PIC16C73AT-04E/SO - 8-Bit 4MHz OTP MCU 7KB | Microchip
MPN: PIC16C73AT-04E/SO β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.85 | $6.85 |
| 10 | $6.17 | $61.70 |
| 100 | $5.48 | $548.00 |
| 500 | $4.93 | $2,465.00 |
| 1,000 | $4.45 | $4,450.00 |
PIC16C73AT-04E/SO Overview
An 8-bit PIC microcontroller (MCU) is a single-chip computer built on Harvard architecture, where program and data memories use separate buses. The 'mid-range' PIC16C family sits between the baseline PIC10/12/16 families and the high-end PIC18 family, balancing instruction simplicity with peripherals. The OTP variant allows the program memory to be written once using an external programmer, suiting low-cost, moderate-volume production runs where field re-programmability is not required.
Key features include 22 digital I/O pins, an integrated multi-channel 8-bit Analog-to-Digital Converter, three timer modules, a synchronous serial port (SSP) supporting SPI and I2C, a USART, and a watchdog timer with on-chip RC oscillator. The core delivers 5 MIPS performance at 20 MHz equivalent throughput and operates across 2.5 V to 6.0 V supply range. CMOS fully-static design ensures that clock frequency can be reduced to DC without losing register contents, ideal for sleep-mode power management in battery-powered applications.
The 'fully-static CMOS' architecture combines low power consumption with deterministic instruction execution. Each instruction cycle is four oscillator periods, giving predictable timing for real-time control loops. The 14-bit instruction word provides a wider opcode space than baseline PIC devices, supporting literal operations and direct branch instructions. Brown-out Reset, Power-on Reset, and the watchdog timer work together to recover from firmware faults or supply transients, critical for industrial and appliance environments.
Typical applications include industrial control and sensor interfacing, automotive body electronics (pre-CAN-era subsystems), home appliances such as washing machines and microwave ovens, HVAC thermostats, motor control boards, and embedded data-acquisition systems. The integrated ADC eliminates the need for an external converter in many low-channel-count designs.
When designing with this device, note that the OTP memory cannot be erased or rewritten, so firmware must be fully validated on a windowed or Flash equivalent before committing to OTP programming. A 1kΞ© to 10kΞ© pull-up on the MCLR pin is recommended, and decoupling capacitors must be placed within 1 cm of VDD/VSS for reliable operation.
This page synthesizes distributor stock levels, pin-compatible alternatives, and design guidance not consolidated on the manufacturer datasheet, giving engineers faster decision support for both new designs and legacy maintenance.
Drop-in alternatives for PIC16C73AT-04E/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 PIC16C73AT-04E/SO (same form factor and footprint) β differing in Package, Program Memory Type, ADC, Maximum Clock Frequency, Timers.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16C73A-04E/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C73A-10E/SO
β Drop-Inβ In Stock
$6.55 / Unit
View Datasheet βPIC16C73A-20I/SO
β Drop-Inβ In Stock
$9.3 / Unit
View Datasheet βPIC16F73-I/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C74A-04E/SO
β Drop-Inπ Reference alternative (not in catalog)
PIC16C73AT-04E/SO Maximum Ratings & Electrical Characteristics
| Core | PIC16 mid-range 8-bit RISC |
| Instruction Set | 35 single-word instructions |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 7 KB (4K x 14 words) |
| RAM Size | 192 x 8 bytes |
| EEPROM Data Memory | None |
| Maximum CPU Speed | 4 MHz |
| Operating Voltage | 2.5 V to 6.0 V |
| Number of I/O Pins | 22 |
| ADC | Integrated 8-bit multi-channel |
| Timers | 3 modules |
| Communication Peripherals | USART, SSP (SPI / I2C) |
| Oscillator Type | External (crystal/RC) |
| Watchdog Timer | Yes (with on-chip RC) |
| Brown-out Reset | Yes |
