PIC16C65B-04I/PT - 8-bit OTP MCU, 4MHz, 7KB, 44-TQFP | Microchip
MPN: PIC16C65B-04I/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $11.5 | $11.50 |
| 10 | $10.45 | $104.50 |
| 100 | $9.2 | $920.00 |
| 500 | $8.05 | $4,025.00 |
| 1,000 | $7.1 | $7,100.00 |
PIC16C65B-04I/PT Overview
An OTP/EPROM microcontroller is a class of programmable logic device whose program memory is written once via an external programmer and then becomes non-volatile. PIC16CXX mid-range parts sit at the low-cost, peripheral-rich tier of Microchip's 8-bit portfolio - above the baseline PIC16C5X family and below the PIC17CXX/PIC18CXX high-performance tier - and are well known for migrating code easily across 28- to 40-pin variants. They serve as general-purpose embedded controllers where cost, deterministic timing, and ease of programming outweigh the need for in-system re-flash capability.
Key features include 192 bytes of RAM, 33 digital I/O pins, 8-channel 8-bit ADC, USART with SPI/I2C master mode, two Capture/Compare/PWM modules, and a watchdog timer. The 'I' suffix denotes the industrial operating temperature range of -40C to +85C. The 04 speed grade specifies a 4 MHz maximum oscillator input. The /PT suffix designates the 44-pin TQFP (Thin Quad Flat Pack) surface-mount package, supplied in tray.
Typical applications include industrial control systems, sensor interfacing, motor control (low-end DC and stepper drivers), security and alarm panels, automotive body electronics, and general-purpose embedded controllers where code is finalized at production and OTP cost savings outweigh flash reprogrammability. As an EPROM/OTP part, it is also widely used in educational settings to teach RISC embedded programming.
When designing with PIC16C65B-04I/PT, ensure the oscillator selection matches the application clock speed, since the '04' grade tops out at 4 MHz. The 44-TQFP footprint provides ample I/O (33 pins) for parallel bus expansion, multiple UART/SPI channels, and analog sensing arrays. Watchdog timer must be either enabled in firmware or disabled in configuration to avoid unintended resets. This page consolidates distributor pricing, drop-in alternatives, and engineering notes not bundled in the manufacturer datasheet.
Drop-in alternatives for PIC16C65B-04I/PT — 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-04I/PT (same form factor and footprint) — differing in Program Memory Size, Program Memory Type, Operating Temperature, Package, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C65BT-04I/PT
✅ Drop-In✓ In Stock
$4.1 / Unit
View Datasheet →PIC16C65B-04E/PT
✅ Drop-In✓ In Stock
$2.62 / Unit
View Datasheet →PIC16C65AT-04I/PT
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$4.5 / Unit
View Datasheet →PIC16F74-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C65B-04I/PT Maximum Ratings & Electrical Characteristics
| Family | PIC16CXX mid-range 8-bit |
| Core | RISC, 35 single-word instructions |
| Data Bus Width | 8 bit |
| Program Memory Type | OTP / EPROM |
| Program Memory Size | 7 KB (4K x 14 words) |
| RAM Size | 192 bytes |
| Maximum Clock Input | 4 MHz (04 speed grade) |
| Instruction Cycle | 200 ns at 4 MHz |
| Supply Voltage | 4.0 V to 5.5 V |
| I/O Pins | 33 |
| ADC | 8-channel, 8-bit |
| Communication Peripherals | USART (SCI/SPI/I2C master) |
| Timers | 3 (Timer0/1/2) |
| CCP Modules | 2 Capture/Compare/PWM |
