PIC18F84J90T-I/PT - 8-Bit 40MHz 16KB Flash MCU | Microchip
MPN: PIC18F84J90T-I/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.65 | $7.65 |
| 10 | $7.1 | $71.00 |
| 100 | $6.45 | $645.00 |
| 500 | $5.92 | $2,960.00 |
| 1,000 | $5.4 | $5,400.00 |
PIC18F84J90T-I/PT Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory (Flash/ROM), working memory (RAM), and a rich set of peripherals such as timers, ADC, communication interfaces, and I/O pins. The PIC18 family is built on an enhanced Harvard RISC architecture, where the 8-bit data bus is paired with a separate, wider program-memory bus for instructions. Within the PIC18 hierarchy, the J-series parts add large I/O counts and LCD drive capability, positioning the PIC18F84J90 in the LCD PIC18F subfamily intended for human-interface designs.
Key features include 16 KB self-programmable Flash, 1 KB RAM, 70 I/O pins, hardware LCD driver, 10-bit ADC channels, multiple USART/SPI/I2C peripherals, and nanoWatt power management. The 16-bit instruction word (8K x 16) enables compact C code and larger constant tables. The wide I/O count (70 pins) and large pin-count package make the part suitable for color TFT or segment LCD panels.
Architecturally the part combines an 8-bit RISC core with a 16-bit program path and hardware multiplier, supporting C-optimized instruction set including multiply and hardware divide assist. The LCD module, ADC, and PWM peripherals share DMA-capable I/O allowing deterministic refresh of large graphical displays without CPU intervention.
Typical applications include handheld meters, thermostats, home security panels, and power/gas/water metering. The integrated LCD controller with dedicated charge-pump makes the PIC18F84J90 ideal for battery-powered utility metering with graphical or segment displays.
When designing, verify that the 4.2 V minimum supply (J-series constraint) is compatible with your power rail; K-series parts accept 1.8-5.5 V. Decouple VDD/VSS with 100 nF ceramic placed within 3 mm of each supply pin group.
This page synthesizes distributor pricing, parametric drop-in alternatives, and practical design notes curated for the PIC18F84J90 family - a synthesis not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC18F84J90T-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 PIC18F84J90T-I/PT (same form factor and footprint) — differing in Package, I/O Pins, Operating Temperature, ADC, Timers.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F84J90-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F8490-I/PT
✅ Drop-In✓ In Stock
$5.55 / Unit
View Datasheet →PIC18F8410-I/PT
✅ Drop-In✓ In Stock
$6.85 / Unit
View Datasheet →PIC18F67J90-I/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$5.64 / Unit
View Datasheet →PIC18F84J11-I/PT
✅ Drop-In✓ In Stock
$4.2 / Unit
View Datasheet →PIC18F6722-I/PT
✅ Drop-In✓ In Stock
$5.32 / Unit
View Datasheet →PIC18F84J90T-I/PT Maximum Ratings & Electrical Characteristics
| Core | PIC18 8-bit RISC |
| Instruction Width | 16-bit (8K x 16 program memory) |
| Data Bus Width | 8-bit |
| Maximum Clock Speed | 40 MHz |
| Program Memory (Flash) | 16 KB (8K x 16) |
| RAM | 1 KB (1024 bytes) |
| I/O Pins | 70 |
| Supply Voltage (VDD) | 4.2 V to 5.5 V |
| Operating Temperature | -40C to +85C (Industrial, -I suffix) |
| Package | 80-pin TQFP (PT) 12x12 mm |
| Mounting Type | Surface Mount |
| Series | PIC18J |
| ROM Type | Flash (self-programmable) |
| Lifecycle Stage | Active |
| RoHS Status | Compliant |
