PIC16C72AT-04/SO - 8-Bit OTP MCU 4MHz 3.5KB 28-SOIC | Microchip
MPN: PIC16C72AT-04/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.3 | $5.30 |
| 10 | $4.77 | $47.70 |
| 100 | $4.24 | $424.00 |
| 500 | $3.82 | $1,910.00 |
| 1,000 | $3.5 | $3,500.00 |
PIC16C72AT-04/SO Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, working RAM, and peripheral interfaces. PIC microcontrollers use a Harvard RISC core with only 35 single-word instructions, where every instruction executes in one instruction cycle except program branches, which take two. This compact instruction set keeps firmware small and deterministic, which is why PIC MCUs remain common in cost-sensitive industrial and consumer products.
Key features include five 8-bit I/O ports, a 5-channel 8-bit Analog-to-Digital Converter (ADC), a Capture/Compare/PWM (CCP) module, a Synchronous Serial Port (SSP) supporting SPI and I2C, a USART for asynchronous serial communication, and two 8-bit timers plus one 16-bit timer. These integrated peripherals allow a single MCU to replace multiple external components, reducing BOM cost and PCB area in sensor-interface, motor-control, and human-machine interface designs.
The PIC16C72A uses a 14-bit instruction word and the standard mid-range PIC core, which means existing PIC16C7x firmware and development tools can be ported with minimal changes. The 4 MHz speed grade is the slowest of the PIC16C72A family (which also includes 10 MHz and 20 MHz grades), making the -04 part suitable for applications where low electromagnetic emissions or relaxed timing budgets are more important than raw throughput. According to the Microchip datasheet, the device supports in-circuit serial programming via two pins on most package variants.
Typical applications include simple motor control loops using the CCP PWM channel, sensor data acquisition with the 8-bit ADC, RS-232 bridges using the USART, and front-panel controllers for appliances and industrial equipment. The OTP program memory is programmed once at production time, which makes the PIC16C72AT-04/SO well suited to high-volume, fixed-function products where firmware rarely changes.
When designing with this device, ensure the brown-out reset voltage is correctly configured in the configuration word and that decoupling capacitors (typically 0.1 uF) are placed close to VDD and VSS pins. OTP memory cannot be erased, so verify firmware thoroughly using a windowed (JW) or flash equivalent during development before committing to the OTP part for production.
This page synthesizes distributor pricing, pin-compatible drop-in alternatives (including PIC16C72A and PIC16C72 same-package variants), and practical design notes that supplement the manufacturer datasheet.
Drop-in alternatives for PIC16C72AT-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 PIC16C72AT-04/SO (same form factor and footprint) — differing in Core Architecture, Package, Timers, ADC, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C72A-04/SO
✅ Drop-In✓ In Stock
$5.22 / Unit
View Datasheet →PIC16C72-04/SO
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$3.45 / Unit
View Datasheet →PIC16C72A-10/SO
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC16C72A-20/SO
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC16C72-10I/SO
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$4.25 / Unit
View Datasheet →PIC16C72AT-04/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC RISC (mid-range) |
| Program Memory Type | OTP (One-Time-Programmable) EPROM |
| Program Memory Size | 3.5 KB (2K x 14 words) |
| RAM | 128 bytes |
| Data EEPROM | Not present |
| Maximum CPU Clock | 4 MHz |
| Supply Voltage (VDD) | 4 V to 5.5 V |
| I/O Pins | 22 |
| ADC | 5-channel, 8-bit |
| Timers | 2 x 8-bit + 1 x 16-bit |
| CCP Modules | 1 (Capture/Compare/PWM) |
| Serial Interfaces | SSP (SPI/I2C), USART |
| Package | 28-pin SOIC (300 mil, SO) |
