PIC16C57T-LPE/SO - 8-Bit OTP MCU, 3KB, 40MHz, 28-SOIC | Microchip
MPN: PIC16C57T-LPE/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.6 | $5.60 |
| 10 | $5.04 | $50.40 |
| 100 | $4.48 | $448.00 |
| 500 | $4 | $2,000.00 |
| 1,000 | $3.65 | $3,650.00 |
PIC16C57T-LPE/SO Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, working RAM, and peripheral interfaces on one die, and is the foundational building block of embedded systems. The PIC16C5X family specifically occupies the legacy 8-bit RISC tier of Microchip's portfolio, sitting below the PIC16F and PIC18 mid-range families in both program memory and peripheral sophistication. It is used wherever engineers need deterministic, low-cost, OTP-based control with a minimal instruction set of only 33 single-word, single-cycle instructions.
Key features of the PIC16C57T-LPE/SO include an 8-bit accumulator-based Harvard architecture, a 4 MHz nominal oscillator input (with internal divide yielding a 1 MHz instruction cycle at 4 MHz clock), an 8-bit real-time clock/counter (RTCC) with 8-bit prescaler, a Watchdog Timer (WDT) with its own on-chip RC oscillator for reliable operation, and a Power-On Reset (POR) circuit. The low-power 'LP' process allows supply current well below 1 mA in active mode at low clock rates, making the part suitable for battery-influenced designs. Twenty bidirectional I/O pins arranged across ports A, B and C can source or sink current directly to drive LEDs, relays and small solenoids.
Typical applications for this device include simple appliance control, remote keyless-entry transmitters, low-end consumer electronics, HVAC sequencers, security keypads, and other cost-sensitive embedded products where OTP programmability is acceptable in production volumes. The device is also widely used as an educational platform for embedded-systems courses that teach the original PIC instruction set and Harvard memory model. Because the program memory is OTP rather than flash, it is preferred for high-volume production runs rather than engineering prototypes that require frequent code revisions.
When designing with the PIC16C57T-LPE/SO, designers should note that the legacy 12-bit instruction word requires assembly or compiler tools that explicitly target the PIC16C5X core (modern MPLAB XC8 supports the family in legacy compatibility mode). Watchdog Timer software servicing must be included to recover from transient upsets in electrically noisy environments such as motor-control or relay-driven loads.
Drop-in alternatives for PIC16C57T-LPE/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 PIC16C57T-LPE/SO (same form factor and footprint) — differing in Core Architecture, Package, Timers, Program Memory Size, Program Memory Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C57T-LP/SO
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View Datasheet →PIC16C57T-10/SO
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View Datasheet →PIC16C57T-10I/SO
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View Datasheet →PIC16C57CT-20I/SO
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View Datasheet →PIC16C57CT-04I/SS
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View Datasheet →PIC16C57C-20/SO
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View Datasheet →PIC16C57C-20E/SO
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View Datasheet →PIC16C57CT-04E/SO
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View Datasheet →PIC16C57T-LPE/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC Harvard RISC |
| Family | PIC® 16C |
| Series | PIC16C5X (PIC16C57 sub-family) |
| Program Memory Type | OTP (One-Time Programmable EPROM) |
| Program Memory Size | 3 KB (2K x 12 words) |
| RAM | 72 bytes |
| Maximum CPU Frequency | 40 MHz |
| Instruction Set Width | 12-bit |
| Number of Instructions | 33 (single-word, single-cycle) |
| I/O Pins | 20 |
| Timers | 1 x 8-bit RTCC with 8-bit prescaler |
| Watchdog Timer | Yes, with dedicated on-chip RC oscillator |
| Power-On Reset (POR) | Yes |
| Supply Voltage | 3 V to 5.5 V |
| Package | 28-SOIC (7.50 mm / 0.295 in body width) |
| Mounting Type | Surface Mount |
| Shipping Format | Tape and Reel ('T' suffix) |
| Process Variant | LP (low-power CMOS) |
PIC16C57T-LPE/SO Pin Configuration