PIC18F84J90T-I/PT Pin Configuration
| Pin 1 | RE0 — PORT E bit 0 / LCD segment |
| Pin 2 | RE1 — PORT E bit 1 / LCD segment |
| Pin 3 | RE2 — PORT E bit 2 / LCD segment |
| Pin 4 | RE3 — PORT E bit 3 / LCD segment |
| Pin 5 | RE4 — PORT E bit 4 / LCD segment |
| Pin 6 | RE5 — PORT E bit 5 / LCD segment |
| Pin 7 | RE6 — PORT E bit 6 / LCD segment |
| Pin 8 | RE7 — PORT E bit 7 / LCD segment |
| Pin 9 | VDD — Positive supply (4.2-5.5 V) |
| Pin 10 | VSS — Ground reference |
| Pin 11 | OSC1 — Crystal/oscillator input |
| Pin 12 | OSC2 — Crystal/oscillator output |
| Pin 13 | MCLR — Master clear / programming voltage |
| Pin 14 | RA0 — PORT A bit 0 / analog AN0 |
| Pin 15 | RA1 — PORT A bit 1 / analog AN1 |
| Pin 16 | RA2 — PORT A bit 2 / analog AN2 |
| Pin 17 | RA3 — PORT A bit 3 / analog AN3 / VREF+ |
| Pin 18 | RA4 — PORT A bit 4 / analog AN4 |
| Pin 19 | RA5 — PORT A bit 5 / analog AN5 / VREF- |
| Pin 20 | AVDD — Analog supply |
| Pin 21 | AVSS — Analog ground |
| Pin 22 | RB0 — PORT B bit 0 / INT0 |
| Pin 23 | RB1 — PORT B bit 1 / INT1 |
| Pin 24 | RB2 — PORT B bit 2 / INT2 |
| Pin 25 | RB3 — PORT B bit 3 / INT3 |
| Pin 26 | RB4 — PORT B bit 4 |
| Pin 27 | RB5 — PORT B bit 5 |
| Pin 28 | RB6 — PORT B bit 6 / PGC (programming) |
| Pin 29 | RB7 — PORT B bit 7 / PGD (programming) |
| Pin 30 | VDD — Positive supply |
| Pin 31 | VSS — Ground |
| Pin 32 | RC0 — PORT C bit 0 |
| Pin 33 | RC1 — PORT C bit 1 |
| Pin 34 | RC2 — PORT C bit 2 |
| Pin 35 | RC3 — PORT C bit 3 / SCL |
| Pin 36 | RC4 — PORT C bit 4 / SDA |
| Pin 37 | RC5 — PORT C bit 5 |
| Pin 38 | RC6 — PORT C bit 6 / TX |
| Pin 39 | RC7 — PORT C bit 7 / RX |
| Pin 40 | RD0 — PORT D bit 0 |
| Pin 41 | RD1 — PORT D bit 1 |
| Pin 42 | RD2 — PORT D bit 2 |
| Pin 43 | RD3 — PORT D bit 3 |
| Pin 44 | RD4 — PORT D bit 4 |
| Pin 45 | RD5 — PORT D bit 5 |
| Pin 46 | RD6 — PORT D bit 6 |
| Pin 47 | RD7 — PORT D bit 7 |
| Pin 48 | SEG0 — LCD segment 0 |
| Pin 49 | SEG1 — LCD segment 1 |
| Pin 50 | SEG2 — LCD segment 2 |
| Pin 51 | SEG3 — LCD segment 3 |
| Pin 52 | SEG4 — LCD segment 4 |
| Pin 53 | SEG5 — LCD segment 5 |
| Pin 54 | SEG6 — LCD segment 6 |
| Pin 55 | SEG7 — LCD segment 7 |
| Pin 56 | SEG8 — LCD segment 8 |
| Pin 57 | SEG9 — LCD segment 9 |
| Pin 58 | SEG10 — LCD segment 10 |
| Pin 59 | SEG11 — LCD segment 11 |
| Pin 60 | SEG12 — LCD segment 12 |
| Pin 61 | SEG13 — LCD segment 13 |
| Pin 62 | SEG14 — LCD segment 14 |
| Pin 63 | SEG15 — LCD segment 15 |
| Pin 64 | SEG16 — LCD segment 16 |
| Pin 65 | SEG17 — LCD segment 17 |
| Pin 66 | SEG18 — LCD segment 18 |
| Pin 67 | SEG19 — LCD segment 19 |
| Pin 68 | COM0 — LCD common 0 |
| Pin 69 | COM1 — LCD common 1 |
| Pin 70 | COM2 — LCD common 2 |
| Pin 71 | COM3 — LCD common 3 |
| Pin 72 | VLCD1 — LCD charge pump node |
| Pin 73 | VLCD2 — LCD charge pump node |
| Pin 74 | VLCD3 — LCD charge pump node |
| Pin 75 | RF0 — PORT F bit 0 / LCD segment |
| Pin 76 | RF1 — PORT F bit 1 / LCD segment |
| Pin 77 | RF2 — PORT F bit 2 / LCD segment |
| Pin 78 | RF3 — PORT F bit 3 / LCD segment |
| Pin 79 | RF4 — PORT F bit 4 / LCD segment |
| Pin 80 | RF5 — PORT F bit 5 / LCD segment |
Typical Applications
PIC18F84J90T-I/PT is suitable for 7 applications: Handheld Utility Meters (Electric/Gas/Water), Programmable Thermostats, Home Security Control Panels, Industrial Process Indicator / Data Logger, Medical Infusion / Diagnostic Devices (LCD UI), Automotive Aftermarket Gauges & Accessories, Consumer Appliance HMIs (Washers/Ovens/Coffee Machines).
