PIC16C65B-20I/P - 8-Bit 20MHz OTP MCU, 7KB EPROM, 40-PDIP | Microchip
MPN: PIC16C65B-20I/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.4 | $8.40 |
| 10 | $7.56 | $75.60 |
| 100 | $6.72 | $672.00 |
| 500 | $6.05 | $3,025.00 |
| 1,000 | $5.42 | $5,420.00 |
PIC16C65B-20I/P Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, memory, and peripheral interfaces on one die, forming the lowest tier of the embedded computing hierarchy (microcontroller -> embedded processor -> microprocessor -> computing platform). The PIC16CXX mid-range architecture uses a 14-bit instruction word with a RISC-style 35-instruction set, providing deterministic timing and code density advantages over CISC alternatives. OTP memory allows one-time field programming, which is well suited to mature production runs where code revision is no longer expected.
Key features of the PIC16C65B include two 8-bit timers plus one 16-bit timer, a USART for asynchronous/synchronous serial communication, an MSSP module supporting both SPI and I2C, an 8-bit parallel slave port, and a watchdog timer with its own on-chip RC oscillator for maximum reliability. Compared with its predecessor PIC16C65A, the B revision improves oscillator stability and adds enhanced in-circuit serial programming support per Microchip's compatibility chart.
The PIC16C65B-20I/P's 200 ns instruction execution combined with its 33 I/O pins makes it suited to industrial control panels, instrumentation front-ends, motor control driver boards, and embedded sensor hubs where deterministic interrupt latency and code simplicity outweigh the need for large RAM or in-system reprogrammability. Its wide 4.0-5.5 V supply window tolerates noisy industrial 5 V rails.
When designing with this part, note that OTP cannot be reprogrammed - firmware bugs cannot be patched after programming, so plan for code verification prior to volume programming. Use the MPLAB PM3 Universal Device Programmer or MPLAB ICD in-circuit debugger during development before committing to OTP. An external resonator or crystal with appropriate load capacitors is required for accurate clocking.
Drop-in alternatives for PIC16C65B-20I/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-20I/P (same form factor and footprint) — differing in Package, Timers, Core Architecture, Program Memory Size, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C65A-20I/P
✅ Drop-In✓ In Stock
$6.08 / Unit
View Datasheet →PIC16C65B-04I/P
✅ Drop-In✓ In Stock
$3.75 / Unit
View Datasheet →PIC16C65B-04/PQ
✅ Drop-In✓ In Stock
$10.25 / Unit
View Datasheet →PIC16C65B-04I/PQ
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$5.45 / Unit
View Datasheet →PIC16C65AT-20I/P
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC16C65A-04I/P
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$5.25 / Unit
View Datasheet →PIC16C65B-04E/P
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$5.45 / Unit
View Datasheet →PIC16C65A-20I/PQ
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$8.62 / Unit
View Datasheet →PIC16C65B-20I/P Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16CXX mid-range 8-bit RISC |
| Program Memory (EPROM) | 7 KB (4K x 14-bit) |
| RAM | 192 bytes |
| Data EEPROM | 0 bytes (not present) |
| Maximum Clock Speed | 20 MHz |
| Instruction Execution Time | 200 ns (single cycle) |
| Instruction Set Size | 35 instructions (14-bit word) |
