PIC16C57-HSI/SP - 8-bit EPROM MCU, 3KB, 20MHz, SPDIP-28 | Microchip
MPN: PIC16C57-HSI/SP ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.07 | $4.07 |
| 10 | $3.62 | $36.20 |
| 100 | $3.3 | $330.00 |
| 500 | $3 | $1,500.00 |
| 1,000 | $2.7 | $2,700.00 |
PIC16C57-HSI/SP Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, non-volatile program memory, working RAM, and peripheral interfaces such as timers, I/O ports, and interrupt controllers into one package. The PIC16C5X family occupies the entry-level, cost-sensitive tier of the broader 8-bit microcontroller category, sitting below PIC16 enhanced mid-range parts and PIC18 high-performance 8-bit families in the Microchip hierarchy. PIC microcontrollers are widely used as the "brain" of embedded systems that require deterministic real-time response, low power consumption, and reprogrammability during prototyping.
Key features of the PIC16C57-HSI/SP include an 8-bit real-time clock/counter (TMR0) with an 8-bit programmable prescaler, a two-level deep hardware stack for subroutine nesting, and three addressing modes: direct, indirect, and relative. The device offers seven or eight special-function hardware registers, an internal reset circuit, and a watchdog timer option that can be enabled via configuration bits. Power consumption is low due to CMOS technology, with multiple sleep/idle modes for battery-powered designs. I/O pins can source or sink up to 25mA per pin, allowing direct drive of LEDs and small relays.
Typical applications span consumer electronics, appliance control, automotive subsystems, industrial sensor interfaces, and educational/development platforms. The 20 I/O lines support keypad scanning, LED multiplexing, LCD bias generation, and serial communication via bit-banged protocols (UART, SPI, I2C implemented in software). The 28-pin SPDIP package makes the part well suited for hand-soldered prototypes, breadboards, and low-volume production runs where through-hole assembly is preferred.
When designing with the PIC16C57-HSI/SP, note that the part is OTP (one-time-programmable) and does not support in-circuit reprogramming. The "HSI" suffix denotes a high-speed crystal/oscillator mode with a 20MHz maximum frequency, distinct from "RC" (resistor-capacitor timing) and "LP" (low-power crystal) oscillator variants. Choose the HSI version when instruction throughput is critical; choose RC or LP when cost, board space, or power consumption is the priority.
This page synthesizes distributor pricing, package-compatible drop-in alternatives from the same PIC16C5X family, and practical design notes not found in the manufacturer datasheet. For OEM-scale volumes consider the mask-ROM equivalents (PIC16CR57) for unit-cost reduction once firmware is finalized.
Drop-in alternatives for PIC16C57-HSI/SP — 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 PIC16C57-HSI/SP (same form factor and footprint) — differing in Package, Program Memory Size, Program Memory Type, Timers, Watchdog Timer.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C57-HSI/P
✅ Drop-In✓ In Stock
$1.89 / Unit
View Datasheet →PIC16C57-HS/P
✅ Drop-In✓ In Stock
$4.62 / Unit
