PIC18F66J65T-I/PT - 8-bit MCU 96KB Flash 10BASE-T Ethernet | Microchip
MPN: PIC18F66J65T-I/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.5 | $7.50 |
| 10 | $6.85 | $68.50 |
| 100 | $5.92 | $592.00 |
| 500 | $5.31 | $2,655.00 |
| 1,000 | $4.78 | $4,780.00 |
PIC18F66J65T-I/PT Overview
A microcontroller (MCU) is a single-chip computer containing a CPU, program memory (Flash), data memory (RAM), timers, communication peripherals, and I/O. The PIC18 family uses a 16-bit modified Harvard RISC architecture targeting high-throughput 8-bit applications where deterministic interrupt response matters more than raw MHz. Embedded Ethernet MCUs like the PIC18F66J65 form a sub-category at the intersection of microcontrollers and network interface ICs, combining an HTTP/TCP-friendly stack with general-purpose digital I/O.
Key features include 54 digital I/O pins organized across multiple ports, an integrated 10BASE-T Ethernet MAC with HP Auto-MDIX PHY, full-speed USB 2.0 (device/host/OTG), two CAN modules (ECAN), two UART/USART modules, SPI and I2C peripherals, 16-channel 10-bit ADC, and four 16-bit timers with CCP/ECCP modules. The on-chip RTCC with timestamp enables time-stamped event logging critical for industrial controllers. An LCD driver with charge pump supports up to 132 segments, eliminating external display drivers in HMI designs.
Architecture-wise, the device uses Microchip's nanoWatt XLP technology for low-power sleep modes (down to 100 nA typical standby), making it deployable in battery-backed remote monitoring nodes. Hardware AES/DES encryption accelerators and a true random number generator support secure remote-management firmware updates. The 64-pin TQFP package exposes ample peripherals, including parallel master/slave port for bus expansion.
Typical applications include industrial Ethernet sensors, building automation gateways, remote monitoring controllers, intelligent HVAC nodes, networked laboratory instruments, and automotive infotainment auxiliary modules. Its combination of 10BASE-T, USB, CAN, and ADC simplifies multi-protocol field nodes that previously required a separate Ethernet controller.
When designing with this MCU, allocate sufficient Flash headroom for the TCP/IP stack (roughly 40 KB of the 96 KB), use the integrated MAC/PHP+PHYs and an external 25 MHz crystal reference, and follow Microchip's TCP/IP stack Application Note AN833 for buffer sizing. EMC layout requires guarding the analog AVdd rail and isolating the Ethernet magnetics by at least 4 mm of copper-free PCB area.
This page synthesizes distributor pricing, drop-in alternatives from the same PIC18 family, and practical Ethernet-PCB design notes not found in the standalone manufacturer datasheet.
Drop-in alternatives for PIC18F66J65T-I/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 PIC18F66J65T-I/PT (same form factor and footprint) — differing in Package, Program Memory (Flash), ADC, I/O Pins, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F67J60-I/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$5.2 / Unit
View Datasheet →PIC18F96J65-I/PT
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18F86J65-I/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$5.8 / Unit
View Datasheet →PIC18F66J65-I/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$5.4 / Unit
View Datasheet →PIC18F67J10-I/PT
✅ Drop-In✓ In Stock
$5.4 / Unit
View Datasheet →PIC18F66J65T-I/PT Maximum Ratings & Electrical Characteristics
| Architecture | PIC18 (8-bit RISC, Harvard) |
| Instruction Set | PIC18 (16-bit instructions) |
| Program Memory (Flash) | 96 KB |
