PIC16C73B-04I/SO - 8-Bit OTP MCU, 7KB, 22 I/O, 28-SOIC | Microchip
MPN: PIC16C73B-04I/SO β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $10.79 | $10.79 |
| 10 | $9.85 | $98.50 |
| 100 | $8.92 | $892.00 |
| 500 | $7.95 | $3,975.00 |
| 1,000 | $7.1 | $7,100.00 |
PIC16C73B-04I/SO Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, program memory, data memory, and peripherals on one die. The PIC16C73B belongs to Microchip's PIC16 mid-range family, which sits hierarchically under the PIC16 family, then the broader PIC architecture, then Microcontrollers, then Microprocessors & Controllers, then Semiconductors. OTP (One-Time Programmable) memory is mask-ROM-like flash that can be written only once with a device programmer - cheaper than flash but not re-programmable in-circuit, suiting cost-optimized production volumes.
Key features of the PIC16C73B include a 5-channel 8-bit Analog-to-Digital Converter (ADC), two 8-bit timers (Timer0 and Timer2) plus one 16-bit timer (Timer1), two Capture/Compare/PWM (CCP) modules, a synchronous Serial Peripheral Interface (SPI) or Inter-Integrated Circuit (I2C) port, and a Universal Asynchronous Receiver Transmitter (USART) for serial communication. The 28-SOIC package provides 22 I/O lines plus dedicated VDD/VSS/OSC/RESET pins, supporting through-hole replacement and surface-mount reflow at industrial volumes.
The PIC16C73B uses a 14-bit instruction word and a 4-clock-per-instruction cycle, yielding 5 MIPS at 20 MHz. OTP memory is cheaper than flash and is targeted at high-volume consumer and industrial products where firmware is finalized before production. The Harvard bus architecture separates program and data memory, enabling deterministic instruction fetch and simplifying pipeline operation.
Typical applications include consumer appliance controllers, industrial sensor interfaces, automotive body electronics, low-speed data acquisition systems, and embedded control boards. Designers should note that OTP parts cannot be re-programmed in-circuit and require a device programmer for firmware loading. The 28-SOIC footprint allows hand-soldering on prototype boards and standard reflow on production lines, and the SOIC-28 pinout is widely supported across the PIC16C7xx family for easy migration.
Drop-in alternatives for PIC16C73B-04I/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 PIC16C73B-04I/SO (same form factor and footprint) β differing in Package, Operating Temperature, Timers, ADC, RoHS Status.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16C73B-04/SO
β Drop-Inβ In Stock
$4.65 / Unit
View Datasheet βPIC16C73B-20I/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C73B-04E/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16F73-I/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16F873A-I/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C73AT-20I/SO
β Drop-Inβ In Stock
$5.75 / Unit
View Datasheet βPIC16C73B-04I/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16 (8-bit Harvard RISC) |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 7 KB (4K x 14 words) |
| RAM Size | 192 bytes |
| Maximum Clock Frequency | 4 MHz |
| Instruction Cycle Time | 200 ns |
| Instruction Set Size | 35 single-word instructions |
| I/O Pins | 22 |
| ADC | 5 channels, 8-bit resolution |
| Timers | 1 x 8-bit (Timer0), 1 x 16-bit (Timer1), 1 x 8-bit (Timer2) |
| CCP Modules | 2 (Capture/Compare/PWM) |
| Serial Interfaces | SPI/I2C (SSP) + USART (SCI) |
| Supply Voltage | 4.0 V to 5.5 V |
| Operating Temperature | -40C to +85C (industrial) |
| Package | 28-pin SOIC (SO, 0.300 inch body) |
| Mounting Type | Surface Mount |
| RoHS Status | non_compliant (windowed/cerdip SKUs exist in family) |
PIC16C73B-04I/SO Pin Configuration
| Pin 1 | MCLR/VPP β Master Clear (Reset) input or programming voltage |
| Pin 2 | RA0/AN0 β PORTA bit 0 / Analog input 0 |
| Pin 3 | RA1/AN1 β PORTA bit 1 / Analog input 1 |
