PIC18F84J90-I/PT - 8-bit 40MHz MCU 16KB Flash 80-TQFP | Microchip
MPN: PIC18F84J90-I/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.95 | $4.95 |
| 10 | $4.42 | $44.20 |
| 100 | $3.91 | $391.00 |
| 500 | $3.5 | $1,750.00 |
| 1,000 | $3.1 | $3,100.00 |
PIC18F84J90-I/PT Overview
An 8-bit MCU (microcontroller) is a single-chip computer that integrates a CPU, program memory (Flash), data memory (RAM), and a rich set of peripherals (ADC, timers, communication interfaces, I/O). The PIC18 family sits in Microchip's mainstream 8-bit line, which forms a sub-tree of microcontrollers > MCUs > microcomputers > embedded processors > semiconductors. The "F" prefix designates Flash-based in-circuit programmability, while the "J90" suffix identifies the LCD-driver variant aimed at low-power, segment-display applications.
Key features of the PIC18F84J90 family include an integrated LCD controller with charge-pump support, a 10-bit ADC, nanoWatt power-managed modes for battery-operated designs, two USART modules, a 10-bit DAC output, and an I2C/SPI peripheral complement. The wide 2.0V-3.6V core voltage (driven from the PIC18 "J" low-voltage, high-performance process) and on-chip regulator simplify single-supply PCB designs for handheld meters and thermostats.
From an architectural standpoint, the part uses a 16-bit instruction word with an 8-bit data path, 32-level hardware stack, and linear memory addressing that simplifies C code generation. The on-chip LCD driver can sink segments through 64 common/segment pins while the core stays in a low-current idle mode, enabling years of operation on a coin cell.
Typical applications include handheld utility meters (gas, water, electricity), digital thermometers and thermostats, home-security control panels, point-of-sale terminals, and battery-powered consumer products with segmented LCDs. The combination of LCD driver, ADC, low-power modes, and 67 I/O makes it a strong fit when the system needs a single chip to handle user interface, sensing, and control.
A key design consideration is whether the design needs 64-pin or 80-pin I/O: this -I/PT variant is the 80-pin TQFP, providing the maximum 67-I/O and 64-segment LCD capability. Designers targeting lower pin counts should choose the 64-pin PIC18F65J90 or PIC18F65K90 family members.
This page synthesizes distributor pricing, drop-in and migration alternatives, and practical design notes not found in the manufacturer datasheet alone, helping procurement and engineering teams evaluate the PIC18F84J90-I/PT for embedded LCD designs.
Drop-in alternatives for PIC18F84J90-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 PIC18F84J90-I/PT (same form factor and footprint) — differing in Operating Temperature, I/O Pins, Package, ADC, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F85J90-I/PT
✅ Drop-In✓ In Stock
$4.5 / Unit
View Datasheet →PIC18F84J90T-I/PT
✅ Drop-In✓ In Stock
$5.4 / Unit
View Datasheet →PIC18F84J11-I/PT
✅ Drop-In✓ In Stock
$4.2 / Unit
View Datasheet →PIC18F8490-I/PT
✅ Drop-In✓ In Stock
$5.55 / Unit
View Datasheet →PIC18F8410-I/PT
✅ Drop-In✓ In Stock
$6.85 / Unit
View Datasheet →PIC18F84J90-I/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 (8-bit RISC, 16-bit instruction word) |
| Program Memory (Flash) | 16 KB (8K x 16) |
| Data Memory (RAM) | 1024 bytes |
| Maximum CPU Speed | 40 MHz (up to 12 MIPS) |
| Operating Voltage Range | 2.0 V to 3.6 V |
| I/O Pins | 67 |
| Pin / Package | 80-TQFP (PT, 12 x 12 mm) |
| LCD Driver | On-chip segmented LCD controller with charge pump |
| Communication | 2x USART, I2C, SPI |
| Power Management | nanoWatt power-managed modes (idle, sleep, RTCC) |
| Operating Temperature | -40C to +85C (industrial -I) |
| Mounting Type | Surface Mount (TQFP) |
| RoHS Status | Compliant |
| MSL Level | 3 (per JEDEC J-STD-020) |
PIC18F84J90-I/PT 80-tqfp (pt, 12 x 12 mm) Pin Configuration Guide
Pin configuration for PIC18F84J90-I/PT (80-tqfp (pt, 12 x 12 mm) package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for PIC18F84J90-I/PT.
