PIC16C65AT-04I/PT - 8-bit OTP MCU, 7KB, 33 I/O, 44-TQFP | Microchip
MPN: PIC16C65AT-04I/PT β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.2 | $6.20 |
| 10 | $5.85 | $58.50 |
| 100 | $5.4 | $540.00 |
| 500 | $4.95 | $2,475.00 |
| 1,000 | $4.5 | $4,500.00 |
PIC16C65AT-04I/PT Overview
An 8-bit OTP microcontroller (MCU) is a Harvard-architecture CMOS device that executes one instruction per clock cycle from non-volatile program memory. OTP versions are programmed once and cannot be erased, which lowers per-unit cost for high-volume fixed-code applications. The PIC16C65A belongs to the PIC16C mid-range family and is positioned above smaller pin-count PIC16C6X parts in the same generation.
Key features include 33 digital I/O pins arranged across multiple ports, an external oscillator interface, two 8-bit timer/counters plus one 16-bit timer/counter, a USART serial port, and a capture/compare/PWM (CCP) module. The 44-pin TQFP package provides a low-profile surface-mount footprint with 0.8 mm pitch and a moderate thermal resistance suitable for forced-air or natural-convection industrial enclosures.
Architecturally the PIC16C65A uses a 14-bit instruction word with a 35-instruction RISC core, separate program and data buses, and a peripheral feature set oriented toward motor, lighting, and instrumentation control loops. Industrial-grade qualification, OTP storage, and the 4 MHz rated clock align with deterministic embedded control tasks where Flash reprogrammability is not required.
Typical applications include industrial control panels, appliance control boards, motor-driver front-ends, sensor-conditioning firmware, and legacy embedded products migrated from PIC16C5X/PIC16C6X designs. Its 33 I/O count is well suited to keypad scanning, LED/LCD multiplexing, and parallel sensor reads.
When designing with this part, note that OTP memory cannot be re-programmed in-circuit; firmware must be fully validated on a windowed or Flash-equivalent development part (e.g. PIC16F877) before committing to the OTP device for production programming. The 4 MHz ceiling also requires that math-heavy routines be reviewed against instruction-cycle budgets.
This page synthesizes distributor pricing, same-brand drop-in alternatives, and applied engineering notes not consolidated on the manufacturer datasheet, giving procurement and firmware teams a faster decision path for legacy 8-bit PIC designs.
Drop-in alternatives for PIC16C65AT-04I/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 PIC16C65AT-04I/PT (same form factor and footprint) β differing in RoHS Status, Program Memory Type, Timers, ADC, Core Architecture.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16C65AT-04E/PT
β Drop-Inβ In Stock
$7.55 / Unit
View Datasheet βPIC16C65A-04I/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC16C65A-20I/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC16C65A-20E/PT
β Drop-Inβ In Stock
$11.85 / Unit
View Datasheet βPIC16C65A-04/PQ
β Drop-Inπ Reference alternative (not in catalog)
PIC16C65AT-04I/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16C6X, 8-bit RISC, 14-bit instruction word |
| Program Memory Type | One-Time Programmable (OTP) ROM |
