PIC16LC64A-04/PQ - 4MHz 8-bit OTP MCU, 3.5KB, 33 I/O | Microchip
MPN: PIC16LC64A-04/PQ ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $12.5 | $12.50 |
| 10 | $11.25 | $112.50 |
| 100 | $9.85 | $985.00 |
| 500 | $8.6 | $4,300.00 |
| 1,000 | $7.4 | $7,400.00 |
PIC16LC64A-04/PQ Overview
An 8-bit microcontroller (MCU) is a single-chip computer built around an 8-bit data path, ROM/Flash program memory, RAM, and peripherals such as timers, ADC, and communication interfaces. Within the broader taxonomy, the PIC16LC64A belongs to the PIC16 family -> 8-bit PIC microcontrollers -> microcontrollers -> embedded processors -> semiconductors. The 'LC' prefix denotes the low-power CMOS process variant, while the 'C' suffix historically marked the OTP (One-Time-Programmable) EPROM-based core that preceded Flash PICs. PIC16C/LC devices were widely deployed in the late 1990s and early 2000s in appliances, automotive body modules, and industrial control.
Key features include a RISC instruction set with only 35 single-word instructions (most single-cycle, branches two-cycle), 8-bit ALU, four interrupt sources, two 8-bit timers and one 16-bit timer/counter, and a 10-bit ADC (per datasheet family). Peripherals such as the USART, PSP (parallel slave port), and capture/compare/PWM modules make the PIC16LC64A suitable for mixed-signal embedded designs. The MQFP-44 (PQ) surface-mount package provides ample pin count for parallel bus expansion in legacy embedded systems.
Typical applications include industrial control panels, HVAC thermostats, automotive body electronics, consumer appliances, and legacy remote sensor/actuator nodes. The wide 3.0-5.5 V supply range allows direct connection to 5 V logic rails used in many industrial installations, while brown-out detect and watchdog timer add reliability for unattended deployments.
When designing with this device, account for the OTP memory constraint - code cannot be field-updated - and verify the 4 MHz maximum clock speed against timing requirements. Consider migrating to a Flash-based PIC16F or PIC18 successor for new designs.
Drop-in alternatives for PIC16LC64A-04/PQ — 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 PIC16LC64A-04/PQ (same form factor and footprint) — differing in Instruction Set, Program Memory Size, Core Architecture, Package, Peripherals.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LC64A-04I/PQ
✅ Drop-In✓ In Stock
$4.62 / Unit
View Datasheet →PIC16LC64AT-04I/PQ
✅ Drop-In✓ In Stock
$6.1 / Unit
View Datasheet →PIC16LC64A-04/L
✅ Drop-In✓ In Stock
$5.48 / Unit
View Datasheet →PIC16F877A-I/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LC64A-04/PQ Maximum Ratings & Electrical Characteristics
| Core Processor | PIC16 |
| Core Size | 8-bit |
| Maximum Clock Speed | 4 MHz |
| Program Memory Size | 3.5 KB (2K x 14) OTP |
| RAM Size | 128 bytes |
| Number of I/O Pins | 33 |
| Supply Voltage Range | 3.0 V to 5.5 V |
| Connectivity | I2C, SPI |
| Peripherals | Brown-out Detect/Reset, POR, PWM, WDT |
| Package | 44-pin MQFP (PQ) |
| Mounting Type | Surface Mount |
| Instruction Set | 35 single-word instructions, RISC |
| RoHS Status | unknown |
| Lifecycle Stage | Obsolete |
PIC16LC64A-04/PQ Pin Configuration
| Pin 1 | OSC1/CLKIN — Oscillator crystal input or external clock input |
| Pin 2 | OSC2/CLKOUT — Oscillator crystal output or clock output |
| Pin 3 | MCLR/VPP — Master clear reset (active low) / programming voltage input |
| Pin 4 | RA0/AN0 — PORTA bit 0 / Analog input 0 |
| Pin 5 | RA1/AN1 — PORTA bit 1 / Analog input 1 |
| Pin 6 | RA2/AN2 — PORTA bit 2 / Analog input 2 |
| Pin 7 | RA3/AN3/VREF — PORTA bit 3 / Analog input 3 / Voltage reference |
| Pin 8 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 9 | RA5/SS/AN4 — PORTA bit 5 / SPI slave select / Analog input 4 |
| Pin 10 | VSS — Ground reference |
| Pin 11 | VDD — Positive supply voltage |
| Pin 12 | RB0/INT — PORTB bit 0 / External interrupt |
| Pin 13 | RB1 — PORTB bit 1 |
| Pin 14 | RB2 — PORTB bit 2 |
| Pin 15 | RB3 — PORTB bit 3 |
| Pin 16 | RB4 — PORTB bit 4 |
| Pin 17 | RB5 — PORTB bit 5 |
| Pin 18 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 19 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 20 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 21 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 |
