PIC16C73AT-04I/SO - 8-Bit 4MHz OTP MCU 7KB Flash | Microchip
MPN: PIC16C73AT-04I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.18 | $6.18 |
| 10 | $5.42 | $54.20 |
| 100 | $4.66 | $466.00 |
| 500 | $4.08 | $2,040.00 |
| 1,000 | $3.55 | $3,550.00 |
PIC16C73AT-04I/SO Overview
What is a PIC mid-range 8-bit microcontroller? The PIC16CXX mid-range family is a Harvard-architecture RISC MCU family from Microchip Technology, characterized by a 14-bit instruction word, 8-bit data path, single accumulator (W) plus up to four banked file registers, and a deterministic instruction pipeline. The 16C sub-family is the OTP-only classic variant that preceded the flash-based 16F series, and remains in active production for legacy industrial and embedded designs where code is finalized and field re-programmability is not required.
Key features of this PIC16C73AT-04I/SO include the integrated 5-channel 8-bit ADC that allows direct interface with analog sensors without an external ADC, the USART module for asynchronous serial communication, and the I2C/SPI-compatible Synchronous Serial Port (SSP). The 22 I/O pins are 5V-tolerant and can source/sink up to 25 mA each, supporting direct LED drive and small relay coils. Brown-out Reset, Power-on Reset, Watchdog Timer with on-chip RC oscillator, and In-Circuit Serial Programming (ICSP) round out the standard PIC16C7X feature set.
The 28-SOIC industrial-temperature variant (-40C to +85C, indicated by the 'I' suffix) is housed in a 7.50 mm body width SOIC package, suitable for hand-soldered prototypes, low-volume production, and through-hole-friendly SMT assembly. The -04 speed grade limits the clock to 4 MHz maximum (10 MHz would be -10, 20 MHz would be -20), reducing EMI in noise-sensitive instrumentation.
Typical applications include industrial control panels, motor driver front-ends (gate-driver sequencing and fault monitoring), instrumentation with local A/D conversion, legacy 5V embedded systems, automotive body controllers (non-safety), and consumer appliances. The integrated ADC and USART allow a single-chip solution for sensor reading and host communication.
When designing with this device, mind the OTP memory limitation: code is committed at the final programming step and cannot be re-flashed. Use the 16F73 or 16F873A flash-based cousin for development phases. Ensure the MCLR pin has the correct decoupling and that the oscillator configuration bits match the crystal or resonator selected.
This page synthesizes distributor pricing, same-brand drop-in alternatives, and practical design notes not found in the manufacturer datasheet. Engineers evaluating PIC16C73AT-04I/SO for new designs should weigh the OTP constraint against the legacy 5V supply, integrated ADC, and proven PIC16C7X peripheral set.
Drop-in alternatives for PIC16C73AT-04I/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 PIC16C73AT-04I/SO (same form factor and footprint) — differing in Maximum Clock Frequency, Package, Program Memory Type, Mounting Type, Program Memory Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C73A-04I/SO
✅ Drop-In✓ In Stock
$4.78 / Unit
View Datasheet →PIC16C73AT-04E/SO
✅ Drop-In✓ In Stock
$4.45 / Unit
View Datasheet →PIC16C73A-20I/SO
✅ Drop-In✓ In Stock
$9.3 / Unit
View Datasheet →PIC16C73A-10I/SO
✅ Drop-In✓ In Stock
$3.55 / Unit
View Datasheet →PIC16C73A-10E/SO
✅ Drop-In✓ In Stock
$6.55 / Unit
View Datasheet →PIC16C74AT-04I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C73AT-04I/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16CXX mid-range 8-bit RISC (Harvard) |
| Instruction Word Size | 14 bits |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 7 KB (4K x 14 words) |
| RAM Size | 192 x 8 bytes |
| Maximum Clock Frequency | 4 MHz |
| Number of I/O Pins | 22 |
| ADC | 5-channel, 8-bit |
| Operating Voltage | 5 V nominal (PIC16C7X standard) |
| Package | 28-SOIC (0.295", 7.50 mm body width) |
| Mounting Type | Surface Mount |
| Operating Temperature Range | -40C to +85C (Industrial, 'I' suffix) |
| Oscillator Type | External (crystal/resonator/RC) |
| Peripherals | USART, SSP (SPI/I2C), CCP, Timers, WDT, BOR, POR |
| Speed Grade Suffix | -04 = 4 MHz maximum clock |
| Lead-Free / RoHS | Lead-free matte-tin finish; RoHS compliance status per Microchip product documentation |
PIC16C73AT-04I/SO Pin Configuration
| Pin 1 | MCLR — Master Clear (Reset) input, active low |
| 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 | RE0/RD/AN5 — PORTE bit 0 / Read control for parallel slave port / Analog input 5 |
| Pin 9 | RE1/WR/AN6 — PORTE bit 1 / Write control / Analog input 6 |
| Pin 10 | RE2/CS/AN7 — PORTE bit 2 / Chip select / Analog input 7 |
| Pin 11 | VDD — Positive power supply (+5V) |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKIN — Oscillator input / external clock input |
| Pin 14 | OSC2/CLKOUT — Oscillator output / clock output |
| Pin 15 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 16 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 output |
| Pin 17 | RC2/CCP1 — PORTC bit 2 / CCP1 I/O |
| Pin 18 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 19 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 20 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 21 | RC6/TX/CK — PORTC bit 6 / USART TX / USART clock |
| Pin 22 | RC7/RX/DT — PORTC bit 7 / USART RX / USART data |
| Pin 23 | RB0/INT — PORTB bit 0 / External interrupt |
| Pin 24 | RB1 — PORTB bit 1 |
| Pin 25 | RB2 — PORTB bit 2 |
| Pin 26 | RB3/PGM — PORTB bit 3 / Low-voltage programming |
| Pin 27 | RB4 — PORTB bit 4 |
| Pin 28 | RB5 — PORTB bit 5 |
Typical Applications
PIC16C73AT-04I/SO is suitable for 7 applications: Industrial Control Panels, Motor Driver Front-End Sequencing, Instrumentation with Local A/D Conversion, Legacy 5V Embedded Systems, Automotive Body Controllers (Non-Safety), Consumer Appliance Control, Sensor Node with Local Display.
