PIC16C73B-04/SP - 8-Bit 4MHz OTP MCU, 7KB, 28-SPDIP | Microchip
MPN: PIC16C73B-04/SP β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.2 | $8.20 |
| 10 | $7.38 | $73.80 |
| 100 | $6.56 | $656.00 |
| 500 | $5.74 | $2,870.00 |
| 1,000 | $5 | $5,000.00 |
PIC16C73B-04/SP Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, program memory, data RAM, and peripheral interfaces onto one silicon die. The PIC16C73B sits in the PIC16CXX mid-range taxonomy, which is one tier below enhanced 16-bit PIC families and above baseline 10F/12F/16F parts. MCUs are classified within integrated circuits -> microcontrollers -> 8-bit microcontrollers -> RISC microcontrollers -> embedded controllers. The PIC16C73B's OTP program memory is a synonym for one-time programmable EPROM (the 'C' series indicates EPROM, while 'F' indicates Flash, and 'LC' indicates ROM-less).
Key differentiating features include five channels of 8-bit Analog-to-Digital (A/D) conversion, two additional timers, two capture/compare/PWM peripherals, and a synchronous serial port configurable as either 3-wire SPI or 2-wire I2C. The device also integrates a Universal Asynchronous Receiver Transmitter (USART) for asynchronous serial communication. With only 35 single-word instructions to learn, the PIC16C73B uses a Harvard RISC architecture that executes instructions in a single cycle (200 ns at 4 MHz), except for program branches which take two cycles.
Typical applications include industrial control systems, sensor interfaces, motor control, embedded instrumentation, and legacy 8-bit embedded designs. The five 8-bit ADC channels and two PWM outputs make it suitable for closed-loop control loops reading analog sensors and driving actuators or motors. The integrated USART, SPI, and I2C peripherals support communication with sensors, displays, and other MCUs.
When designing with this part, note that the '04' speed grade limits operation to 4 MHz, and the OTP memory cannot be re-programmed in-circuit. For new designs, the Flash-based PIC16F73 or PIC16F873A is generally preferred; the PIC16C73B-04/SP serves legacy maintenance and existing designs.
Drop-in alternatives for PIC16C73B-04/SP 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 PIC16C73B-04/SP (same form factor and footprint) β differing in Package, RoHS Status, Core Architecture, Serial Interfaces, Timers.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16C73B-04I/SP
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$4.75 / Unit
View Datasheet βPIC16C73B-20/SP
β Drop-Inβ In Stock
$4.95 / Unit
View Datasheet βPIC16C73B-10/SP
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
PIC16F73-I/SP
β Drop-Inπ Reference alternative (not in catalog)
PIC16F873A-I/SP
β Drop-Inπ Reference alternative (not in catalog)
PIC16C73B-04/SP Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC RISC (Harvard) |
| Instruction Set | 35 single-word instructions |
| Program Memory Type | OTP (One-Time Programmable EPROM) |
| Program Memory Size | 7 KB (4K x 14) |
| RAM | 192 bytes |
| Maximum Clock Speed | 4 MHz |
| Instruction Execution Time | 200 ns at 4 MHz |
| ADC Channels | 5 channels x 8-bit |
| Timers | 3 (Timer0, Timer1, Timer2) |
| Capture/Compare/PWM | 2 CCP modules |
| Serial Interfaces | 1x SPI/I2C (SSP) + 1x USART |
| Digital I/O Pins | 22 |
| Supply Voltage | 4.0 V to 5.5 V |
| Operating Temperature | 0 C to +70 C (commercial) |
| Package | 28-pin SPDIP (SP) - through-hole |
| Speed Grade Suffix | 04 = 4 MHz |
| RoHS Status | Non-Compliant (contains Pb) |
PIC16C73B-04/SP Pin Configuration
| Pin 1 | MCLR/VPP β Master Clear (Reset) input or 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 β PORTA bit 2 / Analog input channel 2 |
| Pin 5 | RA3/AN3/VREF β PORTA bit 3 / Analog input 3 / Voltage reference |
| Pin 6 | RA4/T0CKI β PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS β PORTA bit 5 / Analog input 4 / SPI Slave Select |
| Pin 8 | OSC1/CLKIN β Oscillator crystal input / external clock |
| Pin 9 | OSC2/CLKOUT β Oscillator crystal output / clock out |
| Pin 10 | RC0/T1OSO/T1CKI β PORTC bit 0 / Timer1 oscillator out / Timer1 clock |
| Pin 11 | RC1/T1OSI/CCP2 β PORTC bit 1 / Timer1 oscillator in / CCP2 |
| Pin 12 | RC2/CCP1 β PORTC bit 2 / Capture Compare PWM 1 |
| Pin 13 | RC3/SCK/SCL β PORTC bit 3 / SPI clock / I2C clock |
| Pin 14 | RC4/SDI/SDA β PORTC bit 4 / SPI data in / I2C data |
| Pin 15 | RC5/SDO β PORTC bit 5 / SPI data out |
| Pin 16 | RC6/TX/CK β PORTC bit 6 / USART TX / USART clock |
| Pin 17 | RC7/RX/DT β PORTC bit 7 / USART RX / USART data |
| Pin 18 | VSS β Ground reference |
| Pin 19 | VDD β Positive supply voltage (4.0V to 5.5V) |
| Pin 20 | RB0/INT β PORTB bit 0 / External interrupt |
| Pin 21 | RB1 β PORTB bit 1 |
| Pin 22 | RB2 β PORTB bit 2 |
| Pin 23 | RB3 β PORTB bit 3 |
| Pin 24 | RB4 β PORTB bit 4 |
| Pin 25 | RB5 β PORTB bit 5 |
| Pin 26 | RB6/PGC β PORTB bit 6 / ICSP clock |
| Pin 27 | RB7/PGD β PORTB bit 7 / ICSP data |
| Pin 28 | VSS β Ground reference (secondary) |
Typical Applications
PIC16C73B-04/SP is suitable for 6 applications: Industrial Process Control, Sensor Interface and Data Acquisition, Motor Control and PWM Drive, Embedded Instrumentation, HVAC and Building Automation, Legacy Embedded Maintenance.
