PIC16C73AT-20I/SO - 8-bit MCU 7KB OTP 20MHz 28-SOIC | Microchip
MPN: PIC16C73AT-20I/SO β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.85 | $9.85 |
| 10 | $8.92 | $89.20 |
| 100 | $7.55 | $755.00 |
| 500 | $6.4 | $3,200.00 |
| 1,000 | $5.75 | $5,750.00 |
PIC16C73AT-20I/SO Overview
A microcontroller (MCU) is a single-chip computer containing a CPU, program memory, working RAM, and programmable I/O peripherals. The PIC16C7X family belongs to Microchip's mid-range architecture (a hypernym tree of: 8-bit MCU -> PIC16CXX mid-range -> PIC16C7X family -> PIC16C73A sub-family), which uses a 14-bit instruction word and Harvard bus architecture that lets the CPU fetch instruction and data words in parallel. The 8-bit accumulator-based core executes 35 single-word instructions, most in a single instruction cycle, achieving near 1 MIPS per MHz efficiency.
Key features of the PIC16C73AT-20I/SO include a hardware Universal Synchronous/Asynchronous Receiver-Transmitter (USART/SCI) for serial communication, a Synchronous Serial Port (SSP) supporting SPI and I2C master/slave modes, three timer/counters (Timer0, Timer1, and Timer2 with PWM), a watchdog timer with on-chip RC oscillator, and a 5-channel 8-bit analog-to-digital converter. The 22 programmable I/O pins each source/sink up to 25 mA and feature individual direction registers. Brown-out reset and power-on reset provide reliable boot behavior from unpredictable supply ramps.
Architecturally the PIC16C73A uses CMOS EPROM-based program memory, which is electrically one-time-programmable (OTP) via the Microchip PRO MATE or PICSTART programmer. The Harvard bus, separate instruction and data buses, allows pipelined instruction fetch while the data memory access completes in the same cycle. An integrated 8-bit ADC samples at approximately 20 us per conversion with 8 analog input channels multiplexed onto a single successive-approximation converter.
Typical applications for the PIC16C73AT-20I/SO include industrial process control, instrumentation data acquisition, appliance motor control, automotive body electronics, sensor conditioning, and embedded control boards requiring on-chip A/D conversion. Its 7KB code space comfortably hosts moderate logic density, while the integrated ADC eliminates an external converter in cost-sensitive designs.
Designers should note that this OTP variant is programmed once and cannot be field-upgraded - for development and field-reprogrammable use choose a Flash equivalent such as PIC16F73 in the same 28-SOIC footprint. Programming requires a 5V VPP supply; in-system programming is not supported on the C-series, only via Microchip's parallel programmer.
This page synthesizes verified distributor pricing, same-brand and cross-brand drop-in alternatives in the same 28-SOIC footprint, and practical design notes that go beyond the manufacturer datasheet's specification tables.
Drop-in alternatives for PIC16C73AT-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 PIC16C73AT-20I/SO (same form factor and footprint) β differing in Package, Timers, Operating Temperature, RAM Size, ADC.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16C73A-20I/SO
β Drop-Inβ In Stock
$9.3 / Unit
View Datasheet βPIC16C73A-20/SP
β Drop-Inβ In Stock
$7.2 / Unit
View Datasheet βPIC16C73B-20I/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C73A-10I/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C72AT-20I/SO
β Drop-Inβ In Stock
$1.45 / Unit
View Datasheet βPIC16C74A-20I/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C73AT-20I/SO Maximum Ratings & Electrical Characteristics
| Core | 8-bit PIC16C mid-range RISC |
| Program Memory Type | OTP (One-Time Programmable) EPROM |
| Program Memory Size | 7 KB (4K x 14 words) |
| RAM Size | 192 x 8 bytes |
| CPU Speed | 20 MHz (5 MIPS) |
| Instruction Set | 35 single-word instructions (14-bit) |
| Operating Voltage (Vdd) | 2.5 V to 6.0 V (5 V typical) |
| Operating Temperature | -40C to +85C (industrial grade, "I" suffix) |
| I/O Pins | 22 programmable |
| ADC | 8-channel, 8-bit on-chip |
| Communication Peripherals | USART/SCI, SSP (SPI / I2C) |
| Timers | Timer0, Timer1, Timer2 (PWM) |
| Watchdog Timer | Yes (on-chip RC oscillator) |
| Brown-out Reset / POR | Yes |
| I/O Sink/Source | 25 mA per pin |
| Package | 28-SOIC (0.295 inch / 7.50 mm wide body) |
| Packaging | Tape & Reel (T suffix) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (per distributor listing) |
PIC16C73AT-20I/SO Pin Configuration
