PIC16C72-20/SO - 8-Bit 20MHz CMOS OTP MCU | Microchip
MPN: PIC16C72-20/SO β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.82 | $5.82 |
| 10 | $5.23 | $52.30 |
| 100 | $4.66 | $466.00 |
| 500 | $4.21 | $2,105.00 |
| 1,000 | $3.78 | $3,780.00 |
PIC16C72-20/SO Overview
A microcontroller (MCU) is a single-chip computer containing a processor core, program memory, working RAM, and peripheral blocks such as timers, A/D converters and serial interfaces. The PIC16C7X mid-range family sits in the PIC16CXX hierarchy below enhanced 16-bit families and above baseline 12-bit/14-bit cores; the PIC16C72 specifically targets cost-sensitive embedded control applications that need on-chip analog conversion without the cost of a Flash MCU. Within the power management and signal-conditioning ecosystem the PIC16C72-20/SO is often paired with LDO regulators (for example Microchip MCP1700) to provide a clean 5 V rail from a wider input bus.
Key differentiating features include the integrated 8-bit A/D converter (5 channels), two 8-bit timers plus one 16-bit timer with capture/compare/PWM capability, a synchronous/asynchronous USART for serial communication, and 22 digital I/O pins. The device offers DC to 20 MHz operation, industrial (-40C to +85C) temperature grade in this /SO commercial-rated package, and a brown-out reset (BOR) and watchdog timer for field reliability. The 28-pin SOIC wide-body (SO) footprint provides easier hand-soldering and inspection than SSOP variants while still being surface-mount.
Architecturally the PIC16C72 uses a Harvard architecture with separate program and data buses, a 14-bit instruction word, and a 35-instruction RISC-like instruction set. The OTP program memory is implemented as EPROM cells requiring UV-erasable reprogramming only during development; production units are one-time programmable, which lowers unit cost versus Flash parts. The 8-bit A/D converter is successive-approximation type with a sample-and-hold, selectable reference, and conversion speeds around 20 us, adequate for low-bandwidth sensor sampling. The USART supports both synchronous and asynchronous modes at programmable baud rates.
Typical applications include HVAC thermostat controls, appliance user-interface panels, low-end motor control (fans, small pumps), battery charger front-end controllers, security sensor interface boards, and educational microcontroller teaching kits. The integrated A/D eliminates the need for an external ADC in most analog sensing tasks, and the OTP memory reduces per-unit cost in volume.
When designing with the PIC16C72-20/SO, plan for OTP programming via a Microchip-compatible device programmer (for example PICSTART Plus or MPLAB PM3) since in-system programming is not supported on OTP parts. For new designs consider the Flash-based PIC16F72 as a pin-compatible migration path, since the original PIC16C72 has been superseded by PIC16C72A and PIC16F72 per the Microchip product page. Reserve decoupling of at least 0.1 uF close to VDD and bulk 10 uF on the analog AVdd rail when using the A/D converter.
This page synthesizes distributor stock and pricing, drop-in alternatives sourced from Microchip pin-compatibility charts, and practical design notes not aggregated on the manufacturer datasheet cover.
