PIC16C765-I/PT - 8-Bit USB MCU, 14KB OTP, 44-TQFP | Microchip
MPN: PIC16C765-I/PT β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.05 | $7.05 |
| 10 | $6.4 | $64.00 |
| 100 | $5.75 | $575.00 |
| 500 | $5.2 | $2,600.00 |
| 1,000 | $4.7 | $4,700.00 |
PIC16C765-I/PT Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, non-volatile program memory, working RAM, and configurable peripherals. The PIC16C765 belongs to Microchip's mid-range 8-bit PIC family, which sits in the broader taxonomy of microcontroller -> embedded processor -> semiconductor. Mid-range PICs are widely adopted for cost-sensitive, deterministic control tasks because of their compact instruction set, predictable interrupt latency, and a mature MPLAB X toolchain.
Key features include a USB 1.1 full-speed (12 Mbps) device transceiver compliant with the USB 2.0 specification, an 8-level hardware stack, 33 digital I/O lines, two 8-bit timers and one 16-bit timer, a USART, and an 8-bit successive-approximation ADC with five input channels. The OTP program memory allows one-time field programming suitable for production-grade firmware, while an in-circuit debugger (ICD) interface is supported via the standard Microchip ICSP pinout.
Typical applications include low-speed USB human-interface devices (HID) such as keyboards, mice, and game controllers, USB-to-UART bridges, industrial instrumentation front-ends with local ADC scanning, and legacy embedded control boards that benefit from on-chip USB without external transceivers.
When designing with this device, note that the OTP memory cannot be re-programmed in-circuit, so a windowed CERDIP (JW) variant is required for code development; the 44-TQFP footprint also exposes several pins shared between analog and digital functions, requiring careful pin allocation in mixed-signal layouts.
This page synthesizes distributor pricing, drop-in same-family Microchip alternatives, cross-family comparison data, and practical design notes that are not collected in any single manufacturer datasheet.
Drop-in alternatives for PIC16C765-I/PT β 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 PIC16C765-I/PT (same form factor and footprint) β differing in Core Architecture, Mounting Type, Package.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16C765T-I/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC18F4550-I/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC16C745-I/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC18F45K50-I/PT
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
PIC16C765-I/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16CXX mid-range 8-bit RISC |
| Instruction Set | 35 single-word instructions |
| Maximum Clock Frequency | 24 MHz |
| Instruction Cycle Time | 167 ns |
| MIPS (Peak) | 6 MIPS |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 14 KB (8K x 14 words) |
| Data RAM | 256 bytes |
| Data EEPROM | 0 bytes (not present on this family) |
| USB Interface | USB 1.1 Full-Speed Device (12 Mbps), USB 2.0 compliant |
| ADC | 8-bit resolution, 5 input channels |
| Timers | 2 x 8-bit, 1 x 16-bit |
| Digital I/O Pins | 33 |
| USART | 1 x enhanced USART |
| Interrupt Sources | Multiple internal and external |
| Hardware Stack | 8 levels |
| Operating Temperature Range (Industrial) | -40C to +85C |
| Package | 44-pin TQFP (PT), 10x10 mm |
| Mounting Type | Surface Mount |
| ICSP / ICD Support | Yes (standard 2-wire ICSP) |
PIC16C765-I/PT Pin Configuration
| Pin 1 | MCLR/VPP β Master clear reset / ICSP programming voltage |
| Pin 2 | RA0/AN0 β Port A bit 0 / analog input 0 |
| Pin 3 | RA1/AN1 β Port A bit 1 / analog input 1 |
| Pin 4 | RA2/AN2 β Port A bit 2 / analog input 2 |
| Pin 5 | RA3/AN3/VREF+ β Port A bit 3 / analog input 3 / ADC reference plus |
| Pin 6 | RA4/T0CKI β Port A bit 4 / Timer 0 clock input |
| Pin 7 | RA5/AN4/SS β Port A bit 5 / analog input 4 / SPI slave select |
| Pin 8 | VSS β Ground |
| Pin 9 | OSC1/CLKIN β Oscillator input / external clock in |
| Pin 10 | OSC2/CLKOUT β Oscillator output / clock out |
| Pin 11 | RC0/T1OSO/T1CKI β Port C bit 0 / Timer 1 oscillator output / clock in |
| Pin 12 | RC1/T1OSI/CCP2 β Port C bit 1 / Timer 1 oscillator in / CCP2 |
| Pin 13 | RC2/CCP1 β Port C bit 2 / CCP1 |
