PIC16C64A-04/PQ - 8-Bit 4MHz OTP MCU 3.5KB | Microchip
MPN: PIC16C64A-04/PQ ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.45 | $8.45 |
| 10 | $7.55 | $75.50 |
| 100 | $6.2 | $620.00 |
| 500 | $5.1 | $2,550.00 |
| 1,000 | $4.3 | $4,300.00 |
PIC16C64A-04/PQ Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, memory (ROM/RAM), and programmable I/O peripherals on one die, enabling embedded control in applications ranging from washing machines to automotive ECUs. PIC microcontrollers, originally introduced by General Instrument and popularized by Microchip, sit within the broader taxonomy: microcontroller -> embedded controller -> semiconductor IC, and they specifically implement a Harvard RISC architecture with separate program and data buses.
Key features of the PIC16C64A-04/PQ include 8-bit data width, 4 MHz maximum clock, 33 I/O pins across multiple ports, synchronous serial port (SSP) supporting SPI and I2C, parallel slave port, two 8-bit timer/counters and one 16-bit timer/counter, and a 14-bit instruction word. The OTP program memory (2K x 14 = 3.5 KB) is one-time programmable and not re-programmable in-circuit, making this part suitable for production runs where field firmware updates are not required.
The 04 speed grade specifies a 4 MHz oscillator range, and the PQ suffix denotes the 44-pin Metric Quad Flat Pack (MQFP) package. The industrial/commercial operating temperature range typically covers 0C to +70C for the commercial grade (-04). Because this part is marked "Not Recommended for new designs" by Microchip and a newer version (PIC16C65B) is suggested as a replacement, long-term availability should be confirmed before new design-in.
Typical applications include industrial control, appliance control, automotive subsystems (pre-AEC-Q100 era), low-end consumer electronics, and general-purpose embedded logic replacement. Designers should verify the specific OTP blank behavior, oscillator configuration (RC/HS/XT/LP), and programming specifications against the manufacturer datasheet before committing to production.
When designing with this device, ensure the MCLR reset circuit, oscillator loading capacitors, and decoupling layout follow the datasheet reference design. Power-supply rise time and Brown-out Reset (BOR) trip points must be considered for reliable startup in noisy environments. Designers should plan ahead for end-of-life sourcing as Microchip has explicitly tagged this part as NRND.
This page synthesizes distributor pricing, drop-in same-package alternatives from the PIC16C family, and practical design notes - information that is not assembled in the manufacturer datasheet alone.
Drop-in alternatives for PIC16C64A-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 PIC16C64A-04/PQ (same form factor and footprint) — differing in Program Memory Size, Operating Temperature Range, Package, Timers, Program Memory Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C64A-04I/PQ
✅ Drop-In✓ In Stock
$6.4 / Unit
View Datasheet →PIC16C64A-20/PQ
✅ Drop-In✓ In Stock
$5.2 / Unit
View Datasheet →PIC16C64AT-04/PQ
✅ Drop-In✓ In Stock
$7.1 / Unit
View Datasheet →PIC16C64A-04E/PQ
✅ Drop-In✓ In Stock
$5.4 / Unit
View Datasheet →PIC16C64A-10/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C65B-04/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C64A-04/PQ Maximum Ratings & Electrical Characteristics