| Pin 4 | RA2/AN2 β PORTA bit 2 / Analog input 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 | VSS β Ground reference |
| Pin 9 | OSC1/CLKIN β Oscillator crystal input / external clock input |
| Pin 10 | OSC2/CLKOUT β Oscillator crystal output / clock output |
| Pin 11 | RC0/T1OSO/T1CKI β PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 12 | RC1/T1OSI/CCP2 β PORTC bit 1 / Timer1 oscillator input / CCP2 |
| Pin 13 | RC2/CCP1 β PORTC bit 2 / CCP1 output |
| Pin 14 | RC3/SCK/SCL β PORTC bit 3 / SPI clock / I2C clock |
| Pin 15 | RC4/SDI/SDA β PORTC bit 4 / SPI data in / I2C data |
| Pin 16 | RC5/SDO β PORTC bit 5 / SPI data out |
| Pin 17 | RC6/TX/CK β PORTC bit 6 / USART transmit / clock |
| Pin 18 | RC7/RX/DT β PORTC bit 7 / USART receive / data |
| Pin 19 | VSS β Ground reference |
| Pin 20 | VDD β Positive supply voltage |
| Pin 21 | RB0/INT β PORTB bit 0 / external interrupt |
| Pin 22 | RB1 β PORTB bit 1 |
| Pin 23 | RB2 β PORTB bit 2 |
| Pin 24 | RB3 β PORTB bit 3 |
| Pin 25 | RB4 β PORTB bit 4 |
| Pin 26 | RB5 β PORTB bit 5 |
| Pin 27 | RB6/PGC β PORTB bit 6 / ICSP clock |
| Pin 28 | RB7/PGD β PORTB bit 7 / ICSP data |
Typical Applications
PIC16C73B-04I/SO is suitable for 7 applications: Consumer Appliance Controllers, Industrial Sensor Interface Modules, Low-Speed Data Acquisition Systems, Embedded Control Boards, HVAC Thermostat Controllers, Educational and Hobbyist Development Boards, Security System Keypads and Panels.
Consumer Appliance Controllers
The PIC16C73B-04I/SO fits consumer appliance controllers because its 7 KB OTP memory holds pre-finalized firmware for washing machines, microwave ovens, and air-conditioner control boards. The 22 I/O lines drive relay banks, LED indicators, button matrices, and seven-segment displays without external bus expanders. The 4 MHz clock is adequate for keypad scanning, sensor sampling, and PWM motor control via the two CCP modules. The 28-SOIC package supports standard SMT reflow on appliance control PCBs. Compared with flash MCUs, the OTP cost advantage compounds at high volumes once firmware is locked. Industrial -40C to +85C operation tolerates garage or laundry-room environments.
Recommended
Industrial Sensor Interface Modules
The PIC16C73B-04I/SO suits industrial sensor interface modules requiring multi-channel analog input conditioning. Its 5-channel 8-bit ADC samples thermocouples, pressure transducers, and 4-20 mA loop signals directly without an external ADC. The 192-byte RAM buffers averaged readings, while the USART transmits processed data to a host PLC. The SSP port supports SPI for digital sensor chains. Industrial -40C to +85C operation handles factory-floor thermal swings. OTP memory locks calibration coefficients into firmware at production programming, preventing field tampering.
Recommended
Low-Speed Data Acquisition Systems
The PIC16C73B-04I/SO works for low-speed data acquisition systems sampling at sub-1 kHz per channel, where the 4 MHz clock and 8-bit ADC resolution suffice. Its 5 ADC channels plus 22 digital I/Os capture mixed analog and digital sensor data. The 192-byte RAM stores scan-line buffers, while the USART streams packets to a host computer. Two CCP modules generate timing triggers for synchronized sampling. The 28-SOIC footprint mounts into compact DAQ enclosures. OTP memory secures the proprietary calibration algorithm into the firmware.
Recommended
Embedded Control Boards
The PIC16C73B-04I/SO is well suited for embedded control boards in industrial equipment and OEM subsystems. Its 22 I/O pins drive MOSFET gate drivers, opto-isolated inputs, and HMI keypads. The two CCP modules generate PWM signals for valve control or LED dimming. SPI/I2C interfaces connect to external EEPROM for parameter storage. The 4 MHz clock and 1 MIPS throughput handle straightforward state-machine control loops. Industrial temperature rating ensures reliability in cabinet-mounted installations.
