PIC16C73A-20/SO - 8-bit 20MHz 7KB OTP MCU 28-SOIC | Microchip
MPN: PIC16C73A-20/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.93 | $3.93 |
| 10 | $3.55 | $35.50 |
| 100 | $3.1 | $310.00 |
| 500 | $2.75 | $1,375.00 |
| 1,000 | $2.5 | $2,500.00 |
PIC16C73A-20/SO Overview
An 8-bit microcontroller (MCU) is a programmable integrated circuit containing a CPU, memory, and peripherals on a single die. Within the broader taxonomy, an 8-bit MCU is a member of the microcontroller family, which itself is a subcategory of microcontrollers > microprocessors > semiconductors. The PIC16C73A belongs specifically to Microchip's mid-range PIC16CXXX architecture, which evolved into today's enhanced mid-range PIC16FXXX family. Compared with 16-bit and 32-bit MCUs, 8-bit parts like this one trade raw compute throughput for deterministic timing, low cost, and extreme code density in embedded control applications.
Key specifications include an operating voltage range of 4.0V to 5.5V (with the industrial -I variant supporting 2.5V-6.0V), 8-channel 8-bit A/D converter, three timer modules (Timer0, Timer1, Timer2), a USART, and a synchronous serial port (SPI/I2C) configurable via the MSSP peripheral. The device supports typical operating currents below 2 mA at 5V/4 MHz and standby currents under 1 µA, making it suitable for power-sensitive embedded designs. Integrated peripherals replace external glue logic and reduce BOM cost in motor control, instrumentation, and consumer appliances.
Architecturally, the PIC16C73A uses a Harvard memory structure with separate program and data buses, allowing instruction fetch and operand read to occur in the same cycle. The OTP EPROM-based program memory is one-shot programmable via a standard device programmer, providing flexibility for low- to mid-volume production. The part is specified for the commercial 0°C to +70°C range in the -20 version and the industrial -40°C to +85°C range in the -20I variant.
Typical applications include industrial control systems, automotive body electronics, sensor signal conditioning, low-speed data acquisition, smart sensor hubs, and home appliance controllers. The integrated ADC, timers, and serial peripherals allow direct connection to analog sensors, keypad matrices, and communication buses without external ICs.
When designing with this part, note that it has been superseded by the PIC16C73B and PIC16F73 (Flash-based) variants. New designs should generally migrate to the PIC16F73 or current PIC16F1xxx family for supply longevity. For existing designs with mature firmware, the PIC16C73A-20/SO remains a supported legacy part with active distributor inventory per Microchip's product page.
This page synthesizes distributor pricing across DigiKey, Mouser, LCSC, Octopart and other channels, drop-in same-family Microchip alternatives, and practical design notes not consolidated in the manufacturer datasheet, giving engineers a single-source comparison for sourcing decisions.
Drop-in alternatives for PIC16C73A-20/SO — 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 PIC16C73A-20/SO (same form factor and footprint) — differing in Package, Program Memory Size, Program Memory Type, Timers, Mounting Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C73B-20/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C73A-20I/SO
✅ Drop-In✓ In Stock
$9.3 / Unit
View Datasheet →PIC16F73-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C73A-10E/SO
✅ Drop-In✓ In Stock
$6.55 / Unit
View Datasheet →PIC16F73-E/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C74A-20/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C73A-20/SO Maximum Ratings & Electrical Characteristics
| Product Family | PIC16CXX (mid-range) |
| Core Architecture | 8-bit RISC Harvard |
| CPU Instruction Set | 35 single-word instructions |
| Maximum Clock Frequency | 20 MHz |
| Instruction Cycle Time | 200 ns |
| Performance | 5 MIPS |
| Program Memory Size | 7 KB (4K x 14) OTP EPROM |
| Program Memory Type | OTP (One-Time Programmable) |
| RAM Size | 192 bytes |
| Data EEPROM | Not present |
| I/O Pins | 22 |
| A/D Converter | 8 channels x 8-bit |
| Timers | 3 (Timer0, Timer1, Timer2) |
| Serial Communication | USART + MSSP (SPI/I2C) |
| Supply Voltage | 4.0 V to 5.5 V |
| Typical Operating Current | < 2 mA at 5 V / 4 MHz |
| Standby Current | < 1 µA |
| Operating Temperature | 0°C to +70°C (commercial) |
| Package | 28-pin SOIC (SO) |
| Mounting Type | Surface Mount |
PIC16C73A-20/SO Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (Reset) input / programming voltage |