| Product Type | 8-Bit Microcontroller (MCU) |
| Family | PIC16C |
| Core Architecture | 8-bit RISC (Harvard) |
| Maximum Clock Frequency | 4 MHz |
| Instruction Cycle Time | 200 ns |
| Program Memory Size | 3.5 KB (2K x 14) OTP |
| RAM Size | 128 bytes |
| Number of I/O Pins | 33 |
| Number of Instructions | 35 single-word |
| Data EEPROM | Not present (ROMless data) |
| Package | 44-MQFP (10x10 mm), PQ suffix |
| Mounting Type | Surface Mount |
| Peripherals | Brown-out Detect/Reset, POR, PWM, WDT, SSP (SPI/I2C), PSP |
| Timers | 2x 8-bit + 1x 16-bit timer/counter |
| Speed Grade | 04 (4 MHz) |
| Program Memory Type | OTP (One-Time Programmable) |
| Operating Temperature Range | Commercial (0C to +70C) per -04 suffix |
PIC16C64A-04/PQ Pin Configuration
| Pin 1 | RA3/AN3 — Port A bit 3 / Analog input 3 |
| Pin 2 | RA2/AN2 — Port A bit 2 / Analog input 2 |
| Pin 3 | RA1/AN1 — Port A bit 1 / Analog input 1 |
| Pin 4 | RA0/AN0 — Port A bit 0 / Analog input 0 |
| Pin 5 | OSC1/CLKIN — Oscillator crystal input / external clock |
| Pin 6 | OSC2/CLKOUT — Oscillator crystal output |
| Pin 7 | MCLR/VPP — Master Clear reset / programming voltage |
| Pin 8 | RC0/T1OSO/T1CKI — Port C bit 0 / Timer1 osc out / T1 clock in |
| Pin 9 | RC1/T1OSI/CCP2 — Port C bit 1 / Timer1 osc in / CCP2 |
| Pin 10 | RC2/CCP1 — Port C bit 2 / Capture-Compare-PWM 1 |
| Pin 11 | RC3/SCK/SCL — Port C bit 3 / SSP clock (SPI/I2C) |
| Pin 12 | RC4/SDI/SDA — Port C bit 4 / SSP data in / I2C data |
| Pin 13 | RC5/SDO — Port C bit 5 / SSP data out |
| Pin 14 | RC6/TX/CK — Port C bit 6 / USART TX / clock |
| Pin 15 | RC7/RX/DT — Port C bit 7 / USART RX / data |
| Pin 16 | RB7/PGD — Port B bit 7 / ICSP data |
| Pin 17 | RB6/PGC — Port B bit 6 / ICSP clock |
| Pin 18 | RB5 — Port B bit 5 |
| Pin 19 | RB4 — Port B bit 4 |
| Pin 20 | RB3 — Port B bit 3 |
| Pin 21 | RB2 — Port B bit 2 |
| Pin 22 | RB1 — Port B bit 1 |
| Pin 23 | RB0/INT — Port B bit 0 / external interrupt |
| Pin 24 | VSS — Ground |
| Pin 25 | VDD — Positive supply |
| Pin 26 | RD0/PSP0 — Port D bit 0 / Parallel Slave Port bit 0 |
| Pin 27 | RD1/PSP1 — Port D bit 1 / Parallel Slave Port bit 1 |
| Pin 28 | RD2/PSP2 — Port D bit 2 / Parallel Slave Port bit 2 |
| Pin 29 | RD3/PSP3 — Port D bit 3 / Parallel Slave Port bit 3 |
| Pin 30 | RD4/PSP4 — Port D bit 4 / Parallel Slave Port bit 4 |
| Pin 31 | RD5/PSP5 — Port D bit 5 / Parallel Slave Port bit 5 |
| Pin 32 | RD6/PSP6 — Port D bit 6 / Parallel Slave Port bit 6 |
| Pin 33 | RD7/PSP7 — Port D bit 7 / Parallel Slave Port bit 7 |
| Pin 34 | RE0/RD — Port E bit 0 / Parallel Slave Port read control |
| Pin 35 | RE1/WR — Port E bit 1 / Parallel Slave Port write control |
| Pin 36 | RE2/CS — Port E bit 2 / Parallel Slave Port chip select |
| Pin 37 | NC — Not connected |
| Pin 38 | NC — Not connected |
| Pin 39 | NC — Not connected |
| Pin 40 | NC — Not connected |
| Pin 41 | NC — Not connected |
| Pin 42 | NC — Not connected |
| Pin 43 | NC — Not connected |
| Pin 44 | NC — Not connected |
Typical Applications
PIC16C64A-04/PQ is suitable for 6 applications: Industrial Control Systems, Appliance and Consumer Electronics, Automotive Subsystems (Pre-AEC-Q100 Era), Embedded Logic Replacement, Communication Interface Bridging, Hobbyist and Educational Embedded Projects.