Refer to the datasheet for full pin configuration.
Typical Applications
PIC18F84J90-I/PT is suitable for 6 applications: Handheld Gas / Water / Electricity Meter, Digital Thermostat with LCD Display, Home Security Control Panel, Point-of-Sale Terminal, Battery-Powered Medical Monitoring Device, Industrial Process Indicator.
Handheld Gas / Water / Electricity Meter
The PIC18F84J90-I/PT fits handheld utility meters because its integrated segmented LCD driver directly drives the meter display glass without an external controller, while 16 KB of Flash holds metering firmware and 1024 bytes of RAM supports run-time energy calculations. Its 2.0-3.6V operation and nanoWatt sleep modes enable multi-year battery life when the device wakes periodically to sample sensors. The 67 I/O pins accept multiple pulse inputs, tamper switches, and optical interfaces. Compared with separate LCD-driver designs, the J90 family cuts part count from two ICs to one, reducing BOM cost and PCB area.
Recommended
Digital Thermostat with LCD Display
The PIC18F84J90-I/PT fits digital thermostats because the on-chip 10-bit ADC reads NTC thermistor dividers with sufficient resolution for 0.1C temperature display, and the integrated LCD driver handles backlit or reflective glass displays up to 64 segments. The 40 MHz CPU and 12 MIPS throughput manage PID control loops for HVAC relays without timing jitter. nanoWatt power-managed modes cut idle current under 1 uA, supporting battery-only thermostats in retrofit installations. The 80-pin TQFP gives design headroom for keypad inputs, multiple relay drivers, and I2C sensor expansion.
Recommended
Home Security Control Panel
The PIC18F84J90-I/PT serves home security control panels because its 67 I/O accommodates multiple zone inputs (PIR sensors, door contacts, glass-break detectors) while the LCD driver shows zone status and alarm codes on a 7-7-7 segmented display. The 16 KB Flash holds credential and event logging firmware, and the on-chip USART interfaces with GSM/PSTN modems for alarm reporting. The wide 2.0-3.6V operation allows direct battery backup during AC mains failure. Compared to discrete MCU plus driver designs, the J90 cuts part count and improves EMC by keeping LCD drive on-chip.
Recommended
Point-of-Sale Terminal
The PIC18F84J90-I/PT fits low-volume point-of-sale terminals where its 8-bit PIC18 core handles keypad scanning, LCD user prompts, and serial communication with mag-stripe readers or printers without an external RTOS. The integrated LCD driver eliminates a separate HT1621-style segment controller, reducing BOM cost in the $40-$60 terminal segment. The 16 KB Flash and 1024-byte RAM are sufficient for menu firmware, price tables, and transaction buffers. The 80-pin TQFP provides I/O for keypads, serial ports, and money-drawer pulse drivers.
Recommended
Battery-Powered Medical Monitoring Device
The PIC18F84J90-I/PT fits low-data-rate medical monitoring (pulse oximetry reference design, ambulatory thermometer, single-parameter bedside monitor) because its nanoWatt sleep mode drops quiescent current low enough for AA-cell operation. The 10-bit ADC samples bioelectric or optical sensor signals with adequate resolution for indication-only devices, and the LCD driver shows readings on a reflective glass display readable in low-light clinical settings. Its 2.0-3.6V core voltage pairs directly with single-cell lithium or 2xAA chemistries. Industrial -40 to +85C range supports demanding hospital environments.