| Pin 22 | RC2/CCP1 — PORTC bit 2 / Capture/Compare/PWM1 |
| Pin 23 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 24 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 25 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 26 | RC6/TX/CK — PORTC bit 6 / USART TX / USART clock |
| Pin 27 | RC7/RX/DT — PORTC bit 7 / USART RX / USART data |
| Pin 28 | RE0/RD/AN5 — PORTE bit 0 / Parallel slave read / Analog input 5 |
| Pin 29 | RE1/WR/AN6 — PORTE bit 1 / Parallel slave write / Analog input 6 |
| Pin 30 | RE2/CS/AN7 — PORTE bit 2 / Parallel slave chip select / Analog input 7 |
| Pin 31 | VSS — Ground reference |
| Pin 32 | VDD — Positive supply voltage |
| Pin 33 | RD0/PSP0 — PORTD bit 0 / Parallel slave port bit 0 |
| Pin 34 | RD1/PSP1 — PORTD bit 1 / Parallel slave port bit 1 |
| Pin 35 | RD2/PSP2 — PORTD bit 2 / Parallel slave port bit 2 |
| Pin 36 | RD3/PSP3 — PORTD bit 3 / Parallel slave port bit 3 |
| Pin 37 | RD4/PSP4 — PORTD bit 4 / Parallel slave port bit 4 |
| Pin 38 | RD5/PSP5 — PORTD bit 5 / Parallel slave port bit 5 |
| Pin 39 | RD6/PSP6 — PORTD bit 6 / Parallel slave port bit 6 |
| Pin 40 | RD7/PSP7 — PORTD bit 7 / Parallel slave port bit 7 |
| Pin 41 | NC — Not connected (per datasheet) |
| Pin 42 | NC — Not connected (per datasheet) |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | NC — Not connected (per datasheet) |
Typical Applications
PIC16LC64A-04/PQ is suitable for 6 applications: Industrial Control Panels, HVAC Thermostats, Automotive Body Electronics, Consumer Appliance Controllers, Legacy Remote Sensor Nodes, Educational and Development Platforms.
Industrial Control Panels
The PIC16LC64A-04/PQ's 33 I/O pins and 3.0-5.5 V supply make it a strong fit for industrial control panels driving relays, sensors, and indicator lamps. With 33 I/O pins, the device can directly interface to a 4x4 matrix keypad, multiple LED status indicators, and several relay outputs without external glue logic. The integrated brown-out detect and watchdog timer add the field reliability required by unattended factory installations. Unlike Flash-based PIC16F parts, the OTP memory here locks firmware permanently - a fit for stable, validated production runs where code will not change. The 4 MHz clock provides adequate throughput for PLC-style scan loops up to a few hundred Hz.
Recommended
HVAC Thermostats
The PIC16LC64A-04/PQ's PWM peripherals, ADC channels, and wide 3.0-5.5 V operating range suit HVAC thermostat designs that must read temperature sensors and drive TRIAC-controlled heating/cooling stages. The 35-instruction RISC core executes scan loops quickly enough to handle multiple temperature zones with sub-second response. Brown-out detect prevents undefined behavior during brown-out events common in HVAC wiring. The 44-pin MQFP package provides ample I/O for keypad input, LCD interface, and relay outputs typical of programmable thermostats. The commercial temperature grade covers indoor HVAC environments; choose the '-I' industrial variant for outdoor installations.
Recommended
Automotive Body Electronics
The PIC16LC64A-04/PQ's PWM and WDT peripherals are well-matched to automotive body modules such as seat controllers, mirror adjusters, and lighting drivers. The I2C/SPI connectivity allows interfacing with body control networks and remote sensor clusters. The 33 I/O lines can drive multiple H-bridge outputs, LED arrays, and switch-scan matrices used in body modules. The 4 MHz clock is sufficient for body-control latency budgets in the 10-100 ms range. Choose the '-I' industrial grade variant for under-hood or cabin modules, and verify against AEC-Q100 requirements if automotive qualification is mandated.
Recommended
Consumer Appliance Controllers
The PIC16LC64A-04/PQ's 33 I/O and PWM make it a strong fit for consumer appliances such as washing machines, microwave ovens, and small kitchen devices. The PWM outputs can drive motor speed controls and heating element regulators, while the digital I/O reads button matrices and drives 7-segment or LCD displays. The integrated watchdog timer prevents lock-ups in unattended appliance operation. The 3.0-5.5 V supply matches the 5 V rails common in appliance power supplies. The OTP memory suits high-volume production runs where unit cost dominates and firmware is locked. The commercial temperature grade covers typical indoor appliance environments.
