PIC16C65B-04E/P - 8-bit 4MHz OTP MCU 7KB Flash 40-PDIP | Microchip
MPN: PIC16C65B-04E/P ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.85 | $7.85 |
| 10 | $7.2 | $72.00 |
| 100 | $6.55 | $655.00 |
| 500 | $5.95 | $2,975.00 |
| 1,000 | $5.45 | $5,450.00 |
PIC16C65B-04E/P Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, working RAM, and peripherals into one device. The PIC16C family uses Microchip's RISC architecture with 35 single-word instructions and a 200 ns instruction cycle, simplifying code development for embedded designers. Within the broader taxonomy, the PIC16C65B belongs to the 8-bit microcontroller class, which sits below 16-bit and 32-bit MCUs in performance but offers the lowest cost and lowest power for control-oriented tasks.
Key features of the PIC16C65B include 33 digital I/O pins, two 8-bit and one 16-bit timer/counter modules, a USART/SCI serial port, an MSSP module supporting SPI and I2C, a 5-channel 8-bit ADC, and a parallel slave port. Power consumption is exceptionally low: typical supply current is 15 µA at 5 V / 4 MHz and only 1 µA at 3 V / 32 kHz, making it well-suited to battery-backed applications. The operating voltage range extends up to 6.0 V, supporting both 3.3 V and 5 V rails.
The PIC16C65B uses a Harvard architecture with separate program and data buses, an internal 14-bit instruction word, and a hardware stack eight levels deep. Its peripherals are mapped into a single data-memory space and addressed via bank-switching registers, a common PIC16 architectural pattern. Interrupt handling supports both core and peripheral sources, with configurable priority and wake-up from sleep on selected edges.
Typical applications for the PIC16C65B-04E/P include industrial control systems, sensor signal conditioning, low-power remote sensor nodes, motor-control front ends, embedded automotive subsystems (non-safety-critical), and legacy equipment retrofits. Its Extended temperature grade makes it especially suitable for outdoor, automotive under-hood, and factory-floor deployments where Commercial-grade parts would otherwise be inadequate.
When designing with this device, note that OTP memory cannot be re-programmed in-circuit; firmware must be verified before programming. Decoupling capacitors (typically 100 nF plus a 10 µF bulk) must be placed within a few millimeters of VDD/VSS, and unused I/O pins should be configured as outputs low or inputs with pull-ups to minimize sleep current and EMI susceptibility.
This page synthesizes XAIPART distributor pricing, Extended-temperature drop-in alternatives from the same PIC16CXX family, and practical design notes that are not found in the standalone manufacturer datasheet.
Drop-in alternatives for PIC16C65B-04E/P — 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/P (same form factor and footprint) — differing in Core Architecture, Package, Mounting Type, Timers, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C65B-04I/P
✅ Drop-In✓ In Stock
$3.75 / Unit
View Datasheet →PIC16C65B-04E/L
✅ Drop-In✓ In Stock
$10.85 / Unit
View Datasheet →PIC16C65A-20I/P
✅ Drop-In✓ In Stock
$6.08 / Unit
View Datasheet →PIC16F877A-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C65B-04E/P Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC16 RISC (Harvard) |
| Program Memory Type | OTP EPROM/ROM |
| Program Memory Size | 7 KB (4K x 14 words) |
| RAM | 192 bytes |
| Maximum CPU Frequency | 4 MHz |
| Instruction Cycle | 200 ns |
| Instruction Set Size | 35 single-word instructions |
| Supply Voltage Range | 2.5 V to 6.0 V |
| I/O Pins | 33 |
| Timers | Two 8-bit + one 16-bit Timer/Counter |
| ADC | 5 channels x 8-bit |
| Serial Interfaces | USART/SCI, MSSP (SPI/I2C) |
| Parallel Slave Port | Yes |
| Operating Temperature Range | -40 °C to +125 °C (Extended) |
| Package | 40-pin PDIP (P) |
| Supply Current (typ. 5 V, 4 MHz) | 15 µA typical |
| Supply Current (typ. 3 V, 32 kHz) | 1 µA typical |
| Mounting Type | Through-hole |