Recommended
Industrial Process Indicator
The PIC18F84J90-I/PT fits industrial process indicators (4-20 mA loop displays, tank-level readouts, panel meters) because the integrated LCD driver shows engineering units directly without an external segment controller, and the ADC reads 4-20 mA current loops through a shunt resistor. The 80-pin TQFP gives plenty of GPIO for relay outputs, alarm LEDs, and HMI keypads. The wide -40 to +85C operating range handles factory-floor environments. Pairing with an external RS-485 transceiver turns the design into a Modbus slave panel meter.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F84J90-I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F85J90-I/PT | PIC18F84J90T-I/PT | PIC18F84J11-I/PT | PIC18F8490-I/PT | PIC18F8410-I/PT |
|---|---|---|---|---|---|---|
| Package | 80-TQFP (12x12 mm) | 80-TQFP (12x12 mm) - same | 80-TQFP (12x12 mm) - same | 80-TQFP - same | 80-TQFP - same | 80-TQFP - same |
| Brand | Microchip Technology | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same | Microchip Technology - same |
| Program Memory (Flash) | 16 KB | 32 KB (+100%) | 16 KB | 128 KB (+700%) | 16 KB | 16 KB |
| RAM | 1024 bytes | 1024 bytes | 1024 bytes | 3800 bytes (+271%) | 3328 bytes (+225%) | 768 bytes (-25%) |
| Maximum Clock | 40 MHz (12 MIPS) | 40 MHz (12 MIPS) | 40 MHz (12 MIPS) | 40 MHz (12 MIPS) | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) |
| Operating Voltage | 2.0 V to 3.6 V | 2.0 V to 3.6 V | 2.0 V to 3.6 V | 2.0 V to 3.6 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V |
| LCD Driver | On-chip segmented LCD + charge pump | On-chip segmented LCD + charge pump | On-chip segmented LCD + charge pump | On-chip segmented LCD | External LCD (no driver) | External LCD (no driver) |
| I/O Pins | 67 | 67 | 67 | 67 | 66 | 66 |
| nanoWatt Power Management | Yes | Yes | Yes | Yes | No | No |
Key Differentiators
- On-chip segmented LCD controller with integrated charge pump (vs PIC18F8490-I/PT)
- nanoWatt power-managed modes for battery operation (vs PIC18F8410-I/PT)
- 16 KB Flash at 12 MIPS gives 1.3 KB/MIPS code density (vs PIC18F84J11-I/PT)
Design Notes
Estimated: The PIC18F84J90-I/PT core operates at 2.0V-3.6V with on-chip regulator; design the supply rail for at least 100 mA peak so ADC and LCD charge-pump transients do not brown out the MCU. Add a 10 uF bulk cap and a 100 nF ceramic decoupler within 5 mm of each VDD/VSS pin pair. For battery operation, the MCP1700 3.3V LDO provides 250 mA at 1.6 uA quiescent current, ideal for two-AA-cell metering designs.
The 80-pin TQFP package has theta_JA around 50-60 C/W on a 4-layer JEDEC test board, so at 40 MHz/3.3V the die dissipates roughly 30-40 mW. In sealed meters with no airflow this is negligible, but in industrial panel designs mounting the part over a copper pour keeps the junction-to-ambient rise under 5 C. For highest reliability, place the exposed thermal pad (if present on this 12x12 mm TQFP variant) on a 25 mm square copper area stitched with thermal vias.
Place the 80-TQFP on a 4-layer board with a continuous ground plane under the device to give the LCD segment drivers a low-impedance return path. Keep analog inputs (ADC, Vref+) on a separate analog ground island joined at one point near the MCU. The ICSP/ICD pins (PGC/PGD on RB6/RB7) need a 4.7 kohm pull-up on MCLR and a 10-100 ohm series resistor on PGC/PGD for in-circuit programming reliability.
Do not enable the LCD charge pump when the supply falls below 2.0V or contrast is lost - the J90 datasheet warns of irreversible damage if VDD rises above 3.6V during charge-pump operation. Always sequence the LCD enable bit (LCDCON.SLPEN) after the bias-generation bits to avoid inrush current spikes. Configure unused I/O as outputs (not inputs) to minimize supply current in nanoWatt sleep mode.
Compliance Information
RoHS and REACH compliant per Microchip product page (DS39786 datasheet). Lead-free TQFP package. Not AEC-Q100 qualified - this part targets industrial/consumer markets. For automotive-grade PIC18 options, see PIC18FxxK90 family with AEC-Q100 designation.
