PIC16C505-20E/P - 8-Bit 20MHz 1.5KB OTP MCU | 14-PDIP | Microchip
MPN: PIC16C505-20E/P β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.68 | $1.68 |
| 10 | $1.51 | $15.10 |
| 100 | $1.35 | $135.00 |
| 500 | $1.2 | $600.00 |
| 1,000 | $1.08 | $1,080.00 |
PIC16C505-20E/P Overview
What is a PIC16C5X microcontroller? It is Microchip's original baseline PIC architecture using a 12-bit instruction word and a RISC instruction set of only 33 single-word instructions, packaged in 14 to 28 pins for ultra-low-cost embedded control. The 'C' suffix denotes CMOS EPROM/OTP program memory; later 'F' variants use flash memory. Within the broader taxonomy, the PIC16C505 sits at: PIC16C505 -> PIC16C5X family -> PIC16 -> 8-bit PIC MCU -> Microcontroller -> Integrated Circuit.
Key features include 200 ns instruction execution, 2:1 code compression versus typical 8-bit competitors, a watchdog timer with on-chip RC oscillator, power-on reset, power-saving SLEEP mode, and a wide operating voltage range from 2.5V to 5.5V. The 14-pin DIP package exposes 12 I/O pins, a MCLR reset pin, and two power pins, supporting through-hole prototyping and legacy industrial designs. Compared to PIC16F5X flash variants, the OTP 'C' version offers lower unit cost in volume and is well-suited to mature production programs.
The PIC16C505 uses a Harvard architecture with separate program and data buses, allowing an instruction fetch to overlap with data access. Internal peripherals include a programmable 8-bit prescaler feeding the watchdog timer, an 8-bit RTCC timer/counter, and a software-configurable oscillator that supports external RC, external crystal, and internal RC modes. With 1.5 KB of program memory holding approximately 1024 instructions, firmware development uses the standard PIC16C5X assembly toolchain or Hi-Tech C compiler, with debug support through Microchip's MPLAB ICE and ICD tools.
Typical applications include appliance control, automotive body modules, sensor signal conditioning, remote-control transmitters, security keypads, and any cost-sensitive embedded product that benefits from a small-pin-count OTP MCU. The extended -40C to +125C temperature grade supports under-hood automotive and outdoor industrial environments.
When designing with the PIC16C505, plan for OTP programming: code is finalized before production programming and cannot be updated. For prototype work or field-upgradable firmware, consider the flash-based PIC16F505 in the same 14-pin DIP footprint, which is pin-to-pin compatible.
This page synthesizes distributor pricing, pin-compatible alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16C505-20E/P β 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 PIC16C505-20E/P (same form factor and footprint) β differing in Core Architecture, Package, Watchdog Timer, I/O Pins, Instruction Set.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
No drop-in alternatives available for this product.