| Pin 1 | VDD — Positive supply voltage |
| Pin 2 | RA0 — Bidirectional I/O port A bit 0 |
| Pin 3 | RA1 — Bidirectional I/O port A bit 1 |
| Pin 4 | RA2 — Bidirectional I/O port A bit 2 |
| Pin 5 | RA3 — Bidirectional I/O port A bit 3 |
| Pin 6 | RB0 — Bidirectional I/O port B bit 0 |
| 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 | VSS — Ground reference |
| Pin 15 | RC0 — Bidirectional I/O port C bit 0 |
| Pin 16 | RC1 — Bidirectional I/O port C bit 1 |
| Pin 17 | RC2 — Bidirectional I/O port C bit 2 |
| Pin 18 | RC3 — Bidirectional I/O port C bit 3 |
| Pin 19 | RC4 — Bidirectional I/O port C bit 4 |
| Pin 20 | RC5 — Bidirectional I/O port C bit 5 |
| Pin 21 | RC6 — Bidirectional I/O port C bit 6 |
| Pin 22 | RC7 — Bidirectional I/O port C bit 7 |
| Pin 23 | T0CKI — RTCC timer external clock input |
| Pin 24 | MCLR — Master clear / reset input (active low) |
| Pin 25 | NC — Not connected (per datasheet) |
| Pin 26 | OSC1 — Crystal/oscillator input |
| Pin 27 | OSC2 — Crystal/oscillator output |
| Pin 28 | VSS — Ground reference |
Typical Applications
PIC16C57T-LPE/SO is suitable for 7 applications: Consumer Appliance Control, Remote Keyless Entry (RKE) Transmitters, Security Keypads and Access Panels, HVAC Sequencer Controllers, Educational / Training Boards, LED Display and Signage Controllers, Simple Sensor and Timer Modules.
Consumer Appliance Control
The PIC16C57T-LPE/SO fits consumer appliance control boards because its 3 KB OTP, 20 I/O pins and 33-instruction PIC16C5X core deliver enough headroom for relay sequencing, sensor polling, and indicator-LED multiplexing in toasters, microwave ovens, washing machines and coffee makers. The 40 MHz oscillator ceiling provides sub-millisecond scan times for keypad matrices, while 72 bytes of RAM comfortably holds the state machine for a multi-mode appliance. Quoted at roughly $5.60 per unit at qty-1 as of 2026-09-17, the part targets cost-sensitive BOMs where OTP is acceptable and per-unit savings versus flash MCUs add up over millions of units.
Recommended
Remote Keyless Entry (RKE) Transmitters
The PIC16C57T-LPE/SO's low-power 'LP' CMOS process, 3 KB OTP and 20 I/O pins make it a strong fit for handheld remote keyless-entry transmitters, where the 8-bit core runs the rolling-code encryption state machine while the RTCC timer keeps the wake-up interval. Twenty I/O pins let the design drive multiple push-buttons and a status LED without external multiplexer ICs. The 28-SOIC package is robust for through-hole or hand-soldered prototyping, while the low active-mode supply current extends battery life on coin-cell powered keyfobs.
Recommended
Security Keypads and Access Panels
Security keypad panels benefit from the PIC16C57T-LPE/SO's 20 I/O pins to scan a 4x4 matrix and drive piezo-buzzer PWM, status LED arrays, and a magnetic-door relay directly, eliminating external buffer transistors. The Watchdog Timer with its dedicated on-chip RC oscillator provides fail-safe recovery if firmware locks up due to electrical noise on long cable runs. OTP memory at roughly $3.65 per unit at 1000 pieces makes the device economical for commercial building access panels produced at scale.
Recommended
HVAC Sequencer Controllers
HVAC sequencer boards use the PIC16C57T-LPE/SO to orchestrate compressor, fan and damper actuators in a deterministic state-machine driven by the on-chip 8-bit RTCC with prescaler. The Harvard architecture and single-cycle 12-bit instructions keep interrupt latency predictable, which is important when sequencing contactors to prevent compressor backspin damage. The industrial temperature variants of the PIC16C57 are widely used in heating and cooling controls where the MCU sits near motors and contactors.
Recommended
Educational / Training Boards
The PIC16C57T-LPE/SO is a popular choice for embedded-systems training courses because the original 12-bit PIC instruction set, 33 instructions and Harvard architecture make it pedagogically clean to teach assembly fundamentals. A 28-SOIC breakout board exposing all 20 I/O pins plus VDD/VSS gives students a clear platform for timer, interrupt and I/O lab exercises. Use of OTP parts reinforces lessons about one-time-programmable production memory and why the PIC16F family replaced PIC16C5X for new commercial designs.
