PIC16LC72AT-04/SO - 8-Bit 4MHz MCU 3.5KB OTP 28-SOIC | Microchip
MPN: PIC16LC72AT-04/SO ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.85 | $1.85 |
| 10 | $1.66 | $16.60 |
| 100 | $1.48 | $148.00 |
| 500 | $1.32 | $660.00 |
| 1,000 | $1.18 | $1,180.00 |
| 3,000 | $1.05 | $3,150.00 |
PIC16LC72AT-04/SO Overview
A microcontroller (MCU) is a single-chip computer containing a CPU core, program memory, working RAM, and peripheral set. The PIC16C family uses a Harvard RISC architecture with separate program and data buses, allowing the CPU to fetch an opcode while reading data memory in the same cycle. Within Microchip's taxonomy, the PIC16LC72A sits in the mid-range PIC16 family -> 8-bit PIC microcontroller -> MCU -> semiconductor hierarchy. The '04' speed suffix specifies 4 MHz maximum oscillator frequency, and 'SO' is the package designator for 28-pin 300-mil SOIC.
Key features include the 8-bit accumulator-based ALU, 22 I/O pins with high-current sink/source capability, three hardware timers (Timer0, Timer1, Timer2), a 10-bit successive-approximation ADC with up to 5 channels, a 5-bit digital-to-analog converter (CCP/PWM module), a synchronous/asynchronous serial port (SSP/SPI/I2C), and a USART with on-chip baud-rate generator. Brown-out Reset (BOR), Power-on Reset (POR), and a watchdog timer with its own on-chip RC oscillator are also integrated. The instruction set is 35 single-word instructions, most executing in a single instruction cycle.
The architecture uses a modified Harvard layout with a 14-bit program word and 8-bit data path. The enhanced PIC16C72A silicon revision adds hardware multiply, larger stack depth (8 levels), and improved ADC linearity compared with the original PIC16C72. Internal RC oscillator options and selectable oscillator modes support crystal, resonator, and external clock sources across the 0-4 MHz range. The CMOS process yields typical active current of 2 mA at 4 MHz / 5 V and standby currents under 1 uA at 3.3 V.
Typical applications include low-power embedded control for white goods and small appliances, HVAC fan controllers, security-system sensor nodes, remote-keyless-entry transmitters, low-end motor-control loops (small DC and BLDC fans), battery chargers, and consumer-electronics human-interface panels where deterministic 8-bit control at low cost is preferred over 32-bit performance. The 28-pin SOIC footprint also suits retrofitting older 28-pin PIC16C72 boards with an enhanced-A revision drop-in.
A key design consideration is OTP memory: code cannot be erased after programming, so for in-field firmware updates choose the PIC16F72 (Flash) or PIC16CR72 (ROM) variants instead. Ensure your programmer supports 3.3 V (LC) programming levels and use AC162061-ICD or MPLAB ICD 2/3 in-circuit debug for development with the -ICE/-ICD suffix parts.
This page consolidates distributor pricing, drop-in cross-reference alternatives, and design notes not found in the manufacturer datasheet, giving engineers a single reference for sourcing and replacing the PIC16LC72AT-04/SO.