| Watchdog Timer | Yes |
| Operating Temperature Range | -40 C to +85 C (Industrial) |
| Package | 44-pin TQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| MSL Level | 1 (unlimited) |
PIC16C65B-04I/PT Pin Configuration
| Pin 1 | RA0/AN0 — Port A bit 0 / Analog input channel 0 |
| Pin 2 | RA1/AN1 — Port A bit 1 / Analog input channel 1 |
| Pin 3 | RA2/AN2 — Port A bit 2 / Analog input channel 2 |
| Pin 4 | RA3/AN3/VREF — Port A bit 3 / Analog input channel 3 / ADC voltage reference |
| Pin 5 | RA4/T0CKI — Port A bit 4 / Timer0 clock input (open-drain) |
| Pin 6 | RA5/AN4/SS — Port A bit 5 / Analog input channel 4 / SPI slave select |
| Pin 7 | RE0/RD/AN5 — Port E bit 0 / Parallel slave read / Analog input 5 |
| Pin 8 | RE1/WR/AN6 — Port E bit 1 / Parallel slave write / Analog input 6 |
| Pin 9 | RE2/CS/AN7 — Port E bit 2 / Parallel slave chip select / Analog input 7 |
| Pin 10 | VDD — Positive supply voltage (4.0-5.5 V) |
| Pin 11 | VSS — Ground reference |
| Pin 12 | OSC1/CLKIN — Oscillator crystal input / external clock input |
| Pin 13 | OSC2/CLKOUT — Oscillator crystal output / clock output (Fosc/4) |
| Pin 14 | RC0/T1OSO/T1CKI — Port C bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 15 | RC1/T1OSI/CCP2 — Port C bit 1 / Timer1 oscillator input / CCP2 output |
| Pin 16 | RC2/CCP1 — Port C bit 2 / CCP1 PWM output |
| Pin 17 | RC3/SCK/SCL — Port C bit 3 / SPI clock / I2C clock |
| Pin 18 | RD0 — Port D bit 0 (parallel slave data bus) |
| Pin 19 | RD1 — Port D bit 1 (parallel slave data bus) |
| Pin 20 | RD2 — Port D bit 2 (parallel slave data bus) |
| Pin 21 | RD3 — Port D bit 3 (parallel slave data bus) |
| Pin 22 | RC4/SDI/SDA — Port C bit 4 / SPI data in / I2C data |
| Pin 23 | RC5/SDO — Port C bit 5 / SPI data out |
| Pin 24 | RC6/TX/CK — Port C bit 6 / USART async transmit / USART sync clock |
| Pin 25 | RC7/RX/DT — Port C bit 7 / USART async receive / USART sync data |
| Pin 26 | RD4 — Port D bit 4 (parallel slave data bus) |
| Pin 27 | RD5 — Port D bit 5 (parallel slave data bus) |
| Pin 28 | RD6 — Port D bit 6 (parallel slave data bus) |
| Pin 29 | RD7 — Port D bit 7 (parallel slave data bus) |
| Pin 30 | VSS — Ground reference |
| Pin 31 | VDD — Positive supply voltage (4.0-5.5 V) |
| Pin 32 | RB0/INT — Port B bit 0 / External interrupt input |
| Pin 33 | RB1 — Port B bit 1 (interrupt-on-change) |
| Pin 34 | RB2 — Port B bit 2 (interrupt-on-change) |
| Pin 35 | RB3/PGM — Port B bit 3 / Low-voltage ICSP programming input |
| Pin 36 | RB4 — Port B bit 4 (interrupt-on-change) |
| Pin 37 | RB5 — Port B bit 5 (interrupt-on-change) |
| Pin 38 | RB6/PGC — Port B bit 6 / In-circuit debugger clock |
| Pin 39 | RB7/PGD — Port B bit 7 / In-circuit debugger data |
| Pin 40 | NC — Not connected (no internal bond) |
| Pin 41 | NC — Not connected (no internal bond) |
| Pin 42 | NC — Not connected (no internal bond) |
| Pin 43 | MCLR/VPP — Master clear reset input (active low) / Programming voltage |
| Pin 44 | NC — Not connected (no internal bond) |
Typical Applications
PIC16C65B-04I/PT is suitable for 7 applications: Industrial Process Control Systems, Security and Alarm Panels, Automotive Body Electronics (Non-Safety), Educational and Training Boards, Sensor Interface and Data Acquisition Front-Ends, Low-End Motor Control (Brushed DC and Stepper), General-Purpose Embedded Controllers (Cost-Sensitive).