Recommended
LED Display and Signage Controllers
Indoor LED sign and channel-letter controllers benefit from the PIC16C57T-LPE/SO's 20 I/O pins to drive row/column multiplex of small 7-segment or dot-matrix displays while the 8-bit RTCC timer generates the refresh interrupt. The 3 KB OTP holds character tables and animation sequences for static signage where the program never changes after deployment. The 28-SOIC footprint eases rework on prototype boards, and the low BOM cost supports cost-aggressive retail signage.
Recommended
Simple Sensor and Timer Modules
Industrial sensor-interface modules and stand-alone countdown timers use the PIC16C57T-LPE/SO to read analog signals via external comparator ICs, debounce mechanical inputs, and drive indicator LEDs. The Watchdog Timer recovers from brown-out conditions, while the on-chip POR ensures a clean startup every power cycle. The low-power 'LP' process makes the part appropriate for timer products powered from small transformers or batteries, where the MCU spends most of its life in idle states polled by the RTCC interrupt.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C57T-LPE/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C57T-LP/SO | PIC16C57T-10/SO | PIC16C57T-10I/SO | PIC16C57CT-20I/SO | PIC16C57CT-04I/SS |
|---|---|---|---|---|---|---|
| Package | 28-SOIC | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core | 8-bit PIC16C5X (RISC) | 8-bit PIC16C5X | 8-bit PIC16C5X | 8-bit PIC16C5X | 8-bit PIC16C5X | 8-bit PIC16C5X |
| Program Memory | 3 KB OTP (2K x 12) | 3 KB OTP | 3 KB OTP | 3 KB OTP | 3 KB OTP (ceramic window) | 3 KB OTP (ceramic window) |
| RAM | 72 bytes | 72 bytes | 72 bytes | 72 bytes | 72 bytes | 72 bytes |
| Max Oscillator Frequency | 40 MHz | 40 MHz | 10 MHz | 10 MHz | 20 MHz | 4 MHz |
| I/O Pins | 20 | 20 | 20 | 20 | 20 | 20 |
| Shipping Format | Tape & Reel | Tape & Reel | Tape & Reel | Tape & Reel | Tape & Reel | Tape & Reel |
| Temperature Grade | Extended (E suffix) | Industrial (I suffix) | Commercial | Industrial | Industrial (ceramic) | Industrial (ceramic) |
| Memory Window (Erasable) | No (OTP) | No (OTP) | No (OTP) | No (OTP) | Yes (ceramic window) | Yes (ceramic window) |
Key Differentiators
- Highest oscillator ceiling in the LP family at 40 MHz (vs PIC16C57T-10/SO)
- Extended temperature grade via 'E' suffix (vs PIC16C57T-LP/SO)
- Plastic OTP package optimized for production volumes (vs PIC16C57CT-20I/SO)
Design Notes
The PIC16C57T-LPE/SO operates from a single 3 V to 5.5 V supply. Place a 100 nF decoupling capacitor as close as practical to the VDD pin (pin 1), with a bulk 10 uF tantalum or aluminum capacitor at the board's power-entry point. The on-chip Power-On Reset eliminates the need for an external reset IC in most cost-sensitive designs, but a manual reset button on MCLR (pin 24) is recommended during firmware bring-up.
Route the crystal traces between OSC1 (pin 26) and OSC2 (pin 27) as short and symmetrical as possible, with the crystal and its load capacitors placed within a few millimeters of the MCU. Keep high-current switching traces (relay drivers, LED rows) away from the oscillator area to avoid injected jitter. The 28-SOIC is a fine-pitch surface-mount package, so use a fine-tip stencil and a clean reflow profile during assembly.
OTP program memory cannot be erased electrically, so a bad firmware batch requires new parts. Always program and verify on a known-good engineering sample before committing to a production run, and consider ordering a 5-10 percent over-build for engineering rework. The Watchdog Timer must be periodically cleared (CLRWDT instruction) by the application firmware, otherwise an unexpected reset will occur every few milliseconds; configure the WDT prescaler for the longest tolerable reset interval in your design.
Compliance Information
Compliance flags were not present in the verified web data and are marked unknown per Data Authenticity Rules. AEC-Q100 is not_applicable because the PIC16C57T-LPE/SO is a general-purpose 8-bit MCU, not an automotive-qualified part. Engineers should request the latest material declaration from Microchip Direct before committing to a regulated end product.