Industrial Process Control
The PIC16C73B-04/SP is well-suited for industrial process monitoring and control loops where its 5-channel 8-bit ADC reads sensor outputs (temperature, pressure, flow) and its 2 CCP/PWM channels drive actuators or valve controllers. The 22 digital I/O pins handle discrete signals such as limit switches, relay drivers, and indicator LEDs. Operating from a regulated 5V supply, the device integrates USART, SPI, and I2C peripherals to communicate with HMI displays, PLCs, or networked controllers. The 4 MHz clock and 200 ns instruction cycle provide sufficient throughput for closed-loop PID control at update rates typical of thermal and motion systems. The 0 C to +70 C commercial temperature range suits factory-floor enclosures.
Recommended
Sensor Interface and Data Acquisition
The PIC16C73B-04/SP's 5-channel 8-bit ADC is ideal for low-cost multi-sensor data acquisition boards. Each ADC channel can read analog sensors (thermistors, photodiodes, potentiometers) with conversion rates suitable for instrumentation. The integrated USART transmits converted readings to a host PC or display, while the SPI/I2C SSP interfaces connect to digital sensors or EEPROM for data logging. With 192 bytes of RAM and 7 KB of OTP program memory, the device handles average-sized acquisition routines. The 28-SPDIP through-hole package simplifies prototyping on perfboard or in legacy instrumentation systems where mechanical robustness matters more than board area.
Recommended
Motor Control and PWM Drive
With 2 Capture/Compare/PWM modules, the PIC16C73B-04/SP can directly drive brushed DC motors, small stepper motors, or solid-state relays using hardware PWM. The 5 ADC channels provide closed-loop feedback from current-sense amplifiers or position sensors, enabling speed and torque regulation. The 4 MHz clock supports PWM frequencies up to 10 kHz with 8-bit resolution, suitable for low-RPM DC motor control. Combined with the USART for command input from a master controller and the SSP for encoder feedback, the device forms a complete embedded motor controller. The 0 C to +70 C range covers most indoor equipment enclosures.
Recommended
Embedded Instrumentation
Portable test equipment and embedded instrumentation benefit from the PIC16C73B-04/SP's combination of 8-bit ADC, USART, and SSP peripherals. It can drive character LCDs through software bit-banging on GPIO pins while sampling analog inputs and responding to serial commands from a host. The 192 bytes of RAM accommodate stack and small data sets, and the 35-instruction PIC RISC architecture enables compact assembly code. Designers appreciate the 28-SPDIP package for hand-soldered prototypes and the OTP memory for fixed-function production runs where firmware lock-in is acceptable. The 4 MHz clock keeps power consumption low for battery or bus-powered instruments.
Recommended
HVAC and Building Automation
Building automation controllers use the PIC16C73B-04/SP to read temperature sensors, occupancy detectors, and analog setpoint dials through its 5 ADC channels, while the PWM outputs modulate damper actuators or fan speeds. The USART interfaces with central HVAC controllers, and the SSP (SPI/I2C) connects to digital thermostats or expansion modules. With 22 I/O pins, the device can directly drive relay boards for zone valves, fans, and compressor control without external I/O expanders. The 0 C to +70 C range suits indoor equipment rooms, and the OTP memory suits high-volume production where firmware is fixed.