Drop-in alternatives for PIC16C72-20/SO 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 PIC16C72-20/SO (same form factor and footprint) β differing in Data EEPROM, Package, RoHS Status, Timers, ADC.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16F72-I/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C72A-20/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C72-20I/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C72-20E/SO
β Drop-Inβ In Stock
$2.46 / Unit
View Datasheet βPIC16C73B-20/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C72-10/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C72-04/SO
β Drop-Inβ In Stock
$3.45 / Unit
View Datasheet βPIC16C72-04I/SO
β Drop-Inβ In Stock
$4.71 / Unit
View Datasheet βPIC16C72-20/SO Maximum Ratings & Electrical Characteristics
| Family | PIC16C7X mid-range |
| Core Architecture | 8-bit RISC Harvard |
| Program Memory Type | OTP (EPROM-based) |
| Program Memory Size | 3.5 KB (2K x 14 words) |
| RAM | 128 bytes |
| Data EEPROM | Not present |
| Maximum Clock Frequency | 20 MHz |
| Instruction Cycle Time | 200 ns (at 20 MHz) |
| Supply Voltage (VDD) | 2.5 V to 6.0 V |
| I/O Pins | 22 |
| A/D Converter | 8-bit, 5 channels |
| Timers | Two 8-bit, one 16-bit with CCP |
| Communication | USART (sync/async), SSP/SPI/I2C |
| Package | 28-pin SOIC wide-body (SO) |
| Operating Temperature | 0 C to +70 C (commercial) |
| Watchdog Timer | Yes |
| Brown-Out Reset | Yes |
| RoHS Status | Compliant (lead-free SO package) |
PIC16C72-20/SO Pin Configuration
| Pin 1 | MCLR/VPP β Master Clear (reset, active low) / programming voltage input |
| Pin 2 | RA0/AN0 β PORTA bit 0 / analog input channel 0 |
| Pin 3 | RA1/AN1 β PORTA bit 1 / analog input channel 1 |
| Pin 4 | RA2/AN2 β PORTA bit 2 / analog input channel 2 |
| Pin 5 | RA3/AN3/VREF β PORTA bit 3 / analog input channel 3 / A/D voltage reference |
| Pin 6 | RA4/T0CKI β PORTA bit 4 (open-drain) / Timer0 clock input |
| Pin 7 | RA5/AN4/SS β PORTA bit 5 / analog input channel 4 / SPI slave select |
| Pin 8 | VSS β Ground reference |
| Pin 9 | OSC1/CLKIN β Oscillator crystal input / external clock input |
| Pin 10 | OSC2/CLKOUT β Oscillator crystal output / clock output (Fosc/4) |
| Pin 11 | RC0/T1OSO/T1CKI β PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 12 | RC1/T1OSI/CCP2 β PORTC bit 1 / Timer1 oscillator input / Capture-Compare-PWM 2 |
| Pin 13 | RC2/CCP1 β PORTC bit 2 / Capture-Compare-PWM 1 output |
| Pin 14 | RC3/SCK/SCL β PORTC bit 3 / SPI clock / I2C clock |
| Pin 15 | RC4/SDI/SDA β PORTC bit 4 / SPI data in / I2C data |
| Pin 16 | RC5/SDO β PORTC bit 5 / SPI data out |
| Pin 17 | RC6/TX/CK β PORTC bit 6 / USART async transmit / USART sync clock |
| Pin 18 | RC7/RX/DT β PORTC bit 7 / USART async receive / USART sync data |
| Pin 19 | VSS β Ground reference |
| Pin 20 | VDD β Positive power supply |
| Pin 21 | RB0/INT β PORTB bit 0 / external interrupt input |
| Pin 22 | RB1 β PORTB bit 1 |
| Pin 23 | RB2 β PORTB bit 2 |
| Pin 24 | RB3 β PORTB bit 3 |
| Pin 25 | RB4 β PORTB bit 4 (interrupt-on-change) |
| Pin 26 | RB5 β PORTB bit 5 (interrupt-on-change) |
| Pin 27 | RB6/PGC β PORTB bit 6 / ICSP clock (note: ICSP not supported on OTP PIC16C72) |
| Pin 28 | RB7/PGD β PORTB bit 7 / ICSP data (note: ICSP not supported on OTP PIC16C72) |
Typical Applications
PIC16C72-20/SO is suitable for 6 applications: HVAC Thermostat Control Board, Appliance User-Interface Panel, Low-End DC Motor Speed Controller, Battery Charger Front-End Controller, Security Sensor Interface Board, Educational Microcontroller Teaching Kit.
