PIC16LC73AT-04I/SO - 4MHz 8-bit OTP MCU 7KB Flash 28-SOIC
MPN: PIC16LC73AT-04I/SO ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.2 | $7.20 |
| 10 | $6.48 | $64.80 |
| 100 | $5.76 | $576.00 |
| 500 | $5.18 | $2,590.00 |
| 1,000 | $4.61 | $4,610.00 |
PIC16LC73AT-04I/SO Overview
A microcontroller (MCU) is an integrated circuit combining a processor core, program and data memory, and programmable I/O peripherals on a single die. The 8-bit MCU category sits below 32-bit ARM Cortex-M devices in performance but excels at deterministic bit-manipulation tasks, low-cost motor/relay drivers, and battery-powered nodes. The PIC16C7X mid-range family is positioned between the baseline PIC10/12/16 families and the enhanced PIC18 family, offering richer peripherals such as A/D converters and multiple serial ports while retaining the classic 14-bit instruction word.
Key features include an integrated 8-channel, 8-bit Analog-to-Digital Converter (ADC), two 8-bit timers plus one 16-bit timer, a synchronous Serial Peripheral Interface (SPI), an Inter-Integrated Circuit (I2C) bus, and a Universal Asynchronous Receiver/Transmitter (UART/USART) for asynchronous serial communication. The CPU operates from a 2.5V to 6.0V supply and supports DC to 4 MHz clock input. The 'T' suffix denotes tape-and-reel packaging and 'I' indicates the industrial temperature grade (-40°C to +85°C). On-chip peripherals reduce external glue, reducing real-world design complexity.
Technically, the PIC16LC73AT-04I/SO uses a Harvard architecture with separate program and data buses, allowing simultaneous instruction fetch and operand access. The 14-bit instruction word provides a rich opcode set including literal and control operations. Brown-out Reset, Power-On Reset, and Watchdog Timer with on-chip RC oscillator provide system-level safety. OTP program memory supports one-time programming in production, ideal for mature products not planning firmware.
Typical applications include industrial process control, sensor signal conditioning, automotive body electronics, low-speed motor control, and small consumer appliances. The wide temperature range allows deployment in factory floors and outdoor enclosures, while the modest memory suits fixed-function appliances. In practice, designers select this part where the ADC and serial connectivity meet the bill but FLASH reprogrammability is unnecessary.
Design consideration: OTP memory cannot be field-upgraded - choose FLASH-based PIC16F-series siblings if firmware revisions are anticipated. Additionally, an external decoupling capacitor of at least 0.1 µF is required near the VDD pin.
This page synthesizes Microchip datasheet parameters, real-time distributor pricing, and drop-in alternatives including same-package PIC16LC73A and PIC16C73B variants that distributors list and OTA sites such as DigiKey cross-reference for engineers migrating designs.
Drop-in alternatives for PIC16LC73AT-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 PIC16LC73AT-04I/SO (same form factor and footprint) — differing in Package, Operating Temperature, RoHS Status, Timers, Program Memory Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LC73A-04I/SO
✅ Drop-In✓ In Stock
$4.19 / Unit
View Datasheet →PIC16C73B-04I/SO
✅ Drop-In✓ In Stock
$7.1 / Unit
View Datasheet →PIC16F73-I/SO
✅ Drop-In✓ In Stock
$2.45 / Unit
View Datasheet →PIC16LC73AT-04/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LC72A-04I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LC73AT-04I/SO Maximum Ratings & Electrical Characteristics
| Core Processor | PIC16C |
| Core Size | 8-bit |
| Clock Speed | 4 MHz |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 7 KB (4K x 14) |
| RAM Size | 192 x 8 bytes |
| EEPROM Size | None (not present in datasheet summary) |
| Number of I/O Pins | 22 |
| ADC Resolution | 8-bit |
| ADC Channels | 5 |
| Number of Timers | 3 (2x 8-bit, 1x 16-bit) |
| Connectivity | I2C, SPI, UART/USART |
| Supply Voltage (Vdd) | 2.5 V to 6.0 V |
| Operating Temperature | -40 °C to +85 °C (industrial, 'I' grade) |
| Package | 28-SOIC (0.295", 7.50 mm width) |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel ('T' suffix) |
| RoHS Status | Non-compliant (legacy OTP product) |
PIC16LC73AT-04I/SO Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (reset) input / programming voltage |
| Pin 2 | RA0/AN0 — PORTA bit 0 / ADC input channel 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / ADC input channel 1 |
| Pin 4 | RA2/AN2 — PORTA bit 2 / ADC input channel 2 |
| Pin 5 | RA3/AN3/VREF — PORTA bit 3 / ADC input 3 / ADC reference |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — PORTA bit 5 / ADC input 4 / SPI slave select |
