PIC16C72AT-20I/SO - 8-Bit 20MHz OTP MCU w/ ADC | Microchip
MPN: PIC16C72AT-20I/SO β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.35 | $2.35 |
| 10 | $2.05 | $20.50 |
| 100 | $1.85 | $185.00 |
| 500 | $1.62 | $810.00 |
| 1,000 | $1.45 | $1,450.00 |
PIC16C72AT-20I/SO Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, data RAM, and peripherals such as timers, ADC, and I/O ports. The PIC16C family sits within Microchip's 8-bit mid-range hierarchy: PIC16C sub-family -> PIC16 mid-range -> 8-bit PIC microcontrollers -> microcontrollers (MCU) -> embedded processors -> semiconductors. OTP (One-Time Programmable) versions such as the PIC16C72A use windowless EPROM and are intended for cost-sensitive, code-frozen designs in production.
Key features include five 8-bit A/D converter channels, two additional 8-bit timers/counters (TMR0, TMR1, TMR2), a Capture/Compare/PWM (CCP) module, 22 digital I/O pins, and a synchronous serial port (SSP) supporting SPI and I2C. The device operates from 4.0V to 5.5V with a maximum 20MHz external clock input. Brown-out reset, power-on reset, watchdog timer with on-chip RC oscillator, and an industrial -40C to +85C operating range add ruggedness for embedded deployments.
The PIC16C72A uses a Harvard RISC architecture with separate program and data buses, enabling most instructions to execute in a single instruction cycle. The 8-bit data path, 14-bit instruction word, and 8-level hardware stack keep interrupt latency predictable. With 22 I/O capable of sourcing/sinking 25mA per pin and direct LED drive support, it can serve both as a logic controller and a driver front-end in the same BOM.
Typical applications include industrial control, sensor signal conditioning, motor control loops, automotive body electronics, and consumer appliance controllers. The integrated ADC and CCP module make it well suited to closed-loop systems that read analog sensors and drive PWM outputs from the same chip.
When designing with this part, choose a low-ESR 0.1uF decoupling capacitor on VDD and a 10uF bulk capacitor within 25mm of the supply pin. Place the crystal/oscillator traces short and guard them with a ground ring to keep EMI low. For code-security-sensitive products, prefer a windowed or flash sibling rather than this OTP variant because once programmed it cannot be re-read or changed.
Drop-in alternatives for PIC16C72AT-20I/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 PIC16C72AT-20I/SO (same form factor and footprint) β differing in ADC, Core, Instruction Set, Package, RoHS Status.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16C72A-20I/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C72AT-20I/SO
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$1.45 / Unit
View Datasheet βPIC16C72AT-20/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16F72-I/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C72AT-20E/SO
β Drop-Inβ In Stock
$4.16 / Unit
View Datasheet βPIC16C72-20I/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C72AT-20I/SO Maximum Ratings & Electrical Characteristics
| Core | PIC16C 8-bit RISC |
| Instruction Set | 35 single-word instructions |
| Program Memory (ROM) | 3.5 KB (2K x 14) OTP EPROM |
| Data RAM | 128 bytes |
| Data EEPROM | Not present (OTP-only core) |
| Maximum Clock Frequency | 20 MHz |
| Instruction Cycle Time | 200 ns (DC) |
| I/O Pins | 22 |
| ADC | 5 channels x 8-bit |
| Timers | 3 x 8-bit (TMR0, TMR1, TMR2) |
| Capture/Compare/PWM | 1 CCP module |
| Serial Interfaces | SSP (SPI / I2C) |
| Operating Voltage (Vdd) | 4.0 V to 5.5 V |
| Operating Temperature | -40 C to +85 C (industrial) |
| Package | 28-pin SOIC (SO) |
| Mounting Type | Surface Mount |
| I/O Sink/Source per Pin | 25 mA |
| Watchdog Timer | Yes, with on-chip RC oscillator |
| Brown-out Reset | Yes |
| RoHS Status | Compliant |
PIC16C72AT-20I/SO Pin Configuration
| Pin 1 | MCLR/VPP β Master clear (reset) input / programming voltage |
| 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/VREF- β PORTA bit 2 / Analog input 2 / ADC VREF- |
| Pin 5 | RA3/AN3/VREF+ β PORTA bit 3 / Analog input 3 / ADC VREF+ |
| Pin 6 | RA4/T0CKI β PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/SS/AN4 β PORTA bit 5 / SPI slave select / Analog input 4 |
| Pin 8 | VSS β Ground reference |
| Pin 9 | OSC1/CLKIN β Oscillator crystal input / external clock in |
| Pin 10 | OSC2/CLKOUT β Oscillator crystal output / clock out |
| Pin 11 | RC0 β PORTC bit 0 |
| Pin 12 | RC1 β PORTC bit 1 |
| Pin 13 | RC2 β PORTC bit 2 |
| Pin 14 | RC3 β PORTC bit 3 |
| Pin 15 | RC4 β PORTC bit 4 |
| Pin 16 | RC5 β PORTC bit 5 |
| Pin 17 | RC6 β PORTC bit 6 |
| Pin 18 | RC7 β PORTC bit 7 |
| Pin 19 | VSS β Ground reference |
| Pin 20 | VDD β Positive supply (4.0V to 5.5V) |
| Pin 21 | RB0/INT β PORTB bit 0 / external interrupt |
| 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 |
| Pin 26 | RB5 β PORTB bit 5 |
| Pin 27 | RB6 β PORTB bit 6 |
| Pin 28 | RB7 β PORTB bit 7 |
Typical Applications
PIC16C72AT-20I/SO is suitable for 6 applications: Industrial Sensor Signal Conditioning, Motor Speed and PWM Control, Consumer Appliance Control Board, Automotive Body Electronics (Legacy / Last-Aged), Data Acquisition and Logger Front-End, Educational and Hobbyist Embedded Platform.