| Operating Temperature | 0 C to +70 C (commercial) |
| Instruction Set | 35 instructions, 14-bit word |
| Mounting Type | Surface Mount |
PIC16C72AT-04/SO Pin Configuration
| Pin 1 | RA0/AN0 — Digital I/O / Analog input channel 0 |
| Pin 2 | RA1/AN1 — Digital I/O / Analog input channel 1 |
| Pin 3 | RA2/AN2 — Digital I/O / Analog input channel 2 |
| Pin 4 | RA3/AN3/VREF — Digital I/O / Analog input channel 3 / ADC voltage reference |
| Pin 5 | RA4/T0CKI — Digital I/O / Timer0 clock input |
| Pin 6 | RA5/AN4/SS — Digital I/O / Analog input channel 4 / SPI slave select |
| Pin 7 | VSS — Ground reference |
| Pin 8 | OSC1/CLKIN — Crystal oscillator input / external clock input |
| Pin 9 | OSC2/CLKOUT — Crystal oscillator output / clock output (Fosc/4) |
| Pin 10 | RC0/T1OSO/T1CKI — Digital I/O / Timer1 oscillator output / Timer1 clock input |
| Pin 11 | RC1/T1OSI/CCP2 — Digital I/O / Timer1 oscillator input / Capture-Compare-PWM 2 |
| Pin 12 | RC2/CCP1 — Digital I/O / Capture-Compare-PWM 1 |
| Pin 13 | RC3/SCK/SCL — Digital I/O / SPI clock / I2C clock |
| Pin 14 | RC4/SDI/SDA — Digital I/O / SPI data in / I2C data |
| Pin 15 | RC5/SDO — Digital I/O / SPI data out |
| Pin 16 | RC6/TX/CK — Digital I/O / USART transmit / USART clock |
| Pin 17 | RC7/RX/DT — Digital I/O / USART receive / USART data |
| Pin 18 | VSS — Ground reference (second VSS pin) |
| Pin 19 | VDD — Positive supply voltage |
| Pin 20 | RB0/INT — Digital I/O / External interrupt input |
| Pin 21 | RB1 — Digital I/O |
| Pin 22 | RB2 — Digital I/O |
| Pin 23 | RB3 — Digital I/O |
| Pin 24 | RB4 — Digital I/O |
| Pin 25 | RB5 — Digital I/O |
| Pin 26 | RB6/PGC — Digital I/O / In-circuit debugger clock |
| Pin 27 | RB7/PGD — Digital I/O / In-circuit debugger data |
| Pin 28 | VDD — Positive supply voltage (second VDD pin) |
Typical Applications
PIC16C72AT-04/SO is suitable for 7 applications: Appliance Control Boards, Industrial Sensor Interfaces, Simple Motor Control (PWM), RS-232 / RS-485 Communication Bridges, User Interface / HMI Keypads, Automotive Interior Lighting Modules, Educational and Hobbyist Embedded Projects.
Appliance Control Boards
The PIC16C72AT-04/SO is well suited for fixed-function appliance controllers such as washing-machine front panels, microwave oven keypads, and small kitchen appliances. Its 22 digital I/O lines easily drive 7-segment displays, key-scan matrices, and triac/relay control outputs, while the integrated USART provides a service-port interface for factory calibration. At 4 MHz the MCU runs the main loop with single-cycle instruction execution, leaving headroom for debounce, key-scan, and triac zero-cross timing. The OTP program memory is ideal here because appliance firmware is finalized at production time and never updated in the field, which keeps per-unit cost at the $3-5 range. The CCP/PWM module can also drive low-frequency PWM for buzzer tones or LED dimming without an external timer IC. Brown-out reset and the watchdog timer protect against supply glitches during motor inrush events.
Recommended
Industrial Sensor Interfaces
The PIC16C72AT-04/SO's 5-channel 8-bit ADC is the right resolution for low-cost analog sensor interfaces including thermistor bridges, photodiode amplifiers, and 4-20 mA loop transducers. The ADC multiplexes five analog channels onto a single successive-approximation converter, eliminating the need for an external ADC chip in cost-sensitive designs. The SSP port provides I2C or SPI connectivity to digital sensors such as the Microchip MCP9808 temperature sensor, while the USART bridges to RS-232 or RS-485 transceivers for industrial networks. The 128-byte RAM budget supports short sensor-fusion routines and averaging filters without external memory. Commercial temperature grade and the 28-SOIC surface-mount package suit enclosure-mounted sensor transmitters. The 4 MHz speed grade keeps switching noise low in noise-sensitive analog signal chains.