Industrial Control Panels
The PIC16C73AT-04I/SO fits industrial control panels because of its integrated 5-channel 8-bit ADC that digitizes panel-mounted potentiometers, thermistors, and current-sense signals without an external ADC IC, and the 22 digital I/O that drive relay coils, indicator LEDs, and key-switch inputs at up to 25 mA per pin. The -40C to +85C industrial temperature range handles factory-floor thermal swings, and the 4 MHz -04 speed grade is sufficient for keypad scanning, debounce, and slow-bus communication. Compared with discrete logic controllers, this single-chip solution reduces PCB area and BOM cost while the OTP code lock prevents unauthorized firmware cloning in end equipment.
Recommended
Motor Driver Front-End Sequencing
For BLDC or stepper motor driver boards, the PIC16C73AT-04I/SO delivers the gate-driver sequencing, fault monitoring, and tachometer feedback processing needed between the host controller and the power stage. Its 5-channel ADC reads back shunt current, DC-bus voltage, and temperature sensor outputs, while the Capture/Compare/PWM module generates timing-critical control signals. The 4 MHz clock is adequate for step rates below 10 kstep/s. Engineers should note that the OTP memory requires pre-committed firmware, so the firmware must be fully validated on a flash PIC16F73 prototype before PIC16C73AT-04I/SO production programming.
Recommended
Instrumentation with Local A/D Conversion
Bench-top measurement instruments, HVAC sensors, and environmental loggers benefit from the PIC16C73AT-04I/SO's integrated ADC and USART in a single 28-SOIC part. The MCU samples up to five analog channels at 8-bit resolution, formats the data with a timestamp from Timer0, and transmits over RS-232/RS-485 via the on-chip USART to a host display. The industrial -40C to +85C temperature range suits outdoor and rooftop sensor enclosures. Power consumption is held low by the SLEEP/idle modes plus the Brown-out Reset, which protects RTC state during brown-out events.
Recommended
Legacy 5V Embedded Systems
Brownfield retrofits of 5V-only legacy systems - such as replacing obsolete 8051, Z8, or COP8 controllers on industrial PLCs and older medical devices - often choose the PIC16C73AT-04I/SO because it operates at the standard 5V supply, exposes a familiar 28-SOIC footprint, and delivers more MIPS per MHz than many competitors. The 5V-tolerant I/O and 25 mA sink/source drive TTL loads directly without level shifters. Because the part is OTP, the design team must be certain the firmware is final before committing - use PIC16F73 development boards to validate, then transition to PIC16C73AT-04I/SO for production.
Recommended
Automotive Body Controllers (Non-Safety)
Inside-cabin automotive body controllers - such as window-lift modules, seat-position memories, and climate-control panels - can use the PIC16C73AT-04I/SO because the 22 I/O drive the relay coils and LED indicators, the 5-channel ADC reads potentiometer wiper positions, and the USART links to the body-CAN gateway via an external MCP2551 transceiver. The industrial -40C to +85C grade handles cabin thermal ranges. The PIC16C73AT-04I/SO is NOT AEC-Q100 qualified and therefore cannot be used in safety-critical or under-hood applications; choose AEC-Q100 PIC16F or dsPIC families for those.
Recommended
Consumer Appliance Control
Washing machines, microwave ovens, induction cooktops, and small kitchen appliances employ the PIC16C73AT-04I/SO for user-interface management, sensor readout, and triac/SCR timing. The 5-channel ADC samples temperature probes and water-level sensors, while the 22 I/O scan the keypad matrix, drive 7-segment displays, and trigger the relay outputs. The 4 MHz clock handles all the 10-100 ms timing loops needed for appliance sequencing without consuming noticeable power. OTP memory locks the firmware against unauthorized copies - a feature valued by appliance OEMs shipping thousands of units per month.
