PIC16C65B-04E/L - 8-Bit CMOS OTP MCU, 4MHz, 7KB | Microchip
MPN: PIC16C65B-04E/L ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $18.5 | $18.50 |
| 10 | $16.25 | $162.50 |
| 100 | $13.95 | $1,395.00 |
| 500 | $12.4 | $6,200.00 |
| 1,000 | $10.85 | $10,850.00 |
PIC16C65B-04E/L Overview
What is an 8-bit OTP microcontroller? An 8-bit OTP microcontroller is a single-chip computer that integrates a CPU, program memory, RAM, and peripherals into one package. OTP memory (One-Time-Programmable) uses EPROM cells that can be written once by the user, distinguishing it from Flash (re-programmable) and ROM (factory-masked) variants. The PIC16C65B belongs to the mid-range PIC16 family (PIC16C6x sub-family), which sits between the baseline PIC16C5x and the enhanced PIC16C7x families. It is classified as an embedded microcontroller under the broader category of microcontrollers, embedded processors, and integrated circuits.
Key features include 192 bytes of data RAM, a hardware USART for serial communications, two analog comparators, a programmable Watchdog Timer with on-chip RC oscillator, power-saving Sleep mode, in-circuit serial programming (ICSP) capability, and brown-out reset protection. The 33 I/O pins can each source/sink up to 25 mA, making them capable of directly driving LEDs and small relays. The 5-channel 8-bit ADC is suitable for slow-changing analog signals such as sensor monitoring.
Technically, the PIC16C65B uses a RISC architecture with 35 single-word instructions, a 14-bit instruction word, and a 2-stage pipeline, achieving execution rates close to one instruction per clock cycle at 4 MHz. Its CMOS EPROM/ROM technology yields typical active current around 2 mA at 4 MHz / 5 V and as low as 1 uA at 3 V / 32 kHz in Sleep mode. The 44-pin PLCC package is a JEDEC-standard surface-mount ceramic carrier that has been widely used in industrial through-hole-replacement designs.
Typical applications include industrial process control, instrumentation, motor control interfaces, sensor signal conditioning, embedded control modules, and older telecom peripherals. The wide voltage range (2.5 V to 6.0 V) and Extended temperature rating make it suited to harsh-environment industrial equipment.
When designing with this part, note that OTP memory cannot be erased, so firmware must be 100% verified before programming. A ceramic PLCC socket should be used if field updates are needed. Decoupling capacitors (0.1 uF) must be placed close to VDD/VSS pins, and unused I/O should be configured as outputs to minimize current draw.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16C65B-04E/L — 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 PIC16C65B-04E/L (same form factor and footprint) — differing in Package, Program Memory Type, Timers, Mounting Type, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C65B-04/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C65B-04I/L
✅ Drop-In✓ In Stock
$5.3 / Unit
View Datasheet →PIC16C65B-04I/PQ
✅ Drop-In✓ In Stock
$5.45 / Unit
View Datasheet →PIC16C65B-04E/PQ
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$11.1 / Unit
View Datasheet →PIC16F877A-I/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C65A-04E/L
✅ Drop-In✓ In Stock
$11.2 / Unit
View Datasheet →PIC16C65B-04E/L Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC mid-range (RISC) |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 7 KB (4K x 14) |
| Data RAM | 192 bytes |