Request AlternativesPIC16C505-20E/P Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit Microcontroller (MCU) |
| Core Architecture | PIC16C5X (Harvard, 12-bit instruction word) |
| Program Memory | 1.5 KB OTP (1K x 12) |
| RAM | 72 bytes |
| Instruction Set | 33 single-word instructions |
| Instruction Execution Time | 200 ns at 20 MHz |
| Maximum CPU Frequency | 20 MHz |
| I/O Pins | 12 |
| Timers | 8-bit RTCC timer/counter |
| Watchdog Timer | Yes, with on-chip RC oscillator |
| Supply Voltage (VDD) | 2.5 V to 5.5 V |
| Operating Temperature | -40 C to +125 C (automotive / -E grade) |
| Package | 14-pin PDIP (0.300"/7.62 mm) through-hole |
| Mounting Type | Through-Hole |
| RoHS Status | Compliant |
| Programming Type | OTP (One-Time Programmable) |
PIC16C505-20E/P Pin Configuration
| Pin 1 | RA2/AN2/CLKIN/OSC1 β Port A bit 2 (analog/DAC) / Clock In / Oscillator input |
| Pin 2 | RA3/MCLR/VPP β Port A bit 3 / Master Clear (reset) / Programming voltage |
| Pin 3 | RA4/CLKOUT/OSC2 β Port A bit 4 / Clock Out / Oscillator output |
| Pin 4 | RA5/T0CKI β Port A bit 5 / Timer 0 clock input |
| Pin 5 | VSS β Ground reference |
| Pin 6 | RB0/INT β Port B bit 0 / External interrupt input |
| Pin 7 | RB1 β Port B bit 1 |
| Pin 8 | RB2 β Port B bit 2 |
| Pin 9 | RB3 β Port B bit 3 |
| Pin 10 | RB4 β Port B bit 4 |
| Pin 11 | RB5 β Port B bit 5 |
| Pin 12 | RB6 β Port B bit 6 |
| Pin 13 | RB7 β Port B bit 7 |
| Pin 14 | VDD β Positive supply (2.5 V to 5.5 V) |
Typical Applications
PIC16C505-20E/P is suitable for 6 applications: Automotive Body Control Module, Appliance Control Board, Remote Control Transmitter, Security Keypad Panel, Sensor Signal Conditioning Module, Battery-Powered Smart Meter.
Automotive Body Control Module
The PIC16C505-20E/P's extended -40C to +125C operating range and 14-pin DIP form factor make it a natural fit for under-dash automotive body control modules such as door-lock drivers, mirror actuators, and seat-position relays. With 12 I/O pins it can directly drive relays and read switch inputs without external logic, while the on-chip watchdog timer ensures recovery from electrical noise events typical of automotive 12 V supply rails. The 20 MHz CPU supports 200 ns instruction execution, fast enough for PWM-controlled lighting and motor-timing loops. The OTP program memory locks firmware at production, eliminating field-update risk on safety-relevant functions and lowering per-unit cost versus flash variants.
Recommended
Appliance Control Board
White-goods appliance controllers - washing machines, dishwashers, and microwave oven front panels - benefit from the PIC16C505-20E/P's 2.5 V to 5.5 V operating range, 12 I/O pins, and 1.5 KB OTP program space. The 8-bit RTCC timer drives user-interface timeouts, keypad debouncing, and sensor-sampling cadences without an external RTC, while the SLEEP mode drops quiescent current below 1 uA in idle, helping meet ENERGY STAR standby budgets. The 14-pin DIP through-hole package remains serviceable for field-replacement legacy designs and reduces manufacturing cost versus fine-pitch surface-mount parts.
Recommended
Remote Control Transmitter
Handheld RF remote controls for garage openers, ceiling fans, and consumer audio gear leverage the PIC16C505-20E/P's combination of 12 I/O pins, internal RC oscillator option, and very low SLEEP current. The 200 ns instruction cycle generates accurate 38 kHz / 40 kHz IR carrier modulation for NEC or RC-5 protocols, while the watchdog timer keeps the part responsive after long battery-storage periods. Using the on-chip oscillator eliminates external crystal cost and saves PCB area - critical for credit-card-sized transmitters. The DIP package also simplifies prototyping of custom button layouts.
Recommended
Security Keypad Panel
Wired security-system keypads need a small, reliable MCU with enough I/O to scan a 4x4 matrix and drive LED indicators while rejecting contact bounce in software. The PIC16C505-20E/P's 12 I/O pins, 8-bit RTCC timer, and 33-instruction PIC16C5X RISC core fit this requirement without external glue logic. The OTP memory secures proprietary keypad-mapping firmware against unauthorized read-back, and the -E extended temperature grade supports outdoor or unheated-garage installations. Its 14-pin DIP package also makes hand-soldered repair of legacy panels straightforward for field-service technicians.