Recommended
Sensor Node with Local Display
Remote sensor nodes with local LCD readouts (such as temperature/humidity data loggers and field-measurement handhelds) benefit from the PIC16C73AT-04I/SO because the 22 I/O drive both the LCD segment lines and the SPI/I2C sensor bus, while the integrated ADC provides redundant analog readings. The 4 MHz clock is adequate for periodic sensor sampling at 1-10 Hz rates. The USART or SSP module uploads the collected data to a host PC. For battery-powered nodes, SLEEP mode reduces current consumption to micro-ampere levels during idle intervals.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C73AT-04I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C73A-04I/SO | PIC16C73AT-04E/SO | PIC16C73A-20I/SO | PIC16C73A-10I/SO | PIC16C73A-10E/SO | PIC16C74AT-04I/SO |
|---|---|---|---|---|---|---|---|
| Package | 28-SOIC (0.295", 7.50 mm) | 28-SOIC (0.295", 7.50 mm) - same | 28-SOIC (0.295", 7.50 mm) - same | 28-SOIC (0.295", 7.50 mm) - same | 28-SOIC (0.295", 7.50 mm) - same | 28-SOIC (0.295", 7.50 mm) - same | 28-SOIC (0.295", 7.50 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Maximum Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 10 MHz | 10 MHz | 4 MHz |
| Program Memory Type | OTP | OTP | OTP | OTP | OTP | OTP | OTP |
| Program Memory Size | 7 KB (4K x 14) | 7 KB (4K x 14) | 7 KB (4K x 14) | 7 KB (4K x 14) | 7 KB (4K x 14) | 7 KB (4K x 14) | 7 KB (4K x 14) |
| ADC Channels / Resolution | 5 channels, 8-bit | 5 channels, 8-bit | 5 channels, 8-bit | 5 channels, 8-bit | 5 channels, 8-bit | 5 channels, 8-bit | 8 channels, 8-bit |
| Operating Temperature Range | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +125C (Extended) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +125C (Extended) | -40C to +85C (Industrial) |
| I/O Pin Count | 22 | 22 | 22 | 22 | 22 | 22 | 22 |
| Shipping Format | Tape & Reel (T suffix) | Tube | Tape & Reel (T suffix) | Tube | Tube | Tube | Tape & Reel (T suffix) |
Key Differentiators
- Tape-and-reel format for SMT assembly (vs PIC16C73A-04I/SO)
- Industrial temperature grade for harsh environments (vs PIC16C73AT-04/SO (Commercial))
- 5-channel on-chip 8-bit ADC eliminates external ADC (vs PIC16C711 (no ADC))
- USART + SSP + CCP peripheral set in mid-range core (vs PIC16C71 (baseline core, no peripherals))
Design Notes
Place a 0.1 uF ceramic decoupling capacitor within 5 mm of the VDD pin (pin 11) and a bulk 10 uF tantalum or aluminum capacitor at the board power-entry point. For battery-backed or sleep-mode designs, use MCP1700 or equivalent 3.3V/5V LDO with 1.6 uA quiescent current to minimize standby drain. The PIC16C73AT-04I/SO SLEEP mode reduces current to micro-ampere range; ensure MCLR has a clean RC delay on VDD ramp to avoid spurious resets.
OTP memory is One-Time Programmable - code cannot be re-flashed once committed. Always validate firmware on a flash-based PIC16F73 development board before programming the production PIC16C73AT-04I/SO. Configuration bits (oscillator selection, watchdog enable, brown-out trip voltage, code-protect) are also OTP and cannot be changed; double-check the __CONFIG register values in your source before final programming. Mistakes in configuration can render the part unrecoverable.
Route the crystal/oscillator traces (OSC1 pin 13, OSC2 pin 14) with short, symmetric paths and guard them with a ground pour to minimize EMI coupling. Place load capacitors (typically 15-33 pF for low-frequency crystals) close to the MCU pins. For the analog ADC inputs (RA0-RA5), use a separate analog ground island that joins the digital ground only at the VSS pin to avoid ground-loop noise pickup. Add 100 ohm isolation resistors between digital and analog ground if needed.
The 8-bit ADC on PORTA achieves best accuracy with an external 2.5V-5.0V reference applied to RA3/AN3/VREF. For ratiometric measurements, tie VREF to VDD and add a 10 uF + 100 nF decoupling network on the VREF pin. The ADC requires a minimum acquisition time determined by the source impedance; if driving the ADC from a high-impedance source (above 10 kohm), buffer with an MCP6001 op-amp to avoid linearity errors.
Compliance Information
Lead-free matte-tin finish per Microchip product documentation. Not AEC-Q100 qualified; choose AEC-Q100 PIC16F or dsPIC parts for automotive safety applications. RoHS and REACH compliance per Microchip declaration of conformity.
