PIC16C73AT-04/SO - 4MHz 8-bit CMOS MCU 7KB OTP 28-SOIC | Microchip
MPN: PIC16C73AT-04/SO ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.2 | $4.20 |
| 10 | $3.78 | $37.80 |
| 100 | $3.36 | $336.00 |
| 500 | $2.95 | $1,475.00 |
| 1,000 | $2.61 | $2,610.00 |
PIC16C73AT-04/SO Overview
A microcontroller (MCU) is a single integrated package that combines a CPU core, program memory (ROM/OTP/Flash), data RAM, peripheral interfaces (timers, ADC, communication ports), and I/O pins on one die. Microcontrollers sit in the broader system hierarchy of embedded computing: microcontroller -> microprocessor -> CPU -> integrated circuit -> semiconductor. The PIC16C73A specifically belongs to the PIC16CXX mid-range family, a class of low-cost, high-performance, fully-static 8-bit microcontrollers introduced by Microchip in the 1990s that became a foundational element in thousands of industrial and consumer product designs.
Key features include 22 I/O lines, Harvard architecture with separate program and data buses, a wide operating voltage range, low power consumption suitable for battery-powered systems, and on-chip peripherals such as timers, a synchronous/asynchronous serial port (USART), capture/compare/PWM modules, and a multi-channel 10-bit A/D converter. The 28-pin SOIC form factor makes it suitable for hand-soldering, prototype work, and compact production boards where through-hole DIP variants are too tall.
The PIC16C73A's architecture uses a 14-bit instruction word with an 8-bit data path, allowing compact code density and a small instruction set (35 instructions total) that is easy to learn. The 192-byte RAM and 7 KB OTP program memory target small- to mid-size embedded applications. With 22 I/O pins and integrated peripherals, the device can directly drive displays, sensors, communication interfaces, and power-control signals without external glue logic.
Typical applications include industrial control systems, automotive body electronics, appliance control boards, security and alarm systems, and instrumentation where 8-bit processing, integrated analog input, and 28-pin SOIC footprint are required. Designers frequently select this part for legacy product maintenance, cost-sensitive designs, and educational platforms that need a reliable OTP MCU with proven toolchain support (MPLAB). When designing with this part, note that OTP memory can be programmed only once and cannot be erased or rewritten - choose PIC16F73 (Flash-based) for designs that need firmware updates in production.
Drop-in alternatives for PIC16C73AT-04/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-04/SO (same form factor and footprint) — differing in Package, Timers, Program Memory Type, A/D Converter, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C73A-04/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C73A-20I/SO
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$9.3 / Unit
View Datasheet →PIC16C73A-10E/SO
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$6.55 / Unit
View Datasheet →PIC16C73B-04/SO
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$4.65 / Unit
View Datasheet →PIC16F73-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C73AT-04/SOM
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC16C73AT-04/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16CXX mid-range, 8-bit RISC |
| Instruction Set | 35 instructions, 14-bit instruction word |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 7 KB (4K x 14 words) |
| Data RAM | 192 bytes (192 x 8) |
| Maximum Clock Frequency | 4 MHz |
| Number of I/O Pins | 22 |
| Package | 28-pin SOIC (SOP, gull-wing) |
| Mounting Type | Surface Mount |
| Operating Temperature Grade | Commercial |
| A/D Converter | Yes, multi-channel (per family datasheet) |
| Timers | Yes (per family datasheet) |
| USART | Yes (per family datasheet) |
| Oscillator Type | External (per cross-reference data) |
| Packaging Format | Tape & Reel (T suffix) |
| Terminal Form | GULL WING |
| Number of Terminals | 28 |
| Package Code | SOP |
PIC16C73AT-04/SO Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (reset) input / programming voltage |
| Pin 2 | RA0/AN0 — Digital I/O port A bit 0 / A/D channel 0 |
| Pin 3 | RA1/AN1 — Digital I/O port A bit 1 / A/D channel 1 |