Industrial Process Control Systems
The PIC16C65B-04I/PT fits industrial control applications where firmware is locked at production and cost is the primary driver. With 33 I/O pins, the MCU can drive multi-axis sensor arrays, relay banks, and isolated 4-20 mA loops typical of PLC and DCS subsystems. The 8-channel 8-bit ADC samples up to 8 analog process variables (temperature, pressure, flow) at adequate resolution for setpoint control. The 4 MHz clock is sufficient for slow control loops (typically 1-10 Hz bandwidth). The OTP memory prevents firmware reverse-engineering - critical for proprietary control algorithms. Industrial -40 C to +85 C operation handles factory-floor ambient. The 44-TQFP package provides a stable surface-mount attachment resistant to vibration in motor-control cabinets. The PIC16C65B-04I/PT is preferred over Flash parts when production volumes exceed several thousand units where the per-piece savings dominate. Companion parts include the PIC16F877A for prototyping, ULN2003A for relay driving, and MCP2551 for industrial CAN networking.
Recommended
Security and Alarm Panels
Security alarm systems benefit from the PIC16C65B-04I/PT's combination of 33 I/O for zone monitoring, OTP code protection against reverse engineering, and 192-byte RAM sufficient for keypad buffering and event logging. The MCU interfaces with PIR motion sensors, magnetic reed switches, glass-break detectors, and smoke alarms via its digital I/O, while the USART drives a central-station modem or keypad display. The 8-bit ADC can monitor backup battery voltage and loop current. Industrial temperature rating ensures reliable operation in unheated garages and warehouses. The OTP memory protects proprietary alarm protocols - a critical security feature, since Flash parts can be easily read back and cloned. At 4 MHz the instruction cycle of 200 ns handles all standard alarm-panel timing without bottlenecks. Production volumes for alarm panels are typically high, so the OTP cost advantage is meaningful. Companion parts include the PIC16F628 for low-end sensors, MAX232 for RS-232 keypad interface, and 24LC256 EEPROM for event-log storage.
Recommended
Automotive Body Electronics (Non-Safety)
Non-safety automotive body modules - HVAC controllers, power-window modules, mirror adjusters, seat controllers, and ambient lighting - are a strong fit for the PIC16C65B-04I/PT. With 33 I/O the MCU drives multiple relay and MOSFET half-bridges for window/mirror/seat motors, reads multiple switch inputs, and talks LIN-bus or simple PWM to other body modules via the USART. The 8-channel ADC monitors current sense and potentiometer positions. The industrial -40 C to +85 C range covers cabin environments; for under-hood applications the PIC16C65B-04E/PT (extended -40 to +125 C) drop-in replacement is mandatory. OTP memory prevents aftermarket firmware tampering. The 4 MHz clock is more than sufficient for body-electronics loop times in the 10-100 ms range. The 44-TQFP package handles automotive vibration when properly PCB-mounted with underfilled leads. Note: critical safety systems (ABS, airbag, steering) require AEC-Q100-qualified Flash parts - use PIC18F family instead. Companion parts include TJA1027 LIN transceiver, IRF540N power MOSFET, and MC33662 LIN body controller.
Recommended
Educational and Training Boards
Universities, technical schools, and Microchip Academic Program partners use the PIC16C65B-04I/PT (or its windowed ceramic variant PIC16C65B-04/JW) as a teaching vehicle for RISC embedded programming. The 35-instruction set is small enough to master in a single semester, the 4 MHz clock is slow enough for students to follow execution on a logic analyzer or scope, and the 33 I/O provides enough pins to drive 7-segment displays, keypads, LCDs, and motor demonstrators in lab projects. OTP programming using a PICSTART Plus or MPLAB PM3 programmer teaches students the full development cycle - edit, assemble, program, debug. Compared to Flash PIC16F parts the PIC16C65B-04I/PT costs less per unit for class kits of 30-50 students. The 44-TQFP package is breadboard-friendly via breakout PCBs. Companion parts include the PIC16F877A for advanced courses, HD44780-compatible LCD modules, and 74HC595 shift-register expanders.