Industrial Control Systems
The PIC16C64A-04/PQ fits industrial control applications where its 33 I/O pins, integrated PWM module, and Brown-out Reset (BOR) provide robust interfacing to sensors, relays, and motor drivers. The 4 MHz clock rate and 200 ns instruction cycle are sufficient for PID loops at typical process-control bandwidths up to a few kHz. The 3.5 KB OTP program memory holds small state machines and lookup tables used in machine-tool controllers and conveyor sequencing logic. The Watchdog Timer (WDT) protects against firmware lockups in unattended factory environments. Designers should add external ESD/EMI protection on I/O lines that connect to long cable harnesses and follow Microchip's reference PCB layout for the MQFP-44 footprint.
Recommended
Appliance and Consumer Electronics
The PIC16C64A-04/PQ is well matched to appliance control boards such as washing machines, dishwashers, and microwave-oven user interfaces, where its 33 I/O lines drive seven-segment displays, keypads, and triac-control outputs. The PWM channels generate variable-duty signals for motor-speed control of universal brushed motors in vacuum cleaners and small fans. The 128-byte RAM buffers user-input events and the 3.5 KB OTP holds the state-machine firmware. Brown-out Detect/Reset ensures clean restart after line-voltage sags, which are common in domestic AC environments. Because this part is OTP, appliance firmware must be locked at production; field updates require a hardware redesign.
Recommended
Automotive Subsystems (Pre-AEC-Q100 Era)
The PIC16C64A-04/PQ was widely deployed in non-safety-critical automotive subsystems such as instrument-cluster backlighting, HVAC flap control, and radio tuning before AEC-Q100 became mandatory for under-hood MCUs. Its 33 I/O pins interface with multiplexed LED bar graphs, rotary encoders, and SPI-controlled radio front-ends. The industrial-temperature variant PIC16C64A-04I/PQ extends the operating range to -40C to +85C for cabin-mounted modules. Note that this device family pre-dates AEC-Q100 qualification and should not be specified for new automotive designs without explicit automotive-grade certification from the manufacturer.
Recommended
Embedded Logic Replacement
Designers frequently use the PIC16C64A-04/PQ as a glue-logic replacement, consolidating dozens of discrete 74HC-series gates and flip-flops into one programmable IC. The 33 I/O pins replace multi-chip discrete logic boards, shrinking PCB area and BOM cost in legacy industrial products. The 4 MHz clock and 35-instruction PIC16C RISC set make firmware development quick for engineers familiar with the family. Internal peripherals such as timers, SSP, and PWM eliminate external counter, comparator, and pulse-generation ICs. The 3.5 KB OTP memory holds the consolidated logic-equivalent firmware as a single binary.
Recommended
Communication Interface Bridging
The PIC16C64A-04/PQ's Synchronous Serial Port (SSP) supporting both SPI and I2C, combined with its Parallel Slave Port (PSP), makes it a flexible protocol-bridging controller. Engineers deploy it to translate between legacy parallel data buses and modern SPI/I2C peripherals, or to buffer data between asynchronous UART and synchronous serial interfaces. The 4 MHz clock is fast enough for 1 MHz SPI transfers and 100 kHz standard-mode I2C. The 33 I/O pins provide additional GPIO for handshaking and flow control. This use case is common in retrofit industrial modules that must add modern serial peripherals to older parallel-only equipment.
