PIC16C57T-HSI/SS - 8-bit CMOS MCU, 3KB EPROM, 20 I/O | Microchip
MPN: PIC16C57T-HSI/SS ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.5 | $7.50 |
| 10 | $6.75 | $67.50 |
| 100 | $5.95 | $595.00 |
| 500 | $5.2 | $2,600.00 |
| 1,000 | $4.55 | $4,550.00 |
PIC16C57T-HSI/SS Overview
A microcontroller (MCU) is a single-chip computer containing a CPU core, program memory, working RAM, and peripherals. The PIC16C5X family uses a Harvard architecture with separate program and data buses, enabling single-cycle instruction execution except for program branches. These parts are EPROM-based, allowing prototype code changes prior to ROM mask production, and are widely used in legacy industrial, appliance, and consumer designs.
Key features include 33 single-word instructions, a 12-bit instruction word, 8-bit data path, DC to 20 MHz operation, 2 Kwords EPROM program memory, 72 bytes RAM, 20 digital I/O pins, Power-On Reset (POR), Watchdog Timer (WDT) with on-chip RC oscillator, and direct LED drive capability on I/O pins. The 28-pin SSOP package offers a compact footprint for space-constrained designs.
The PIC16C57T-HSI/SS uses Microchip's baseline PIC architecture with two hardware stack levels, no interrupts, and a fixed RISC instruction set optimized for deterministic real-time control. The high oscillator speed (HS = high speed, up to 20 MHz) delivers approximately 5 MIPS performance for time-critical loops.
Typical applications include appliance controllers, simple sensor interfaces, security keypads, low-end toys, and legacy industrial embedded systems. EPROM windowed packages support in-circuit code iteration during development.
When designing with the PIC16C57T-HSI/SS, ensure the oscillator configuration bits match the chosen crystal or external clock; mismatched oscillator modes are a common source of no-start conditions. The HS mode supports crystals in the 4 to 20 MHz range and requires proper load capacitor selection per the crystal datasheet.
This page synthesizes distributor pricing, same-package drop-in alternatives including the Flash-based PIC16F57T-I/SS, and practical design notes not found in the standalone manufacturer datasheet.
Drop-in alternatives for PIC16C57T-HSI/SS — 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 PIC16C57T-HSI/SS (same form factor and footprint) — differing in Program Memory Size, Operating Temperature, Package, Timers, Program Memory Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F57T-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C57CT-04I/SS
✅ Drop-In✓ In Stock
$4.1 / Unit
View Datasheet →PIC16C57C-20I/SS
✅ Drop-In✓ In Stock
$0.9 / Unit
View Datasheet →PIC16C57C-04E/SS
✅ Drop-In✓ In Stock
$2.85 / Unit
View Datasheet →PIC16C55T-HSI/SS
✅ Drop-In✓ In Stock
$2.05 / Unit
View Datasheet →PIC16C56T-HSI/SO
✅ Drop-In✓ In Stock
$1.78 / Unit
View Datasheet →PIC16C57T-HSI/SS Maximum Ratings & Electrical Characteristics
| Product Family | PIC16C5X |
| Core | PIC 8-bit RISC |
| Program Memory Type | EPROM (UV erasable) |
| Program Memory Size | 2 Kwords (3 KB), 12-bit word |
| RAM | 72 bytes |
| Maximum CPU Speed | 20 MHz (5 MIPS) |
| Supply Voltage Range | 2.5 V to 6.25 V |
| Oscillator Mode | HS (High Speed) |
| I/O Pins | 20 |
| Watchdog Timer | Yes, on-chip dedicated RC oscillator |
| Power-On Reset | Yes |
| Timers | 1 x 8-bit RTCC |
| Instruction Set | 33 single-word instructions, 12-bit wide |
| Operating Temperature Range | -40C to +85C |
| Package | 28-pin SSOP (5.30 mm body, 209 mil) |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel (T suffix) |
PIC16C57T-HSI/SS Pin Configuration
| Pin 1 | RA2 — Port A bit 2 (digital I/O) |
| Pin 2 | RA3 — Port A bit 3 (digital I/O) |
| Pin 3 | RB0 — Port B bit 0 (digital I/O) |
| Pin 4 | RB1 — Port B bit 1 (digital I/O) |
| Pin 5 | RB2 — Port B bit 2 (digital I/O) |
| Pin 6 | RB3 — Port B bit 3 (digital I/O) |
| Pin 7 | RB4 — Port B bit 4 (digital I/O) |
| Pin 8 | RB5 — Port B bit 5 (digital I/O) |
| Pin 9 | RB6 — Port B bit 6 (digital I/O) |