| Program Memory Size | 7KB (4K x 14) |
| RAM Size | 192 x 8 bytes |
| Maximum Clock Frequency | 4 MHz |
| Supply Voltage (Vdd) | 4.0 V to 6.0 V |
| Number of I/O Pins | 33 |
| Oscillator Type | External |
| Package | 44-pin TQFP (PT) |
| Operating Temperature | -40C to +85C (industrial, -I grade) |
| Instruction Count | 35 single-word instructions |
| Timers | Timer0 (8-bit), Timer1 (16-bit), Timer2 (8-bit) |
| Communication Peripherals | USART/SCI |
| CCP Modules | Capture/Compare/PWM x 1 |
| Packaging | Tape & Reel (TR) |
| Mounting Type | Surface Mount |
| Lead-Free / RoHS | Compliant (verify lot-level) |
PIC16C65AT-04I/PT Pin Configuration
| Pin 1 | MCLR β Master Clear (Reset) input, active low |
| Pin 2 | RA0 β PORTA bit 0 (digital I/O) |
| Pin 3 | RA1 β PORTA bit 1 (digital I/O) |
| Pin 4 | RA2 β PORTA bit 2 (digital I/O) |
| Pin 5 | RA3 β PORTA bit 3 (digital I/O) |
| Pin 6 | RA4 β PORTA bit 4 (digital I/O, open-drain option) |
| Pin 7 | RA5 β PORTA bit 5 (digital I/O) |
| Pin 8 | Vss β Ground reference |
| Pin 9 | OSC1 β External oscillator input (crystal/ceramic resonator) |
| Pin 10 | OSC2 β External oscillator output (crystal mode) |
| Pin 11 | RC0 β PORTC bit 0 (digital I/O) |
| Pin 12 | RC1 β PORTC bit 1 (digital I/O) |
| Pin 13 | RC2 β PORTC bit 2 (digital I/O / CCP1) |
| Pin 14 | RC3 β PORTC bit 3 (digital I/O) |
| Pin 15 | RC4 β PORTC bit 4 (digital I/O) |
| Pin 16 | RC5 β PORTC bit 5 (digital I/O) |
| Pin 17 | RC6 β PORTC bit 6 (TX/CK USART) |
| Pin 18 | RC7 β PORTC bit 7 (RX/DT USART) |
| Pin 19 | Vss β Ground reference |
| Pin 20 | Vdd β Positive supply voltage (4.0 V to 6.0 V) |
| Pin 21 | RB0 β PORTB bit 0 (digital I/O, external interrupt) |
| Pin 22 | RB1 β PORTB bit 1 (digital I/O) |
| Pin 23 | RB2 β PORTB bit 2 (digital I/O) |
| Pin 24 | RB3 β PORTB bit 3 (digital I/O) |
| Pin 25 | RB4 β PORTB bit 4 (digital I/O, interrupt-on-change) |
| Pin 26 | RB5 β PORTB bit 5 (digital I/O, interrupt-on-change) |
| Pin 27 | RB6 β PORTB bit 6 (digital I/O / ICSP clock) |
| Pin 28 | RB7 β PORTB bit 7 (digital I/O / ICSP data) |
| Pin 29 | Vss β Ground reference |
| Pin 30 | Vdd β Positive supply voltage (4.0 V to 6.0 V) |
| Pin 31 | RD0 β PORTD bit 0 (digital I/O) |
| Pin 32 | RD1 β PORTD bit 1 (digital I/O) |
| Pin 33 | RD2 β PORTD bit 2 (digital I/O) |
| Pin 34 | RD3 β PORTD bit 3 (digital I/O) |
| Pin 35 | RD4 β PORTD bit 4 (digital I/O) |
| Pin 36 | RD5 β PORTD bit 5 (digital I/O) |
| Pin 37 | RD6 β PORTD bit 6 (digital I/O) |
| Pin 38 | RD7 β PORTD bit 7 (digital I/O) |
| Pin 39 | Vss β Ground reference |
| Pin 40 | Vdd β Positive supply voltage (4.0 V to 6.0 V) |
| Pin 41 | RE0 β PORTE bit 0 (digital I/O / read enable) |
| Pin 42 | RE1 β PORTE bit 1 (digital I/O / write enable) |
| Pin 43 | RE2 β PORTE bit 2 (digital I/O / chip select) |
| Pin 44 | NC β Not connected on 44-pin TQFP package variant (no TOCKI alternate, verify against DS30234D) |
Typical Applications
PIC16C65AT-04I/PT is suitable for 6 applications: Industrial Control Panels, Appliance Control Boards, Motor Driver Front-Ends, Sensor Conditioning Firmware, Legacy Embedded Migration, Lighting Control Systems.
