PIC16C73BT-04/SO - 4MHz 8-bit OTP MCU, 7KB EPROM, 22 I/O | Microchip
MPN: PIC16C73BT-04/SO ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.42 | $7.42 |
| 10 | $6.69 | $66.90 |
| 100 | $5.95 | $595.00 |
| 500 | $5.21 | $2,605.00 |
| 1,000 | $4.65 | $4,650.00 |
PIC16C73BT-04/SO Overview
A microcontroller (MCU) is a single-chip computer containing a CPU core, non-volatile program memory, working RAM, and peripheral set on one die. The PIC16CXX mid-range family sits in the PIC16/17/18/24 hierarchy: PIC16 -> 8-bit PIC mid-range -> PIC16CXX OTP/EPROM family -> PIC16C73B sub-family. The OTP architecture lets the user program the device once via an EPROM-style cell; it cannot be electrically erased, so this part is intended for mature production code rather than field-updatable designs.
Key features of the PIC16C73BT-04/SO include a Harvard RISC CPU with only 35 single-word instructions, an integrated 8-channel 8-bit analog-to-digital converter (ADC), a USART, an MSSP (SPI/I2C) peripheral, two 8-bit timers plus one 16-bit timer with capture/compare/PWM, and a synchronous serial port. Brown-out reset, watchdog timer, power-on reset, and code protection complete the on-chip feature set, making the part suitable for industrial control panels, appliance motor control, instrumentation front-ends, and white-goods embedded designs.
The architecture follows the classic PIC RISC pipeline: one instruction is fetched every clock and executed in four clocks, with a two-stage pipelined design. The CPU uses separate program and data buses (Harvard) so each instruction fetch does not contend with data accesses, enabling deterministic 200 ns instruction execution at the 4 MHz oscillator rating. The internal 8-bit data path pairs with the 14-bit instruction word to give a compact code density typical of mid-range PIC silicon.
Typical applications for the PIC16C73BT-04/SO include industrial automation sensor interfaces, low-cost HVAC control boards, motor drive signal conditioning, smart sensor analog front-ends, white-goods control (washing machines, refrigerators), and embedded instrumentation. The 22 I/O and integrated ADC remove the need for external glue logic, allowing tight PCB layouts in 5V designs.
When designing with this part, plan for the OTP programming constraint: code must be fully validated in development before the production programming step, since EPROM windowed versions are not field-erasable. Account for the SOIC-28 thermal envelope and use proper decoupling: a 0.1 uF ceramic close to VDD plus a bulk electrolytic near the supply pin will keep ADC SNR clean in mixed-signal layouts.
This page synthesizes current distributor pricing, drop-in same-family alternatives from the Site MPN list, and design notes that go beyond the manufacturer datasheet to help engineers select and source the PIC16C73BT-04/SO.
Drop-in alternatives for PIC16C73BT-04/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 PIC16C73BT-04/SO (same form factor and footprint) — differing in Package, Timers, Core Architecture, Program Memory Type, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C73B-04/SO
✅ Drop-In✓ In Stock
$4.65 / Unit
View Datasheet →PIC16C73B-20/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C73B-04I/SO
✅ Drop-In✓ In Stock
$7.1 / Unit
View Datasheet →PIC16C73B-04/SS
✅ Drop-In✓ In Stock
$5.05 / Unit
View Datasheet →PIC16C73B-20/SS
✅ Drop-In✓ In Stock
$4.56 / Unit
View Datasheet →PIC16C73BT-04/SO Maximum Ratings & Electrical Characteristics
| Core | PIC16 / 8-bit RISC |
| Program Memory Type | OTP (EPROM) |
| Program Memory Size | 7 KB (4K x 14) |
| RAM Size | 192 bytes |
| Maximum Clock Frequency | 4 MHz |
| Instruction Cycle | 200 ns (4 clocks per instruction) |
| Supply Voltage | 5 V (nominal, 4.0 V to 6.0 V typical) |
| Number of I/O Pins | 22 |
| ADC | 8 channels, 8-bit |
| Timers | 2 x 8-bit + 1 x 16-bit (with CCP) |
| Communication Peripherals | USART, MSSP (SPI / I2C) |
| Instruction Set | 35 single-word instructions |
| Package | 28-pin SOIC (SO), wide-body |
| Mounting Type | Surface Mount |
| Operating Temperature Range | 0C to +70C (commercial, /SO grade) |
| Watchdog Timer | Yes |
| Brown-Out Reset | Yes |
| Power-On Reset | Yes |
| Speed Grade | 04 (4 MHz) |
PIC16C73BT-04/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 reference voltage |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer 0 clock input |
| Pin 7 | RA5/AN4/SS — PORTA bit 5 / analog input 4 / SPI slave select |
| Pin 8 | OSC1/CLKIN — Oscillator input / external clock input |
| Pin 9 | OSC2/CLKOUT — Oscillator output / clock output |
| Pin 10 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer 1 oscillator output / Timer 1 clock input |
| Pin 11 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer 1 oscillator input / CCP2 output |
| Pin 12 | RC2/CCP1 — PORTC bit 2 / CCP1 output |
| 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 voltage (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 (secondary) |
Typical Applications
PIC16C73BT-04/SO is suitable for 7 applications: Industrial Automation Sensor Interface, White-Goods Appliance Control (Washing Machines, Refrigerators), Low-Cost HVAC Control Board, Embedded Instrumentation and Front-End Controllers, Motor Drive Signal Conditioning, Smart Sensor Analog Front-End, Educational and Hobby Embedded Projects.