| Pin 2 | RA0/AN0 — PORTA bit 0 / analog input 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / analog input 1 |
| Pin 4 | RA2/AN2 — PORTA bit 2 / analog input 2 |
| Pin 5 | RA3/AN3/VREF — PORTA bit 3 / analog input 3 / ADC VREF+ |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — PORTA bit 5 / analog input 4 / SPI slave select |
| Pin 8 | OSC1/CLKIN — Oscillator input / external clock |
| Pin 9 | OSC2/CLKOUT — Oscillator output |
| Pin 10 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock |
| Pin 11 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 |
| Pin 12 | RC2/CCP1 — PORTC bit 2 / Capture/Compare/PWM 1 |
| Pin 13 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 14 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 15 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 16 | RC6/TX/CK — PORTC bit 6 / USART TX / USART clock |
| Pin 17 | RC7/RX/DT — PORTC bit 7 / USART RX / USART data |
| Pin 18 | VSS — Ground |
| Pin 19 | VDD — Positive supply (4.0-5.5V) |
| Pin 20 | RB0/INT — PORTB bit 0 / external interrupt |
| Pin 21 | RB1 — PORTB bit 1 |
| Pin 22 | RB2 — PORTB bit 2 |
| Pin 23 | RB3 — PORTB bit 3 |
| Pin 24 | RB4 — PORTB bit 4 |
| Pin 25 | RB5 — PORTB bit 5 |
| Pin 26 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 27 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 28 | VSS — Ground |
Typical Applications
PIC16C73A-20/SO is suitable for 6 applications: Industrial Control Systems, Automotive Body Electronics, Sensor Signal Conditioning and Data Acquisition, Home Appliance Controllers, Smart Sensor Hubs and IoT Edge Nodes, Low-Speed Motor Control and Stepper Drives.
Industrial Control Systems
The PIC16C73A-20/SO's integrated 8-channel 8-bit ADC, three timers, and 22 digital I/O lines make it well suited to industrial control PLCs and process controllers. Its 5 MIPS throughput at 20 MHz handles PID loops for motor speed, valve positioning, and temperature regulation with deterministic timing. The Harvard architecture and 200 ns instruction cycle give predictable interrupt latency critical for safety interlocks. Supply range of 4.0V to 5.5V (industrial -I variant up to 6.0V) tolerates 24V industrial rails after regulation. Migrate to PIC16F73 if in-field firmware updates are required.
Recommended
Automotive Body Electronics
In automotive body modules such as window controllers, mirror adjusters, and seat controllers, the PIC16C73A-20/SO provides the deterministic I/O response and peripheral integration needed for ECU subsystems. Its 20 MHz core runs multiple sensor sampling tasks while the USART and MSSP drive LIN or serial bus communication to other ECUs. Use the -I or -E industrial/extended temperature variant for underhood environments. The 28-SOIC package is footprint-compatible with PIC16F73 and PIC16C73B, allowing migration to Flash-based or improved-silicon revisions without PCB rework.
Recommended
Sensor Signal Conditioning and Data Acquisition
The PIC16C73A-20/SO's integrated 8-bit ADC with 8 input channels handles direct connection to thermocouples, strain gauges, and 4-20 mA loop sensors after external signal conditioning. Its three timers enable precise sample-rate generation and PWM output for actuator control in data acquisition front-ends. The 192 B RAM is sufficient for time-stamping and circular buffers in low-speed acquisition tasks. Power consumption below 2 mA at 5V/4 MHz supports battery-powered field instrumentation with the OTP memory storing calibration tables.
Recommended
Home Appliance Controllers
White-goods controllers in washing machines, dishwashers, and microwave ovens benefit from the PIC16C73A-20/SO's combination of OTP program memory for cost-sensitive high-volume production and integrated peripherals driving motor TRIACs, relay coils, and user keypads. The MSSP peripheral interfaces with LED or LCD display drivers, while the timers generate zero-cross detection and TRIAC firing delays. Its 5 MIPS throughput handles multi-task scheduling under a simple round-robin or cooperative kernel. Migrate to PIC16F73 if end-of-line programming flexibility is needed.
Recommended
Smart Sensor Hubs and IoT Edge Nodes
For non-connected local sensor aggregation - HVAC zone controllers, building automation I/O expanders, and security panel keypads - the PIC16C73A-20/SO aggregates digital sensors, debounces mechanical inputs, and drives local annunciators. Its USART enables RS-232 or RS-485 communication to upstream controllers or gateways, while the MSSP peripheral supports I2C sensor expansion. The 7 KB OTP memory holds a full state machine plus diagnostic log buffer. Pair with an external ESP-style module if Wi-Fi is required.