Recommended
Legacy Remote Sensor Nodes
The PIC16LC64A-04/PQ's I2C/SPI connectivity and 33 I/O enable legacy remote sensor nodes that aggregate multiple sensor types (temperature, humidity, pressure) over a serial backbone. With 33 I/O, the device can bit-bang multiple SPI or I2C peripherals simultaneously. The 128-byte RAM accommodates small sensor data buffers for polled acquisitions. Brown-out detect and watchdog timer add field reliability for battery or solar-powered deployments. The wide 3.0-5.5 V range simplifies power supply design from varied sources. The commercial temperature grade suits indoor installations; for outdoor, choose the '-I' variant.
Recommended
Educational and Development Platforms
The PIC16LC64A-04/PQ in MQFP-44 package remains in use in educational labs and legacy development platforms teaching 8-bit embedded design. The 35-instruction RISC core is small enough to master in a semester course, and the rich peripheral set (PWM, ADC, I2C, SPI, USART) provides hands-on exposure to embedded concepts. The MQFP-44 footprint is breadboard-friendly with adapter PCBs. The 4 MHz clock allows real-time debugging without timing surprises. Universities teaching PIC assembly can leverage the OTP variant to teach one-time-programming concepts, while students learning firmware iteration should migrate to PIC16F877A-I/PQ.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC64A-04/PQ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LC64A-04I/PQ | PIC16LC64AT-04I/PQ | PIC16LC64A-04/L | PIC16F877A-I/PQ |
|---|---|---|---|---|---|
| Package | MQFP-44 (PQ) | MQFP-44 (PQ) - same | MQFP-44 (PQ) - same | MQFP-44 (PQ) - same | MQFP-44 (PQ) - same |
| Brand | Microchip Technology | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same |
| Maximum Clock Speed | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 20 MHz (+400%) |
| Program Memory | 3.5 KB OTP | 3.5 KB OTP | 3.5 KB OTP | 3.5 KB OTP | 14 KB Flash (+300%) |
| RAM Size | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 368 bytes (+188%) |
| Temperature Grade | Commercial 0C to +70C | Industrial -40C to +85C | Industrial -40C to +85C | Commercial 0C to +70C (windowed) | Industrial -40C to +85C |
| Memory Type | OTP EPROM | OTP EPROM | OTP EPROM | Windowed EPROM (erasable) | Flash (reprogrammable) |
| I/O Pins | 33 | 33 | 33 | 33 | 33 |
| Supply Voltage Range | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 2.0 V to 5.5 V |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Active |
Key Differentiators
- Single best same-footprint industrial temp alternative (vs PIC16LC64A-04I/PQ)
- Field-reprogrammable upgrade path in same footprint (vs PIC16F877A-I/PQ)
- Windowed ceramic variant for development (vs PIC16LC64A-04/L)
Design Notes
OTP memory cannot be field-updated: the PIC16LC64A-04/PQ's One-Time-Programmable EPROM requires fully validated firmware before programming, since mistakes cannot be erased. For prototypes or evolving code, use a windowed ceramic variant (PIC16LC64A-04/L) or migrate to a Flash-based PIC16F877A-I/PQ. Plan for a final ROM mask revision if your design goes to high volume.
Brown-out detect (BOD) must be enabled in configuration fuses to protect against undefined behavior at low VDD. The PIC16LC64A-04/PQ BOD threshold is configurable; for 5 V systems set BOR to 4.0 V, for 3.3 V systems set BOR to 2.7 V. Add a 100 nF decoupling capacitor close to each VDD pin (pins 11 and 32) and a bulk 10 uF tantalum on the supply rail.
The 44-pin MQFP package has 0.8 mm lead pitch; PCB land pattern requires fine-pitch SMT assembly with solder paste stencil and reflow profile. Pin 1 is identified by the dot marker on the package top; orient the IC so that pin 1 aligns with the PCB silkscreen. The exposed pad (if present) should be soldered to a ground copper pour for thermal dissipation and ground return.
Keep the OSC1/OSC2 crystal traces short and symmetrical to minimize stray capacitance; place load capacitors (typically 15-33 pF) as close to the oscillator pins as possible. Route MCLR/VPP separately from digital switching signals to avoid spurious resets. For noise-sensitive ADC applications, separate analog AVdd/AVss pins (if used) from digital VDD/VSS with a ferrite bead.
Compliance Information
Lifecycle: obsolete per Microchip. RoHS/REACH compliance not explicitly stated in retrieved data; pre-2010 PIC16C/LC parts may use tin-lead finish. AEC-Q100 not qualified. Verify with manufacturer for new automotive applications.
