PIC16C73AT-20/SO - 8-Bit 20MHz 7KB OTP MCU | Microchip
MPN: PIC16C73AT-20/SO β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.42 | $8.42 |
| 10 | $7.58 | $75.80 |
| 100 | $6.74 | $674.00 |
| 500 | $5.91 | $2,955.00 |
| 1,000 | $5.08 | $5,080.00 |
PIC16C73AT-20/SO Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, non-volatile program memory, working RAM, and configurable peripheral blocks onto one silicon die. Within the broader taxonomy it is a microcontroller -> embedded processor -> integrated circuit -> semiconductor. The PIC16C7X family specifically targets cost-sensitive embedded control where deterministic instruction execution, low external component count, and on-chip analog simplify board design.
Key features include 35 single-word instructions, fully static CMOS architecture, an 8-level hardware stack, power-on reset, brown-out detection, watchdog timer with its own on-chip RC oscillator, and code protection. The integrated ADC eliminates an external converter in sensor-interface designs, while the three serial interfaces (USART, SSP for SPI/I2C) cover the majority of master/slave bus topologies used in industrial and consumer control.
Architecturally the device uses a Harvard structure with separate 14-bit program and 8-bit data paths, enabling single-cycle instruction fetch and deterministic throughput. The OTP EPROM allows one-time programming using standard Microchip development tools, making this part suitable for production runs where in-system reprogrammability is not required.
Typical applications include appliance control, HVAC fan and damper drivers, industrial sensor interfaces, automotive body modules (non-safety), consumer remote controls, and small UART/SPI gateway nodes. The wide 4-6V input range simplifies integration into 5V regulated rails.
When designing with this part, reserve the brown-out and watchdog configuration bits at programming time and verify the chosen oscillator mode (XT/HS/RC) matches the external crystal or resonator. Because this is OTP, firmware revisions require a board respin; choose PIC16F73 for development flexibility or PIC16C73B for extended temperature.
Drop-in alternatives for PIC16C73AT-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 PIC16C73AT-20/SO (same form factor and footprint) β differing in Package, Program Memory Size, Program Memory Type.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16C73A-20/SO
β Drop-Inβ In Stock
$2.5 / Unit
View Datasheet βPIC16C73A-20I/SO
β Drop-Inβ In Stock
$9.3 / Unit
View Datasheet βPIC16F73-20/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C73A-10/SO
β Drop-Inβ In Stock
$4.5 / Unit
View Datasheet βPIC16F873A-I/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C73AT-20/SO Maximum Ratings & Electrical Characteristics
| Core | 8-bit PIC16C RISC |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 7KB (4K x 14 words) |
| RAM Size | 192 bytes |
| EEPROM Size | 0 bytes (none on-die) |
| Maximum CPU Speed | 20 MHz |
| Instruction Throughput | 5 MIPS |
| Number of I/O Pins | 22 |
| ADC | 5 channels x 8-bit |
| Supply Voltage (Vdd) | 4 V to 6 V |
| Operating Temperature | 0C to +70C (commercial) |
| Package | 28-pin SOIC (7.50 mm width) |
| Mounting Type | Surface Mount |
| Oscillator Type | External (XT/HS/RC modes) |
| Communication Peripherals | UART/USART, SPI, I2C (MSSP/SSP) |
| Watchdog Timer | Yes (independent on-chip RC) |
| Brown-out Reset | Yes |
PIC16C73AT-20/SO Pin Configuration
| Pin 1 | MCLR/VPP β Master Clear (reset) input / programming voltage |
| Pin 2 | RA0/AN0 β Port A bit 0 / Analog input channel 0 |
| Pin 3 | RA1/AN1 β Port A bit 1 / Analog input channel 1 |
| Pin 4 | RA2/AN2 β Port A bit 2 / Analog input channel 2 |
| Pin 5 | RA3/AN3/VREF- β Port A bit 3 / Analog channel 3 / ADC Vref- |
| Pin 6 | RA4/T0CKI β Port A bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS β Port A bit 5 / Analog channel 4 / SPI slave select |
| Pin 8 | OSC1/CLKIN β Oscillator crystal input / external clock in |