| RoHS Status | Unknown (windowed/EPROM family parts historically non-RoHS) |
PIC16C65B-04E/P Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (reset) / Programming voltage input |
| Pin 2 | RA0/AN0 — PORTA bit 0 / Analog input 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / Analog input 1 |
| Pin 4 | RA2/AN2 — PORTA bit 2 / Analog input 2 |
| Pin 5 | RA3/AN3/VREF — PORTA bit 3 / Analog input 3 / ADC reference |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — PORTA bit 5 / Analog input 4 / SPI slave select |
| Pin 8 | OSC1/CLKIN — Oscillator crystal input / external clock |
| Pin 9 | OSC2/CLKOUT — Oscillator crystal output / clock output |
| Pin 10 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / clock input |
| Pin 11 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / Capture-Compare-PWM2 |
| Pin 12 | RC2/CCP1 — PORTC bit 2 / Capture-Compare-PWM1 |
| Pin 13 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 14 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 15 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 16 | RC6/TX/CK — PORTC bit 6 / USART TX / clock |
| Pin 17 | RC7/RX/DT — PORTC bit 7 / USART RX / data |
| Pin 18 | GND — Ground (logic ground, 0 V reference) |
| Pin 19 | RD0/PSP0 — PORTD bit 0 / Parallel slave port bit 0 |
| Pin 20 | RD1/PSP1 — PORTD bit 1 / Parallel slave port bit 1 |
| Pin 21 | RD2/PSP2 — PORTD bit 2 / Parallel slave port bit 2 |
| Pin 22 | RD3/PSP3 — PORTD bit 3 / Parallel slave port bit 3 |
| Pin 23 | RD4/PSP4 — PORTD bit 4 / Parallel slave port bit 4 |
| Pin 24 | RD5/PSP5 — PORTD bit 5 / Parallel slave port bit 5 |
| Pin 25 | RD6/PSP6 — PORTD bit 6 / Parallel slave port bit 6 |
| Pin 26 | RD7/PSP7 — PORTD bit 7 / Parallel slave port bit 7 |
| Pin 27 | RE0/RD — PORTE bit 0 / Read control for PSP |
| Pin 28 | RE1/WR — PORTE bit 1 / Write control for PSP |
| Pin 29 | RE2/CS — PORTE bit 2 / Chip select for PSP |
| Pin 30 | GND — Ground |
| Pin 31 | VDD — Positive supply (logic + I/O) |
| Pin 32 | RB0/INT — PORTB bit 0 / External interrupt input |
| Pin 33 | RB1 — PORTB bit 1 |
| Pin 34 | RB2 — PORTB bit 2 |
| Pin 35 | RB3/PGM — PORTB bit 3 / Low-voltage programming input |
| Pin 36 | RB4 — PORTB bit 4 (interrupt-on-change) |
| Pin 37 | RB5 — PORTB bit 5 (interrupt-on-change) |
| Pin 38 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 39 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 40 | VDD — Positive supply |
Typical Applications
PIC16C65B-04E/P is suitable for 6 applications: Industrial Control Systems, Sensor Signal Conditioning, Low-Power Remote Sensor Nodes, Motor Control Front End, Legacy Equipment Retrofits, Embedded Automotive Subsystems.
Industrial Control Systems
The PIC16C65B-04E/P fits industrial control well: its 33 I/O pins directly drive relays, sensors, and HMI displays, while the 4 MHz RISC core executes 5 MIPS for deterministic PLC-style ladder logic. The Extended -40 °C to +125 °C temperature grade handles factory-floor heat, and the 15 µA typical active current keeps 4-20 mA loop-powered nodes efficient. The MSSP module provides SPI for ADC chips and I2C for EEPROM parameter storage.
Recommended
Sensor Signal Conditioning
The PIC16C65B-04E/P's 5-channel 8-bit ADC and 192-byte RAM handle sensor signal conditioning for up to five analog inputs simultaneously. The 200 ns instruction cycle enables real-time filtering algorithms while Extended temperature grade ensures operation in outdoor or under-hood enclosures. USART connects to host MCUs or wireless modules for data forwarding in distributed sensor networks.
Recommended
Low-Power Remote Sensor Nodes
Drawing only 1 µA typical at 3 V / 32 kHz in sleep mode, the PIC16C65B-04E/P is ideal for battery-backed remote sensor nodes with multi-year battery life targets. The Extended temperature grade tolerates outdoor cabinet conditions from -40 °C winters to +125 °C direct sun, and the 33 I/O pins support multiple sensor interfaces plus a low-power radio enable pin. Wake-up from sleep on interrupt enables duty-cycled measurement.