| RAM | 12 KB |
| CPU Speed | 40 MHz (10 MIPS) |
| Instruction Cycle | 200 ns |
| Supply Voltage (Vdd) | 2.0 V to 3.6 V |
| Wide-range Input Voltage | 4.2 V to 5.5 V |
| I/O Pins | 54 (with digital features) |
| Ethernet | 10BASE-T (integrated MAC + PHY) |
| USB | Full-Speed USB 2.0 (device/host/OTG) |
| CAN | 2x ECAN modules |
| UART/USART | 2x |
| SPI | Yes |
| I2C | Yes |
| ADC | 10-bit, up to 16 channels |
| Timers | 4x 16-bit with CCP/ECCP |
| LCD Driver | Up to 132 segments with charge pump |
| Encryption | AES / DES hardware accelerator |
| Package | 64-pin TQFP (PT), 10x10 mm |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 C to +85 C (Industrial) |
| MSL Level | 3 |
| RoHS Status | Compliant |
PIC18F66J65T-I/PT Pin Configuration
| Pin 1 | RC1/T1OSI/CCP2 — I/O port C bit 1 / Timer1 oscillator input / Capture/Compare 2 |
| Pin 2 | RC2/CCP1 — I/O port C bit 2 / Capture/Compare 1 |
| Pin 3 | RC3/SCK/SCL — I/O port C bit 3 / SPI clock / I2C clock |
| Pin 4 | RC4/SDI/SDA — I/O port C bit 4 / SPI data in / I2C data |
| Pin 5 | RC5/SDO — I/O port C bit 5 / SPI data out |
| Pin 6 | RC6/TX1/CK1 — I/O port C bit 6 / USART1 TX / clock out |
| Pin 7 | RC7/RX1/DT1 — I/O port C bit 7 / USART1 RX / data |
| Pin 8 | RE0/RD — I/O port E bit 0 / parallel slave port read |
| Pin 9 | RE1/WR — I/O port E bit 1 / parallel slave port write |
| Pin 10 | RE2/CS — I/O port E bit 2 / parallel slave port chip select |
| Pin 11 | VDD — Core supply 2.0-3.6 V |
| Pin 12 | VSS — Ground |
| Pin 13 | OSC1/CLKI/RA7 — Crystal input / external clock / port A bit 7 |
| Pin 14 | OSC2/CLKO/RA6 — Crystal output / clock out / port A bit 6 |
| Pin 15 | VDD5V0 — Wide-range 5 V input supply |
| Pin 16 | RH0 — I/O port H bit 0 |
| Pin 17 | RH1 — I/O port H bit 1 |
| Pin 18 | RH2 — I/O port H bit 2 |
| Pin 19 | RH3 — I/O port H bit 3 |
| Pin 20 | RH4/LEDA — I/O port H bit 4 / LCD backlight anode |
| Pin 21 | RH5/LEDK — I/O port H bit 5 / LCD backlight cathode |
| Pin 22 | RH6 — I/O port H bit 6 |
| Pin 23 | RH7/CCP6 — I/O port H bit 7 / Capture/Compare 6 |
| Pin 24 | RG0 — I/O port G bit 0 |
| Pin 25 | RG1/TX2 — I/O port G bit 1 / USART2 TX |
| Pin 26 | RG2/RX2 — I/O port G bit 2 / USART2 RX |
| Pin 27 | RG3/CCP5 — I/O port G bit 3 / Capture/Compare 5 |
| Pin 28 | RG4 — I/O port G bit 4 |
| Pin 29 | MCLR/RE3 — Master clear reset / port E bit 3 |
| Pin 30 | RA0/AN0 — I/O port A bit 0 / analog input 0 |
| Pin 31 | RA1/AN1 — I/O port A bit 1 / analog input 1 |
| Pin 32 | RA2/AN2 — I/O port A bit 2 / analog input 2 |
| Pin 33 | RA3/AN3 — I/O port A bit 3 / analog input 3 |
| Pin 34 | RA4/AN4/T0CKI — I/O port A bit 4 / analog input 4 / Timer0 clock |
| Pin 35 | RA5/AN5 — I/O port A bit 5 / analog input 5 |
| Pin 36 | VSS — Ground |
| Pin 37 | VDD — Core supply 2.0-3.6 V |
| Pin 38 | RB0/AN8 — I/O port B bit 0 / analog input 8 |
| Pin 39 | RB1/AN9 — I/O port B bit 1 / analog input 9 |
| Pin 40 | RB2/AN10 — I/O port B bit 2 / analog input 10 |
| Pin 41 | RB3/AN11 — I/O port B bit 3 / analog input 11 |
| Pin 42 | RB4/AN12 — I/O port B bit 4 / analog input 12 |
| Pin 43 | RB5/AN13 — I/O port B bit 5 / analog input 13 |
| Pin 44 | RB6/AN14/PGC — I/O port B bit 6 / analog input 14 / ICSP clock |
| Pin 45 | RB7/AN15/PGD — I/O port B bit 7 / analog input 15 / ICSP data |
| Pin 46 | AVSS — Analog ground |
| Pin 47 | AVDD — Analog supply (filtered) |
| Pin 48 | RD0/PSP0 — I/O port D bit 0 / parallel slave port 0 |
| Pin 49 | RD1/PSP1 — I/O port D bit 1 / parallel slave port 1 |
| Pin 50 | RD2/PSP2/CANTX1 — I/O port D bit 2 / parallel slave port 2 / CAN1 TX |