| Supply Voltage (Vdd) | 4.0 V to 5.5 V |
| Operating Temperature | -40 C to +85 C (Industrial) |
| I/O Pins | 33 |
| Timers | 2 x 8-bit, 1 x 16-bit |
| Serial Interfaces | USART, SPI (MSSP), I2C (MSSP) |
| Parallel Slave Port | Yes (8-bit PSP) |
| Watchdog Timer | Yes (with dedicated on-chip RC) |
| Package | 40-pin PDIP (through-hole, 0.600 in) |
| Program Memory Type | OTP (One-Time Programmable) EPROM |
| Supply Current (typical) | 15 uA at 5 V/4 MHz; 1 uA at 3 V/32 kHz |
| Mounting Type | Through-Hole (DIP) |
| RoHS Status | Compliant |
PIC16C65B-20I/P Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (reset) input / programming voltage |
| Pin 2 | RA0/AN0 — PORTA bit 0 (digital I/O) |
| Pin 3 | RA1/AN1 — PORTA bit 1 (digital I/O) |
| Pin 4 | RA2/AN2 — PORTA bit 2 (digital I/O) |
| Pin 5 | RA3/AN3/VREF — PORTA bit 3 / VREF (digital I/O) |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input (digital I/O) |
| Pin 7 | RA5/SS/AN4 — PORTA bit 5 / SPI Slave Select (digital I/O) |
| Pin 8 | OSC1/CLKIN — Oscillator input / external clock |
| Pin 9 | OSC2/CLKOUT — Oscillator output |
| Pin 10 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 I/O (digital I/O) |
| Pin 11 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 Osc / CCP2 (digital I/O) |
| Pin 12 | RC2/CCP1 — PORTC bit 2 / Capture-Compare-PWM 1 (digital I/O) |
| Pin 13 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock (digital I/O) |
| Pin 14 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data (digital I/O) |
| Pin 15 | RC5/SDO — PORTC bit 5 / SPI data out (digital I/O) |
| Pin 16 | RC6/TX/CK — PORTC bit 6 / USART TX / clock (digital I/O) |
| Pin 17 | RC7/RX/DT — PORTC bit 7 / USART RX / data (digital I/O) |
| Pin 18 | VSS — Ground reference |
| Pin 19 | VDD — Positive supply (4.0-5.5 V) |
| Pin 20 | RB0/INT — PORTB bit 0 / external interrupt (digital I/O) |
| Pin 21 | RB1 — PORTB bit 1 (digital I/O) |
| Pin 22 | RB2 — PORTB bit 2 (digital I/O) |
| Pin 23 | RB3 — PORTB bit 3 (digital I/O) |
| Pin 24 | RB4 — PORTB bit 4 (digital I/O) |
| Pin 25 | RB5 — PORTB bit 5 (digital I/O) |
| Pin 26 | RB6/PGC — PORTB bit 6 / ICSP clock (digital I/O) |
| Pin 27 | RB7/PGD — PORTB bit 7 / ICSP data (digital I/O) |
| Pin 28 | RD0/PSP0 — PORTD bit 0 / Parallel Slave Port bit 0 (digital I/O) |
| Pin 29 | RD1/PSP1 — PORTD bit 1 / Parallel Slave Port bit 1 (digital I/O) |
| Pin 30 | RD2/PSP2 — PORTD bit 2 / Parallel Slave Port bit 2 (digital I/O) |
| Pin 31 | RD3/PSP3 — PORTD bit 3 / Parallel Slave Port bit 3 (digital I/O) |
| Pin 32 | RD4/PSP4 — PORTD bit 4 / Parallel Slave Port bit 4 (digital I/O) |
| Pin 33 | RD5/PSP5 — PORTD bit 5 / Parallel Slave Port bit 5 (digital I/O) |
| Pin 34 | RD6/PSP6 — PORTD bit 6 / Parallel Slave Port bit 6 (digital I/O) |
| Pin 35 | RD7/PSP7 — PORTD bit 7 / Parallel Slave Port bit 7 (digital I/O) |
| Pin 36 | RE0/RD — PORTE bit 0 / PSP read control (digital I/O) |
| Pin 37 | RE1/WR — PORTE bit 1 / PSP write control (digital I/O) |
| Pin 38 | RE2/CS — PORTE bit 2 / PSP chip select (digital I/O) |
| Pin 39 | VSS — Ground reference |
| Pin 40 | VDD — Positive supply (4.0-5.5 V) |
Typical Applications
PIC16C65B-20I/P is suitable for 7 applications: Industrial Control Panels, Instrumentation Front-Ends, Motor Driver Controller Boards, Embedded Sensor Hubs, POS Terminal Peripherals, Security Keypads and Access Controllers, Automotive Aftermarket Modules.