Recommended
Sensor Signal Conditioning Module
Industrial sensor-interface boards - thermocouple amplifiers, RTD transmitters, and pressure-sensor signal conditioners - often need a small MCU to linearize and serialize readings without paying for an unnecessary full-featured controller. The PIC16C505-20E/P's 1.5 KB OTP holds calibration tables for a single sensor type, while 12 I/O pins provide ample headroom for SPI or UART output, status LEDs, and a calibration push-button. The on-chip watchdog timer prevents lockup in electrically noisy factory environments, and the -40C to +125C range supports outdoor mounting and process-industry cabinets. OTP secures proprietary calibration firmware.
Recommended
Battery-Powered Smart Meter
Smart gas and water meters need a microcontroller that operates from a 3 V lithium primary cell for a decade or more. The PIC16C505-20E/P's SLEEP current below 1 uA, internal low-power RC oscillator, and 2.5 V minimum VDD let it wake periodically to read a pulse-output flow sensor and report over a wired M-Bus link. The OTP memory locks the meter-firmware calibration permanently, an essential tamper-resistance feature for billing-grade metering. The 14-pin DIP package simplifies in-line assembly of meter electronics modules in legacy AMI deployments.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C505-20E/P β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C505-20/P | PIC16C505-04/P | PIC16C505-20I/P | PIC16F505-I/P | PIC16F505-E/P | PIC12F508-I/P |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 14-PDIP (0.300"/7.62 mm) | 14-PDIP - same | 14-PDIP - same | 14-PDIP - same | 14-PDIP - same | 14-PDIP - same | 14-PDIP - same |
| Program Memory | 1.5 KB OTP | 1.5 KB OTP | 1.5 KB OTP | 1.5 KB OTP | 1.5 KB Flash | 1.5 KB Flash | 768 B Flash |
| Max CPU Frequency | 20 MHz | 20 MHz | 4 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Operating Temperature | -40C to +125C (Extended) | 0C to +70C (Commercial) | 0C to +70C (Commercial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +125C (Extended) | -40C to +85C (Industrial) |
| Programming Type | OTP (one-time) | OTP | OTP | OTP | Flash | Flash | Flash |
| RAM | 72 bytes | 72 bytes | 72 bytes | 72 bytes | 72 bytes | 72 bytes | 25 bytes |
| I/O Pins | 12 | 12 | 12 | 12 | 12 | 12 | 6 |
Key Differentiators
- Extended -40C to +125C operating temperature (vs PIC16C505-20/P)
- 20 MHz instruction execution - 5x faster than 4 MHz variant (vs PIC16C505-04/P)
- Pin-compatible flash upgrade path (vs PIC16F505-I/P)
Design Notes
The PIC16C505-20E/P operates from 2.5 V to 5.5 V on VDD; a 100 nF decoupling capacitor must be placed within 5 mm of the VDD pin, with a 10 uF bulk cap on the supply rail if the source impedance is high. The MCLR pin should be tied to VDD through a 10 kohm resistor and have a 0.1 uF cap to ground for noise filtering - omitting this is a common cause of spurious resets in electrically noisy environments. The internal POR is enabled by configuration bit, so verify it is set in the configuration word before prototype testing.
For crystal or resonator mode, place the oscillator components within 10 mm of OSC1/OSC2 (pins 1 and 3) and route the traces over a continuous ground pour to minimize EMI injection. The 14-pin PDIP package has sufficient lead length to add a shield can over the oscillator area for high-noise designs. The MCLR trace should be kept short and away from switching nodes such as relay drivers on adjacent pins.
Because PIC16C505 is OTP, an errant configuration word (e.g., selecting the wrong oscillator mode or disabling the watchdog) cannot be corrected after programming - the part must be discarded. Always prototype with the flash PIC16F505-E/P, verify the configuration word, then move to PIC16C505-20E/P for production. The 12 I/O pins share RA and RB banks; ensure high-impedance analog inputs and digital outputs are not assigned to pins that conflict with the oscillator (OSC1/OSC2) or MCLR.
Compliance Information
RoHS and REACH compliance declared by Microchip for the PIC16C505 family. AEC-Q100 is not applicable (Microchip's automotive qualification path is distinct from AEC-Q100); -E grade covers -40C to +125C temperature only.