| Maximum CPU Frequency | 4 MHz |
| Operating Voltage Range | 2.5 V to 6.0 V |
| Digital I/O Pins | 33 |
| I/O Source/Sink Current | 25 mA per pin |
| Timers | 3 x 8-bit Timer/Counter |
| CCP Modules | 2 (Capture/Compare/PWM) |
| ADC | 5-channel, 8-bit |
| Communication Peripherals | USART, I2C/SPI synchronous serial port |
| Comparators | 2 analog comparators |
| Watchdog Timer | Yes, with on-chip RC oscillator |
| Brown-out Reset | Yes |
| In-Circuit Serial Programming (ICSP) | Yes |
| Instruction Set | 35 single-word instructions, 14-bit width |
| Package | 44-pin PLCC (L) |
| Operating Temperature Range | -40 C to +125 C (Extended) |
| Mounting Type | Surface Mount (PLCC socket recommended for OTP) |
PIC16C65B-04E/L Pin Configuration
| Pin 1 | OSC1/CLKIN — Oscillator crystal input or external clock input |
| Pin 2 | RA0/AN0 — Digital I/O / ADC analog input 0 |
| Pin 3 | RA1/AN1 — Digital I/O / ADC analog input 1 |
| Pin 4 | RA2/AN2 — Digital I/O / ADC analog input 2 |
| Pin 5 | RA3/AN3/VREF — Digital I/O / ADC analog input 3 / ADC reference voltage |
| Pin 6 | RA4/T0CKI — Digital I/O / Timer 0 clock input |
| Pin 7 | RA5/AN4/SS — Digital I/O / ADC analog input 4 / SPI slave select |
| Pin 8 | RE0/RD/AN5 — Digital I/O / Parallel Slave Port read / ADC input 5 |
| Pin 9 | RE1/WR/AN6 — Digital I/O / Parallel Slave Port write / ADC input 6 |
| Pin 10 | RE2/CS/AN7 — Digital I/O / Parallel Slave Port chip select / ADC input 7 |
| Pin 11 | VDD — Positive logic supply voltage |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC2/CLKOUT — Oscillator crystal output / clock output |
| Pin 14 | RC0/T1OSO/T1CKI — Digital I/O / Timer 1 oscillator output / clock input |
| Pin 15 | RC1/T1OSI/CCP2 — Digital I/O / Timer 1 oscillator input / CCP2 I/O |
| Pin 16 | RC2/CCP1 — Digital I/O / CCP1 I/O |
| Pin 17 | RC3/SCK/SCL — Digital I/O / SPI clock / I2C clock |
| Pin 18 | RC4/SDI/SDA — Digital I/O / SPI data in / I2C data |
| Pin 19 | RC5/SDO — Digital I/O / SPI data out |
| Pin 20 | RC6/TX/CK — Digital I/O / USART async transmit or sync clock |
| Pin 21 | RC7/RX/DT — Digital I/O / USART async receive or sync data |
| Pin 22 | RD0/PSP0 — Digital I/O / Parallel Slave Port bit 0 |
| Pin 23 | RD1/PSP1 — Digital I/O / Parallel Slave Port bit 1 |
| Pin 24 | RD2/PSP2 — Digital I/O / Parallel Slave Port bit 2 |
| Pin 25 | RD3/PSP3 — Digital I/O / Parallel Slave Port bit 3 |
| Pin 26 | RD4/PSP4 — Digital I/O / Parallel Slave Port bit 4 |
| Pin 27 | RD5/PSP5 — Digital I/O / Parallel Slave Port bit 5 |
| Pin 28 | RD6/PSP6 — Digital I/O / Parallel Slave Port bit 6 |
| Pin 29 | RD7/PSP7 — Digital I/O / Parallel Slave Port bit 7 |
| Pin 30 | VSS — Ground reference |
| Pin 31 | VDD — Positive logic supply voltage |
| Pin 32 | RB0/INT — Digital I/O / External interrupt input |
| Pin 33 | RB1 — Digital I/O |
| Pin 34 | RB2 — Digital I/O |
| Pin 35 | RB3 — Digital I/O |
| Pin 36 | RB4 — Digital I/O |
| Pin 37 | RB5 — Digital I/O |
| Pin 38 | RB6/PGC — Digital I/O / ICSP clock |
| Pin 39 | RB7/PGD — Digital I/O / ICSP data |
| Pin 40 | MCLR/VPP — Master clear reset / programming voltage |
| 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
PIC16C65B-04E/L is suitable for 6 applications: Industrial Process Controllers, Embedded Sensor Interface Modules, Motor Control and PWM Drivers, Instrumentation Front Panels, Telecom Peripheral and Legacy Interface Cards, Automotive Body Control Modules (Legacy).