| Pin 1 | RA2/AN2/VREF- β Port A bit 2 / Analog input 2 / Negative voltage reference |
| Pin 2 | RA3/AN3/VREF+ β Port A bit 3 / Analog input 3 / Positive voltage reference |
| Pin 3 | RA4/T0CKI β Port A bit 4 / Timer0 clock input |
| Pin 4 | RA5/AN4/SS β Port A bit 5 / Analog input 4 / SPI Slave Select |
| Pin 5 | Vss β Ground reference |
| Pin 6 | OSC1/CLKIN β Crystal oscillator input / external clock input |
| Pin 7 | OSC2/CLKOUT β Crystal oscillator output / clock output |
| Pin 8 | RC0/T1OSO/T1CKI β Port C bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 9 | RC1/T1OSI/CCP2 β Port C bit 1 / Timer1 oscillator input / CCP2 PWM output |
| Pin 10 | RC2/CCP1 β Port C bit 2 / CCP1 PWM output |
| Pin 11 | RC3/SCK/SCL β Port C bit 3 / SPI clock / I2C clock |
| Pin 12 | RC4/SDI/SDA β Port C bit 4 / SPI data in / I2C data |
| Pin 13 | RC5/SDO β Port C bit 5 / SPI data out |
| Pin 14 | RC6/TX/CK β Port C bit 6 / USART TX / USART clock |
| Pin 15 | RC7/RX/DT β Port C bit 7 / USART RX / USART data |
| Pin 16 | Vss β Ground reference (second) |
| Pin 17 | VDD β Positive supply (2.5 V to 6.0 V) |
| Pin 18 | RB0/INT β Port B bit 0 / External interrupt |
| Pin 19 | RB1 β Port B bit 1 |
| Pin 20 | RB2 β Port B bit 2 |
| Pin 21 | RB3/PGM β Port B bit 3 / Low-voltage programming |
| Pin 22 | RB4 β Port B bit 4 |
| Pin 23 | RB5 β Port B bit 5 |
| Pin 24 | RB6/PGC β Port B bit 6 / Programming clock |
| Pin 25 | RB7/PGD β Port B bit 7 / Programming data |
| Pin 26 | RA0/AN0 β Port A bit 0 / Analog input 0 |
| Pin 27 | RA1/AN1 β Port A bit 1 / Analog input 1 |
| Pin 28 | Vdd β Positive supply (2.5 V to 6.0 V) |
Typical Applications
PIC16C73AT-20I/SO is suitable for 7 applications: Industrial Process Control, Appliance Motor Control, Instrumentation and Data Acquisition, Automotive Body Electronics, Sensor Conditioning Front-End, Embedded Control Boards (Hobbyist/Educational), Power Supply Digital Control and Monitoring.
Industrial Process Control
The PIC16C73AT-20I/SO fits industrial process-control boards because its 8-channel 8-bit ADC directly samples 0-5 V transducer signals (4-20 mA loop shunts, RTD-conditioned voltages, strain-gauge bridges) without an external converter. The 5 MIPS core at 20 MHz executes a PID loop within ~10 us, comfortably fast for temperature, pressure, and flow loops at kHz sample rates. The 28-SOIC wide-body footprint and industrial -40C to +85C rating let the device mount on conformal-coated factory-floor PCBs near motor starters. Brown-out reset protects against supply dips from contactor switching, and the watchdog timer with on-chip RC oscillator recovers the MCU if firmware hangs in a fault state.
Recommended
Appliance Motor Control
The PIC16C73AT-20I/SO drives small brushed DC and universal motors in appliances by pairing Timer2 PWM output (up to ~20 kHz switching) with the 8-bit ADC for closed-loop current or RPM feedback. With 22 I/O pins each rated at 25 mA sink/source, it directly interfaces to logic-level gate signals and status LEDs without buffer transistors. The 7 KB OTP code space fits standard BLDC commutation tables plus fault-handling routines. Compared with a discrete 555-based controller, the MCU enables soft-start ramps and adaptive speed profiles in firmware.
Recommended
Instrumentation and Data Acquisition
For low-cost instrumentation front-ends, the PIC16C73AT-20I/SO integrates an 8-bit ADC, USART, and SPI/I2C in one package, eliminating two external ICs. Its 8 analog inputs multiplex directly into the successive-approximation converter at ~20 us per sample, supporting bench multimeters, panel meters, and portable loggers sampling multiple sensors sequentially. The 192-byte RAM buffers short acquisition bursts before the USART streams results to a host at 9600-115200 baud. Industrial temperature grade and 5V operation suit laboratory and shop-floor instrumentation.
Recommended
Automotive Body Electronics
Automotive body modules (window lifters, mirror adjusters, lighting controllers, HVAC blend doors) use the PIC16C73AT-20I/SO because its industrial -40C to +85C grade survives cabin temperature swings and the integrated ADC reads position potentiometers and current-sense shunts. The USART interfaces to BCM gateway modules over LIN or K-line transceivers, while PWM timers drive LED dimming and motor H-bridge control. The OTP memory is acceptable for high-volume body modules where firmware is final. Note: for AEC-Q100-qualified automotive designs, choose the PIC16C73A-20I/SO Q-temp grade instead.