Industrial Control Panels
The PIC16C65AT-04I/PT is well suited to industrial control panels that scan keypads, multiplex 7-segment or character LCDs, and drive relay or SSR outputs via opto-isolated GPIOs. With 33 digital I/O organized across five ports and 192 bytes of SRAM, it can poll 4x4 key matrices, decode rotary-encoder inputs, and sequence indicator LEDs without external I/O expanders. The 4 MHz clock sustains >1 MHz instruction throughput, enough for 50 Hz debounce filtering, state-machine control logic, and Modbus-RTU framing through the on-chip USART. Industrial -40C to +85C rating supports factory-floor enclosures; OTP memory fits fixed firmware shipped in high panel volumes.
Recommended
Appliance Control Boards
The PIC16C65AT-04I/PT serves as the main controller in white-goods and small-appliance boards, where fixed-function OTP code is acceptable and bill-of-material cost is critical. The on-chip 8-bit and 16-bit timer/counters handle motor RPM sensing (via tachogenerator or Hall sensor), triac zero-crossing detection for AC load switching, and PWM generation for variable-speed fan or pump drives through the CCP module. 7KB of program memory accommodates state-machine firmware for washing-machine cycles, dishwasher routines, or HVAC damper control with non-volatile parameter storage in external EEPROM. Industrial -I temp grade withstands appliance-internal hotspots up to 85C.
Recommended
Motor Driver Front-Ends
In small DC and stepper motor driver boards, the PIC16C65AT-04I/PT generates step/direction signals, monitors current-sense amplifiers, and implements closed-loop acceleration/deceleration profiles via the on-chip CCP/PWM and 16-bit Timer1 modules. 33 I/O pins drive multi-axis stepper logic (up to 4 axes with step+direction+enable+microstep lines), read end-stop and encoder inputs, and toggle H-bridge enable lines. The 4 MHz instruction rate is sufficient for trapezoidal-velocity profiling at step rates up to ~10 kHz, and OTP memory locks the velocity tables to prevent field tampering in OEM motor-control products.
Recommended
Sensor Conditioning Firmware
The PIC16C65AT-04I/PT is widely used in multi-channel sensor signal-conditioning boards that read thermocouples, RTDs, load cells, and 4-20 mA loops via external analog front-ends. The PIC16C65A does not have on-chip ADC, so an external ADC such as MCP3202/MCP3204 is paired via SPI, with the MCU performing linearization, cold-junction compensation, and digital filtering. 7KB program memory holds full IEEE 754 floating-point thermocouple tables in lookup form, while 192 bytes of SRAM provides working buffer for moving-average and median filters. Industrial temp grade ensures stable readings across plant environments.
Recommended
Legacy Embedded Migration
The PIC16C65AT-04I/PT is a target for products migrating from earlier PIC16C5X or PIC16C6X designs where the PIC16 mid-range architecture, register file, and 14-bit instruction set are preserved while gaining larger memory and more I/O. The PIC16C65A shares the same core instruction set, peripheral library naming, and configuration-bit semantics as the entire PIC16 mid-range family, allowing engineers to re-target MPASM or XC8 source files with minimal rewrites. With 7KB of OTP memory, it gives a moderate code-size upgrade over PIC16C55/PIC16C57 while keeping the OTP cost advantage of high-volume production runs.
