PIC18F4523T-I/ML - 8-bit 32KB Flash MCU, 40MHz, TQFP-44
MPN: PIC18F4523T-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.85 | $6.85 |
| 10 | $6.18 | $61.80 |
| 100 | $5.47 | $547.00 |
| 500 | $4.92 | $2,460.00 |
| 1,000 | $4.41 | $4,410.00 |
PIC18F4523T-I/ML Overview
What is a PIC18 microcontroller? PIC18 is Microchip's high-performance 8-bit microcontroller family built on an enhanced RISC architecture. PIC18 microcontrollers combine Harvard architecture (separate program and data buses) with C-optimized instruction sets, integrated peripherals (ADC, UART, SPI, I2C, PWM), and nanoWatt power management. They sit within the broader hierarchy: PIC18 -> 8-bit MCU -> microcontroller -> embedded processor -> semiconductor. The PIC18F4523 specifically belongs to the PIC18F4520/4523 family of 28/40/44-pin enhanced flash MCUs with 12-bit A/D, designed for mixed-signal embedded designs.
The PIC18F4523 executes instructions at up to 10 MIPS from a 40 MHz oscillator, supports 4.2V to 5.5V single-supply operation, and provides 36 digital I/O pins. Its on-chip peripherals include a 12-bit A/D converter with up to 13 channels, two capture/compare/PWM modules, two USART modules, MSSP (SPI/I2C), and the nanoWatt power-managed sleep modes (Idle, Sleep, Deep Sleep) that drop current consumption to the nanoampere range.
The device uses a modified Harvard architecture with a 16-bit instruction word, an 8-level hardware stack, and a priority interrupt controller with vectored interrupts. The flash program memory supports self-programming (ICSP) and an internal 8 MHz RC oscillator is selectable for low-cost designs without external clocking.
Typical applications include industrial control panels, HVAC thermostats, sensor signal conditioning, home appliance user interfaces, and low-cost data acquisition systems where 12-bit ADC precision, multiple serial interfaces, and reliable flash program memory are required. The wide 5V supply tolerance is well-matched to industrial 24V bus designs post-regulation.
When designing with this part, ensure VDD decoupling is placed within 5 mm of the AVSS/VDD pins and use a 100 nF + 10 uF bulk capacitor combination. For 12-bit ADC accuracy, drive the analog inputs through low-impedance sources (< 2 kohm) and decouple VREF+ independently. The exposed thermal pad (ML package) must be soldered to the PCB ground plane for thermal dissipation.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found on a single datasheet page. Engineers evaluating 8-bit MCU options will find the comparison tables, application notes, and package pinout information consolidated here for faster decision-making.
Drop-in alternatives for PIC18F4523T-I/ML — 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 PIC18F4523T-I/ML (same form factor and footprint) — differing in Package, Program Memory (Flash), Timers, Operating Temperature, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F4523-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4523T-I/PT
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PIC18F4523-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4520-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4423-I/ML
✅ Drop-In✓ In Stock
$4.05 / Unit
View Datasheet →PIC18F44K22-I/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.1 / Unit
View Datasheet →PIC18F4458-I/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$5.95 / Unit
View Datasheet →PIC18F4515-I/ML
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$4.1 / Unit
View Datasheet →PIC18F4523T-I/ML Maximum Ratings & Electrical Characteristics
| Core | PIC18 8-bit RISC enhanced |
| Program Memory (Flash) | 32 KB |
| RAM | 1.5 KB (1536 bytes) |
| EEPROM | 256 bytes |
| Maximum CPU Speed | 40 MHz / 10 MIPS |
| Operating Voltage | 4.2 V to 5.5 V |
| Digital I/O Pins | 36 |
| A/D Converter | 12-bit, up to 13 channels |
| Timers (8-bit/16-bit) | 1 x 8-bit, 3 x 16-bit |
| Capture/Compare/PWM | 2 CCP modules |
| Serial Interfaces | 2x USART, 1x MSSP (SPI/I2C) |