Industrial Process Controllers
The PIC16C65B-04E/L is well suited for industrial process controllers thanks to its 5-channel 8-bit ADC for sensor inputs (temperature, pressure, flow), 33 digital I/O lines rated 25 mA for direct relay and solenoid drive, and Extended temperature rating (-40C to +125C) for harsh factory-floor environments. The hardware USART provides robust RS-232/485 comms to a central PLC or HMI panel. Compared to a switching-power design, the PIC16C65B's 2.5 V to 6.0 V supply range allows direct operation from 24 V industrial bus rails via a simple linear regulator, simplifying BOM. The 7 KB OTP program memory is ample for typical PID loop, sequencing, and alarm logic code. Real-world deployments include motor starters, conveyor controllers, and valve actuation modules where OTP security is acceptable.
Recommended
Embedded Sensor Interface Modules
Sensor interface modules benefit from the PIC16C65B-04E/L's combination of 5-channel 8-bit ADC, two analog comparators for threshold detection, I2C/SPI synchronous serial port for digital sensors, and 192 bytes of data RAM for buffering samples. At a 4 MHz CPU clock the device can sample at rates up to ~50 kS/s, which is more than sufficient for thermocouple, RTD, and load-cell conditioning. The PIC16C65B's hardware USART allows the module to forward processed data to a host controller over RS-485. The Extended temperature rating ensures stable operation in outdoor enclosures. Compared to baseline PIC16C5x parts, this PIC16C6x adds the CCP/PWM peripherals that drive indicator LED brightness or PWM-controlled fan speeds in sensor hubs.
Recommended
Motor Control and PWM Drivers
The PIC16C65B-04E/L's two Capture/Compare/PWM (CCP) modules, three 8-bit timers, and 33 high-current (25 mA) I/O pins make it a viable controller for low-to-medium power brushed DC motor drivers, stepper motor sequencers, and PWM-controlled fan or pump speed regulators. The 4 MHz clock combined with the 8-bit PWM resolution yields ~15.6 kHz PWM frequency at 8-bit duty, well above the audible band. The two analog comparators can be used for current sensing via shunt resistors, enabling closed-loop current limiting. Compared to discrete analog PWM circuits, the PIC16C65B-based design offers firmware-reprogrammable (during OTP blank-check stage) duty cycles and fault handling in a 16.59 x 16.59 mm PLCC footprint suitable for space-constrained driver boards.
Recommended
Instrumentation Front Panels
Instrumentation front panels - including bench meters, data loggers, and lab instrument controllers - leverage the PIC16C65B-04E/L's USART for SCPI-style command interfaces, 33 I/O pins for keypad scanning and 7-segment LCD/LED multiplexing, and CCP modules for tone generation or PWM-driven backlight brightness. The 7 KB OTP memory holds menu structures, calibration tables, and command parsers comfortably. Extended temperature rating suits laboratory cold-room or industrial oven instrumentation. Compared to a discrete 8051 design, the PIC16C65B's single-cycle 35-instruction RISC core simplifies C compiler code density and reduces firmware development time.
Recommended
Telecom Peripheral and Legacy Interface Cards
Legacy telecom peripheral cards, including ISDN terminal adapters, PBX line cards, and serial-port multiplexer blades, have historically used the PIC16C65B-04E/L due to its hardware USART, I2C/SPI master capability for peripheral control, and 33 I/O for parallel bus glue logic. The Extended temperature rating covers outdoor cabinet and central-office thermal environments. The 2.5 V to 6.0 V supply range supports both -48 V telecom bus-derived rails and standard 5 V logic rails. Compared to newer ARM Cortex-M0 parts, the PIC16C65B's mature toolchain (MPLAB, MPASM, Hi-Tech PICC) preserves installed firmware bases - critical when redesign certification costs are prohibitive.