| Pin 14 | RC3 β Port C bit 3 |
| Pin 15 | RC4/D-/VM β Port C bit 4 / USB D- / USB VBUS monitor |
| Pin 16 | RC5/D+/VP β Port C bit 5 / USB D+ / USB VBUS pulse |
| Pin 17 | RC6/TX/CK β Port C bit 6 / USART TX / USART clock |
| Pin 18 | RC7/RX/DT β Port C bit 7 / USART RX / USART data |
| Pin 19 | VSS β Ground |
| Pin 20 | VDD β Positive supply |
| Pin 21 | RB0/INT β Port B bit 0 / external interrupt |
| Pin 22 | RB1 β Port B bit 1 |
| Pin 23 | RB2 β Port B bit 2 |
| Pin 24 | RB3 β Port B bit 3 |
| Pin 25 | RB4 β Port B bit 4 |
| Pin 26 | RB5 β Port B bit 5 |
| Pin 27 | RB6/PGC β Port B bit 6 / ICSP clock |
| Pin 28 | RB7/PGD β Port B bit 7 / ICSP data |
| Pin 29 | VUSB β USB internal 3.3 V regulator output (decoupling) |
| Pin 30 | VDD β Positive supply |
| Pin 31 | VSS β Ground |
| Pin 32 | RD0 β Port D bit 0 |
| Pin 33 | RD1 β Port D bit 1 |
| Pin 34 | RD2 β Port D bit 2 |
| Pin 35 | RD3 β Port D bit 3 |
| Pin 36 | RD4 β Port D bit 4 |
| Pin 37 | RD5 β Port D bit 5 |
| Pin 38 | RD6 β Port D bit 6 |
| Pin 39 | RD7 β Port D bit 7 |
| Pin 40 | RE0/RD β Port E bit 0 / parallel slave port read |
| Pin 41 | RE1/WR β Port E bit 1 / parallel slave port write |
| Pin 42 | RE2/CS β Port E bit 2 / parallel slave port chip select |
| Pin 43 | VDD β Positive supply |
| Pin 44 | VSS β Ground |
Typical Applications
PIC16C765-I/PT is suitable for 6 applications: USB HID Keyboard / Mouse, USB-to-UART Bridge, Industrial Instrumentation Front-End, USB Data Acquisition Module, Legacy Embedded Control Board, USB Security Dongle / Token.
USB HID Keyboard / Mouse
The PIC16C765-I/PT is well suited for low-speed USB HID peripherals such as keyboards, mice, and game controllers. Its integrated USB 1.1 full-speed (12 Mbps) device transceiver eliminates the need for an external USB chip, and the 14 KB OTP is sufficient to host a typical HID class descriptor, report protocol, and scan matrix handler. The 8-bit 5-channel ADC can monitor key-switch bounce and battery voltage, while the two 8-bit timers and one 16-bit timer provide precise USB frame timing and debounce intervals. Designers should budget 6 MIPS of CPU throughput, which is adequate for polled matrices up to 8x24 without optimization.
Recommended
USB-to-UART Bridge
Using the PIC16C765-I/PT to implement a USB-to-serial bridge leverages its USB device module plus the enhanced USART to expose a virtual COM port to a host PC. The 256-byte RAM buffer is sufficient for typical UART rates up to 115200 bps with handshake flow control, and the 14 KB OTP hosts the CDC class driver plus command interpreter. Compared to dedicated bridge chips such as the FT232R, this approach requires firmware development but allows custom baud rates, GPIO toggling, and bootloader updates on the flash-based PIC18F4550 replacement. The 33 I/O pins can also drive status LEDs and DTR/RTS handshakes.
Recommended
Industrial Instrumentation Front-End
The PIC16C765-I/PT works as a low-cost local controller in industrial instruments where a small number of analog sensors (up to 5 single-ended channels) need to be digitized and forwarded over USB to a host PC for logging. Its 8-bit ADC provides 1/256 LSB resolution suitable for thermistor, potentiometer, and 4-20 mA sense resistor monitoring, while the 24 MHz CPU supports a 10 Hz scan rate per channel with on-chip averaging. The -I industrial temperature grade (-40C to +85C) operates in cabinet environments, and the 33 I/O pins can drive relays, opto-isolators, and segment displays. The 44-TQFP footprint also simplifies IR-reflow assembly on multi-layer control boards.
Recommended
USB Data Acquisition Module
Combining the integrated USB device, the 8-bit 5-channel ADC, and three timers, the PIC16C765-I/PT can host a low-cost streaming DAQ peripheral. The on-chip ADC supports up to roughly 50 ksps aggregate throughput in practice, sufficient for audio-bandwidth sub-Nyquist sampling or vibration analysis when paired with an external anti-alias filter. The 256-byte RAM holds a short circular buffer that is double-buffered into USB IN endpoints, while the 14 KB OTP is enough to implement a vendor-class driver with bulk transfers. The PIC18F4550-I/PT drop-in adds 10-bit ADC and 2 KB of RAM for higher-fidelity designs.