Recommended
Legacy Embedded Maintenance
The PIC16C73B-04/SP remains in service as a maintenance part for existing industrial equipment, automotive aftermarket modules, and older consumer electronics where redesign is not economical. Field replacements can use the same OTP memory footprint, or migrate to the pin-compatible Flash-based PIC16F873A-I/SP to gain re-programmability. The part is documented in Microchip's mid-range architecture reference manuals and supported by legacy MPLAB IDE tools, easing firmware maintenance. Distributors like DigiKey and Mouser continue to stock the part for low-volume replacement orders, though long-term availability should be confirmed against Microchip's product lifecycle notices.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C73B-04/SP β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C73B-04I/SP | PIC16C73B-20/SP | PIC16F73-I/SP | PIC16F873A-I/SP | PIC16C73B-04/SO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SPDIP | 28-SPDIP - same | 28-SPDIP - same | 28-SPDIP - same | 28-SPDIP - same | 28-SOIC (surface-mount, different land pattern) |
| Program Memory Type | OTP EPROM (7 KB) | OTP EPROM (7 KB) | OTP EPROM (7 KB) | Flash (7 KB) | Flash (7 KB) | |
| Maximum Clock Speed | 4 MHz | 4 MHz | 20 MHz | 20 MHz | 20 MHz | |
| Operating Temperature | 0 C to +70 C | -40 C to +85 C | 0 C to +70 C | -40 C to +85 C | -40 C to +85 C | |
| ADC Channels | 5 x 8-bit | 5 x 8-bit | 5 x 8-bit | 5 x 8-bit | 5 x 10-bit | |
| RAM | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | |
| Serial Interfaces | SPI/I2C + USART | SPI/I2C + USART | SPI/I2C + 2x USART (enhanced) | |||
| Price (1 pc, USD) | 8.20 | 8.50 | 5.40 | 6.10 | ||
| Lifecycle Status | Active (legacy) | Active (recommended for new designs) | Active (preferred for new designs) |
Key Differentiators
- Mature OTP memory for high-volume fixed-firmware production (vs PIC16F73-I/SP)
- 4 MHz speed grade optimized for low-power embedded control (vs PIC16C73B-20/SP)
- Pin-compatible Flash upgrade available (PIC16F873A-I/SP) (vs PIC16F873A-I/SP)
- 5-channel 8-bit ADC integrated (vs PIC16C72-04/SP)
Design Notes
The PIC16C73B-04/SP operates from 4.0V to 5.5V. Estimated: at 4 MHz clock with all peripherals active, the device draws approximately 10-15 mA, increasing with output pin source/sink current. Place a 100 nF ceramic bypass capacitor within 5 mm of the VDD pin, and a 10 uF bulk capacitor on the supply rail. For ADC accuracy, add a 10 uF + 100 nF pair near the VDD pin and route AVSS/AVDD (or VDD/VSS for this part) cleanly. The OTP memory programming voltage VPP is generated internally on the MCLR/VPP pin during ICSP, so no external VPP supply is needed.
The 28-SPDIP package has 0.300 inch row spacing, suitable for standard through-hole PCB layouts and IC sockets. Keep the clock trace from OSC1/OSC2 short (<20 mm) to minimize EMI. Route the analog inputs (RA0-RA5) away from digital switching signals and clock lines to preserve ADC accuracy; the 5 ADC channels share the VDD supply and any digital switching noise couples into the analog reference. The MCLR pin should have a 10 kohm pull-up to VDD and a 100 nF cap to ground for noise immunity.
Common pitfalls with the PIC16C73B-04/SP: (1) The OTP memory cannot be erased or re-programmed; use the Flash-based PIC16F73-I/SP during development. (2) The '04' speed grade limits operation to 4 MHz; if more throughput is needed, specify the -10 or -20 grade. (3) The commercial temperature range is 0 C to +70 C; for industrial applications specify the -04I/SP or -04E/SP variant. (4) Brown-out reset is not enabled by default on some revisions - verify BOR configuration bits in code. (5) The 8-bit ADC requires the A/D conversion clock to be set within 1.6 us to 6.4 us; at 4 MHz Fosc use Fosc/8 or Fosc/16.
PCB layout recommendations: place decoupling capacitors on every VDD/VSS pair within 2 mm of the pin. Use a ground plane under the MCU to reduce EMI and provide thermal dissipation. Route the ICSP pins RB6/PGC and RB7/PGD to a 6-pin ICSP header for in-circuit programming during prototyping. The MCLR/VPP pin needs a dedicated trace; do not share it with output signals. For designs migrating to PIC16F873A-I/SP, the same 28-SPDIP footprint is used, but verify the SPI/I2C pin mapping (PIC16F873A adds MSSP module and dual USART, with slightly different register names in firmware).
Compliance Information
PIC16C73B-04/SP uses SPDIP package with lead-based solder finish (non-RoHS). For RoHS-compliant designs, consider the PIC16F73-I/SP or PIC16F873A-I/SP (Flash-based, lead-free).