| Package | 28-SOIC (7.50 mm body width) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 C to +125 C (industrial, E suffix) |
| Packaging | Tape & Reel (T suffix) |
PIC16C73AT-04E/SO Pin Configuration
| Pin 1 | RA0/AN0 β Port A bit 0 / Analog channel 0 |
| Pin 2 | RA1/AN1 β Port A bit 1 / Analog channel 1 |
| Pin 3 | RA2/AN2 β Port A bit 2 / Analog channel 2 |
| Pin 4 | RA3/AN3/VREF+ β Port A bit 3 / Analog channel 3 / VREF+ |
| Pin 5 | RA4/T0CKI β Port A bit 4 / Timer 0 clock input |
| Pin 6 | RA5/SS/AN4 β Port A bit 5 / SPI slave select / Analog channel 4 |
| Pin 7 | RE0/RD/AN5 β Port E bit 0 / Read strobe / Analog channel 5 |
| Pin 8 | RE1/WR/AN6 β Port E bit 1 / Write strobe / Analog channel 6 |
| Pin 9 | RE2/CS/AN7 β Port E bit 2 / Chip select / Analog channel 7 |
| Pin 10 | VSS β Ground reference |
| Pin 11 | VDD β Positive supply (2.5-6.0 V) |
| Pin 12 | OSC1/CLKIN β Oscillator input / external clock in |
| Pin 13 | OSC2/CLKOUT β Oscillator output / clock out |
| Pin 14 | RC0/T1OSO/T1CKI β Port C bit 0 / Timer 1 oscillator output / clock in |
| Pin 15 | RC1/T1OSI/CCP2 β Port C bit 1 / Timer 1 oscillator in / CCP2 |
| Pin 16 | RC2/CCP1 β Port C bit 2 / Capture-Compare-PWM 1 |
| Pin 17 | RC3/SCK/SCL β Port C bit 3 / SPI clock / I2C clock |
| Pin 18 | RC4/SDI/SDA β Port C bit 4 / SPI data in / I2C data |
| Pin 19 | RC5/SDO β Port C bit 5 / SPI data out |
| Pin 20 | RC6/TX/CK β Port C bit 6 / USART TX / clock |
| Pin 21 | RC7/RX/DT β Port C bit 7 / USART RX / data |
| Pin 22 | RB0/INT β Port B bit 0 / External interrupt |
| Pin 23 | RB1 β Port B bit 1 |
| Pin 24 | RB2 β Port B bit 2 |
| Pin 25 | RB3 β Port B bit 3 |
| Pin 26 | RB4 β Port B bit 4 |
| Pin 27 | RB5 β Port B bit 5 |
| Pin 28 | RB6 β Port B bit 6 |
Typical Applications
PIC16C73AT-04E/SO is suitable for 6 applications: Industrial Sensor Interface Boards, Home Appliance Control (Washing Machines, Microwave Ovens), HVAC Thermostat and Climate Control, Automotive Body Electronics (Pre-CAN Era), Embedded Data Acquisition Systems, Motor Control and Small BLDC/PMSM Drivers.
Industrial Sensor Interface Boards
The PIC16C73AT-04E/SO's integrated 8-bit multi-channel ADC, 22 digital I/O pins, and USART make it a natural fit for industrial sensor interface boards. The on-chip ADC eliminates the external converter that would otherwise be needed, allowing direct connection of 4-20 mA loop transducers through simple signal conditioning. At 4 MHz the MCU delivers 1 MIPS, sufficient for polled scanning of 8-12 sensor channels with averaging and threshold detection. Brown-out reset and watchdog timer ensure reliable recovery from industrial supply transients, while the 2.5-6.0 V supply range supports both 3.3 V and 5 V industrial backplanes.
Recommended
Home Appliance Control (Washing Machines, Microwave Ovens)
The PIC16C73AT-04E/SO is widely deployed in legacy home appliance controllers such as washing-machine front panels, microwave-oven user interfaces, and dishwasher pumps, where its 22 I/O pins drive multiplexed keypads, LED displays, triac outputs, and buzzer feedback. The integrated SSP (SPI/I2C) and USART let the MCU talk to peripheral display drivers and Hall-effect sensors over a two-wire bus. The OTP memory prevents accidental firmware tampering after production, a security plus for sealed consumer appliances. The 28-SOIC wide-body package fits the typical appliance PCB form factor with adequate creepage.
Recommended
HVAC Thermostat and Climate Control
Thermostats and HVAC control boards benefit from the PIC16C73AT-04E/SO's low power consumption, integrated ADC for thermistor reading, and ability to drive triacs or relay coils through its I/O pins. The 2.5-6.0 V supply range allows direct operation from a 24 VAC rectified supply with simple regulation, and the brown-out reset prevents the controller from entering undefined states during brown-outs. With 4 MIPS-equivalent throughput at 4 MHz, the MCU can poll temperature, schedule, and user-input channels while driving a multiplexed LCD or seven-segment display. The OTP variant also prevents field-firmware tampering, useful for compliance.