View Datasheet →PIC16C57-HSE/SO
✅ Drop-In✓ In Stock
$5.18 / Unit
View Datasheet →PIC16C57C-40/P
✅ Drop-In✓ In Stock
$3.82 / Unit
View Datasheet →PIC16C57C-20/SO
✅ Drop-In✓ In Stock
$2.89 / Unit
View Datasheet →PIC16C57-10I/P
✅ Drop-In✓ In Stock
$1.75 / Unit
View Datasheet →PIC16C57CT-20I/SO
✅ Drop-In✓ In Stock
$4.05 / Unit
View Datasheet →PIC16C57CT-40/SO
✅ Drop-In✓ In Stock
$5.45 / Unit
View Datasheet →PIC16C57-HSI/SP Maximum Ratings & Electrical Characteristics
| Family | PIC16C5X (PIC16C57) |
| Core | 8-bit RISC PIC |
| Program Memory Type | EPROM (OTP) |
| Program Memory Size | 3 KB (2K x 12) |
| RAM Size | 72 bytes |
| Data EEPROM | Not available |
| Number of I/O Pins | 20 |
| Maximum Clock Frequency | 20 MHz |
| Instruction Cycle Time | 200 ns at 20 MHz |
| Oscillator Type | External high-speed crystal/oscillator (HSI mode) |
| Supply Voltage (Vdd) | 3.0 V to 5.5 V (3.3V/5V operation) |
| Timers | 1 x 8-bit (TMR0) with 8-bit prescaler |
| Hardware Stack | 2 levels |
| Watchdog Timer | Yes (configuration-bit enabled) |
| Package | 28-pin SPDIP (Skinny Plastic DIP, through-hole) |
| Mounting Type | Through-Hole |
| Operating Temperature | 0C to +70C (commercial) |
| Instruction Word Width | 12 bits |
| Data Path Width | 8 bits |
| I/O Sink/Source Current | 25 mA per pin (max) |
| RoHS Status | Non-RoHS (legacy through-hole OTP) |
PIC16C57-HSI/SP Pin Configuration
| Pin 1 | RA2 — Bidirectional I/O pin, Port A bit 2 |
| Pin 2 | RA3 — Bidirectional I/O pin, Port A bit 3 |
| Pin 3 | T0CKI — Timer0 clock input / RA4 I/O |
| Pin 4 | MCLR — Master Clear (active-low reset input) |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0 — Bidirectional I/O pin, Port B bit 0 |
| Pin 7 | RB1 — Bidirectional I/O pin, Port B bit 1 |
| Pin 8 | RB2 — Bidirectional I/O pin, Port B bit 2 |
| Pin 9 | RB3 — Bidirectional I/O pin, Port B bit 3 |
| Pin 10 | RB4 — Bidirectional I/O pin, Port B bit 4 |
| Pin 11 | RB5 — Bidirectional I/O pin, Port B bit 5 |
| Pin 12 | RB6 — Bidirectional I/O pin, Port B bit 6 |
| Pin 13 | RB7 — Bidirectional I/O pin, Port B bit 7 |
| Pin 14 | VSS — Ground reference (secondary) |
| Pin 15 | OSC2 — Oscillator output (crystal connection) |
| Pin 16 | OSC1 — Oscillator input (crystal connection) |
| Pin 17 | RC0 — Bidirectional I/O pin, Port C bit 0 |
| Pin 18 | RC1 — Bidirectional I/O pin, Port C bit 1 |
| Pin 19 | RC2 — Bidirectional I/O pin, Port C bit 2 |
| Pin 20 | RC3 — Bidirectional I/O pin, Port C bit 3 |
| Pin 21 | RC4 — Bidirectional I/O pin, Port C bit 4 |
| Pin 22 | RC5 — Bidirectional I/O pin, Port C bit 5 |
| Pin 23 | RC6 — Bidirectional I/O pin, Port C bit 6 |
| Pin 24 | RC7 — Bidirectional I/O pin, Port C bit 7 |
| Pin 25 | VDD — Positive supply voltage (3.0V to 5.5V) |
| Pin 26 | RA0 — Bidirectional I/O pin, Port A bit 0 |
| Pin 27 | RA1 — Bidirectional I/O pin, Port A bit 1 |
| Pin 28 | VDD — Positive supply voltage (secondary) |
Typical Applications
PIC16C57-HSI/SP is suitable for 6 applications: Consumer Appliance Control, Automotive Body Electronics, Industrial Sensor Interfaces, Educational Microcontroller Trainers, Hobbyist Embedded Projects, Security and Access Control Panels.