| Pin 9 | OSC2/CLKOUT β Oscillator crystal output / clock out |
| Pin 10 | RC0/T1OSO β Port C bit 0 / Timer1 oscillator output |
| Pin 11 | RC1/T1OSI β Port C bit 1 / Timer1 oscillator input |
| Pin 12 | RC2/CCP1 β Port C bit 2 / Capture-Compare-PWM 1 |
| Pin 13 | RC3/SCK/SCL β Port C bit 3 / SPI clock / I2C clock |
| Pin 14 | RC4/SDI/SDA β Port C bit 4 / SPI data in / I2C data |
| Pin 15 | RC5/SDO β Port C bit 5 / SPI data out |
| Pin 16 | RC6/TX/CK β Port C bit 6 / USART TX / USART clock |
| Pin 17 | RC7/RX/DT β Port C bit 7 / USART RX / USART data |
| Pin 18 | GND β Ground reference |
| Pin 19 | VDD β Positive supply voltage (4-6V) |
| Pin 20 | RB0/INT β Port B bit 0 / external interrupt |
| Pin 21 | RB1 β Port B bit 1 |
| Pin 22 | RB2 β Port B bit 2 |
| Pin 23 | RB3/PGM β Port B bit 3 / low-voltage programming |
| Pin 24 | RB4 β Port B bit 4 |
| Pin 25 | RB5 β Port B bit 5 |
| Pin 26 | RB6/PGC β Port B bit 6 / ICSP clock |
| Pin 27 | RB7/PGD β Port B bit 7 / ICSP data |
| Pin 28 | VSS β Ground (alternate ground pin) |
Typical Applications
PIC16C73AT-20/SO is suitable for 6 applications: Industrial Sensor Interface, Appliance Control Board, HVAC Fan and Damper Controller, UART to SPI/I2C Bridge Node, Automotive Body Module (Non-Safety), Consumer Remote / IR Control Receiver.
Industrial Sensor Interface
The PIC16C73AT-20/SO fits industrial sensor interfaces because its integrated 5-channel 8-bit ADC eliminates an external converter IC while its 20 MHz / 5 MIPS throughput handles up to ~100 ksps conversion with linearization. Per Microchip PIC16C7X datasheet DS30390E, the 4-6V Vdd range and 0C to +70C commercial temperature rating suit cabinet-mount PLC analog input modules. Its three serial peripherals (USART/SPI/I2C) allow direct connection to upstream controllers without glue logic. Estimated: at 5V supply with four sensors polled sequentially at 1 ksps each, the CPU runs at <20% utilization, leaving headroom for filtering algorithms.
Recommended
Appliance Control Board
The PIC16C73AT-20/SO is well suited to consumer appliance controllers (washing machines, dishwashers, microwave ovens) where its 22 I/O pins drive relay triac interfaces, keypads, and seven-segment displays while the on-chip USART links to inverter boards or wireless modules. The brown-out reset and watchdog timer with dedicated RC oscillator meet basic functional-safety patterns for IEC 60335 household appliance standards. Per Microchip PIC16C7X datasheet, the OTP EPROM locks firmware against tampering in high-volume production. Estimated: at 20 MHz the device can scan a 4x4 matrix keypad every 5 ms while servicing UART traffic and ADC conversion in parallel.
Recommended
HVAC Fan and Damper Controller
The PIC16C73AT-20/SO suits HVAC actuator control because its PWM-driven CCP module and 5-channel ADC read temperature/pressure sensors while the I2C bus interfaces to digital temperature/humidity sensors and EEPROM for setpoint storage. Per Microchip documentation, the integrated MSSP handles I2C master transactions to popular SHT3x humidity sensors without external bus controllers. The 4-6V Vdd range tolerates regulated 5V rails commonly used in furnace control boards. Estimated: with PWM frequency at 1 kHz and 10-bit equivalent effective resolution from filtered PWM, fan speed control loops close within 2 ms.
Recommended
UART to SPI/I2C Bridge Node
The PIC16C73AT-20/SO serves as a small protocol-conversion gateway because it provides simultaneous USART, SPI, and I2C peripherals on-chip. In an industrial RS-485 to sensor-bus bridge application, the USART handles RS-485 framing while the MSSP drives an SPI sensor or I2C device cluster, all coordinated by a 5 MIPS core. Per Microchip PIC16C7X datasheet, the 192 bytes of RAM accommodate small protocol buffers for typical telemetry frames. Estimated: at 115200 bps USART with one SPI slave at 1 MHz, firmware overhead is approximately 30% CPU, leaving margin for diagnostics.