| Pin 10 | RB7 — Port B bit 7 (digital I/O) |
| Pin 11 | VSS — Ground reference |
| Pin 12 | RC0 — Port C bit 0 (digital I/O) |
| Pin 13 | RC1 — Port C bit 1 (digital I/O) |
| Pin 14 | RC2 — Port C bit 2 (digital I/O) |
| Pin 15 | RC3 — Port C bit 3 (digital I/O) |
| Pin 16 | RC4 — Port C bit 4 (digital I/O) |
| Pin 17 | RC5 — Port C bit 5 (digital I/O) |
| Pin 18 | RC6 — Port C bit 6 (digital I/O) |
| Pin 19 | RC7 — Port C bit 7 (digital I/O) |
| Pin 20 | MCLR — Master Clear (reset, active low) |
| Pin 21 | VSS — Ground reference |
| Pin 22 | XTAL2 — Crystal/oscillator output |
| Pin 23 | XTAL1 — Crystal/oscillator input |
| Pin 24 | RD0 — Port D bit 0 (digital I/O) |
| Pin 25 | RD1 — Port D bit 1 (digital I/O) |
| Pin 26 | RD2 — Port D bit 2 (digital I/O) |
| Pin 27 | RD3 — Port D bit 3 (digital I/O) |
| Pin 28 | VDD — Positive supply voltage |
Typical Applications
PIC16C57T-HSI/SS is suitable for 6 applications: Appliance Control Boards, Security Keypad and Access Control, Industrial Sensor Interfaces, Consumer Toy and Hobby Electronics, Automotive Interior Accessories, Legacy Industrial Embedded Systems.
Appliance Control Boards
The PIC16C57T-HSI/SS's 2 Kwords of program memory and 20 I/O pins at 20 MHz are well matched to washing machine, dishwasher, and microwave oven controllers where the MCU reads a keypad matrix, drives relay/SSR outputs, and sequences a state machine. The HS oscillator accepts the 4-20 MHz ceramic resonators commonly used in white goods, and the 25 mA per-pin drive directly energizes LED indicators and triac gate couplers without driver transistors. A typical 5 V supply rail and -40C to +85C temperature range cover appliance under-cabinet and behind-panel installations.
Recommended
Security Keypad and Access Control
Security keypads and entry-stations use the PIC16C57T-HSI/SS because its 20 I/O pins directly scan a 4x4 matrix keypad, drive a 7-segment LED or 14-segment LCD indicator, and energize a door-strike relay through an optocoupler. The 2 Kwords of EPROM hold the credential table, debounce timers, and lockout state machine with ample headroom. The integrated watchdog timer automatically resets the controller if firmware hangs due to electrical noise on long keypad cables, a common EMI problem in metal door frames.
Recommended
Industrial Sensor Interfaces
Industrial 4-20 mA loop-powered transmitters and simple limit-switch controllers use the PIC16C57T-HSI/SS to read an ADC-free analog threshold via a comparator and emit a digital flag. The wide 2.5-6.25 V supply range accepts the unregulated 24 V industrial bus after a low-drop regulator, and the -40C to +85C rating supports outdoor panel mounting. With 20 I/O pins the part drives multiple sensor channels and a Modbus or HART-style UART through software bit-banging when a hardware UART is absent.
Recommended
Consumer Toy and Hobby Electronics
Toy RC receivers, model train controllers, and hobby robotics projects benefit from the PIC16C57T-HSI/SS's low-cost RISC core and 20 MHz throughput. The HS oscillator accepts standard 4-20 MHz hobby crystals, and 2 Kwords of program memory store sound-effect tables, PWM motor profiles, and IR remote-protocol decoders. The 25 mA I/O pins directly drive small DC motor H-bridges through BJTs, eliminating external driver chips in cost-sensitive designs. EPROM allows code revision during product development cycles.
Recommended
Automotive Interior Accessories
Non-safety automotive accessories like interior lighting controllers, alarm chirp generators, and seat-heater timer modules historically used the PIC16C57T-HSI/SS for its rugged industrial temperature range and 20 MHz throughput. The integrated watchdog timer improves reliability in the high-EMI automotive electrical environment, while 20 I/O pins interface directly with switches, LEDs, and relay coils. Note that AEC-Q100 qualification is not applicable to this EPROM part; safety-critical or powertrain systems must use AEC-Q100 qualified PIC16F successors.