Industrial Sensor Signal Conditioning
The PIC16C72AT-20I/SO fits industrial sensor-conditioning front-ends because it integrates a 5-channel 8-bit ADC with adequate noise margin for thermocouples, RTDs, and 4-20mA loops when paired with external signal conditioning. Its 20MHz CPU delivers a 200ns instruction cycle, sufficient for 8-bit PDM oversampling at rates up to ~50kS/s aggregate. The -40C to +85C industrial rating lets it ride inside IP65 enclosures on factory floors, and the brown-out reset prevents latch-up on noisy 24V industrial backplanes converted to 5V. The 22 I/O pins drive relays, opto-isolators, and status LEDs directly via 25mA source/sink, eliminating external drivers for sub-3A contactors. Its watchdog timer with on-chip RC oscillator enables safe firmware recovery in unattended installations, making the PIC16C72AT-20I/SO a robust drop-in for PLC analog-input modules.
Recommended
Motor Speed and PWM Control
The PIC16C72AT-20I/SO fits brushed DC and small BLDC motor drives where the integrated Capture/Compare/PWM (CCP) module generates the gate-drive waveform for the power stage. Its TMR2-driven PWM can run up to the 20MHz clock divided by 4, giving ~78kHz PWM resolution sufficient to keep the DC-DC inductor in continuous conduction above the audible band. With three 8-bit timers (TMR0, TMR1, TMR2), one CCP channel, and 25mA per-pin drive, the chip can run a back-EMF ADC sample, time the commutation, and PWM the FET bridge from a single die. Industrial-temperature qualification, brown-out reset, and a watchdog timer keep motor control loops safe on noisy backplanes; sourced from automotive-grade cousins like the PIC16F72 for AEC-Q100 ECU variants.
Recommended
Consumer Appliance Control Board
The PIC16C72AT-20I/SO is a cost-effective controller for white-goods main boards such as washing machines, dishwashers, and microwave ovens where a microcontroller must read button matrices, drive 7-segment or LCD displays, time relays, and sense water-level or temperature sensors. Its 28-pin SOIC footprint is compact, and 22 I/O with 25mA drive eliminates external transistors for indicator LEDs and small relays. The integrated 5-channel 8-bit ADC handles NTC thermistor, water-level probe, and door-latch sensor inputs without external analog ICs. The SSP peripheral supports SPI or I2C EEPROM for storing user settings, and the watchdog timer prevents lock-ups in unattended appliances. Despite its NRND status, the OTP-EPROM code-once-and-ship nature makes it ideal for high-volume, code-frozen designs where cost beats re-programmability.
Recommended
Automotive Body Electronics (Legacy / Last-Aged)
Although the PIC16C72AT-20I/SO itself is NOT AEC-Q100 qualified, the part has historically been deployed in non-safety automotive body-electronics nodes such as seat controllers, mirror adjusters, and HVAC-line damper drivers where the part can be sourced and qualified through Microchip's automotive program. Its 4.0V to 5.5V supply range tolerates cranking transients when paired with TVS clamps, and the brown-out reset prevents lock-up under cold-start battery drops. The PIC16C72AT-20I/SO drives up to 22 brushed-DC loads via 25mA I/O pins and reads 5 analog sensors over its ADC. New designs requiring AEC-Q100 Grade 1 should migrate to the PIC16F72-I/SO automotive grade; the PIC16C72AT-20I/SO is best reserved for legacy maintenance and last-time-buy windows.
Recommended
Data Acquisition and Logger Front-End
The PIC16C72AT-20I/SO fits low-cost, low-speed data-acquisition front-ends and stand-alone logging nodes where its 5-channel 8-bit ADC samples sensors and stores results to external SPI/I2C memory. Its 20MHz instruction cycle supports ~50kS/s aggregate sampling when the ADC is polled sequentially, and its 128B RAM buffers a few seconds of slow-changing telemetry such as temperature, humidity, and battery voltage. The 28-pin SOIC footprint keeps PCB cost low, and its industrial -40C to +85C range handles outdoor enclosures. The watchdog timer and brown-out reset protect unattended loggers from lock-ups during brown-outs. Engineers prototyping should pair the PIC16C72AT-20I/SO with a 24LC256 IEEP for 32KB of non-volatile log retention, and a DS1307 RTC for time-stamping.