Recommended
HVAC Thermostat Controllers
The PIC16C73B-04I/SO fits HVAC thermostat controllers needing temperature sensing, relay switching, and keypad/display interface. The 5-channel ADC reads thermistor or solid-state temperature sensors, while the two CCP modules drive PWM outputs for proportional heating/cooling valve control. The USART connects to a wall-mounted display board or remote sensor. OTP memory locks vendor-specific calibration tables. The 28-SOIC package fits inside compact thermostat housings with standard SMT assembly. Industrial temperature rating handles attic and outdoor cabinet installations.
Recommended
Educational and Hobbyist Development Boards
The PIC16C73B-04I/SO serves educational microcontroller courses and hobbyist projects because of its accessible 28-SOIC through-hole-compatible SPDIP sibling in the same family. Students learn RISC architecture, ADC programming, and serial communication protocols using the 35-instruction set. The 22 I/O pins provide ample experimentation surface for LED arrays, motor control, and sensor integration. OTP memory enforces the production-programming mindset in advanced labs. Industrial temperature tolerance allows rugged lab and field use.
Recommended
Security System Keypads and Panels
The PIC16C73B-04I/SO works in security system keypads and alarm panels where the 22 I/O pins scan 4x4 button matrices and drive status LEDs without external logic. The 4 MHz clock provides debounce-free keypad scanning. OTP memory locks the security access codes and panel configuration into firmware at production. The USART interfaces with a central alarm panel or modem. The industrial temperature range ensures reliability in unheated garages and outdoor enclosures. The 28-SOIC package enables compact SMT design in modern panel housings.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C73B-04I/SO β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C73B-04/SO | PIC16C73B-20I/SO | PIC16F73-I/SO | PIC16F873A-I/SO | PIC16C73AT-20I/SO |
|---|---|---|---|---|---|---|
| Package | 28-SOIC | 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 |
| Memory Type | OTP | OTP | OTP | Flash | Flash | OTP |
| Program Memory | 7 KB | 7 KB | 7 KB | 7 KB | 7 KB | 7 KB |
| RAM | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes |
| Max Clock Frequency | 4 MHz | 4 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Operating Temperature | -40C to +85C (industrial) | 0C to +70C (commercial) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) |
| In-Circuit Reprogramming | No (OTP) | No (OTP) | No (OTP) | Yes (Flash + ICSP) | Yes (Flash + ICSP) | No (OTP) |
Key Differentiators
- Lower cost OTP memory for high-volume production (vs PIC16F73-I/SO)
- Industrial -40C to +85C operating range vs commercial (vs PIC16C73B-04/SO)
- 4 MHz clock for low-power or noise-sensitive applications (vs PIC16C73B-20I/SO)
Design Notes
The PIC16C73B-04I/SO requires a stable 5.0V supply (4.0-5.5V range) with proper decoupling. Place a 100 nF ceramic capacitor directly between VDD (pins 7 and 28) and VSS (pins 8 and 19) with traces shorter than 5 mm. For applications with noisy relay or motor switching, add a bulk 10 uF tantalum or electrolytic capacitor on the main 5V rail. The device draws approximately 2-15 mA active depending on clock and peripheral configuration.
Keep the oscillator traces between OSC1 (pin 9) and OSC2 (pin 10) short and surrounded by a ground guard ring to minimize EMI coupling. Use a crystal with the load capacitance specified in the datasheet (typically 15-33 pF) and place load capacitors as close as possible to the oscillator pins. For high-EMI environments, consider a 4-layer PCB with a dedicated ground plane beneath the MCU to improve noise immunity.
The OTP memory cannot be re-programmed in-circuit - verify firmware thoroughly using a windowed CERDIP sample or PIC16F73 flash equivalent before committing to OTP production programming. The MCLR pin (pin 1) requires a 10 kohm pull-up to VDD and should not be left floating. The ADC requires the A/D acquisition time delay before conversion; refer to the datasheet section for the correct Tad setting. Do not exceed the 5.5V absolute maximum on any pin.
Compliance Information
SOIC variant is non-RoHS due to lead-bearing terminators; not AEC-Q100 qualified for automotive. RoHS-compliant flash equivalent is PIC16F73-I/SO. REACH and halogen status not explicitly stated in available data.