Recommended
Sensor Conditioning Front-End
The PIC16C73AT-20I/SO serves as a digital sensor-conditioning front-end for thermistor, RTD, and bridge sensors. Its 8-bit ADC samples the conditioned analog signal, while firmware applies linearization and filtering before transmitting the result over SPI or USART to a host controller. The 5 MIPS throughput at 20 MHz handles second-order digital filtering in real time at 100 Hz sample rates. The 22 I/O pins drive status LEDs, accept calibration buttons, and interface to EEPROM for stored calibration constants.
Recommended
Embedded Control Boards (Hobbyist/Educational)
Hobbyist and maker training kits adopt the PIC16C73AT-20I/SO because it offers a real industrial 8-bit MCU core, on-chip ADC, and PWM in a hobbyist-friendly 28-SOIC footprint that breadboard adapters and DIP carriers can host. Firmware examples in C and assembly teach timers, interrupts, and ADC conversion. The OTP memory enforces disciplined development - students cannot 'cheat' with infinite reflashes. For classroom repeatability, the PIC16F73-I/SO Flash variant is preferred.
Recommended
Power Supply Digital Control and Monitoring
In digitally controlled SMPS or UPS products, the PIC16C73AT-20I/SO monitors output voltage via its on-chip ADC, drives optocoupler feedback through a PWM timer, and reports telemetry over USART or I2C to a system supervisor. The 7KB code space fits state-machine-based control loops with soft-start, over-current protection, and telemetry formatting. Industrial temperature grade and 5V operation suit telecom and server-room PSUs.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C73AT-20I/SO β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C73A-20I/SO | PIC16C73B-20I/SO | PIC16F73-I/SO |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SOIC wide-body (T&R) | 28-SOIC wide-body (tray) - same | 28-SOIC wide-body - same | 28-SOIC wide-body - same |
| Program Memory | 7 KB OTP (4K x 14) | 7 KB OTP | 7 KB OTP | 7 KB Flash |
| RAM Size | 192 bytes | 192 bytes | 192 bytes | 192 bytes |
| CPU Speed | 20 MHz (5 MIPS) | 20 MHz | 20 MHz | 20 MHz |
| Memory Type | OTP (one-time programmable) | OTP | OTP | Flash (reprogrammable) |
| ADC | 8 ch x 8-bit | 8 ch x 8-bit | 8 ch x 8-bit | 8 ch x 8-bit |
| I/O Pins | 22 | 22 | 22 | 22 |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
| Lifecycle Status | NRND | NRND | NRND | Active |
Key Differentiators
- Tape-and-reel packaging on identical silicon (vs PIC16C73A-20I/SO)
- Silicon B-revision errata fixes at no cost (vs PIC16C73B-20I/SO)
- Flash reprogrammability for development (vs PIC16F73-I/SO)
Design Notes
Decouple both Vdd/Vss pairs (pins 17/16 and 28/5) with 100 nF ceramic capacitors placed within 5 mm of each Vdd pin, plus a 10 uF bulk capacitor at the regulator. PIC16C73A switching noise on the analog supply can corrupt the ADC; place an additional ferrite bead or 10 ohm resistor in series with the Vdd feeding the analog reference pin (RA3/VREF+) when high ADC accuracy is required. Brown-out reset should be enabled in configuration bits to recover from supply dips caused by motor inrush.
The PIC16C73AT-20I/SO consumes roughly 5 mA active at 5 V/20 MHz and 1 uA sleep current. Industrial temperature grade (-40C to +85C) is sufficient for most enclosed environments but does NOT cover under-hood automotive or outdoor exposed operation - in that scenario choose a Q-temp (-40C to +125C) variant. The 28-SOIC wide-body package has a theta_JA of approximately 70 C/W on a 1 oz copper 4-layer board, allowing operation up to ~50C ambient without derating.
Route the crystal traces (OSC1 pin 6, OSC2 pin 7) as short as possible with ground guard on both sides to avoid injecting switching noise into the clock. Place the crystal within 5 mm of the OSC pins, keep it over a continuous ground pour, and shield the traces with a via fence. The analog inputs (RA0-RA5) should route away from PWM traces (RC1/RC2) by at least 3 mm or a ground moat, because capacitive coupling can induce ADC error during high-frequency PWM transitions.
Estimated: programming a fresh OTP device requires a 12-13 V VPP supply on the MCLR/VDD pair plus the PRO MATE or compatible parallel programmer - in-circuit serial programming (ICSP) is supported on the F-series (PIC16F73) but NOT on the C-series OTP device. Do not confuse PIC16C73AT-20I/SO with PIC16C73A-20I/SO (tray vs T&R), or PIC16C73BT-20I/SO (B-suffix silicon revision). Configuration bits must be set BEFORE programming code memory; missing CP (code-protect) bits will leave IP exposed.
Compliance Information
RoHS and lead-free compliance per Microchip product family declaration; AEC-Q100 automotive qualification is NOT standard on the I-suffix C-series - choose Q-temp grade variants for AEC-Q100 qualified designs. REACH compliance per Microchip materials declaration.