Handheld Utility Meters (Electric/Gas/Water)
The PIC18F84J90T-I/PT is purpose-built for battery-powered metering. Its integrated LCD controller with internal charge pump drives up to 192 segments directly without an external driver IC, while the 4.2-5.5 V supply supports single-cell Li or two-cell alkaline packs through a boost converter. The 1 KB RAM holds billing-cycle tables, and the 10 MIPS throughput handles segmented display refresh, ADC sampling of current sensors, and tamper detection simultaneously. The 70 I/O pins expose multiple UART channels for AMR (automatic meter reading) modules and pulse inputs for mechanical meter interfaces.
Recommended
Programmable Thermostats
Residential and commercial thermostats rely on segment or dot-matrix LCDs for temperature readouts, schedule icons, and humidity graphs. The PIC18F84J90T-I/PT's hardware LCD driver with variable bias eliminates the cost of an external HT1621 or similar, while 70 I/O accommodate multiple NTC thermistor inputs, relay triac controls for HVAC stages, and rotary encoder or capacitive touch keys. The 16 KB Flash fits 7-day programmable schedules with hysteresis logic, and the nanoWatt power modes extend battery life during brownout events.
Recommended
Home Security Control Panels
Security panels integrate keypad entry, PIR sensors, door/window contacts, sirens, and LCD status displays. The PIC18F84J90T-I/PT delivers 70 I/O to wire multiple zones directly without I/O expanders, while the LCD segment driver shows zone status, arm/disarm state, and event logs. Hardware AES not present, but software AES fits in 16 KB Flash for encrypted wireless sensor links. The -40C to +85C industrial range ensures reliable operation in unheated garages and outdoor enclosures across seasons.
Recommended
Industrial Process Indicator / Data Logger
Process indicators display tank level, pressure, or temperature from 4-20 mA loops and log data to non-volatile memory. The PIC18F84J90T-I/PT's 10-bit ADC and 70 I/O accept multiple analog inputs plus digital switch contacts, while the segment LCD reports real-time readings. For data logging, external EEPROM or FRAM connects over I2C, and the 16 KB Flash holds Modbus RTU or HART-like stack firmware. Wide -40C to +85C operation tolerates panel-mount enclosures with poor ventilation.
Recommended
Medical Infusion / Diagnostic Devices (LCD UI)
Battery-powered medical infusion pumps, glucose meters, and point-of-care diagnostics all benefit from the PIC18F84J90T-I/PT's integrated segment LCD driver and 70 I/O for keypad, motor drive, and sensor interfaces. The 4.2-5.5 V supply accommodates two AA cells with boost regulation. The 40 MHz core executes PID loop control for fluid delivery at deterministic intervals, while the hardware LCD refresh runs without CPU intervention, freeing MIPS for safety monitoring.