Recommended
Motor Control Front End
The PIC16C65B-04E/P serves as a motor-control front end, generating PWM via its 16-bit timer for H-bridge drivers while reading back EMF and current via the 5-channel ADC. The 33 I/O pins accommodate direction, brake, and fault signals alongside the PWM outputs. Extended temperature grade and 4 MHz deterministic RISC core ensure consistent commutation timing even in harsh industrial enclosures above 85 °C ambient.
Recommended
Legacy Equipment Retrofits
Many industrial controllers built in the late 1990s and early 2000s use PIC16C65B silicon, and the PIC16C65B-04E/P serves as a direct form-fit-function replacement when original parts reach end of life. Its 40-pin PDIP package matches legacy footprints exactly, and the same PIC16C instruction set means existing firmware binaries written for the original part continue to run without recompilation, simplifying MRO operations.
Recommended
Embedded Automotive Subsystems
The PIC16C65B-04E/P's Extended -40 °C to +125 °C temperature range suits non-safety automotive subsystems such as body controllers, lighting drivers, climate-control panels, and accessory multiplexers. The 5-channel ADC reads thermistors and switches, the MSSP drives LIN or CAN transceivers via SPI, and the 4 MHz core provides deterministic response to switch events. Not AEC-Q100 qualified, so it is not intended for safety-critical ECUs.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C65B-04E/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C65B-04I/P | PIC16C65B-04E/L | PIC16C65A-20I/P | PIC16F877A-I/P |
|---|---|---|---|---|---|
| Package | 40-PDIP | 40-PDIP (same) | 40-CDIP windowed (same footprint) | 40-PDIP (same) | 40-PDIP (same) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core Frequency | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 20 MHz |
| Temperature Range | -40 °C to +125 °C (Extended) | -40 °C to +85 °C (Industrial) | -40 °C to +125 °C (Extended) | -40 °C to +85 °C (Industrial) | -40 °C to +85 °C (Industrial) |
| Program Memory | 7 KB OTP | 7 KB OTP | 7 KB OTP (windowed) | 7 KB OTP | 14 KB Flash |
| RAM | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 368 bytes |
| I/O Pins | 33 | 33 | 33 | 33 | 33 |
| Lifecycle Status | NRND | NRND | NRND | NRND | Active |
| Memory Type | OTP (one-time programmable) | OTP | OTP (windowed erasable) | OTP | Flash (re-programmable) |
Key Differentiators
- Extended temperature grade for harsh-environment deployment (vs PIC16C65B-04I/P)
- Highest same-package memory at 4 MHz for legacy code preservation (vs PIC16C64A-04/P)
- Production-active flash alternative available in same package (vs PIC16F877A-I/P)
- Windowed ceramic variant for prototype code iteration (vs PIC16C65B-04E/P (production OTP))
Design Notes
Place a 100 nF ceramic decoupling capacitor within 5 mm of each VDD/VSS pin pair (pins 11/12 and 31/30 on the 40-PDIP). Add a single 10 µF tantalum or aluminum bulk capacitor near the MCU to handle transient load steps from the digital I/O banks. Estimated: at 5 V / 4 MHz, total current including I/O toggling stays below 20 mA, so a small LDO (e.g. MCP1700) easily supplies this load.
OTP memory is one-time programmable: there is no in-circuit re-programming path. Always validate firmware on a windowed ceramic variant (PIC16C65B-04E/L) or a flash equivalent before committing OTP units to production. Bit failures and code bugs are permanent and require board-level rework or scrap. Use ICSP via RB6/RB7 with appropriate VPP sequencing.
Unused I/O pins should be configured as outputs driving low (never left floating) to minimize sleep current and EMI susceptibility. The MCLR pin requires a 10 kΩ pull-up to VDD for normal operation; do not leave it floating. For high-noise environments, add a 100 nF capacitor between MCLR and ground to filter transient resets from EMI events.
The PIC16C65B-04E/P Extended temperature grade is -40 °C to +125 °C junction. Estimated: at 4 MHz with all 33 I/O pins toggling at 50% duty, die power dissipation is roughly 50 mW, resulting in a junction temperature rise of only a few degrees above ambient - well within the thermal envelope. No special heatsinking is required for any deployment scenario.
Compliance Information
PIC16C65B-04E/P is part of Microchip's older OTP/EPROM PIC16C family. RoHS compliance status is unknown from verified data and historically EPROM-programmed windowed/OTP MCUs were non-RoHS. Not AEC-Q100 qualified - not recommended for safety-critical automotive ECUs. For new automotive designs, use AEC-Q100 qualified PIC16F or dsPIC equivalents.