| Package | TQFP-44 (ML) 10x10 mm with exposed pad |
| Operating Temperature | -40C to +85C (Industrial) |
| MSL Level | 3 (per JEDEC J-STD-020) |
| RoHS Status | Compliant |
| Lead-Free | Yes |
| Programming Method | ICSP (In-Circuit Serial Programming) |
| Power-Saving Modes | Run, Idle, Sleep, Deep Sleep (nanoWatt) |
PIC18F4523T-I/ML Pin Configuration
| Pin 1 | RA0/AN0 — Port A bit 0 / Analog input 0 |
| Pin 2 | RA1/AN1 — Port A bit 1 / Analog input 1 |
| Pin 3 | RA2/AN2/VREF- — Port A bit 2 / Analog input 2 / ADC VREF- |
| Pin 4 | RA3/AN3/VREF+ — Port A bit 3 / Analog input 3 / ADC VREF+ |
| Pin 5 | RA4/T0CKI — Port A bit 4 / Timer0 clock input |
| Pin 6 | RA5/AN4/SS1 — Port A bit 5 / Analog input 4 / SPI1 slave select |
| Pin 7 | RA6/OSC2 — Port A bit 6 / Crystal oscillator output |
| Pin 8 | RA7/OSC1 — Port A bit 7 / Crystal oscillator input |
| Pin 9 | RE0/RD — Port E bit 0 / Parallel port read control |
| Pin 10 | RE1/WR — Port E bit 1 / Parallel port write control |
| Pin 11 | RE2/CS — Port E bit 2 / Parallel port chip select |
| Pin 12 | VDD — Positive supply voltage (4.2V-5.5V) |
| Pin 13 | VSS — Ground reference |
| Pin 14 | OSC1/CLKI — Crystal oscillator input or external clock |
| Pin 15 | OSC2/CLKO — Crystal oscillator output or clock output |
| Pin 16 | RC0/T1OSO — Port C bit 0 / Timer1 oscillator output |
| Pin 17 | RC1/T1OSI — Port C bit 1 / Timer1 oscillator input |
| Pin 18 | RC2/CCP1 — Port C bit 2 / Capture/Compare/PWM 1 |
| Pin 19 | RC3/SCL1 — Port C bit 3 / I2C1 clock |
| Pin 20 | RC4/SDA1 — Port C bit 4 / I2C1 data |
| Pin 21 | RC5/SDO1 — Port C bit 5 / SPI1 data out |
| Pin 22 | RC6/TX1/CK1 — Port C bit 6 / USART1 transmit / clock |
| Pin 23 | RC7/RX1/DT1 — Port C bit 7 / USART1 receive / data |
| Pin 24 | RD0/PSP0 — Port D bit 0 / Parallel Slave Port bit 0 |
| Pin 25 | RD1/PSP1 — Port D bit 1 / Parallel Slave Port bit 1 |
| Pin 26 | RD2/PSP2 — Port D bit 2 / Parallel Slave Port bit 2 |
| Pin 27 | RD3/PSP3 — Port D bit 3 / Parallel Slave Port bit 3 |
| Pin 28 | RD4/PSP4 — Port D bit 4 / Parallel Slave Port bit 4 |
| Pin 29 | RD5/PSP5 — Port D bit 5 / Parallel Slave Port bit 5 |
| Pin 30 | RD6/PSP6 — Port D bit 6 / Parallel Slave Port bit 6 |
| Pin 31 | RD7/PSP7 — Port D bit 7 / Parallel Slave Port bit 7 |
| Pin 32 | VSS — Ground reference |
| Pin 33 | VDD — Positive supply voltage (4.2V-5.5V) |
| Pin 34 | RB0/INT0 — Port B bit 0 / External interrupt 0 |
| Pin 35 | RB1/INT1 — Port B bit 1 / External interrupt 1 |
| Pin 36 | RB2/INT2 — Port B bit 2 / External interrupt 2 |
| Pin 37 | RB3/CCP2 — Port B bit 3 / Capture/Compare/PWM 2 |
| Pin 38 | RB4 — Port B bit 4 |
| Pin 39 | RB5 — Port B bit 5 |
| Pin 40 | RB6/PGC — Port B bit 6 / ICSP clock |
| Pin 41 | RB7/PGD — Port B bit 7 / ICSP data |
| Pin 42 | AVSS — Analog ground reference |
| Pin 43 | AVDD — Analog positive supply (filtered VDD) |
| Pin 44 | MCLR/VPP — Master clear reset / Programming voltage |
Typical Applications
PIC18F4523T-I/ML is suitable for 6 applications: Industrial Control Panel MCU, HVAC Thermostat Controller, Sensor Signal Conditioning Hub, Home Appliance User Interface, Low-Cost Data Acquisition System, Motor Drive Auxiliary Controller.
Industrial Control Panel MCU
The PIC18F4523T-I/ML is a strong fit for industrial control panel applications because of its 36 digital I/O pins, 5V supply tolerance matching industrial 24V bus post-regulation, 12-bit ADC precision for analog sensor reading, and -40C to +85C industrial temperature rating. Its dual USART enables simultaneous master/slave Modbus RTU communication with a host PLC and an external HMI display. The 32 KB flash comfortably holds C-compiled state machines plus I/O scheduling firmware. With the nanoWatt power management, the MCU can drop to < 1 uA sleep current between operator keypresses, extending panel backup battery life. Circuit role: central supervisory MCU reading discrete inputs, driving relay outputs, and arbitrating RS-485 traffic; benefit over a 3.3V-only MCU is direct 5V digital I/O without level shifters.