Drop-in alternatives for PIC16LC72AT-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 PIC16LC72AT-04/SO (same form factor and footprint) — differing in ADC, Package, Timers, Operating Temperature, Program Memory Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C72AT-04/SO
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$3.5 / Unit
View Datasheet →PIC16LC72A-04/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LC72AT-04I/SO
✅ Drop-In✓ In Stock
$2.65 / Unit
View Datasheet →PIC16LC72-04/SO
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1.95 / Unit
View Datasheet →PIC16F72-I/SO
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1.95 / Unit
View Datasheet →PIC16LC72AT-04/SO Maximum Ratings & Electrical Characteristics
| Core Processor | PIC |
| Core Size | 8-bit |
| Core Architecture | RISC (Harvard, modified) |
| Series | PIC 16C |
| Program Memory Type | OTP (One-Time-Programmable) |
| Program Memory Size | 3.5 KB (2K x 14) |
| Data RAM Size | 128 bytes |
| Maximum Clock Frequency | 4 MHz |
| Instruction Cycle Time | 1 MIPS at 4 MHz |
| Supply Voltage Range | 2.5 V to 6.0 V (typical 3.3 V / 5 V) |
| I/O Pins | 22 |
| ADC | 10-bit, up to 5 channels |
| Timers | 3 x 8/16-bit (Timer0, Timer1, Timer2) |
| Serial Interfaces | SSP/SPI/I2C, USART with BRG |
| PWM / CCP Modules | 1 CCP, 10-bit PWM |
| Watchdog Timer | Yes (with on-chip RC oscillator) |
| Brown-out Reset / POR | Yes / Yes |
| Operating Temperature | -40C to +85C (industrial) |
| Package | 28-pin SOIC (SO), wide-body 300-mil |
| Mounting Type | Surface Mount |
| Silicon Revision | A (enhanced vs. original PIC16C72) |
PIC16LC72AT-04/SO Pin Configuration
| Pin 1 | MCLR/Vpp — Master Clear (Reset) input / programming voltage |
| Pin 2 | RA0/AN0 — Digital I/O / analog input channel 0 |
| Pin 3 | RA1/AN1 — Digital I/O / analog input channel 1 |
| Pin 4 | RA2/AN2 — Digital I/O / analog input channel 2 |
| Pin 5 | RA3/AN3/Vref — Digital I/O / analog input 3 / ADC Vref |
| Pin 6 | RA4/T0CKI — Digital I/O / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — Digital I/O / analog input 4 / SPI slave select |
| Pin 8 | Vss — Ground reference |
| Pin 9 | OSC1/CLKIN — Oscillator crystal input / external clock in |
| Pin 10 | OSC2/CLKOUT — Oscillator crystal output / clock out |
| Pin 11 | RC0/T1OSO/T1CKI — Digital I/O / Timer1 oscillator out / Timer1 clock |
| Pin 12 | RC1/T1OSI/CCP2 — Digital I/O / Timer1 oscillator in / CCP2 |
| Pin 13 | RC2/CCP1 — Digital I/O / CCP1 PWM output |
| Pin 14 | RC3/SCK/SCL — Digital I/O / SPI clock / I2C clock |
| Pin 15 | RC4/SDI/SDA — Digital I/O / SPI data in / I2C data |
| Pin 16 | RC5/SDO — Digital I/O / SPI data out |
| Pin 17 | RC6/TX/CK — Digital I/O / USART TX / USART clock |
| Pin 18 | RC7/RX/DT — Digital I/O / USART RX / USART data |
| Pin 19 | Vss — Ground reference |
| Pin 20 | Vdd — Positive supply voltage |
| Pin 21 | RB0/INT — Digital I/O / external interrupt |
| Pin 22 | RB1 — Digital I/O |
| Pin 23 | RB2 — Digital I/O |
| Pin 24 | RB3/PGM — Digital I/O / LVP programming entry |
| Pin 25 | RB4 — Digital I/O |
| Pin 26 | RB5 — Digital I/O |
| Pin 27 | RB6/PGC — Digital I/O / ICD clock |
| Pin 28 | RB7/PGD — Digital I/O / ICD data |
Typical Applications
PIC16LC72AT-04/SO is suitable for 6 applications: Low-Power White Goods Control, HVAC Fan Motor Controller, Security System Sensor Node, Remote Keyless Entry Transmitter, Consumer Audio Volume / Tone Control, Battery Charger Controller.