| Pin 8 | VSS — Ground reference |
| Pin 9 | OSC1/CLKIN — Oscillator crystal input / external clock |
| Pin 10 | OSC2/CLKOUT — Oscillator crystal output / clock output |
| Pin 11 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock |
| Pin 12 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 |
| Pin 13 | RC2/CCP1 — PORTC bit 2 / Capture/Compare/PWM 1 |
| Pin 14 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 15 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 16 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 17 | RC6/TX/CK — PORTC bit 6 / USART TX / USART clock |
| Pin 18 | RC7/RX/DT — PORTC bit 7 / USART RX / USART data |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage (2.5 V to 6.0 V) |
| Pin 21 | RB0/INT — PORTB bit 0 / external interrupt |
| Pin 22 | RB1 — PORTB bit 1 |
| Pin 23 | RB2 — PORTB bit 2 |
| Pin 24 | RB3 — PORTB bit 3 |
| Pin 25 | RB4 — PORTB bit 4 |
| Pin 26 | RB5 — PORTB bit 5 |
| Pin 27 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 28 | RB7/PGD — PORTB bit 7 / ICSP data |
Typical Applications
PIC16LC73AT-04I/SO is suitable for 6 applications: Industrial Process Control, Automotive Body Electronics, Consumer Appliance Control, Low-Speed Motor Control, Sensor Signal Conditioning, Security and Access Control Panels.
Industrial Process Control
The PIC16LC73AT-04I/SO fits industrial process control because its 5-channel 8-bit ADC handles analog sensor inputs from temperature, flow, and pressure transducers, while the integrated I2C and SPI buses interface with digital sensors and EEPROM dataloggers. With 7 KB OTP program memory and 192 bytes of RAM, the MCU executes fixed-function control loops for valve positioning and pump staging reliably. The industrial -40 °C to +85 °C operating temperature range allows deployment in factory-floor panels without thermal management. Brown-out reset and watchdog timer provide system-level safety against supply glitches and firmware lockups. Recommended companion products include PIC16F73-I/SO for FLASH-based variants, MCP9700 temperature sensor for analog inputs, and 24LC256 EEPROM for parameter storage.
Recommended
Automotive Body Electronics
The PIC16LC73AT-04I/SO supports automotive body electronics modules such as seat controllers, mirror adjusters, and lighting drivers because its 22 GPIO pins drive relays and MOSFET arrays directly without external glue logic. The integrated USART interfaces with body control modules via LIN or K-line transceivers, while the 8-bit ADC monitors battery voltage and current sense inputs. Operating from a 12 V vehicle rail stepped down to 5 V, the device tolerates supply transients up to 6.0 V. The wide -40 °C to +85 °C industrial temperature range covers cabin and under-hood environments for non-powertrain applications. OTP memory locks the firmware, preventing field tampering. Recommended companion products include PIC16F73-I/SO for firmware updates and MCP2551 CAN transceiver for networked nodes.
Recommended
Consumer Appliance Control
The PIC16LC73AT-04I/SO powers consumer appliance control boards including washing machines, dishwashers, and microwave ovens because its 4 MHz execution speed handles user-interface scanning, motor timing, and sensor sampling with comfortable margin. The 7 KB OTP program memory accommodates fixed appliance state machines, while 192 bytes of RAM covers real-time variables and stack depth for nested interrupts. The 5-channel ADC reads water level, temperature, and door-switch sensors, and the integrated timers generate PWM outputs for motor speed control and buzzer drive. Industrial temperature range suits garage and basement installations. Watchdog timer recovers from ESD-induced firmware lockups. Recommended companion products include PIC16F73-I/SO for new designs and ULN2003A driver for relay arrays.
Recommended
Low-Speed Motor Control
The PIC16LC73AT-04I/SO is well-suited to low-speed DC motor and stepper control applications including HVAC damper actuators, valve positioners, and small-pump drivers because its 16-bit timer generates precise PWM outputs at standard 1-25 kHz switching frequencies. The 8-bit ADC monitors motor current via shunt amplifiers for closed-loop torque limiting, while 192 bytes of RAM hold PID controller state and lookup tables. Two 8-bit timers handle quadrature encoder inputs for position control. Brown-out reset prevents motor coasting during brown-out events. Recommended companion products include PIC16F73-I/SO for FLASH flexibility and DRV8871 motor driver IC.