Recommended
Simple Motor Control (PWM)
The PIC16C72AT-04/SO's Capture/Compare/PWM (CCP) module generates PWM signals suitable for low-power brushed DC motor speed control in fans, pumps, and small actuators. The PWM frequency and duty cycle are software-programmable, allowing closed-loop speed control when paired with a tachometer input on the capture channel. The 4 MHz instruction rate provides 10-bit PWM resolution at typical 10-20 kHz switching frequencies, which keeps motor acoustic noise below audible thresholds. The MCU's 22 I/O lines interface directly to H-bridge drivers such as the Microchip TC4427 or to discrete MOSFET gate drivers. Brown-out reset and the watchdog timer protect the motor under stalled-rotor fault conditions.
Recommended
RS-232 / RS-485 Communication Bridges
The PIC16C72AT-04/SO's integrated USART and 4-5.5V supply directly interface to RS-232 transceivers such as the MAX232 and to RS-485 transceivers such as the MAX485, enabling protocol-conversion bridges and field-bus nodes. The 22 I/O pins handle direction-control, fault, and indicator LED signals alongside the serial port. The OTP program memory is ideal for production-quantity bridges where the firmware is locked at order time. At 4 MHz the USART supports standard baud rates up to 38.4 kbaud with low interrupt overhead. The mid-range PIC core's deterministic interrupt latency keeps timing-margin tight for time-sensitive protocols such as DMX-512 or Modbus RTU.
Recommended
User Interface / HMI Keypads
The PIC16C72AT-04/SO is a natural fit for matrix-keypad and 7-segment user-interface panels in instrumentation and industrial control equipment. Its 22 I/O lines scan up to a 4x5 keypad matrix without external pull-ups, and directly drive common-cathode 7-segment displays via current-limiting resistors. The 4 MHz instruction rate debounces mechanical switches with simple software loops. The 5-channel ADC accepts analog control inputs such as rotary encoders (via RC timing) or potentiometers for trim adjustments. OTP memory secures the firmware against unauthorized field modification - important in regulated or warranty-controlled products.
Recommended
Automotive Interior Lighting Modules
Although the PIC16C72AT-04/SO is rated for the commercial 0-70 C temperature range, it is widely used in non-safety automotive interior modules such as ambient lighting, dashboard dimming controllers, and decorative LED drivers. The CCP/PWM module generates PWM dimming signals up to 1 kHz - well above the flicker-fusion threshold - for smooth LED brightness control. The USART supports LIN-bus slave communication via a simple software UART bit-banged on the remaining I/O pins, allowing the module to participate in body-control networks. The 28-SOIC package is robust for through-hole-friendly hand-soldering during prototyping and small-batch production. OTP memory secures the firmware against tampering in aftermarket automotive accessories.