Low-Power White Goods Control
The PIC16LC72AT-04/SO suits white-goods control boards (washing-machine user interfaces, dishwasher timers, microwave keypads) where its 3.5 KB OTP, 128 B RAM, and 22 I/O pins handle button-scanning, LED driving, and relay logic. The LC variant's 2.5-6.0 V supply supports 3.3 V appliance rails, drawing under 2 mA active at 4 MHz. Its 10-bit ADC reads water-level thermistors, and the CCP/PWM modulates buzzer tones. Compared with 32-bit alternatives, the 8-bit core delivers deterministic interrupt latency critical for safety timers.
Recommended
HVAC Fan Motor Controller
In HVAC indoor-unit fan controllers, the PIC16LC72AT-04/SO drives a triac-fired BLDC or shaded-PEL motor via its 10-bit PWM module. The 'AT-04' speed grade provides the 4 MHz / 1 MIPS throughput needed for closed-loop RPM sensing via the input-capture pin. The 10-bit ADC samples tachometer feedback and thermistor inputs, while the USART links to a wall thermostat. The 28-SOIC footprint is well-proven in production HVAC boards, and the enhanced 'A' silicon revision's hardware multiply accelerates FIR-filter RPM calculations.
Recommended
Security System Sensor Node
In PIR motion detectors, door/window contact sensors, and glass-break detectors, the PIC16LC72AT-04/SO operates from a 3 V lithium battery, exploiting the LC variant's sub-1 uA sleep current and <2 mA active draw. The 22 I/O pins read multiple reed switches, drive an RF transmitter (via USART/SPI), and blink a status LED via Timer2 PWM. The 3.5 KB OTP holds pet-immune algorithms and pulse-counting logic. Brown-out Reset prevents corruption when batteries age below 2.5 V. The 28-SOIC footprint enables compact PCBs behind wall-mount sensor housings.
Recommended
Remote Keyless Entry Transmitter
For automotive RKE fobs the PIC16LC72AT-04/SO provides the 8-bit control core that reads button-matrix inputs, encrypts rolling codes, and drives a 315/433 MHz SAW-resonator-based transmitter via OOK/FSK modulation. The 4 MHz / 1 MIPS timing is sufficient for 100 us button-debounce loops and Manchester-encoded data streams. The LC process yields years of standby on a CR2032 cell, and the 28-SOIC enables thin fob PCB layouts. Industrial -40 to +85C variants (PIC16LC72AT-04I/SO) handle automotive thermal-cycling requirements.
Recommended
Consumer Audio Volume / Tone Control
In low-cost audio equipment (boomboxes, mini Hi-Fi amplifiers, PA mixers) the PIC16LC72AT-04/SO drives rotary encoder inputs and LED VU-meter displays while communicating with digital potentiometers or DSP volume chips over I2C. The 10-bit PWM generates beep tones and click-suppression ramps; the 10-bit ADC monitors supply voltage for brown-out muting. The 3.3 V LC variant runs from the audio rail directly. 28-SOIC packaging suits through-hole-friendly retrofit boards in legacy audio products.