Recommended
Automotive Aftermarket Gauges & Accessories
Aftermarket digital gauges (boost, oil pressure, EGT) and accessory controllers use segment LCDs to display real-time engine data. The PIC18F84J90T-I/PT handles CAN or LIN messages via software bit-banging (no hardware CAN), drives the LCD directly, and reads multiple analog channels for sensor inputs. Industrial -40C to +85C operation covers most cabin and engine-bay environments, though under-hood installations should specify AEC-Q100 parts such as PIC18F66K90T-I/PT for full automotive qualification.
Recommended
Consumer Appliance HMIs (Washers/Ovens/Coffee Machines)
White-goods HMIs combine segment or dot-matrix LCDs, capacitive touch, rotary encoders, and triac-driven motor/relay controls. The PIC18F84J90T-I/PT's 70 I/O drive multiple triac optocouplers, accept keypad matrix scans, and refresh segment LCDs for cycle status. The 4.2-5.5 V supply operates directly from rectified 5 V standby rails. Hardware timers support zero-cross detection for triac dimming in ovens and coffee machines.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F84J90T-I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F84J90-I/PT | PIC18F8490-I/PT | PIC18F8410-I/PT | PIC18F84J11-I/PT | PIC18F6722-I/PT |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 80-pin TQFP (PT) 12x12 mm | 80-pin TQFP (PT) 12x12 mm | 80-pin TQFP (PT) 12x12 mm | 80-pin TQFP (PT) 12x12 mm | 80-pin TQFP (PT) 12x12 mm | 80-pin TQFP (PT) 12x12 mm |
| Core | PIC18 8-bit RISC | PIC18 8-bit RISC | PIC18 8-bit RISC | PIC18 8-bit RISC | PIC18 8-bit RISC | PIC18 8-bit RISC |
| Flash Memory | 16 KB (8K x 16) | 16 KB (8K x 16) | 32 KB (16K x 16) | 32 KB (16K x 16) | 32 KB (16K x 16) | 128 KB |
| RAM | 1 KB | 1 KB | 2 KB | 2 KB | 2 KB | 3.8 KB |
| I/O Pins | 70 | 70 | 70 | 70 | 70 | 70 |
| Maximum Clock | 40 MHz | 40 MHz | 40 MHz | 40 MHz | 40 MHz | 40 MHz |
| Supply Voltage | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V |
| Integrated LCD Driver | Yes (segment + charge pump) | Yes | Yes | Yes | Yes | Yes (PIC18 non-J) |
Key Differentiators
- Tape-and-reel packaging for high-volume SMT assembly (vs PIC18F84J90-I/PT)
- Optimised 16 KB Flash / 1 KB RAM for cost-sensitive metering (vs PIC18F8490-I/PT (32 KB Flash / 2 KB RAM))
- Hardware charge-pump LCD driver eliminates external VLCD boost (vs PIC18F6722-I/PT (older non-J LCD PIC18))
Design Notes
The PIC18F84J90T-I/PT requires 4.2 V minimum supply. Designers migrating from K-series parts (1.8 V minimum) must add a boost regulator for 3.3 V-only rails. Decouple every VDD/VSS pair with 100 nF X7R ceramic placed within 3 mm of the pin. Bulk decoupling of 10 uF tantalum near the IC handles the LCD charge-pump load transients during display refresh cycles.
The 80-pin TQFP (12x12 mm) has a 0.5 mm pitch. Use 4 mil trace/space rules with micro-vias to fan out from inner pads; keep all traces at least 0.2 mm from package edges to avoid solder bridges. Place the IC on the top side with decoupling on the opposite side using short vias. Reserve a 4-layer stack-up with a continuous ground plane beneath the part for EMI suppression.
Do not connect AVDD/AVSS to the same net as digital VDD/VSS - the PIC18F84J90 needs separate analog/digital supplies for ADC accuracy. The MCLR pin must have a 10 kohm pull-up to VDD; floating MCLR causes spurious resets. Programming pins RB6/PGC and RB7/PGD must not be pulled low at startup or the part enters debug mode inadvertently. Always configure the watchdog timer in software to recover from firmware lockups.
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified; use PIC18F66K90T-I/PT for automotive under-hood applications. Industrial -40C to +85C operating range (-I suffix).