Recommended
Educational and Hobbyist Embedded Projects
The PIC16C72AT-04/SO and its development ecosystem remain popular in university embedded-systems courses and hobbyist projects. The mid-range PIC core's 35-instruction RISC architecture is small enough to teach assembly fundamentals in a single semester, and the integrated ADC, PWM, and serial peripherals cover the standard introductory topics. The 28-SOIC package is breadboard-friendly when paired with an SOIC-to-DIP adapter PCB, and the PIC16C72/JW windowed CERDIP variant allows UV erasure for iterative development. The 4 MHz speed grade keeps instruction timing easy to count by hand. Microchip's MPLAB IDE and the CCS C compiler both support the device, providing a low-cost on-ramp to embedded firmware development.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C72AT-04/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C72A-04/SO | PIC16C72-04/SO | PIC16C72A-10/SO | PIC16C72A-20/SO | PIC16C72-10I/SO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SOIC (SO) | 28-SOIC (SO) - same | 28-SOIC (SO) - same | 28-SOIC (SO) - same | 28-SOIC (SO) - same | 28-SOIC (SO) - same |
| Maximum Clock Speed | 4 MHz | 4 MHz | 4 MHz | 10 MHz | 20 MHz | 10 MHz |
| Program Memory | 3.5 KB OTP (2K x 14) | 3.5 KB OTP (2K x 14) | 3.5 KB OTP (2K x 14) | 3.5 KB OTP (2K x 14) | 3.5 KB OTP (2K x 14) | 3.5 KB OTP (2K x 14) |
| RAM | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 128 bytes |
| I/O Pins | 22 | 22 | 22 | 22 | 22 | 22 |
| ADC | 5-ch, 8-bit | 5-ch, 8-bit | 5-ch, 8-bit | 5-ch, 8-bit | 5-ch, 8-bit | 5-ch, 8-bit |
| Operating Temperature | 0 C to +70 C (commercial) | 0 C to +70 C (commercial) | 0 C to +70 C (commercial) | 0 C to +70 C (commercial) | 0 C to +70 C (commercial) | -40 C to +85 C (industrial) |
| Shipping Format | Tape & Reel | Tube | Tube | Tube | Tube | Tube |
Key Differentiators
- Industrial temperature option available in same package (vs PIC16C72-10I/SO)
- Higher speed grades available in identical 28-SOIC package (vs PIC16C72A-20/SO)
- OTP memory secures firmware against tampering (vs PIC16C72/JW (windowed CERDIP-28))
- Same-silicon tape-and-reel format vs tube shipping (vs PIC16C72A-04/SO (tube))
Design Notes
Place a 0.1 uF decoupling capacitor as close as possible to each VDD pin (pins 19 and 28) with a short trace to the corresponding VSS pin (pins 7 and 18). Add a bulk 10 uF tantalum or aluminum electrolytic capacitor on the VDD rail within 1 inch of the MCU. For OTP-programmed production parts, ensure the VDD ramp during power-up meets the brown-out reset configuration in the configuration word to prevent code-execution from corrupted program memory.
Keep the crystal/oscillator traces (OSC1/OSC2, pins 8-9) short and surrounded by a ground guard ring to minimize radiated EMI. Place the crystal within 0.5 inch of the MCU and avoid routing digital signals beneath the oscillator. The ICSP pins RB6/PGC (pin 26) and RB7/PGD (pin 27) should be accessible on the PCB - either through test pads or an in-circuit programming header - to allow factory programming of the OTP memory and field firmware updates during development.
OTP memory cannot be erased, so development and prototyping should use either the flash-based PIC16F72 (note: not pin-compatible for program memory) or the windowed PIC16C72/JW CERDIP-28 device, then commit the verified firmware to the PIC16C72A-04/SO OTP part for production. Configuration-word bits (especially the watchdog timer, brown-out reset, and oscillator mode) must be set explicitly; an unprogrammed configuration word defaults to settings that may not match the application's needs. The USART requires the BRG register to be loaded based on Fosc, not Fosc/4, when the high-speed baud-rate mode is selected.
The 8-bit ADC has an input leakage of +/- 1 uA typical; source impedance above 10 kohm will degrade acquisition time and effective resolution. Add a 100 nF ceramic bypass capacitor close to each analog input pin and consider an op-amp buffer for high-impedance sensors. The ADC reference voltage (RA3/AN3/VREF, pin 4) should be decoupled with 10 uF + 100 nF and driven from a low-impedance source; using VDD as the reference saves pins but reduces ADC accuracy to approximately 7 bits due to VDD noise coupling into the conversion.
Compliance Information
RoHS and lead-free status not stated in the verified distributor pages; consult Microchip's product environmental compliance page for the latest declarations. The part is not AEC-Q100 qualified - it targets commercial-temperature embedded designs, not automotive safety.