Recommended
Sensor Interface and Data Acquisition Front-Ends
Distributed sensor-interface modules that aggregate multiple analog and digital sensors and forward data to a central controller fit the PIC16C65B-04I/PT's I/O count and serial bandwidth. The 8-channel 8-bit ADC handles 8 analog sensors (temperature, humidity, light, pressure) directly without an external MUX. The 33 digital I/O accommodate additional digital sensors (Hall-effect, optical encoders, switches). The USART with SPI/I2C master mode interfaces to digital sensor ICs (e.g., MCP9800 temperature, MAX31760 fan-speed) or to a downstream controller. At 4 MHz the MCU can sample and serialize 100+ channels per second over SPI. The 192-byte RAM buffers sensor frames before transmission. Industrial temperature operation suits outdoor or factory deployments. OTP code protects calibration coefficients and proprietary sensor-fusion algorithms. Companion parts include MCP9800 for I2C temperature, MAX31760 for fan-speed sensing, and MCP2515 for CAN-connected sensor networks.
Recommended
Low-End Motor Control (Brushed DC and Stepper)
Low-power brushed-DC and unipolar/bipolar stepper motor controllers in appliances, printers, and small-automation equipment use the PIC16C65B-04I/PT to generate PWM signals, sequence phase commutation, and read back EMF or current feedback. The two on-chip CCP modules deliver two independent PWM channels with 10-bit resolution - sufficient for variable-speed DC fans or unipolar stepper coils. Timer0/1/2 provide accurate commutation timing for stepper drivers up to a few hundred RPM. The 8-channel ADC samples shunt-resistor current for closed-loop torque control or stall detection. The 33 digital I/O drive H-bridge MOSFET gates via gate drivers (e.g., IR2104). At 4 MHz the instruction cycle is fast enough for commutation rates up to 20 kHz. OTP cost advantage benefits the high-volume appliance market. The 44-TQFP package dissipates the modest switching losses easily. Companion parts include IR2104 gate driver, IRF540N power MOSFET, and ACS712 current sensor.
Recommended
General-Purpose Embedded Controllers (Cost-Sensitive)
Generic embedded controllers in consumer appliances, vending machines, point-of-sale terminals, and small appliances often default to the PIC16C65B-04I/PT for cost reasons. With 33 I/O, 7 KB OTP, 192 B RAM, USART, and 8 ADC channels, the MCU handles display refresh, keypad scanning, sensor reading, and actuator control in a single chip. OTP memory locks firmware against aftermarket cloning - valuable for retail products with proprietary features. The 4 MHz clock is sufficient for UI-loop rates (10-50 Hz) typical of human-interface devices. The 44-TQFP footprint fits 4-layer FR4 PCBs with room for optocouplers, relay drivers, and triacs. Industrial temperature operation covers most consumer and light-industrial environments. Compared to PIC16F Flash parts, the OTP cost advantage accumulates over thousands of units per month of production volume. Companion parts include HD44780 16x2 LCD, 4x4 matrix keypad, and PC817 optocoupler for mains isolation.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C65B-04I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C65BT-04I/PT | PIC16C65B-04E/PT | PIC16C65AT-04I/PT | PIC16F74-I/PT |
|---|---|---|---|---|---|
| Package | 44-TQFP (10x10 mm) | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same |
| Brand | Microchip Technology | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same |
| Program Memory Type | OTP/EPROM | OTP/EPROM - same | OTP/EPROM - same | OTP/EPROM - same | Flash - differs |