Recommended
Automotive Body Control Modules (Legacy)
Pre-CAN automotive body control modules - including window lifters, mirror controllers, and seat adjusters - adopted the PIC16C65B-04E/L for its 33 I/O lines capable of directly driving small relays and LEDs, two CCP modules for PWM mirror-fold and seat-motor control, and 5-channel ADC for switch and potentiometer feedback. The Extended temperature rating covers under-dash automotive thermal cycles (-40C to +125C). The hardware USART interfaces with body-control gateways over LIN or K-Line protocols via external transceivers. Compared to modern PIC18 or dsPIC parts, the PIC16C65B's mature OTP-proven firmware base supports long-lifecycle vehicle platforms where redesign is uneconomical.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C65B-04E/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C65B-04/L | PIC16C65B-04I/L | PIC16F877A-I/L | PIC16C65A-04E/L |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-pin PLCC (L) | 44-pin PLCC (L) - same | 44-pin PLCC (L) - same | 44-pin PLCC (L) - same | 44-pin PLCC (L) - same |
| Program Memory Type | OTP EPROM, 7 KB | OTP EPROM, 7 KB - same | OTP EPROM, 7 KB - same | Flash, 14 KB | OTP EPROM, 7 KB - same |
| Maximum CPU Frequency | 4 MHz | 4 MHz - same | 4 MHz - same | 20 MHz | 4 MHz - same |
| Data RAM | 192 bytes | 192 bytes - same | 192 bytes - same | 368 bytes | 192 bytes - same |
| ADC | 5-channel, 8-bit | 5-channel, 8-bit - same | 5-channel, 8-bit - same | 8-channel, 10-bit | 5-channel, 8-bit - same |
| Digital I/O Pins | 33 | 33 - same | 33 - same | 33 - same | 33 - same |
| Operating Temperature Range | -40C to +125C (Extended) | 0C to +70C (Commercial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +125C (Extended) - same |
| USART | Yes | Yes - same | Yes - same | Yes | Yes - same |
Key Differentiators
- OTP EPROM memory security at production cost (vs PIC16F877A-I/L)
- Extended temperature grade to +125C (vs PIC16C65B-04/L)
- Parallel Slave Port (PSP) on PORTD (vs PIC16C65A-04E/L)
Design Notes
OTP (One-Time-Programmable) EPROM memory cannot be erased after programming - a single bit error or final code bug means the entire PIC16C65B-04E/L unit must be discarded. Best practice is to prototype and fully verify firmware on a PIC16F877A-I/L (same 44-pin PLCC footprint, Flash memory) and migrate the final lock-step firmware to the OTP part only after production sign-off. This avoids the USD 10-18 unit cost penalty of OTP mis-programming and the lead-time risk of re-stocking.
Place a 0.1 uF decoupling capacitor as close as possible to each VDD/VSS pin combination (pins 11/12 and pins 30/31 on the 44-PLCC). Add a bulk 10 uF tantalum or aluminum capacitor at the supply entry. The PIC16C65B's two VDD/VSS pin pairs are not internally shorted on all silicon revisions; routing both pairs to the same supply plane with vias under the PLCC socket is recommended. Keep the OSC1/OSC2 traces short and guard the crystal with a ground ring to reduce EMI susceptibility.
The PIC16C65B-04E/L draws approximately 2 mA active at 5 V / 4 MHz and as little as 1 uA in Sleep mode at 3 V / 32 kHz, but its brown-out reset threshold is approximately 4.0 V (VBOR). For industrial 24 V bus operation, use a low-dropout regulator (e.g., MIC29150-05) with proper input filtering to keep VDD above VBOR during load transients. The MCLR pin (pin 40) must be pulled up to VDD through a 10 kohm resistor and a 100 nF capacitor for noise-free reset behavior.
Compliance Information
Compliance status for PIC16C65B-04E/L not present in Verified Web Data. As an NRND OTP part from the early 2000s, lead-free / RoHS status should be verified against the manufacturer lot-level documentation before use in new designs requiring modern environmental compliance.