Industrial Automation Sensor Interface
The PIC16C73BT-04/SO is well suited to industrial sensor-interface boards that read 4-20 mA loops, thermistors, or 0-10 V analog signals. Its 5-channel 8-bit ADC with 22 digital I/O lets a single chip service multiple sensor channels plus digital control lines, while the 35-instruction RISC core keeps the firmware footprint inside the 7 KB OTP. The integrated USART enables Modbus RTU or custom serial protocols over RS-485 transceivers, and the 4 MHz oscillator is adequate for 9600-115200 baud polling loops typical in PLC analog front-ends. Brown-out reset and watchdog timer provide the robustness required by IEC 61131 industrial environments.
Recommended
White-Goods Appliance Control (Washing Machines, Refrigerators)
Home appliance main boards use the PIC16C73BT-04/SO to drive triac-controlled motors, read user keypad inputs, and display status on LED or LCD panels. The 22 I/O pins directly support keypad scanning, relay drivers, and zero-cross detection, while the MSSP peripheral drives an I2C EEPROM for cycle parameters and the USART to communicate with inverter modules. The 4 MHz oscillator and 5V supply align with the legacy MCU ecosystem still common in major appliance designs. OTP memory locks down the firmware to prevent field tampering, which is a regulatory plus for safety-critical appliance control. Brown-out reset ensures clean recovery after line-voltage brown-outs in white goods.
Recommended
Low-Cost HVAC Control Board
Heating, ventilation, and air-conditioning controllers often use the PIC16C73BT-04/SO as the main MCU to read temperature sensors, drive blower motors via triacs, and manage thermostat user interfaces. The 5-channel ADC supports multiple thermistor inputs (return air, supply air, outdoor air) plus humidity sensor inputs, while the PWM CCP channel modulates blower or compressor speed. At 4 MHz the part performs sensor linearization, hysteresis control, and scheduling within the 200 ns instruction cycle budget comfortably. The MSSP port drives I2C expansion for display modules and real-time clocks, and the OTP memory locks the calibration constants in production.
Recommended
Embedded Instrumentation and Front-End Controllers
Bench instruments, data loggers, and process-control front-ends benefit from the PIC16C73BT-04/SO's combination of 8-bit ADC, USART, MSSP, and CCP peripherals in a 28-pin SOIC. The MSSP drives an SPI ADC or DAC front-end at high speed, the USART streams readings to a host PC or PLC, and the CCP generates timing-critical trigger pulses for sample-and-hold circuits. The 7 KB OTP holds calibration tables and linearization routines for sensors like load cells, strain gauges, and RTDs. Industrial users rely on brown-out reset and watchdog timer for unattended, safety-relevant installations where firmware hangs must self-recover.
Recommended
Motor Drive Signal Conditioning
Small BLDC and stepper motor controllers use the PIC16C73BT-04/SO for the low-level signal conditioning stage: Hall sensor decoding, back-EMF zero-cross detection, current-sense amplification, and PWM command generation. The 16-bit CCP module produces the 25 kHz center-aligned PWM typical of sensorless BLDC commutation, while the 5-channel ADC reads phase currents via shunt resistors for closed-loop torque control. The 4 MHz clock gives 200 ns instruction resolution - sufficient for state machines running at a few kHz but tight for high-RPM sensorless algorithms. OTP memory freezes the firmware version and motor calibration parameters.
Recommended
Smart Sensor Analog Front-End
Smart sensor transmitters (pressure, flow, level) use the PIC16C73BT-04/SO to digitize a bridge or RTD input and output a calibrated 4-20 mA or 0-10 V industrial signal. The 8-bit ADC (5 analog inputs) is adequate for moderate-resolution pressure transducers and the CCP generates the PWM-from-digital conversion for current-loop DACs. The USART drives HART protocol modems or RS-485 fieldbuses, and the MSSP runs an SPI interface to external flash for data logging. OTP memory locks calibration constants and linearization coefficients against field tampering - a regulatory requirement in many process industries.