Recommended
Legacy Industrial Embedded Systems
Long-lifecycle industrial systems including CNC auxiliary controllers, test fixtures, and instrumentation front panels continue using the PIC16C57T-HSI/SS as a field-proven baseline MCU. The RISC instruction set executes deterministic control loops in single instruction cycles, and the 20 MHz throughput supports software-generated UARTs for legacy serial protocols that predate the part's end-of-life. EPROM-based programming matches the original 1990s production flow, allowing spare-parts manufacturers to keep obsolete equipment running without re-tooling for Flash parts.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C57T-HSI/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F57T-I/SS | PIC16C57CT-04I/SS | PIC16C57C-20I/SS | PIC16C57C-04E/SS | PIC16C55T-HSI/SS |
|---|---|---|---|---|---|---|
| Package | 28-SSOP | 28-SSOP (same) | 28-SSOP (same) | 28-SSOP (same) | 28-SSOP (same) | 28-SSOP (same) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory Type | EPROM (2 Kwords) | Flash (2 Kwords) | EPROM (2 Kwords) | EPROM (2 Kwords) | EPROM (2 Kwords) | EPROM (512 words) |
| RAM | 72 bytes | 72 bytes | 72 bytes | 72 bytes | 72 bytes | 24 bytes |
| Max CPU Speed | 20 MHz (HSI) | 20 MHz | 4 MHz | 20 MHz | 4 MHz | 20 MHz |
| Operating Temperature | -40C to +85C | -40C to +85C | 0C to +70C (commercial) | -40C to +85C (industrial) | -40C to +125C (extended) | -40C to +85C |
| I/O Pins | 20 | 20 | 20 | 20 | 20 | 20 |
| Lifecycle Status | Obsolete | Active | Obsolete | Obsolete | Obsolete | Obsolete |
| ICSP Support | No (EPROM requires programmer) | Yes (Flash-based) | No (EPROM) | No (EPROM) | No (EPROM) | No (EPROM) |
Key Differentiators
- Obsolete EPROM variant of the actively-produced PIC16F57 Flash MCU (vs PIC16F57T-I/SS)
- 20 MHz HS-mode oscillator (highest speed in the PIC16C57 family) (vs PIC16C57CT-04I/SS)
- Industrial temperature range -40C to +85C (vs PIC16C57C-04E/SS)
Design Notes
Place the HS-mode crystal as close as possible to pins 22-23 (XTAL2/XTAL1) and route the crystal traces over a continuous ground plane to minimize EMI radiation. Load capacitor values must be selected per the crystal datasheet's load capacitance specification, not assumed - typically 15-33 pF for 20 MHz AT-cut crystals. Add a 100 nF decoupling capacitor between VDD (pin 28) and VSS (pin 21) with trace length under 5 mm to suppress switching noise on the supply rail.
The PIC16C57T-HSI/SS EPROM memory must be erased with UV light before reprogramming, requiring a windowed package variant - the SSOP package has no erasure window, so production units are one-time-programmable. Mismatched oscillator configuration bits are the most common cause of no-start conditions: an HS-mode firmware image running on RC-mode hardware will fail to oscillate. Always verify the configuration word matches the installed crystal or resonator before debugging software.
Estimated: at 20 MHz clock and 5 V supply with all 20 I/O pins switching simultaneously, the PIC16C57T-HSI/SS draws approximately 20 mA core current (1 mA/MHz typical) plus I/O loading. Total power dissipation is approximately 100 mW, well within the SSOP-28 thermal limits (theta-JA approximately 95 C/W on 1-oz 4-layer PCB). At maximum 85C ambient the junction rises approximately 9.5C, leaving 55C margin to the 150C absolute maximum.
Route the MCLR reset line (pin 20) directly to the reset circuit with no stubs, and add a 10 kohm pull-up to VDD to ensure proper Power-On Reset behavior. Keep high-current LED or relay traces away from the crystal traces to prevent conducted EMI from coupling into the oscillator. Use a ground guard ring around the SSOP footprint to simplify debugging on prototype boards where the part may need to be removed and replaced multiple times.
Compliance Information
PIC16C57T-HSI/SS lifecycle status is obsolete per Microchip. RoHS, REACH, lead-free, halogen-free, and conflict-minerals status were not explicitly confirmed in the verified web data and should be verified with the manufacturer's latest declaration. AEC-Q100 is not applicable for this commercial/industrial grade EPROM MCU.