Consumer Appliance Control
The PIC16C57-HSI/SP is well-suited as the central controller in washing machines, microwave ovens, dishwashers, and other white goods where a deterministic 8-bit MCU manages user inputs, drives relay outputs, and sequences timed events. The 20 MHz clock yields 5 MIPS throughput, which is more than sufficient for sensor polling, keypad debounce, and display multiplexing. With 20 I/O pins and 25 mA sink/source capability, the part can directly drive LED indicators, seven-segment displays, and small relays without external buffers. The 3 KB OTP EPROM stores the final production firmware once development is complete, providing the lowest unit cost in volume. The 28-pin SPDIP through-hole package simplifies manufacturing for cost-sensitive consumer products where automated SMT assembly is not yet justified.
Recommended
Automotive Body Electronics
Within automotive body control modules such as seat controllers, mirror adjusters, and simple lighting drivers, the PIC16C57-HSI/SP offers the ruggedness and deterministic response needed for in-vehicle environments. The 20 I/O pins handle switch inputs, potentiometer wiper inputs, and PWM-output loads for motors and lamps, all without requiring complex peripherals. The two-level hardware stack and small interrupt latency guarantee bounded response to sensor events, critical for safety-related functions. The 3 KB EPROM holds fixed control algorithms such as motor speed curves and lamp fade profiles. Designers targeting modern automotive designs should verify AEC-Q100 qualification and consider Flash-based PIC16F or PIC18 successors; the PIC16C57-HSI/SP is appropriate for retrofit and aftermarket modules where its legacy pinout is mandated.
Recommended
Industrial Sensor Interfaces
The PIC16C57-HSI/SP serves as a compact protocol converter and signal-conditioning controller in industrial sensor front ends, where it reads analog signals via external comparator or ADC, scales them, and transmits the result over bit-banged UART or SPI links. The 20 MHz instruction throughput supports modest baud rates (up to 9600 bps software UART) and 10 kHz SPI clock for sensor readout. The 8-bit TMR0 with 8-bit prescaler enables precise interval timing for periodic sampling loops. Industrial designers benefit from the simple ICE-less programming model: firmware is burned once via OTP and the part operates without firmware update infrastructure. For new industrial designs requiring field-updatable firmware or on-chip ADC, consider PIC16F1xxx or PIC18F1xxx successors in the same 28-pin SPDIP footprint.
Recommended
Educational Microcontroller Trainers
Universities, technical colleges, and hobbyist electronics courses have used the PIC16C57 family since the 1990s as the canonical teaching vehicle for 8-bit embedded programming. The PIC16C57-HSI/SP provides students hands-on exposure to a simple RISC instruction set (33 instructions), 12-bit opcode architecture, and direct register manipulation without the abstraction layers of modern Cortex-M cores. Its 28-pin SPDIP package plugs directly into breadboards and solderless prototyping boards, allowing rapid experiment assembly without SMT rework tools. Lab exercises typically cover GPIO, timer interrupts, software UART, and EEPROM emulation. While OTP prevents in-circuit reprogramming, instructors can pre-program each lab session's firmware on individual chips, giving each student a fresh device for every assignment.
Recommended
Hobbyist Embedded Projects
For maker projects, retro computing reproductions, and DIY electronics, the PIC16C57-HSI/SP provides a low-cost 8-bit MCU with a famously simple toolchain and well-documented instruction set. Hobbyists can build Morse code beacons, LED chasers, simple robots, and homebrew computer peripherals using only a programmer (such as the Microchip MPLAB PM3) and the part itself. The 20 MHz clock and 5 MIPS throughput are more than adequate for bit-banged protocols, sensor reading, and display driving. Through-hole SPDIP construction is accessible to hand-soldering and breadboard prototyping without specialized SMT equipment. The active online community around the PIC16C5X family supplies sample code and reference designs, even though the part itself is now NRND and best reserved for legacy or learning purposes.