Recommended
Automotive Body Electronics (Pre-CAN Era)
In pre-CAN automotive body modules - such as mirror controllers, seat adjusters, and lighting controllers - the PIC16C73AT-04E/SO provided an integrated ADC, USART for diagnostic communication, and 22 robust I/O pins for relay and lamp drivers. Its industrial -40 C to +125 C temperature range handles under-dash environments. Today, new designs use CAN-capable PIC18 or dsPIC parts, but the legacy PIC16C73A still runs in millions of vehicles. The wide 28-SOIC footprint gives good solder-joint reliability in high-vibration mounting zones compared to smaller QFN alternatives.
Recommended
Embedded Data Acquisition Systems
Multi-channel data loggers benefit from the PIC16C73AT-04E/SO's integrated 8-bit ADC, USART for PC connectivity, and 192-byte RAM for buffering samples before batch transfer. With 4 MIPS throughput, the MCU can sample up to 8 channels at moderate rates, perform digital averaging, and forward data over RS-232 to a host PC. The fully-static CMOS design allows clock stretching for very low sample rates without register loss, supporting long-interval battery-powered monitoring. Brown-out reset and watchdog timer protect field-deployed loggers from supply glitches and firmware lockups.
Recommended
Motor Control and Small BLDC/PMSM Drivers
Although not a dedicated motor-control MCU, the PIC16C73AT-04E/SO handles simple brushed-DC and small BLDC motor commutation by combining its 22 I/O pins (used for phase drivers and Hall-sensor inputs), three timers (for PWM and back-EMF sampling), and ADC (for current sensing). The 4 MHz clock is sufficient for low-RPM commutation control, while the wide 2.5-6.0 V supply range accepts directly regulated battery voltages. Engineers migrating from this part to newer designs often step up to the PIC16F1939 or dsPIC33FJ series for advanced PWM and field-oriented control.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C73AT-04E/SO β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C73A-04E/SO | PIC16F73-I/SO | PIC16C74A-04E/SO |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SOIC (7.50 mm) | 28-SOIC (7.50 mm) | 28-SOIC (7.50 mm) | 28-SOIC (7.50 mm) |
| Core | PIC16 mid-range 8-bit | PIC16 mid-range 8-bit | PIC16 mid-range 8-bit | PIC16 mid-range 8-bit |
| Max CPU Speed | 4 MHz | 4 MHz | 20 MHz | 4 MHz |
| Program Memory | 7 KB OTP | 7 KB OTP | 7 KB Flash | 7 KB OTP |
| RAM Size | 192 bytes | 192 bytes | 192 bytes | 192 bytes |
| I/O Pins | 22 | 22 | 22 | 22 |
| ADC | 8-bit, 8 channels | 8-bit, 8 channels | 8-bit, 8 channels | 8-bit, 8 channels |
| ICSP Support | No (OTP only) | No (OTP only) | Yes (Flash, ICSP) | No (OTP only) |
| Lifecycle Status | Obsolete | Obsolete | Active | Obsolete |
Key Differentiators
- OTP memory provides hardware-level firmware immutability (vs PIC16F73-I/SO)
- Same die across all -04E, -10E, and -20E speed grades (vs PIC16C73A-10E/SO)
- Wide 28-SOIC (7.50 mm) footprint for industrial solder reliability (vs PIC16F73-I/SO in SSOP)
Design Notes
The PIC16C73AT-04E/SO operates from 2.5 V to 6.0 V. Estimated: at 4 MHz and 5 V supply, core current consumption is approximately 2-4 mA active and <1 uA in sleep mode. Place a 100 nF ceramic decoupling capacitor within 1 cm of VDD (pin 11) and VSS (pin 10), with an additional 10 uF bulk capacitor on the supply rail. For battery-powered applications, use the SLEEP instruction to drop current below 1 uA between ADC conversion cycles.
OTP memory can be programmed only once. Do not prototype production firmware directly on this part - validate on a PIC16C73JW (windowed EPROM) or PIC16F73 (Flash) first. Once sealed, the OTP cannot be erased, so any firmware bug becomes a hardware rework. Also note that the 'E' suffix denotes industrial temperature range (-40 C to +125 C); do not substitute an 'I' suffix part if industrial range is required.
The 28-SOIC wide-body (7.50 mm) footprint gives better creepage than narrow-body SOIC variants. Route the crystal traces (OSC1/OSC2, pins 12-13) as short and symmetric as possible, with a ground guard ring around the crystal to reduce EMI coupling. Keep ADC traces (RA0-RA5, RE0-RE2) away from digital switching lines such as PWM outputs and the USART lines to minimize crosstalk into analog readings.
Compliance Information
Detailed RoHS/REACH status not stated in the verified web data; Microchip typically ships legacy OTP parts in lead-free finishes but designers should request a compliance certificate for new designs.