| Pin 51 | RD3/PSP3/CANRX1 — I/O port D bit 3 / parallel slave port 3 / CAN1 RX |
| Pin 52 | RD4/PSP4 — I/O port D bit 4 / parallel slave port 4 |
| Pin 53 | RD5/PSP5/CANTX2 — I/O port D bit 5 / parallel slave port 5 / CAN2 TX |
| Pin 54 | RD6/PSP6/CANRX2 — I/O port D bit 6 / parallel slave port 6 / CAN2 RX |
| Pin 55 | RD7/PSP7 — I/O port D bit 7 / parallel slave port 7 |
| Pin 56 | VMGR — Ethernet voltage regulator bypass |
| Pin 57 | VDDRX — Ethernet receiver supply |
| Pin 58 | VSSRX — Ethernet receiver ground |
| Pin 59 | TPOUT+ — Ethernet twisted pair output + |
| Pin 60 | TPOUT- — Ethernet twisted pair output - |
| Pin 61 | TPIN+ — Ethernet twisted pair input + |
| Pin 62 | TPIN- — Ethernet twisted pair input - |
| Pin 63 | RBIAS — Ethernet bias reference resistor |
| Pin 64 | VSS — Ground |
Typical Applications
PIC18F66J65T-I/PT is suitable for 6 applications: Industrial Ethernet Sensor Gateway, Building Automation Controller, Networked Remote Monitoring Node, USB-CAN-Ethernet Multi-Protocol Bridge, Intelligent HVAC Control Unit, Security and Access Control Panel.
Industrial Ethernet Sensor Gateway
The PIC18F66J65T-I/PT's integrated 10BASE-T MAC with HP Auto-MDIX eliminates the need for an external Ethernet controller, making it ideal for cost-optimized industrial sensor gateways. The 96 KB Flash comfortably hosts Microchip's TCP/IP stack (Application Note AN833) with room left for Modbus TCP server and edge data filtering. With 54 I/O pins, multiple sensors can be aggregated before transmission over Ethernet. Operating from -40 C to +85 C, the part handles factory floor temperatures, while its 100 nA nanoWatt standby enables solar or battery-backed remote sensor nodes that wake, push data, and return to sleep.
Recommended
Building Automation Controller
The PIC18F66J65T-I/PT combines Ethernet connectivity with two ECAN modules, making it well suited to building automation controllers bridging CAN-based HVAC/lighting fieldbuses to BACnet/Modbus TCP over Ethernet. Its 16-channel 10-bit ADC interfaces directly with temperature, humidity, and CO2 sensors without external analog front-ends, while four 16-bit timers drive PWM-controlled damper and valve actuators. The integrated LCD driver with charge pump supports up to 132 segments for in-wall HMI displays, eliminating external display driver ICs. Wide-range 4.2-5.5 V input is compatible with common 24 V industrial building-automation backplanes.
Recommended
Networked Remote Monitoring Node
The PIC18F66J65T-I/PT enables compact remote monitoring nodes that report sensor readings over Ethernet to a central SCADA server. The hardware AES engine encrypts telemetry for secure transmission, and the RTCC with timestamp tags each packet for accurate event correlation in industrial environments. Its 54 I/O pins handle multiple sensor types - digital inputs, analog outputs, and pulse counters - all in a single chip. The 96 KB Flash holds the TCP/IP stack plus custom application logic such as alarm thresholds and local control loops.
Recommended
USB-CAN-Ethernet Multi-Protocol Bridge
For industrial protocol bridges, the PIC18F66J65T-I/PT uniquely combines full-speed USB 2.0 (device/host/OTG), two ECAN controllers, and 10BASE-T Ethernet on a single die. This triple-protocol capability allows one chip to translate CAN messages to Ethernet (or USB to CAN), eliminating the usual multi-IC bridge. USB OTG enables field configuration from tablets or smartphones without a host PC, useful during commissioning. The 12 KB RAM supports buffer management between the three bus speeds without packet loss.