Recommended
Security and Access Control Panels
The PIC16C57-HSI/SP can manage keypad scanning, door strike timing, alarm zone monitoring, and simple LED status indication in low-end security panels. With 20 I/O pins, the MCU can read up to 16 keypad switches (4x4 matrix) plus several sensor zones and status LEDs, all while sequencing the lock relay with millisecond precision. The 8-bit TMR0 generates the periodic scan interrupt used to debounce inputs and drive the sounder. The OTP EPROM ensures that once programmed with the panel firmware, the device cannot be tampered with by firmware-rewrite attacks, which is a security advantage for fixed-function security products. Designers building new security panels should evaluate whether Flash-based parts with secure firmware-update mechanisms would better serve modern threat models, while the PIC16C57-HSI/SP remains a viable choice for legacy panel redesigns.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C57-HSI/SP — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C57-HSI/P | PIC16C57-HS/P | PIC16C57-HSE/SO | PIC16C57C-40/P |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-pin SPDIP | 28-pin SPDIP - same | 28-pin SPDIP - same | 28-pin SPDIP - same | 28-pin SPDIP - same |
| Program Memory Type | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM (C revision) |
| Program Memory Size | 3 KB | 3 KB | 3 KB | 3 KB | 3 KB |
| Maximum Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 40 MHz |
| RAM Size | 72 bytes | 72 bytes | 72 bytes | 72 bytes | 72 bytes |
| Number of I/O Pins | 20 | 20 | 20 | 20 | 20 |
| Supply Voltage | 3.0V to 5.5V | 3.0V to 5.5V | 3.0V to 5.5V | 3.0V to 5.5V | 3.0V to 5.5V |
Key Differentiators
- Highest 20 MHz throughput in original PIC16C5X OTP family (vs PIC16C57-10I/P)
- OSC2 oscillator amplifier optimized for HS crystals (vs PIC16C57-HS/P)
- Legacy Microchip PIC16C5X pinout enables socket-level upgrade path (vs PIC16C57C-40/P)
Design Notes
The PIC16C57-HSI/SP draws a few mA active at 20 MHz and approximately 1-5 microamps in sleep mode, depending on oscillator and watchdog settings. Place a 100 nF ceramic decoupling capacitor as close as possible to the VDD pin (pin 25) and a bulk capacitor (10 uF tantalum or aluminum) at the PCB power entry. If the application uses the MCLR pin as a reset input, add a 10 kohm pull-up to VDD and a 100 nF capacitor to ground for proper power-on reset timing; omitting this RC network can cause intermittent startup failures.
The HSI suffix specifies a high-speed oscillator amplifier optimized for crystals in the 4-20 MHz range. Use a parallel-resonant fundamental-mode crystal with load capacitors sized by the formula CL = (C1 x C2) / (C1 + C2) + Cstray, where Cstray is approximately 5-10 pF. Typical 20 MHz designs use 15-33 pF ceramic capacitors. Series resistor (Rs) of 100-330 ohm in series with OSC2 can dampen harmonic distortion and improve startup margin in electrically noisy environments.
Critical pitfalls: (1) OTP EPROM cannot be erased - the part must be programmed correctly the first time, so use a ZIF socket or adapter during development. (2) The PIC16C5X has only a 2-level hardware stack, limiting nested subroutines to depth 2; deep recursion will cause stack overflow and unpredictable return. (3) Watchdog timer, if enabled in configuration bits, must be periodically cleared in firmware or it will reset the part; leave it disabled if not needed. (4) The T0CKI pin shares with RA4 - configuring it as timer input disables RA4 as GPIO. (5) Port pins default to input mode on reset; configure TRIS registers before driving outputs.
Layout guidelines: keep the crystal and its load capacitors within 5 mm of OSC1 and OSC2 pins to minimize stray capacitance and EMI pickup. Route MCLR trace away from high-current switching nodes (relays, motor drivers) and place the reset RC network close to the MCLR pin. Provide a solid ground plane under the MCU for stable logic reference, and keep I/O traces short to reduce radiated emissions from 20 MHz edges. If the design includes a programming header (ICSP), follow Microchip's recommended 6-pin ICSP layout to allow field programming without desoldering.
Compliance Information
Legacy through-hole OTP MCU predates RoHS conversion; lead-free and halogen-free status not verified. Not AEC-Q100 qualified for automotive use. REACH SVHC declaration available on Microchip product page.