Recommended
Educational and Hobby Embedded Projects
The PIC16C73BT-04/SO is used in university embedded-systems labs and hobby projects that want a 28-pin SOIC mid-range PIC with ADC, USART, and MSSP in one chip. Its 7 KB OTP gives students room to program non-trivial algorithms (PID control, FSM implementations, FFT) while the 35-instruction RISC core keeps the assembly language approachable. The SOIC-28 wide-body package is breadboard-friendly with SOIC-to-DIP adapter boards, and the 4 MHz oscillator works with low-cost ceramic resonators. Although the OTP constraint prevents field re-programming, students use UV-erasable windowed PIC16C73B variants (JW package) for development.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C73BT-04/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C73B-04/SO | PIC16C73B-20/SO | PIC16C73B-04I/SO | PIC16C73B-04/SS | PIC16C73B-20/SS |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | SOIC-28 (wide-body) | SOIC-28 (wide-body) | SOIC-28 (wide-body) | SOIC-28 (wide-body) | SSOP-28 | SSOP-28 |
| Maximum Clock Frequency | 4 MHz | 4 MHz | 20 MHz | 4 MHz | 4 MHz | 20 MHz |
| Program Memory | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP |
| RAM | 192 B | 192 B | 192 B | 192 B | 192 B | 192 B |
| ADC | 5-channel 8-bit | 5-channel 8-bit | 5-channel 8-bit | 5-channel 8-bit | 5-channel 8-bit | 5-channel 8-bit |
| Operating Temperature Range | 0C to +70C (commercial) | 0C to +70C (commercial) | 0C to +70C (commercial) | -40C to +85C (industrial) | 0C to +70C (commercial) | 0C to +70C (commercial) |
| Packaging Carrier | Tape & Reel (T) | Tube / bulk | Tube / bulk | Tube / bulk | Tube / bulk | Tube / bulk |
Key Differentiators
- Tape-and-reel carrier for high-volume pick-and-place production (vs PIC16C73B-04/SO)
- Lower power dissipation at default volume (vs PIC16C73B-04/SO)
- 4 MHz speed grade for low-power sensor applications (vs PIC16C73B-20/SO)
Design Notes
The PIC16C73BT-04/SO uses OTP (one-time-programmable) EPROM program memory. Unlike flash PIC16F variants, this part CANNOT be electrically erased or re-programmed in-circuit. Always validate firmware on a windowed JW-package PIC16C73B or on a PIC16F73 flash equivalent before committing to OTP production programming. A single bit error in the OTP image permanently bricks the device. Build a robust programming flow that verifies the entire code space with checksum and blank-check operations after each program cycle.
Decouple VDD with a 0.1 uF ceramic capacitor placed within 5 mm of the VDD pin (pin 19), plus a 10 uF bulk electrolytic on the board supply rail. The analog AVdd/AVss pins, if connected separately, should each have their own 0.1 uF + 10 uF decoupling pair to keep ADC SNR clean. Brown-out reset (BOR) is enabled by configuration fuses and ensures the MCU resets cleanly if VDD dips below the BOR threshold (typically 4.0V). Plan BOR hold time at 100 ms minimum to allow power supply stabilization on appliance-style 5V rails with heavy inrush loads.
The 28-pin SOIC wide-body package (7.5 mm body, 1.27 mm pitch) is forgiving for hand-soldering but requires thermal relief spokes on power and ground pads if using a hot-air reflow process with a large copper pour. Route the analog inputs AN0-AN4 away from digital switching traces; the integrated 8-bit ADC is sensitive to digital noise coupling through the substrate. Keep the MCLR/VPP trace short and place the MCLR pull-up resistor (typically 10 kohm) close to the pin to ensure reliable reset behavior during power-up and brown-out recovery.
For optimal ADC accuracy, dedicate the AVdd pin to a quiet supply derived from VDD through a ferrite bead plus 10 uF/0.1 uF decoupling, and tie AVss to a clean ground island that joins the digital ground only at one point near the MCU. The 8-bit ADC on the PIC16C73BT-04/SO has a typical DNL of +/-1 LSB; route the analog input traces as short as possible and place a small RC filter (1 kohm + 100 nF) at the MCU input pin to limit input bandwidth and suppress aliasing. Avoid running analog traces under the oscillator traces or near PWM outputs.
Estimated: The PIC16C73BT-04/SO SOIC-28 package has a typical theta_JA of 50-70 C/W depending on PCB copper area. With 5V supply, 4 MHz oscillator, and typical 2-5 mA active current, total power dissipation is 10-25 mW - well within the thermal envelope. At the industrial -40C to +85C range (use PIC16C73B-04I/SO for that grade), thermal derating is not a concern for this MCU family. No external heatsink is required for any plausible SOIC-28 design.
Compliance Information
RoHS status not confirmed for this OTP PIC16C part in verified data; PIC16CXX OTP/EPROM family is generally pre-RoHS and may contain lead-bearing solder terminations. AEC-Q100 not applicable for non-automotive MCU. Verify RoHS with Microchip or distributor for new production runs.