| Pin 4 | RA2/AN2 — Digital I/O port A bit 2 / A/D channel 2 |
| Pin 5 | RA3/AN3/VREF — Digital I/O port A bit 3 / A/D channel 3 / VREF |
| Pin 6 | RA4/T0CKI — Digital I/O port A bit 4 / Timer 0 clock input |
| Pin 7 | RA5/AN4/SS — Digital I/O port A bit 5 / A/D channel 4 / SPI slave select |
| Pin 8 | OSC1/CLKIN — Oscillator crystal input / external clock input |
| Pin 9 | OSC2/CLKOUT — Oscillator crystal output / clock output |
| Pin 10 | RC0/T1OSO/T1CKI — Digital I/O port C bit 0 / Timer 1 oscillator output / Timer 1 clock input |
| Pin 11 | RC1/T1OSI/CCP2 — Digital I/O port C bit 1 / Timer 1 oscillator input / CCP2 |
| Pin 12 | RC2/CCP1 — Digital I/O port C bit 2 / Capture/Compare/PWM 1 |
| Pin 13 | RC3/SCK/SCL — Digital I/O port C bit 3 / SPI clock / I2C clock |
| Pin 14 | RC4/SDI/SDA — Digital I/O port C bit 4 / SPI data in / I2C data |
| Pin 15 | RC5/SDO — Digital I/O port C bit 5 / SPI data out |
| Pin 16 | RC6/TX/CK — Digital I/O port C bit 6 / USART transmit / USART clock |
| Pin 17 | RC7/RX/DT — Digital I/O port C bit 7 / USART receive / USART data |
| Pin 18 | VSS — Ground reference |
| Pin 19 | VDD — Positive supply voltage |
| Pin 20 | RB0/INT — Digital I/O port B bit 0 / external interrupt |
| Pin 21 | RB1 — Digital I/O port B bit 1 |
| Pin 22 | RB2 — Digital I/O port B bit 2 |
| Pin 23 | RB3 — Digital I/O port B bit 3 |
| Pin 24 | RB4 — Digital I/O port B bit 4 |
| Pin 25 | RB5 — Digital I/O port B bit 5 |
| Pin 26 | RB6/PGC — Digital I/O port B bit 6 / ICSP clock |
| Pin 27 | RB7/PGD — Digital I/O port B bit 7 / ICSP data |
| Pin 28 | VSS — Ground reference |
Typical Applications
PIC16C73AT-04/SO is suitable for 7 applications: Industrial Control Systems, Automotive Body Electronics, Home Appliance Control Boards, Security and Alarm Systems, Test and Measurement Instrumentation, Embedded Educational Platforms, Power Supply Monitoring and Battery Management.
Industrial Control Systems
The PIC16C73AT-04/SO is well suited for industrial control boards where 8-bit processing, integrated 10-bit A/D conversion, and 22 I/O lines simplify factory automation designs. The 4 MHz clock and 7 KB OTP memory fit deterministic control loops driving sensors, relays, and motor drivers. The 28-pin SOIC package supports compact production boards, and its commercial temperature grade suits indoor control cabinets. With built-in USART and capture/compare/PWM, it can directly drive valve actuators and read encoder feedback without external glue logic, reducing BOM cost.
Recommended
Automotive Body Electronics
In automotive body modules such as seat controllers, mirror adjusters, or HVAC actuators, the PIC16C73AT-04/SO provides sufficient I/O count and an integrated A/D converter for position feedback. Its 5V operation, robust CMOS design, and proven PIC16C7X architecture have a long track record in pre-CAN body electronics. The 4 MHz speed grade is adequate for slow control loops. For modern automotive designs requiring CAN bus, consider adding an external MCP2551 CAN transceiver, or migrate to the PIC16F73 family for firmware-update capability.
Recommended
Home Appliance Control Boards
The PIC16C73AT-04/SO is widely used in home appliances such as washing machines, microwave ovens, dishwashers, and refrigerator control boards. Its 22 I/O pins can directly interface with keypads, LED/LCD indicator panels, temperature sensors via the A/D converter, and triac-driven motor/relay loads. The 7 KB OTP memory holds fixed-function appliance firmware, and the 4 MHz clock is sufficient for keypad debounce, sensor polling, and PWM-driven motor control. The 28-SOIC package simplifies single-side PCB assembly for high-volume production.
Recommended
Security and Alarm Systems
The PIC16C73AT-04/SO is suitable for alarm panels, PIR motion-detector signal processors, and access-control reader boards. Its integrated A/D converter reads analog sensor channels (PIR, smoke, gas), and its 22 I/O pins handle keypads, sirens, relay outputs, and status LEDs. The Harvard RISC architecture executes alarm-decision logic deterministically within microseconds, ensuring reliable event response. The 28-SOIC package is well suited to compact alarm-system PCBs, and the part's OTP memory locks firmware against reverse engineering.
