5V supply. Its low component count (no external oscillator beyond a 4 MHz resonator or internal RC) keeps the BOM under $2, critical for high-volume residential panels. The watchdog timer with on-chip RC oscillator prevents code lock-up if the supply is interrupted. SLEEP mode with the watchdog enabled keeps standby current under 10 uA, extending backup-battery runtime during AC outages. OTP firmware prevents unauthorized code extraction from stolen modules. Brown-out reset ensures clean recovery after deep battery discharge.
Recommended
Low-Cost Sensor Interface
For thermistor-based temperature transmitters, optical encoders and simple pulse-counting flow meters, the PIC16C56A-04E/P offers enough MIPS to linearize sensors and drive a 4-20 mA loop or UART-style current loop. The 12 I/O pins handle multiple analog channels via a resistor mux to a single comparator, or count quadrature encoder pulses with TMR0. With 1.5KB of OTP, designers can implement lookup tables for NTC thermistor linearization, hysteresis filters and calibration constants. The wide 2.5V-5.5V supply range supports both 3.3V and 5V sensor rails. SLEEP mode plus watchdog wake-up extends battery life to several years on a single lithium cell.
Recommended
Replacement of 555-Timer Discrete Logic
Many legacy products use 555-timer astables, CD4017 decade counters and discrete flip-flops to generate sequence logic. The PIC16C56A-04E/P can replace an entire board of glue logic with a single chip, reducing PCB area by 60-80% and BOM cost by 30-50%. Its 33-instruction RISC core easily handles monostable/astable equivalents, sequencers, and frequency dividers that previously required dozens of CMOS gates. The OTP memory lets designers commit custom timing diagrams, eliminating the need for trim pots. Brown-out reset and watchdog improve reliability over the discrete 555 circuits that often hang under transient supply noise.
Recommended
Industrial Timer and Counter Modules
DIN-rail industrial timers, cycle counters and process-interval relays use the PIC16C56A-04E/P for time-base generation, button debouncing and relay output control. The TMR0 with 8-bit prescaler provides accurate 100 ms / 1 s / 1 min time bases from a 4 MHz resonator; combined with software counters, this implements timing ranges from milliseconds to hours. The 12 I/O pins drive up to 4 SPDT relays and read 4 user inputs. OTP memory ensures the timing parameters cannot drift in the field. The -40C to +125C extended temperature grade tolerates unheated control cabinets and outdoor enclosures. Brown-out reset prevents relay chattering during supply dips.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C56A-04E/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C55A-04E/P | PIC16C57C-04E/P | PIC16C558-04E/P | PIC16F54-I/P |
|---|---|---|---|---|---|
| Package | PDIP-18 (through-hole) | PDIP-18 - same | PDIP-18 - same | PDIP-18 - same | PDIP-18 - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 1.5 KB OTP | 0.75 KB OTP (-50%) | 3 KB OTP (+100%) | 2 KB OTP (+33%) | 0.75 KB Flash |
| RAM | 25 bytes | 25 bytes - same | 72 bytes (+188%) | 128 bytes (+412%) | 25 bytes - same |
| Maximum Clock | 4 MHz | 4 MHz - same | 4 MHz - same | 4 MHz - same | 20 MHz (+400%) |
| Memory Type | OTP (one-time) | OTP - same | OTP - same | OTP - same | Flash (reprogrammable) |
| I/O Pins | 12 | 12 - same | 20 (in PDIP-28 package) | 13 (+1) | 12 - same |
| Operating Temperature | -40C to +125C (Extended) | -40C to +125C - same | -40C to +125C - same | -40C to +125C - same | -40C to +85C (Industrial) |
| Supply Voltage | 2.5V to 5.5V | 2.5V to 5.5V - same | 2.5V to 5.5V - same | 2.5V to 5.5V - same | 2.0V to 5.5V |
Key Differentiators
- Largest OTP program memory in PIC16C5X family at 1.5KB (vs PIC16C55A-04E/P)
- Automotive extended temperature grade (-40C to +125C) (vs PIC16F54-I/P)
- Single 8-bit timer vs PIC16C558's enhanced peripheral set (vs PIC16C558-04E/P)
Design Notes
Decouple VDD (pin 14) with a 100 nF ceramic capacitor placed within 5 mm of the pin, plus a 10 uF bulk capacitor if the supply is shared with relays or other switching loads. The PIC16C56A-04E/P draws about 2 mA at 4 MHz and 5 V; brown-out reset holds the part in reset if VDD drops below 2.5 V, so bulk capacitance is also useful for ride-through during brief supply dips.
Keep the 4 MHz crystal (or ceramic resonator) traces on pin 15 (OSC2) and pin 16 (OSC1) short (<10 mm) and surrounded by a ground pour to minimize EMI pickup. The MCLR/Vpp pin (4) requires a 10 kohm pull-up to VDD for normal operation; if in-circuit programming is needed, route MCLR to a dedicated ICSP header rather than a noisy reset source.
PIC16C56A-04E/P is OTP and CANNOT be reprogrammed. For prototype development, order the windowed ceramic PIC16C56A-04/JW (UV-erasable) or the flash-based PIC16F54-I/P to avoid scrapping boards. Also note that the baseline PIC16C5X architecture does NOT have an interrupt controller - the TMR0 overflow and external INT on RB0/INT must be polled; do not write code expecting vectored interrupts.
Compliance Information
RoHS and lead-free per Microchip product page. AEC-Q100 not formally qualified but -40C to +125C extended grade makes it suitable for many non-safety-critical automotive body modules.