Industrial Control Panels
The PIC16C65B-20I/P fits industrial control panels because its 33 I/O lines can directly drive relay coils, keypad matrices, and 7-segment LED displays without external multiplexing ICs. The 5 V supply tolerance handles the noisy 24 V-derived industrial bus, and the -40 C to +85 C industrial range covers cabinet environments. Its 200 ns deterministic interrupt latency ensures timely response to limit-switch and emergency-stop inputs. Compared to flash-based MCUs, OTP is acceptable because panel firmware is mature and rarely revised.
Recommended
Instrumentation Front-Ends
In instrumentation front-ends, the PIC16C65B-20I/P serves as the system controller that drives LCD displays, scans keypads, and serializes measurement data via its USART to a host PC. The MSSP peripheral supports both SPI (for ADC/DAC chips) and I2C (for EEPROM/IO expanders), reducing external component count. Its 15 uA typical operating current at 4 MHz keeps heat dissipation negligible, important for precision analog front-ends where thermal gradients cause offset drift.
Recommended
Motor Driver Controller Boards
The PIC16C65B-20I/P is well suited to stepper and brushed DC motor control boards where its 16-bit timer generates precise PWM carrier waveforms and the 8-bit timers handle encoder input capture. The parallel slave port allows high-bandwidth command injection from a host motion controller without burdening the USART. Its wide 4.0-5.5 V supply tolerates the inductive voltage transients from H-bridge switching when paired with proper snubbing. OTP is appropriate because motor-control firmware is version-locked at production.
Recommended
Embedded Sensor Hubs
The PIC16C65B-20I/P aggregates multiple sensor inputs via I2C and SPI buses from external sensor ICs and repackages the data over its USART for transmission to a gateway or PLC. With 33 I/O and flexible peripheral mapping, it can simultaneously host a temperature sensor on I2C, an SPI pressure sensor, and several discrete switch inputs. The 1 uA sleep current at 32 kHz makes it practical for battery-backed sensor nodes that wake periodically to scan and report.
Recommended
POS Terminal Peripherals
Point-of-sale peripherals such as receipt printer controllers, magnetic-stripe readers, and barcode scanner interfaces leverage the PIC16C65B-20I/P's combination of USART, SPI, and parallel slave port to bridge multiple IO types. The 200 ns instruction execution supports the real-time bit-banging often needed for legacy peripherals, and the wide operating voltage handles power-rail transients in shared electrical environments. Its 5 V logic is directly compatible with many older POS peripheral interfaces.
Recommended
Security Keypads and Access Controllers
The PIC16C65B-20I/P powers standalone security keypads and access controllers where deterministic scan timing, low standby current, and long-term Microchip supply are valued. Its 33 I/O easily handles a 4x4 matrix keypad plus relay/buzzer outputs, while the USART enables logging to a central controller. The OTP memory prevents malicious firmware tampering after deployment - a security advantage over flash parts that can be rep-attacked. Industrial temperature range supports outdoor or unheated enclosures.