HVAC Thermostat Control Board
The PIC16C72-20/SO is well-suited for HVAC thermostat control boards where it reads temperature sensors through its 5-channel 8-bit A/D converter, drives TRIAC-controlled HVAC loads via PORTB and PORTC PWM outputs, and manages user inputs through interrupt-on-change capable RB pins. The integrated 8-bit ADC eliminates the need for an external temperature sensor digitizer, reducing BOM cost. The 20 MHz instruction cycle (200 ns per instruction) provides fast response for thermistor sampling at 1 Hz to 10 Hz, with sufficient headroom for keypad debounce and display multiplexing. The 22 digital I/O pins can drive a 4-digit 7-segment LCD or LED display directly without external driver ICs, and the USART enables connectivity to a network gateway for smart-thermostat features.
Recommended
Appliance User-Interface Panel
In washing machine, dishwasher, and microwave oven user-interface panels, the PIC16C72-20/SO scans matrix keypads through PORTA and PORTB while driving multiplexed LED or VFD displays with its PWM and timer peripherals. The OTP memory secures firmware against reverse engineering while keeping unit cost low for high-volume consumer appliances. The integrated A/D converter reads humidity, temperature, or weight sensor inputs with sufficient resolution for cycle-control decisions, and the USART enables communication with a main control board or wireless module. The 28-pin SOIC wide-body package is easier to hand-solder than SSOP, simplifying factory rework and field repair.
Recommended
Low-End DC Motor Speed Controller
The PIC16C72-20/SO controls small DC motors and fans in the 12V to 24V range using its 16-bit Timer1 with capture/compare/PWM (CCP) module to generate PWM drive signals. The integrated 8-bit A/D converter reads back-EMF or tachometer feedback through a sense resistor, enabling closed-loop speed regulation without external ADC hardware. Brown-out reset prevents motor stalls during power dips, and the watchdog timer recovers from firmware lockups in unattended installations. The 20 MHz clock supports PWM frequencies above 25 kHz to avoid audible motor whine, while the wide-body SOIC package handles the modest thermal dissipation of digital-only switching.
Recommended
Battery Charger Front-End Controller
The PIC16C72-20/SO provides intelligent charging control for lead-acid, NiMH, and lithium-ion battery packs in the 1A to 10A range, using its 8-bit A/D converter to monitor battery voltage, charge current, and pack temperature. The PWM module regulates a buck or flyback converter at 50 kHz to 100 kHz, while the watchdog timer prevents charging faults during firmware anomalies. OTP memory ensures the firmware is locked at production time and cannot be reflashed in the field, which is desirable for safety-critical charging applications. The USART enables status reporting to a host system, and the integrated timers handle safety timeouts and charge-state transitions.
Recommended
Security Sensor Interface Board
In PIR motion detector, smoke detector, and door/window sensor interface boards, the PIC16C72-20/SO reads analog sensor signals through its 8-bit A/D converter and drives relay or solid-state outputs through its GPIO. The interrupt-on-change feature of PORTB enables low-power operation - the MCU sleeps in microamp-range quiescent state and wakes only on a sensor edge, achieving multi-year battery life. The watchdog timer ensures recovery from electrical noise-induced firmware lockups in alarm installations. OTP memory prevents field firmware tampering, and the 28-SOIC package provides reliable mechanical connections in vibration-prone mounting locations.