Recommended
Intelligent HVAC Control Unit
With 16 analog inputs, four 16-bit timers, and integrated Ethernet, the PIC18F66J65T-I/PT is a strong choice for intelligent HVAC controllers. The 10-bit ADC samples multiple temperature zones and air-quality sensors while the ECCP modules drive variable-speed fan motors and damper actuators. Real-time communication with building management systems occurs over Ethernet, and the nanoWatt XLP sleep reduces standby power when the system is in eco-mode. The industrial -40 C to +85 C range handles rooftop and plant-room installations without thermal concerns.
Recommended
Security and Access Control Panel
The PIC18F66J65T-I/PT supports security access panels that report door state, badge events, and alarm triggers over Ethernet to a centralized access-control server. Hardware AES/DES acceleration secures credential data, while the RTCC timestamps every event for audit logs. The integrated LCD controller drives local keypads and indicator panels without external drivers. With 54 I/O, the same MCU handles multiple doors (each needing card reader, exit button, magnetic sensor, and buzzer), reducing per-door cost in multi-door installations.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F66J65T-I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F67J60-I/PT | PIC18F96J65-I/PT | PIC18F86J65-I/PT | PIC18F67J10-I/PT |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | TQFP-64 (PT) 10x10 mm | TQFP-64 (PT) - same | TQFP-64 (PT) - same | TQFP-64 (PT) - same | TQFP-64 (PT) - same |
| Flash Memory | 96 KB | 128 KB | 96 KB | 96 KB | 128 KB |
| RAM | 12 KB | 8 KB | 12 KB | 12 KB | 3.8 KB |
| Integrated Ethernet | 10BASE-T MAC+PHY | 10BASE-T MAC+PHY | 10BASE-T MAC+PHY | 10BASE-T MAC+PHY | No |
| CAN Modules | 2x ECAN | 2x ECAN | 2x ECAN | 2x ECAN | 1x ECAN |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | 0 C to +70 C (lower) | -40 C to +85 C |
Key Differentiators
- Integrated 10BASE-T MAC+PHY eliminates external Ethernet controller cost (vs PIC18F67J10-I/PT)
- 128 KB Flash headroom in pin-compatible upgrade path (vs PIC18F67J60-I/PT)
- Dual ECAN modules for redundant fieldbus comms (vs PIC18F66J55-I/PT)
Design Notes
Route the Ethernet differential pair (TPOUT+/TPOUT- and TPIN+/TPIN-) with controlled 100-ohm differential impedance and keep the pair length-matched within 2 mm. Place the 49.9-ohm RBIAS resistor to VDDRX directly adjacent to pin 63 to set the integrated PHY bias current accurately. Maintain at least 4 mm of copper-free PCB area between the analog AVdd island and the noisy digital TQFP-64 power pins, and place a ferrite bead in series with the VDD5V0 input to suppress switching regulator noise from injecting into the Ethernet PHY supply rail.
Both core Vdd (2.0-3.6 V) and wide-range VDD5V0 (4.2-5.5 V) pins must be bypassed individually. Use one 100 nF X7R ceramic per Vdd pin and one bulk 10 uF tantalum close to the regulator output. The internal 2.5 V regulator that feeds VMGR (Ethernet) and VDDRX must have its own 10 uF + 100 nF capacitor stack on those output pins. Do NOT power the part only via VDD5V0 without the core Vdd rail, as Ethernet MAC logic derives from the internal regulator and requires both supplies for proper operation.
Do not exceed the 25 MHz reference crystal load-capacitance tolerance, as the integrated Ethernet MAC uses that clock to derive TX/RX timings; exceeding 30 ppm mismatch causes link-up failures or packet CRC errors. The MCLR reset pin requires a 10 kohm pull-up to Vdd with a 100 nF capacitor for noise immunity - missing this RC leads to random brown-out resets near the Ethernet isolation barrier. Avoid enabling the LCD charge pump until AVdd stabilizes, or the charge-pump capacitor pin draws inrush current that can momentarily collapse AVdd.
At 40 MHz CPU core and active Ethernet MAC, the PIC18F66J65T-I/PT dissipates approximately 150 mW typical and 250 mW peak under sustained operation. In a thermally constrained enclosure (sealed IP65 field box), provide at least 1 square inch of exposed inner ground copper under the TQFP thermal pad to keep junction below 125 C. At -40 C minimum, allow 50 ms warmup before activating the Ethernet PHY to prevent lock-up of the bias network.
Compliance Information
RoHS and REACH compliance confirmed in Mouser distributor listing; automotive AEC-Q100 qualification does not apply to this industrial-grade part (no -V or -Q suffix).