Recommended
Automotive Aftermarket Modules
Although not AEC-Q100 qualified, the PIC16C65B-20I/P has historically been used in non-safety automotive aftermarket modules such as alarm systems, remote-start controllers, and dashboard accessories. Its wide 4.0-5.5 V supply tolerates 12 V battery transients when properly regulated, and the USART supports OBD-II diagnostic communication. For OEM automotive designs, AEC-Q100-qualified PIC18F variants are mandatory; this part suits hobbyist and retrofit applications only.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C65B-20I/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C65A-20I/P | PIC16C65B-04I/P | PIC16C65B-04/P | PIC16C65AT-20I/P |
|---|---|---|---|---|---|
| Package | PDIP-40 | PDIP-40 - same | PDIP-40 - same | PDIP-40 - same | PDIP-40 - same |
| Brand | Microchip Technology | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same |
| Program Memory | 7 KB (4K x 14) OTP EPROM | 7 KB OTP EPROM - same | 7 KB OTP EPROM - same | 7 KB OTP EPROM - same | 7 KB OTP EPROM - same |
| Maximum Clock Speed | 20 MHz | 20 MHz - same | 4 MHz (-80%) | 4 MHz (-80%) | 20 MHz - same |
| Instruction Cycle | 200 ns | 200 ns - same | 1000 ns | 1000 ns | 200 ns - same |
| RAM | 192 bytes | 192 bytes - same | 192 bytes - same | 192 bytes - same | 192 bytes - same |
| Operating Temperature | -40 C to +85 C (Industrial) | -40 C to +85 C - same | -40 C to +85 C - same | 0 C to +70 C (Commercial) | -40 C to +85 C - same |
| I/O Pins | 33 | 33 - same | 33 - same | 33 - same | 33 - same |
| Lifecycle Status | Active | Active | Active | Active | Active |
Key Differentiators
- Wide 5 V industrial tolerance without LDO (vs PIC16C65A-20I/P)
- 33 I/O in 40-pin PDIP for direct legacy interface (vs PIC16C65B-04I/P)
- 5x faster than -04 speed grade at same price tier (vs PIC16C65B-04/P)
- Industrial temperature grade with same specs as commercial (vs PIC16C65B-04I/PQ)
Design Notes
OTP (One-Time Programmable) EPROM cannot be erased or reprogrammed. A single bit error in your firmware forces scrap of the programmed device. Use a JW (windowed) ceramic package variant or an F-series flash equivalent (PIC16F77-I/P) during development and validation. Verify all firmware via MPLAB X simulation, hardware emulation with PICkit 3, and full regression testing before committing any PIC16C65B-20I/P to a programmer socket. Estimated cost impact: a single OTP mis-program can waste $5-8 in parts alone.
Place a 100 nF decoupling capacitor as close as possible to each VDD pin (pins 19 and 40), with a wide ground trace back to VSS (pins 18 and 39). For the 40-pin PDIP, both VDD/VSS pairs MUST be decoupled - the PIC16CXX core draws brief high-current spikes during instruction execution. A bulk 10 uF tantalum or ceramic capacitor on the main 5 V rail near the IC provides additional high-frequency energy storage. Keep the MCLR/VPP trace short and route it away from high-current switching nodes.
The OSC1/OSC2 crystal oscillator traces must be kept short (under 10 mm) and routed symmetrically to maintain duty cycle. Place load capacitors (typically 15-33 pF for a 20 MHz crystal) immediately adjacent to the oscillator pins, with their ground returns tied directly to the nearest VSS pin rather than a shared ground bus. For noisy environments, add a 100 ohm series resistor at OSC2 output to dampen overdrive. Failure to follow these guidelines can cause oscillator start-up failure or excessive EMI.
The PIC16C65B-20I/P operates from 4.0 V to 5.5 V. For designs deriving power from a 12 V or 24 V industrial bus, use a low-dropout linear regulator (e.g., Microchip MCP1700) or a small switching regulator with adequate filtering. The MCU itself draws only 15 uA typical at 5 V/4 MHz, but I/O drive current peaks during port transitions can reach 25 mA per pin (100 mA total per port) - size your regulator and traces accordingly. Estimated: 33 I/O x 4 mA average = 132 mA peak port current in worst-case simultaneous switching scenarios.
The Parallel Slave Port (PORTD + PORTE) operates as an 8-bit bus and is sensitive to reflections on traces longer than 50 mm. For long bus connections, add 33 ohm series damping resistors near the MCU pins, especially on the RD0-RD7 data lines. The PSP is rated for read/write rates up to the system clock divided by 2, but signal integrity typically limits practical cable length to under 200 mm without additional buffering. Use HC/HCT-series bus buffers (e.g., 74HCT245) for off-board expansion.
Compliance Information
Per Microchip product page. Industrial temperature grade but NOT AEC-Q100 qualified - use PIC18F or dsPIC AEC-Q100 variants for automotive OEM designs. Lead-free PDIP package is RoHS compliant. REACH compliance per Microchip declaration.