Recommended
Educational Microcontroller Teaching Kit
The PIC16C72-20/SO is widely used in university embedded systems and microcontroller courses because its 35-instruction RISC architecture is approachable for students while still demonstrating real-world peripheral integration including A/D conversion, PWM, timers, and serial communication. The 28-pin SOIC wide-body package is easy to breadboard and hand-solder, simplifying student lab exercises and prototyping. The 20 MHz clock provides real-time response for robotics, sensor interfacing, and data-acquisition projects without requiring high-speed design considerations. The PIC16F72 (pin-compatible Flash version) is recommended for student projects because it supports ICSP reprogramming throughout the development cycle.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C72-20/SO β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F72-I/SO | PIC16C72A-20/SO | PIC16C72-20I/SO | PIC16C73B-20/SO | PIC16C72-10/SO |
|---|---|---|---|---|---|---|
| Package | 28-SOIC wide body | 28-SOIC wide body - same | 28-SOIC wide body - same | 28-SOIC wide body - same | 28-SOIC wide body - same | 28-SOIC wide body - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 3.5 KB OTP | 3.5 KB Flash | 3.5 KB OTP (enhanced) | 3.5 KB OTP | 8 KB OTP | 3.5 KB OTP |
| Maximum Clock | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 10 MHz |
| RAM | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 192 bytes | 128 bytes |
| A/D Converter | 8-bit, 5 channels | 8-bit, 5 channels | 8-bit, 5 channels | 8-bit, 5 channels | 8-bit, 5 channels | 8-bit, 5 channels |
| In-Circuit Programming | No (OTP) | Yes (ICSP) | No (OTP) | No (OTP) | No (OTP) | No (OTP) |
| Operating Temperature | 0C to +70C (commercial) | -40C to +85C (industrial) | 0C to +70C (commercial) | -40C to +85C (industrial) | 0C to +70C (commercial) | 0C to +70C (commercial) |
| Lifecycle Status | NRND | Active | NRND | NRND | NRND | NRND |
Key Differentiators
- OTP (One-Time-Programmable) memory at lower unit cost vs Flash PIC16F72 (vs PIC16F72-I/SO)
- Pin-compatible migration to active-production PIC16F72 (vs PIC16C73B-20/SO)
- Integrated 8-bit 5-channel A/D converter eliminates external ADC cost (vs PIC16C72-10/SO)
Design Notes
Place a 0.1 uF decoupling capacitor within 5 mm of the VDD pin (pin 20) and a bulk 10 uF tantalum or aluminum electrolytic capacitor on the same supply rail. When using the A/D converter, also decouple AVdd (which shares VDD on PIC16C72) with a separate 10 uF bulk capacitor and 0.1 uF ceramic; failure to isolate AVdd from digital switching noise degrades A/D accuracy by 1-2 LSB. Estimated: AVDD noise ripple target is below 50 mV pk-pk for 8-bit A/D performance.
The PIC16C72-20/SO is OTP (One-Time-Programmable) and does NOT support In-Circuit Serial Programming (ICSP) like Flash-based PIC16F72. Production programming requires a parallel programmer (PICSTART Plus, MPLAB PM3, or equivalent) supplying 13V on VPP during the write cycle. Plan for programming fixture cost and programming time in your NPI schedule. Attempting to reflash an already-programmed OTP device will fail silently; verify code in a Flash PIC16F72 prototype before committing to OTP production parts.
Keep crystal traces (OSC1/OSC2, pins 9-10) short and surrounded by a ground guard ring or ground pour to reduce EMI coupling into adjacent signal traces. Place the crystal within 10 mm of the MCU and route the traces symmetrically. The MCLR/VPP pin (pin 1) requires a 10 kohm pull-up to VDD and a 100 nF decoupling cap; an optional diode from VDD to MCLR provides additional ESD protection during in-circuit programming fixture contact.
Estimated: The PIC16C72-20/SO at 20 MHz and 5 V draws approximately 20 mA active and 5 uA sleep, dissipating roughly 100 mW peak. The 28-SOIC wide-body package has theta_JA around 50-70 C/W depending on PCB copper area, so a 4-layer board with ground plane keeps junction rise below 5C. No heatsinking required. For high-temperature applications use the industrial-grade PIC16C72-20I/SO rated -40C to +85C instead of the commercial-grade 0C to +70C variant.
For analog sensor inputs on PORTA (AN0-AN4), use source impedances below 2 kohm to avoid A/D conversion errors - the PIC16C72 sample-and-hold requires the input to settle within 1/2 LSB during the sample window (~20 us at 20 MHz). Add an op-amp buffer if the sensor source impedance exceeds 2 kohm, or place a 100 pF to 1 nF capacitor at the ADC input to provide local charge reservoir. PORTA pins RA3/VREF+ can be configured as the A/D voltage reference for ratiometric measurements.
Compliance Information
RoHS and lead-free compliant per Microchip product page. Not AEC-Q100 qualified (consumer/industrial MCU). Refer to Microchip cross-reference tool and pin-compatibility chart document 00148J2 for detailed cross-reference data.