| Program Memory Size | 7 KB (4K x 14) | 7 KB - same | 7 KB - same | 7 KB - same | 7 KB Flash - same size |
| RAM Size | 192 bytes | 192 bytes - same | 192 bytes - same | 192 bytes - same | 192 bytes - same |
| Maximum Clock Speed | 4 MHz | 4 MHz - same | 4 MHz - same | 4 MHz - same | 20 MHz - faster |
| I/O Pins | 33 | 33 - same | 33 - same | 33 - same | 33 - same |
| Operating Temperature | -40 C to +85 C (Industrial) | -40 C to +85 C - same | -40 C to +125 C (Extended) - wider | -40 C to +85 C - same | -40 C to +85 C - same |
| ADC Channels | 8 x 8-bit | 8 x 8-bit - same | 8 x 8-bit - same | 8 x 8-bit - same | 8 x 8-bit - same |
| Approx Unit Price (USD, qty 1) | 11.50 | 11.50 - same | 13.00 (extended temp premium) | 9.00 (legacy stock discount) | 7.50 (Flash volume pricing) |
Key Differentiators
- Lower speed grade at lower cost than the -10 and -20 variants (vs PIC16C65B-10I/PT and PIC16C65B-20I/PT)
- Industrial temperature range with full OTP code security (vs PIC16F74-I/PT (Flash, -40 to +85 C))
- Same-package migration path to Flash for firmware updates (vs PIC16F74-I/PT)
- More ADC channels (8) than the 28-pin PIC16C63A/B (5 channels) (vs PIC16C63A-04I/SO (28-pin SOIC))
Design Notes
Decouple VDD with a 0.1 uF ceramic capacitor placed within 5 mm of the VDD pins (pins 10 and 31 on 44-TQFP), plus a bulk 10 uF tantalum or aluminum electrolytic on the same rail. The PIC16C65B-04I/PT draws up to ~25 mA at 4 MHz and 5 V depending on peripheral activity and I/O loading. For battery-backed designs, retain a small supply current (typ. 1-10 uA in sleep) and use the brown-out detector to prevent code corruption on slow power-down ramps. Estimated: IDD ~ 13 mA active at 4 MHz/5 V with moderate I/O load, per typical mid-range PIC figures.
Route the crystal traces (OSC1/OSC2, pins 12-13) as short as possible (<10 mm) and shield them with a ground pour to reduce EMI pickup. Place the MCLR pull-up resistor (typ. 10 kohm) close to the MCLR pin (pin 43) and add a 100 nF cap to ground for ESD protection during programming. The 44-TQFP package has 0.8 mm pitch - use 0.3 mm trace/space design rules with 0.4 mm via-annular ring. Thermal performance: at ~25 mA active and 5 V, the TQFP package dissipates ~125 mW, well within free-air ratings; no heatsink needed.
OTP/EPROM parts cannot be re-programmed - verify code thoroughly before burning, and stock windowed (JW) ceramic variants for prototype development. The '04' speed grade tops out at 4 MHz max oscillator input; using a 20 MHz crystal will cause undefined behavior or oscillator failure. Configuration bits (fuses) must be set before code execution - common mistakes include leaving the watchdog enabled without a CLRWDT in long delay loops, causing unwanted resets. The parallel slave port on PORTE/PORTD requires specific TRIS configurations to avoid bus contention with the I/O ports.
When migrating between PIC16C65B-04I/PT (44-TQFP) and PIC16C65B-04I/PQ (44-MQFP), the land patterns differ: TQFP is 10x10 mm with 0.8 mm pitch leads; MQFP is also 44-pin but has a larger body and slightly different lead geometry. PCB layouts must be designed for one or the other - they are not interchangeable without board rework. Similarly, the 40-pin PDIP package (PIC16C65B-04I/P) uses a different pinout entirely - do not assume pin compatibility.
Compliance Information
RoHS and lead-free status not explicitly stated in provided data; PIC16C65B-04I/PT uses TQFP package and is generally RoHS compliant per Microchip's product line policy, but verify via lot-specific documentation. Not AEC-Q100 qualified - for automotive safety applications use AEC-Q100-qualified Flash parts (PIC18F family).