Recommended
Low-Speed Motor Control and Stepper Drives
Stepper motor sequencing, brushed DC motor PWM, and small BLDC commutation can be implemented on the PIC16C73A-20/SO using its three timers for PWM generation, Timer1 for commutation timing, and the ADC for back-EMF or current sensing. The 5 MIPS throughput handles up to four PWM channels in software while the USART provides position-command input from a host. The 28-SOIC package is suitable for integration on stepper driver carrier boards. Use the industrial -I variant for factory-automation ambient temperatures.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C73A-20/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C73B-20/SO | PIC16C73A-20I/SO | PIC16F73-I/SO | PIC16C73A-10E/SO | PIC16F73-E/SO | PIC16C74A-20/SO |
|---|---|---|---|---|---|---|---|
| Package | 28-SOIC | 28-SOIC (same) | 28-SOIC (same) | 28-SOIC (same) | 28-SOIC (same) | 28-SOIC (same) | 28-SOIC (same) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core / Architecture | 8-bit RISC Harvard (PIC16 mid-range) | 8-bit RISC Harvard (same) | 8-bit RISC Harvard (same) | 8-bit RISC Harvard (Flash) | 8-bit RISC Harvard (same) | 8-bit RISC Harvard (Flash) | 8-bit RISC Harvard (same family) |
| Maximum Clock | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 10 MHz (-50%) | 20 MHz | 20 MHz |
| Program Memory | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB Flash | 7 KB OTP | 7 KB Flash | 7 KB OTP |
| RAM | 192 B | 192 B | 192 B | 192 B | 192 B | 192 B | 192 B |
| I/O Pins | 22 | 22 | 22 | 22 | 22 | 22 | 33 (+50%) |
| Supply Voltage | 4.0-5.5 V | 4.0-5.5 V | 2.5-6.0 V (extended) | 2.5-5.5 V | 4.0-5.5 V | 2.5-5.5 V | 4.0-5.5 V |
| Temperature Range | 0°C to +70°C (commercial) | 0°C to +70°C | -40°C to +85°C (industrial) | -40°C to +85°C | -40°C to +125°C (extended) | -40°C to +125°C | 0°C to +70°C |
Key Differentiators
- Pin-compatible Flash alternative with ICSP support (vs PIC16F73-I/SO)
- Extended industrial temperature range (vs PIC16C73A-20I/SO)
- Higher I/O count within same PIC16C7x family (vs PIC16C74A-20/SO)
Design Notes
Place a 100 nF ceramic decoupling capacitor as close as possible to the VDD pin (pin 20) of the PIC16C73A-20/SO, plus a bulk 10 µF tantalum or aluminum electrolytic capacitor on the same supply rail. The device draws brief current spikes during ADC conversion and Timer1 oscillator start-up; inadequate bulk capacitance on the VDD pin causes ADC reference droop and timer jitter. The PIC16C73A-20/SO is specified for 4.0V to 5.5V, so a 5V LDO (e.g., MCP1700) is recommended for battery-backed designs.
Because the PIC16C73A-20/SO uses One-Time Programmable (OTP) EPROM, once a part is programmed it cannot be re-blanked and reprogrammed. Always program and verify engineering samples first, and use Microchip's ICSP-compatible device programmer (e.g., PICkit 3 or MPLAB PM3) to confirm OTP window usage before committing to production volumes. For designs that may need firmware updates, prefer the PIC16F73 (Flash) drop-in alternative.
Route the OSC1/OSC2 crystal traces as short and symmetric as possible with a grounded guard ring to reduce EMI coupling to sensitive analog inputs. The 22 I/O pins include analog-capable pins on PORTA (RA0-RA5) and PORTB; when using the ADC, set the TRIS register correctly and apply adequate acquisition time (minimum 19.7 µs at 5V per the datasheet). Place analog and digital ground returns to the VSS pin (pin 8 and pin 28) separately to avoid ground-loop noise on ADC readings.
When using the MSSP peripheral in I2C mode, install pull-up resistors (typically 4.7 kΩ to 10 kΩ, sized for bus capacitance and 400 kHz fast-mode operation) on the SCL (RC3) and SDA (RC4) lines. For SPI master mode, ensure the SCK (RC3) signal rise time is below the slave's setup requirement; a series resistor (22 kΩ to 33 kΩ) at SCK can dampen reflections on long traces. Always check the PIC16C73A datasheet errata for known peripheral limitations in your silicon revision before committing to layout.
Compliance Information
Compliance information not present in the Verified Web Data. MSL Level and RoHS status marked as [DATA_NEEDED] in specs. The PIC16C73A is a legacy OTP part; for AEC-Q100 automotive-qualified operation, contact Microchip for the latest Q-grade variants.