Recommended
Battery Charger Controller
NiCd/NiMH/Li-ion charger designs use the PIC16LC72AT-04/SO for delta-V peak detection, temperature monitoring, and PWM control of the charging current via a MOSFET driver. The 10-bit ADC samples battery voltage and thermistor inputs at 4 MHz / 1 MIPS throughput, while the CCP/PWM module regulates charge current at up to 10-bit resolution. The LC variant's 2.5-6.0 V supply matches single-cell Li-ion rails, and the BOR prevents over-discharge damage. The 28-SOIC footprint accommodates thermal copper pours for the power section.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC72AT-04/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C72AT-04/SO | PIC16LC72A-04/SO | PIC16LC72AT-04I/SO | PIC16LC72-04/SO | PIC16F72-I/SO |
|---|---|---|---|---|---|---|
| Package | 28-SOIC | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory Type | OTP 3.5 KB | OTP 3.5 KB | OTP 3.5 KB | OTP 3.5 KB | OTP 3.5 KB | Flash 3.5 KB (reprogrammable) |
| Silicon Revision | Enhanced A (hardware multiply) | Enhanced A | Enhanced A | Enhanced A | Original (no HW multiply) | Flash-based A-equivalent |
| Supply Voltage | 2.5 V to 6.0 V (LC) | 4.5 V to 5.5 V (standard C) | 2.5 V to 6.0 V (LC) | 2.5 V to 6.0 V (LC) | 2.5 V to 6.0 V (LC) | 2.0 V to 5.5 V (F) |
| Max Clock Frequency | 4 MHz (1 MIPS) | 4 MHz (1 MIPS) | 4 MHz (1 MIPS) | 4 MHz (1 MIPS) | 4 MHz (1 MIPS) | 20 MHz (5 MIPS) |
| Operating Temperature | 0C to +70C (commercial) | 0C to +70C (commercial) | 0C to +70C (commercial) | -40C to +85C (industrial) | 0C to +70C (commercial) | -40C to +85C (industrial) |
| Tape & Reel Suffix | Yes (T in MPN) | Yes | No (tray/tube) | Yes | No (tray/tube) | No (tray/tube) |
| Param Match Percentage | 100% | 90% (supply voltage differs) | 100% | 95% (temp range only) | 80% (no HW multiply) | 80% (Flash vs OTP, faster clock) |
Key Differentiators
- Enhanced 'A' silicon revision with hardware multiply (vs PIC16LC72-04/SO)
- Low-voltage LC process for 3.3 V battery operation (vs PIC16C72AT-04/SO)
- Industrial temperature grade option in same package (vs PIC16LC72AT-04I/SO)
Design Notes
The PIC16LC72AT-04/SO requires a clean 2.5-6.0 V supply; place a 100 nF decoupling capacitor within 5 mm of Vdd (pin 20) and a bulk 10 uF tantalum or ceramic on the same rail. For battery applications, add a 100 kohm pull-down on MCLR/Vpp to avoid floating-reset lockups. Brown-out Reset is enabled by config bit BODEN; configure BOR voltage to 2.5 V or 4.0 V via the BORV1:BORV0 bits in the configuration word.
Layout: keep the 28-SOIC footprint on a 1.27 mm pitch (300-mil SOIC). Place the crystal/oscillator within 5 mm of OSC1 (pin 9) and OSC2 (pin 10) to minimize parasitic capacitance. Route analog signals (RA0-RA5) away from digital switching traces, and add a ground guard ring around AVss if used. The exposed-pad (none on SOIC) is not present, but thermal relief is generally unnecessary given the device's 2 mA typical active current.
OTP memory warning: code programmed into the PIC16LC72AT-04/SO cannot be erased. Use MPLAB X with the PICkit 3/4 or ICD 3/4 in DEBUG mode on the PIC16C72A-ICD equivalent for development, then program the OTP production units only after firmware is final. In-circuit Serial Programming (ICSP) requires Vpp = 13 V on MCLR/Vpp - ensure your programmer supports the PIC16C72A device ID (0x162 or 0x172 family).
The PIC16LC72AT-04/SO has limited ADC input impedance (~10 kohm). For high-impedance sensor sources, add a 100 nF capacitor on the analog input and a unity-gain buffer (MCP6022 op-amp) to drive the ADC channel. Configure the ADC acquisition time via ADCON1 register to allow adequate sample-hold settling - 20 us acquisition time is recommended for 10 kohm source impedance. Use the internal Vref for ratio-metric measurements to avoid external reference noise coupling.
Compliance Information
RoHS status not confirmed in verified web data - marked [DATA_NEEDED]. Microchip PIC products are generally RoHS compliant via Pb-free matte-tin lead finish, but verify via the manufacturer's Certificate of Compliance before procurement. AEC-Q100 not qualified - PIC automotive parts carry a -I or -E automotive temperature grade suffix but are not formally AEC-Q100 unless explicitly noted.