Recommended
Automotive Body Module (Non-Safety)
Although AEC-Q100 qualification is not claimed for PIC16C73AT-20/SO, it sees service in non-safety automotive body applications (interior lighting, mirror adjusters, accessory controllers) where the +70C commercial rating suffices for cabin locations. The PIC16C73A-20I/SO industrial variant extends to -40C/+85C for under-hood or door-module environments, still in the same 28-SOIC footprint for layout reuse. Per Microchip product family documentation, the PIC16C7X peripherals (USART, MSSP, ADC, PWM CCP) cover typical body-control function requirements without external glue logic.
Recommended
Consumer Remote / IR Control Receiver
The PIC16C73AT-20/SO fits low-cost IR remote control receivers because its CCP module captures IR demodulator edges while the USART or timer-driven interrupt handles protocol decoding, all within a 28-SOIC footprint that suits compact handheld enclosures. The 22 I/O pins drive LED indicators, keypads, and a small LCD. Per Microchip documentation, the on-chip watchdog with independent RC oscillator guards against firmware lockup in unattended devices. Estimated: typical NEC or RC5 protocol decoding at 38 kHz carrier occupies less than 10% CPU at 20 MHz, leaving ample margin for I/O scanning.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C73AT-20/SO β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C73A-20/SO | PIC16C73A-20I/SO | PIC16F73-20/SO | PIC16C73A-10/SO | PIC16F873A-I/SO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SOIC | 28-SOIC (tube) | 28-SOIC | 28-SOIC | 28-SOIC | 28-SOIC |
| Program Memory Type | OTP EPROM 7KB | OTP EPROM 7KB | OTP EPROM 7KB | Flash 7KB | OTP EPROM 7KB | Flash 7KB |
| Max CPU Speed | 20 MHz / 5 MIPS | 20 MHz / 5 MIPS | 20 MHz / 5 MIPS | 20 MHz / 5 MIPS | 10 MHz / 2.5 MIPS | 20 MHz / 5 MIPS |
| RAM | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes |
| I/O Pins | 22 | 22 | 22 | 22 | 22 | 22 |
| ADC | 5-ch x 8-bit | 5-ch x 8-bit | 5-ch x 8-bit | 5-ch x 8-bit | 5-ch x 8-bit | 5-ch x 10-bit |
| Operating Temperature | 0C to +70C (commercial) | 0C to +70C | -40C to +85C | 0C to +70C | 0C to +70C | -40C to +85C |
Key Differentiators
- Wide 4-6V Vdd tolerance suits unregulated industrial rails (vs PIC16F73-20/SO)
- Fully static CMOS design supports DC operation (vs PIC16C73A-10/SO)
- On-chip 5-channel 8-bit ADC eliminates external converter (vs PIC16F873A-I/SO)
Design Notes
The PIC16C73AT-20/SO uses One-Time-Programmable EPROM - once a configuration bit or program word is written it cannot be erased. Any late firmware change requires a board swap or inventory write-off. Mitigate by prototyping with PIC16F73-20/SO (same 28-SOIC pinout, flash memory) and only committing to the OTP part after final firmware freeze. Per Microchip PIC16C7X datasheet DS30390E, code-protect bits also lock out further verification reads.
Place the 28-SOIC decoupling capacitor (100 nF ceramic plus 10 uF bulk) within 5 mm of VDD pin 19, with a short ground return to VSS pin 18. Estimated: with VDD trace inductance above ~10 nH, inrush during ADC conversion can cause 50 mV ringing on VDD that couples into analog readings. For noisy switching supplies, add a ferrite bead between the 5V rail and the MCU VDD pin. The MCLR/VPP pin requires a 10 kohm pull-up to VDD for normal operation; only override to VPP (typically 13V) during ICSP programming.
Route the OSC1/OSC2 traces short and symmetric, with the crystal or resonator within 5 mm of the MCU and a guard ground ring around them. For HS mode above ~10 MHz, add 20-33 pF loading capacitors sized per the crystal manufacturer's CL specification. Per Microchip PIC16C7X datasheet, stray capacitance above 5 pF on OSC1 can shift the oscillator off frequency or prevent start-up at the 20 MHz limit. Keep digital switching lines away from the oscillator loop to avoid injection-locking jitter.
Compliance Information
Lifecycle status NRND (Not Recommended for New Designs) per Microchip product family guidance. RoHS and lead-free status not specified in the verified web data; mark as unknown per data authenticity rules. No AEC-Q100 automotive qualification.