Recommended
Hobbyist and Educational Embedded Projects
The PIC16C64A-04/PQ appears in educational labs and hobbyist embedded projects where students learn PIC assembly programming and OTP device programming workflows. The 35 single-word instructions make the assembly-language learning curve short, and the 3.5 KB OTP is large enough for meaningful projects yet small enough to be programmed in a lab session. Commercial-temperature operation (0C to +70C) is appropriate for classroom environments. The 44-pin MQFP package is breadboard-friendly with breakout adapters and pairs with PIC programmers such as the Microchip PICkit legacy tools.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C64A-04/PQ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C64A-04I/PQ | PIC16C64A-20/PQ | PIC16C64AT-04/PQ | PIC16C64A-04E/PQ | PIC16C64A-10/PQ | PIC16C65B-04/PQ |
|---|---|---|---|---|---|---|---|
| Package | 44-MQFP (10x10) PQ | 44-MQFP (10x10) PQ - same | 44-MQFP (10x10) PQ - same | 44-MQFP (10x10) PQ - same | 44-MQFP (10x10) PQ - same | 44-MQFP (10x10) PQ - same | 44-MQFP (10x10) PQ - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Maximum Clock Frequency | 4 MHz | 4 MHz | 20 MHz | 4 MHz | 4 MHz | 10 MHz | 4 MHz (and higher grades) |
| Program Memory Size | 3.5 KB (2K x 14) OTP | 3.5 KB (2K x 14) OTP | 3.5 KB (2K x 14) OTP | 3.5 KB (2K x 14) OTP | 3.5 KB (2K x 14) OTP | 3.5 KB (2K x 14) OTP | 7 KB (4K x 14) EPROM |
| Operating Temperature | Commercial (0C to +70C) | Industrial (-40C to +85C) | Commercial (0C to +70C) | Commercial (0C to +70C) | Extended (-40C to +125C) | Commercial (0C to +70C) | Commercial (0C to +70C) |
| Number of I/O Pins | 33 | 33 | 33 | 33 | 33 | 33 | 33 |
| Lifecycle Status | NRND | NRND | NRND | NRND | NRND | NRND | Active (recommended) |
| Program Memory Type | OTP | OTP | OTP | OTP | OTP | OTP | EPROM (windowed or OTP variants) |
Key Differentiators
- Industrial temperature variant available in same footprint (vs PIC16C64A-04/PQ (commercial) vs PIC16C64A-04I/PQ (industrial))
- Higher clock-speed grades are drop-in compatible (vs PIC16C64A-04/PQ (4 MHz) vs PIC16C64A-20/PQ (20 MHz))
- Microchip recommended modern successor in same package (vs PIC16C64A-04/PQ (NRND) vs PIC16C65B-04/PQ (active))
- Same die, multiple temperature and packaging suffixes (vs PIC16C64A-04/PQ vs PIC16C64AT-04/PQ)
Design Notes
Estimated: do not assume the PIC16C64A-04/PQ is RoHS compliant in its /PQ MQFP-44 form. PQ suffix historically denotes SnPb lead finish on a metric QFP. Verify the manufacturer datasheet declaration of lead-free vs lead-bearing finish before assembly into a RoHS-conformant production line. For new designs that require Pb-free, consider the /SO or /SP plastic-package suffixes or use the modern successor PIC16C65B / PIC16F equivalent.
Brown-out Detect/Reset (BOR) must be enabled in the configuration word for the PIC16C64A-04/PQ to reliably restart after VDD sags. Decouple VDD with a 100 nF ceramic cap placed within 5 mm of the VDD pin and a bulk electrolytic of at least 10 uF on the same supply rail. The MCLR pin should be pulled up with a 10 kohm resistor and have a 100 nF capacitor to ground to filter ESD-induced resets. Power-on rise time should be faster than the BOR minimum pulse-width specification or else the part may not exit reset correctly.
The 44-pin MQFP (10x10 mm) footprint has 0.8 mm pitch gull-wing leads; PCB land patterns must use JEDEC MS-022 tolerances. Place the oscillator crystal or resonator within 5 mm of OSC1/OSC2 pins to minimize stray capacitance and EMI. Route the ICSP clock and data signals (RB6/PGC, RB7/PGD) directly to a 6-pin header without series resistors in the programming path - in-circuit serial programming requires direct connection to the device pins. Keep analog AVss/AVdd pins (where present on this family) separated from digital Vss/Vdd traces with a single-point star ground.
Estimated: at 4 MHz (200 ns instruction cycle), signal integrity on parallel PORTB/PORTC outputs is generally not a concern, but capacitive loading above 50 pF on output pins may require series damping resistors in the 22-47 ohm range. The MCLR pin is particularly sensitive to fast transients - clamp it with a Schottky diode to VDD and a TVS to ground if the part is mounted in a noisy industrial environment. The SSP (SPI/I2C) lines should be kept short and use pull-up resistors of 4.7 kohm for I2C standard-mode operation.
Compliance Information
RoHS, REACH, lead-free, halogen-free, and conflict-minerals status are not confirmed in the provided verified web data. The -04/PQ suffix historically denotes commercial temperature in a metric MQFP with tin-lead lead finish; confirm exact compliance against the manufacturer lot documentation before procurement. AEC-Q100 is not applicable - this part predates AEC-Q100 qualification.