Recommended
Legacy Embedded Control Board
Many long-lifecycle industrial and medical products designed in the late 1990s still build around the PIC16C765-I/PT. The OTP memory locks the firmware at production, supporting regulatory trace and field-forensic analysis, while the 44-TQFP footprint has been validated on hundreds of board revisions. The -I industrial temperature grade, the 6 MIPS throughput, and the deterministic 167 ns instruction cycle also help with IEC 60730 safety-software class B analysis. For service and repair scenarios where exact firmware re-validation is required, the OTP-based PIC16C765 remains preferable to a flash-based alternative.
Recommended
USB Security Dongle / Token
The PIC16C765-I/PT can implement a USB token or software-protection dongle because the OTP memory cannot be read back after programming, providing a hardware-level barrier against firmware cloning. The integrated USB 1.1 device handles enumeration, while vendor-class bulk transfers carry authentication challenges to the host application. The 256-byte RAM and 14 KB OTP can host a small cryptographic state machine plus vendor ID/product ID customization. For new dongle designs the PIC18F45K50-I/PT adds AES-friendly core features on the same 44-TQFP footprint.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C765-I/PT β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C765T-I/PT | PIC18F4550-I/PT | PIC16C745-I/PT | PIC18F45K50-I/PT |
|---|---|---|---|---|---|
| Package | 44-TQFP (PT), 10x10 mm | 44-TQFP (PT) - same | 44-TQFP (PT) - same | 44-TQFP (PT) - same | 44-TQFP (PT) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory Type | OTP 14 KB | OTP 14 KB | Flash 32 KB | OTP 14 KB | Flash 32 KB |
| USB Interface | USB 1.1 FS device | USB 1.1 FS device | USB 2.0 FS device | None | USB 2.0 FS device |
| ADC Resolution / Channels | 8-bit / 5 ch | 8-bit / 5 ch | 10-bit / 13 ch | 8-bit / 5 ch | 10-bit / 14 ch |
| Data RAM | 256 bytes | 256 bytes | 2048 bytes | 256 bytes | 2048 bytes |
| Maximum Clock | 24 MHz (6 MIPS) | 24 MHz (6 MIPS) | 48 MHz (12 MIPS) | 24 MHz (6 MIPS) | 48 MHz (12 MIPS) |
| Lifecycle Status | Obsolete (NRND) | Obsolete (NRND) | Active | Obsolete (NRND) | Active |
Key Differentiators
- Integrated USB 1.1 full-speed transceiver removes external USB chip (vs PIC16C745-I/PT)
- Flash-based replacement available on same 44-TQFP footprint (vs PIC18F4550-I/PT)
- OTP memory locks firmware at production (vs PIC18F4550-I/PT)
Design Notes
OTP memory cannot be re-programmed in-circuit, so do not use the PIC16C765-I/PT for development. Engineer firmware on a windowed CERDIP (PIC16C765-JW) variant or migrate to the flash-based PIC18F4550-I/PT for new boards. Programming voltages up to 13.5 V on MCLR/VPP (pin 1) must be applied according to the Microchip PIC16C745/765 datasheet programming specification; exceeding the voltage or duty cycle can damage the device.
The USB D+/D- lines (pins 16/15) are 90-ohm differential and must be routed as a matched pair. According to the Microchip datasheet, the D+/D- traces should be length-matched within 2 mm, surrounded by a continuous ground pour, and routed over an unbroken reference plane to meet USB 1.1 full-speed signal-integrity requirements. Place the VUSB decoupling capacitor (typically 220 nF) within 2 mm of pin 29 to filter the internal 3.3 V USB regulator.
Place 100 nF decoupling capacitors on each VDD pin (11, 30, 43) and a bulk 4.7-10 uF tantalum near the package. According to the Microchip datasheet, VDD must be stable before the USB transceiver starts enumerating, so the bulk capacitor must hold VDD above 4.0 V during USB host inrush events. Avoid routing analog and digital returns through the same ferrite to prevent ADC noise on the 8-bit conversion results.
Keep the 24 MHz crystal or ceramic resonator within 5 mm of pins 9 and 10, surrounded by a grounded guard ring to reduce EMI. According to the Microchip datasheet, oscillator loading capacitors should be sized based on the crystal manufacturer's CL specification and stray capacitance, typically 22-33 pF for a fundamental-mode 24 MHz AT-cut crystal. Route the ICSP clock (PGC, pin 27) and ICSP data (PGD, pin 28) away from the USB differential pair to avoid in-system programming crosstalk.
Compliance Information
RoHS, REACH, lead-free, and halogen-free status for the PIC16C765-I/PT (44-TQFP -I industrial grade) was not present in the verified web data; consult Microchip's latest material declaration before committing to a compliance-driven production run. AEC-Q100 is not applicable because the part is a general-purpose industrial MCU, not an automotive-qualified part.