Recommended
Lighting Control Systems
In DMX-512 or DALI lighting fixtures and architectural dimmer panels, the PIC16C65AT-04I/PT acts as the protocol decoder and PWM generator, leveraging its USART for DMX reception and its CCP/PWM channels plus Timer0/Timer2 for triac-fired or MOSFET-driven dimming. 33 I/O can drive multi-channel RGBW LED drivers via shift-register expanders, support rotary encoder input for manual dim/preset selection, and toggle relays for scene switching. OTP memory secures the fixture personality from field modification, which is a hard requirement in many entertainment-lighting installations. Industrial temp grade survives stage-lighting rack ambient conditions.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C65AT-04I/PT β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C65AT-04E/PT | PIC16C65A-04I/PT | PIC16C65A-20I/PT | PIC16C65A-20E/PT | PIC16C65A-04/PQ |
|---|---|---|---|---|---|---|
| Package | 44-TQFP (PT) | 44-TQFP (PT) - same | 44-TQFP (PT) - same | 44-TQFP (PT) - same | 44-TQFP (PT) - same | 44-MQFP (PQ) - same footprint family |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Max Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 20 MHz | 4 MHz |
| Program Memory | 7KB OTP | 7KB OTP | 7KB OTP | 7KB OTP | 7KB OTP | 7KB OTP |
| Operating Temperature | -40C to +85C (industrial) | -40C to +125C (extended) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +125C (extended) | -40C to +85C (industrial) |
| Number of I/O | 33 | 33 | 33 | 33 | 33 | 33 |
| Packaging | Tape & Reel | Tape & Reel | Tray | Tray | Tray | Tray |
| Approx Unit Price (qty 100) | USD 5.40 | USD 6.10 (extended temp premium) | USD 5.20 | USD 5.80 (20 MHz premium) | USD 6.40 | USD 5.30 |
| Family / Silicon Revision | PIC16C65A (Rev. A) | PIC16C65A (Rev. A) | PIC16C65A (Rev. A) | PIC16C65A (Rev. A) | PIC16C65A (Rev. A) | PIC16C65A (Rev. A) |
Key Differentiators
- Industrial -40C to +85C temperature grade for factory-floor and outdoor enclosures (vs PIC16C65A-04E/PT)
- Tape-and-reel packaging for high-volume SMT assembly (vs PIC16C65A-04I/PT (tray))
- Lower-frequency 4 MHz bin optimizes oscillator stability for cost-sensitive designs (vs PIC16C65A-20I/PT (20 MHz grade))
Design Notes
The PIC16C65AT-04I/PT draws a few mA in active mode and falls to the microampere range in Sleep; the Vdd range of 4.0 V to 6.0 V is narrower than Flash PIC16F parts. Place a 100 nF ceramic decoupling capacitor close to each Vdd pin (pins 20, 30, 40) and a single 10 uF bulk electrolytic or tantalum cap on the main 5 V rail to suppress switching transients from relay or triac loads sharing the same supply. The MCU has no internal brown-out reset (BOR); add an external voltage supervisor such as MCP100-4.6V for safety-critical applications.
For the 44-pin TQFP (PT) footprint, follow Microchip recommended land pattern with 0.4 mm lead pitch and 0.3 mm pad width. Keep the ICSP clock/data lines (RB6/RB7) and MCLR trace short (less than 50 mm) to ensure reliable in-circuit programming via PICkit or ICD tools. Place the 4 MHz crystal or ceramic resonator within 10 mm of OSC1/OSC2 pins and route the OSC traces over a continuous ground pour to minimize EMI coupling into adjacent analog or timer-input traces.
OTP memory cannot be erased or rewritten once programmed; any firmware bug in the production OTP image is unrecoverable. Always develop and validate code on a windowed (JW) or Flash-equivalent part (e.g. PIC16F877A-I/PT) before committing firmware to the OTP PIC16C65AT-04I/PT for volume production. Watch configuration bits carefully: disabling the Watchdog Timer (WDT) for sleep-mode tests, selecting the correct oscillator mode (XT for 4 MHz crystal), and enabling the power-on timer (PWRT) are common sources of dead-on-arrival boards.
RB0 supports edge-triggered external interrupt; keep the RB0 trace short and routed away from the OSC1/OSC2 traces to avoid false interrupts from oscillator coupling. PORTE pins (RE0/RE1/RE2) double as control lines for a parallel slave port on the PIC16C65A; if not used for PSP operation, configure them as digital I/O in firmware to avoid floating inputs that consume extra supply current and can trigger spurious interrupt-on-change events on PORTB.
Compliance Information
RoHS and lead-free per Microchip product-page declarations for the 44-TQFP (PT) OTP PIC16C6X family; verify lot-level RoHS certificate at order time. Not AEC-Q100 qualified; for AEC-Q100 designs, migrate to PIC16F or PIC18 automotive-graded siblings.