Recommended
Educational and Hobbyist Embedded Platform
The PIC16C72AT-20I/SO is also commonly found on educational development boards and hobbyist projects because the PIC16C72A instruction set is small (35 single-word instructions), the PICmicro Mid-Range Reference Manual (DS33023) is freely available, and Microchip's MPLAB IDE supports the device through legacy compilers. Students learning 8-bit embedded design, IO can program the OTP variant once on a programmer and explore ADC sampling, PWM, SPI/I2C, and timer interrupts without firmware-update complexity. For learning, the flash-based PIC16F72-I/SO is now recommended because it allows re-flashing during homework. The PIC16C72AT-20I/SO is best for educational projects where the one-time-programmable nature forces good code discipline before commit.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C72AT-20I/SO β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C72A-20I/SO | PIC16F72-I/SO | PIC16C72AT-20/SO | PIC16C72AT-20E/SO | PIC16C72-20I/SO |
|---|---|---|---|---|---|---|
| Package | 28-pin SOIC (SO) | 28-pin SOIC (SO) - same | 28-pin SOIC (SO) - same | 28-pin SOIC (SO) - same | 28-pin SOIC (SO) - same | 28-pin SOIC (SO) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 3.5 KB OTP EPROM (2K x 14) | 3.5 KB OTP EPROM | 3.5 KB Flash | 3.5 KB OTP EPROM | 3.5 KB OTP EPROM | 2 KB OTP EPROM (-43%) |
| Data RAM | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 128 bytes |
| Maximum Clock | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| ADC Channels | 5 x 8-bit | 5 x 8-bit | 5 x 8-bit | 5 x 8-bit | 5 x 8-bit | 4 x 8-bit |
| Operating Voltage | 4.0 V to 5.5 V | 4.0 V to 5.5 V | 2.0 V to 5.5 V (wider) | 4.0 V to 5.5 V | 4.0 V to 5.5 V | 4.0 V to 5.5 V |
| Memory Type | OTP EPROM | OTP EPROM | Flash (re-programmable) | OTP EPROM | OTP EPROM | OTP EPROM |
| Temperature Range | -40 C to +85 C (industrial) | -40 C to +85 C | -40 C to +85 C | 0 C to +70 C (commercial) | -40 C to +125 C (extended) | -40 C to +85 C |
| Lifecycle | NRND (Not Recommended for New Designs) | NRND | Active | NRND | NRND | EOL |
Key Differentiators
- Five 8-bit ADC channels vs four in the original PIC16C72 (vs PIC16C72-20I/SO)
- Flash-based equivalent for active product development (vs PIC16F72-I/SO)
- Industrial temperature qualification in same package (vs PIC16C72AT-20/SO)
Design Notes
Place a 0.1 uF low-ESR ceramic decoupling capacitor within 5 mm of the VDD pin (pin 20) and a 10 uF bulk tantalum or ceramic capacitor on the same net. Add a 10 kohm pull-up on the MCLR/VPP pin (pin 1) to prevent spurious resets; MCLR must NOT be left floating. For noisy 24V industrial backplanes, add a 5.1V TVS clamp across VDD to ground to absorb transients above 6V and protect the PIC16C72AT-20I/SO from brown-out conditions that the on-chip brown-out reset may not catch in time.
Do not confuse the OTP PIC16C72A with the original PIC16C72: the A-revision has 3.5 KB program memory and 5 ADC channels versus the original 2 KB and 4 ADC channels. Cross-reference the Microchip Pin and Code Compatibility Chart (DS00148J2) before substituting. Also note that the PIC16C72AT-20/SO (commercial 0-70 C) is NOT a drop-in for designs that need -40 C to +85 C industrial temperature - use the PIC16C72AT-20I/SO suffix 'I' explicitly.
Route the OSC1/OSC2 traces (pins 9-10) as short as possible, guard them with a ground ring, and place the load capacitors (typically 15-33 pF for a 20 MHz crystal) within 5 mm of the oscillator pins. Keep the ADC analog inputs (RA0-RA5) away from digital switching traces; if the layout forces proximity, add a ground pour between them to keep digital switching noise from coupling into the 5-channel ADC during sampling windows. The 25 mA per-pin I/O drive means traces should be at least 0.25 mm wide for typical 5V CMOS loads.
Estimated: at 20 MHz full speed and 5.0 V supply, the PIC16C72AT-20I/SO consumes roughly 10 mA active (50 mW). The 28-pin SOIC theta_JA is approximately 80 C/W on a 1 oz copper 4-layer board; the resulting junction temperature rise is ~4 C above ambient. For sealed enclosures with no airflow, derate clock speed to 4 MHz or supply 3.3V via an external LDO to keep junction rise under 50 C.
Compliance Information
RoHS compliant per Microchip product page. Industrial temperature (-40C to +85C) but NOT AEC-Q100 qualified - migrate to PIC16F72-I/SO automotive grade for AEC-Q100 applications. Halogen-free status not specified in available data.