Recommended
Test and Measurement Instrumentation
For low-cost digital multimeters, panel meters, and handheld instrumentation, the PIC16C73AT-04/SO provides integrated 10-bit A/D conversion suitable for measuring voltage, current, and temperature-derived signals. Its 22 I/O pins drive LCD segments, button inputs, and range-selection logic. The 7 KB OTP memory holds calibration tables and linearization routines. The 4 MHz instruction rate delivers ample processing throughput for RMS calculation, auto-ranging, and serial output via USART to a host PC or display module.
Recommended
Embedded Educational Platforms
The PIC16C73AT-04/SO is a classic teaching MCU for embedded-systems courses covering RISC architecture, peripheral programming, and assembly/C development using Microchip's MPLAB toolchain. The 28-SOIC package is breadboard-friendly with a SOIC-to-DIP adapter, and the PIC16C7X family datasheet (DS30390) is widely available as a learning resource. The 7 KB OTP and 192-byte RAM provide enough headroom for student projects involving A/D conversion, PWM motor control, and serial communication. New courses typically prefer the PIC16F73 for its Flash-based in-circuit reprogramming.
Recommended
Power Supply Monitoring and Battery Management
The PIC16C73AT-04/SO suits battery chargers, UPS monitoring boards, and DC power-supply supervisory modules. Its integrated 10-bit A/D converter measures battery voltage, charge current, and temperature with sufficient resolution for state-of-charge estimation. The USART reports telemetry to a host controller, and 22 I/O pins control charging MOSFETs, relay cutoffs, and LED status indicators. The 4 MHz instruction rate handles PID control loops for constant-current/constant-voltage charging. For new designs, pair with a PIC16F73-I/SO to gain firmware-update capability during product refinement.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C73AT-04/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C73A-04/SO | PIC16C73A-20I/SO | PIC16C73A-10E/SO | PIC16C73B-04/SO | PIC16F73-I/SO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SOIC (SOP) | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same |
| Program Memory Type | OTP (7 KB) | OTP (7 KB) | OTP (7 KB) | OTP (7 KB) | OTP (7 KB) | Flash (7 KB) |
| Maximum Clock Speed | 4 MHz | 4 MHz | 20 MHz | 10 MHz | 4 MHz | 20 MHz |
| Data RAM | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes |
| Number of I/O Pins | 22 | 22 | 22 | 22 | 22 | 22 |
| Temperature Grade | Commercial | Commercial | Industrial | Extended | Commercial | Industrial |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Active |
Key Differentiators
- Tape & Reel packaging format for high-volume production (vs PIC16C73A-04/SO)
- Flash memory allows in-system reprogramming (vs PIC16F73-I/SO)
- Lower-cost legacy OTP for high-volume fixed-function designs (vs PIC16F73-I/SO)
Design Notes
Estimated: The PIC16C73AT-04/SO uses OTP memory that can be programmed only once - any code bug or field-update requirement cannot be addressed after programming. For new designs or designs likely to require firmware updates, choose the PIC16F73-I/SO (Flash-based) which is in active production and shares the same 28-SOIC footprint, peripheral set, and 22 I/O architecture. Migration to PIC16F73 requires no PCB changes and uses the same MPLAB toolchain.
When designing the 28-pin SOIC PCB layout, follow Microchip's mid-range family reference design: place a 0.1 uF decoupling capacitor within 5 mm of the VDD pin (pin 19) with a short ground trace to VSS (pin 28). Add a 10 kohm pull-up on MCLR/VPP (pin 1) to VDD for normal operation. If using an external crystal oscillator, place the crystal within 10 mm of pins 9/8 with grounded traces surrounding the oscillator traces to minimize EMI.
Estimated: At 4 MHz clock rate, the PIC16C73AT-04/SO instruction cycle is 1 MHz (4 clocks per instruction). With 7 KB OTP and 192 bytes RAM, deeply nested interrupt handlers or large lookup tables can quickly exhaust RAM - estimate 8-16 bytes per stack frame plus data buffer usage. For complex interrupt-driven designs, consider migrating to PIC16F73 (Flash, same RAM) or PIC16F876 (368 bytes RAM) if stack depth is a concern.
Compliance Information
RoHS, REACH, lead-free, and halogen-free compliance not stated in verified web data. PIC16C7X family parts produced in the late 1990s often predate RoHS requirements - assume non-compliant unless explicitly certified by manufacturer documentation. AEC-Q100 not qualified; for automotive, choose automotive-grade variants.