Recommended
Sensor Signal Conditioning
The PIC16LC73AT-04I/SO performs sensor signal conditioning and linearization for thermocouples, RTDs, and bridge pressure sensors because its 8-bit ADC plus digital filtering delivers calibrated outputs to upstream controllers. The integrated I2C bus reads digital temperature and humidity sensors, while the USART transmits ASCII or Modbus frames over RS-232 or RS-485 transceivers. Operating from 2.5 V to 6.0 V, the device powers directly from battery stacks or regulated 5 V rails. The 7 KB OTP program memory accommodates calibration tables and linearization polynomials. Recommended companion products include PIC16F73-I/SO for firmware-updatable sensors and MCP9700 analog temperature sensor.
Recommended
Security and Access Control Panels
The PIC16LC73AT-04I/SO powers security and access control panels for alarm keypads, card readers, and door controllers because its 22 GPIO pins directly drive LED indicators, piezo buzzers, and relay coils for maglocks. The I2C bus interfaces with RFID reader modules and EEPROM credential storage, while the USART links to central monitoring panels at 9600-115200 baud. The integrated ADC monitors backup-battery voltage for low-battery alerts. The 7 KB OTP program memory stores fixed firmware routines for credential validation and alarm logic. Industrial temperature range supports outdoor cabinet installation. Recommended companion products include PIC16F73-I/SO for FLASH-upgradable firmware and 24LC256 EEPROM for credential storage.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC73AT-04I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LC73A-04I/SO | PIC16C73B-04I/SO | PIC16F73-I/SO | PIC16LC73AT-04/SO | PIC16LC72A-04I/SO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SOIC | 28-SOIC (same) | 28-SOIC (same) | 28-SOIC (same) | 28-SOIC (same) | 28-SOIC (same) |
| Clock Speed | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 4 MHz | 4 MHz |
| Program Memory | 7 KB OTP (4K x 14) | 7 KB OTP | 7 KB OTP | 4 KB FLASH | 7 KB OTP | 3.5 KB OTP |
| RAM Size | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 128 bytes |
| ADC | 8-bit, 5 ch | 8-bit, 5 ch | 8-bit, 5 ch | 8-bit, 5 ch | 8-bit, 5 ch | 8-bit, 5 ch |
| Operating Temperature | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | 0 °C to +70 °C | -40 °C to +85 °C |
| Program Memory Type | OTP | OTP | OTP | FLASH (reprogrammable) | OTP | OTP |
| Lifecycle Status | NRND | NRND | NRND | Active | NRND | NRND |
Key Differentiators
- Mature PIC16C7X architecture with extensive design heritage (vs PIC16F73-I/SO)
- Lower unit cost at high quantities (vs PIC16F73-I/SO)
- Wider supply voltage range supports unregulated rails (vs PIC16C73B-04I/SO)
Design Notes
Place a 0.1 µF ceramic decoupling capacitor within 5 mm of the VDD pin (pin 20) and a bulk 10 µF tantalum or aluminum electrolytic on the same supply rail. The PIC16LC73AT-04I/SO internal ADC requires a clean VDD; if supply noise exceeds 50 mV ripple, add a 10 Ω series ferrite bead between the regulator and VDD. The MCLR pin (pin 1) requires a 10 kΩ pull-up to VDD and a 100 nF capacitor to ground for proper reset during power-up.
Route the analog ADC inputs (RA0-RA5) away from digital switching traces to minimize crosstalk. Maintain at least 3x trace-width spacing between analog and digital signals, and place a ground guard ring around analog traces tied to analog ground (VSS at pin 8). Keep crystal traces (OSC1/OSC2) short and symmetric, with the crystal case grounded to reduce EMI. Avoid running high-current traces under the IC.
OTP program memory cannot be erased or rewritten. Verify all firmware thoroughly on a FLASH-based development part (PIC16F73) before committing to OTP production programming. Configuration bits must be set correctly to enable the watchdog timer, brown-out reset, and oscillator mode; an unconfigured part will not execute code. The ADC requires a minimum acquisition time of 19 µs; reading channels faster than this produces inaccurate conversions.
Compliance Information
Non-RoHS compliant legacy OTP product. NRND lifecycle as of 2026-09-22 per Microchip product page. Lead finish contains Pb (no-lead variant not offered for this part).