Recommended
HVAC Thermostat Controller
The PIC18F4523T-I/ML suits HVAC thermostat designs that demand 5V supply robustness from 24VAC rectified rails and high-precision temperature sensing. Its 12-bit ADC over 13 channels reads thermistor inputs, humidity sensors, and setpoint potentiometers with sufficient resolution to control to within +/- 0.1 C after averaging. The two CCP modules drive PWM-controlled fan stages or triac-fired compressor relays. Flash endurance of 10,000 cycles supports over-the-air firmware updates via ICSP, while nanoWatt sleep modes reduce idle consumption to under 1 uA between temperature samples taken every 5 seconds. Compared to PIC18F4520 the 12-bit ADC eliminates an external signal-conditioning stage; compared to PIC18F46J50 the 5V supply removes the need for a boost regulator.
Recommended
Sensor Signal Conditioning Hub
The PIC18F4523T-I/ML is well-matched to sensor-signal-conditioning hubs that aggregate multiple analog inputs and forward digital readings to a host system. Its 13-channel 12-bit ADC handles strain gauges, thermocouples with cold-junction compensation, and pressure transducers simultaneously with one MCU. MSSP supports both SPI (for digital accelerometers) and I2C (for digital temp/humidity sensors) on the same peripheral. The 256-byte EEPROM stores per-channel calibration coefficients across 100,000 write cycles, surviving firmware updates and power cycles. Compared to an FPGA-based signal chain, the PIC18F4523 integrates the ADC, communication, and control logic in one chip with 10 MIPS processing headroom for FIR filtering.
Recommended
Home Appliance User Interface
The PIC18F4523T-I/ML drives appliance user interfaces such as washing-machine control boards, dishwasher panels, and oven controllers. Its 36 I/O pins multiplex keypads, 7-segment or LCD displays, and rotary encoder inputs without external glue logic. The 12-bit ADC reads NTC temperature probes with sufficient resolution for closed-loop thermal control. Two USARTs allow service technicians to connect a diagnostic terminal without interrupting field operation. Flash ICSP lets manufacturers apply post-assembly firmware updates. Compared to PIC18F4520 the 12-bit ADC improves temperature regulation accuracy by 4x, eliminating a separate thermistor-conditioning IC; nanoWatt sleep modes lower standby power to meet ENERGY STAR appliance requirements.
Recommended
Low-Cost Data Acquisition System
The PIC18F4523T-I/ML forms the core of a low-cost multi-channel data acquisition system for laboratory and field measurement. Its 12-bit ADC over 13 channels provides 4096-step resolution at up to 100 ksps aggregate, sufficient for slow industrial telemetry. The 32 KB flash accommodates averaging/filtering algorithms and FAT12 file-system drivers for SD-card storage via SPI. Dual USART supports simultaneous GPS time-stamping and remote telemetry uplink. NanoWatt sleep modes between sample bursts preserve battery life in field-deployable units. Compared to PIC18F4423 (16 KB flash) the extra 16 KB stores longer continuous recordings; compared to PIC18F46J50 the 5V analog inputs accommodate higher-voltage sensors without dividers.
Recommended
Motor Drive Auxiliary Controller
The PIC18F4523T-I/ML serves as an auxiliary controller in motor-drive systems, handling I/O expansion, fault monitoring, and user-interface tasks alongside a primary motor-control MCU. Its 36 I/O pins read end-of-travel limit switches, fault outputs from gate drivers, and encoder channels. Two CCP modules generate PWM for cooling-fan speed control and brake actuation. The 12-bit ADC monitors DC bus voltage and motor temperature via NTC sensors. ICSP flash programming supports field firmware updates. Compared to a dsPIC33 dedicated motor controller, the PIC18F4523 is more cost-effective for the supervisory layer and integrates cleanly with the dsPIC's PWM/SPI fault-reporting scheme.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F4523T-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F4523-I/ML | PIC18F4523T-I/PT | PIC18F4520-I/ML | PIC18F4423-I/ML | PIC18F44K22-I/ML |
|---|---|---|---|---|---|---|
| Package | TQFP-44 (ML) with exposed pad | TQFP-44 (ML) - same | TQFP-44 (PT) - no exposed pad | TQFP-44 (ML) - same | TQFP-44 (ML) - same | TQFP-44 (ML) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory (Flash) | 32 KB | 32 KB | 32 KB | 32 KB | 16 KB | 16 KB |
| RAM | 1.5 KB (1536 bytes) | 1.5 KB | 1.5 KB | 1.5 KB | 768 bytes | 1 KB |
| ADC Resolution | 12-bit | 12-bit | 12-bit | 10-bit | 12-bit | 10-bit |
| Maximum CPU Speed | 40 MHz / 10 MIPS | 40 MHz / 10 MIPS | 40 MHz / 10 MIPS | 40 MHz / 10 MIPS | 40 MHz / 10 MIPS | 64 MHz / 16 MIPS |
| Operating 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 | 1.8 V to 5.5 V |
| I/O Pins | 36 | 36 | 36 | 36 | 36 | 36 |
| EEPROM | 256 bytes | 256 bytes | 256 bytes | 256 bytes | 256 bytes | 256 bytes |
| Automotive Grade | No (Industrial) | No | No | No | No | No |
| Lifecycle Status | Active | Active | Active | Active | Active | Active |
Key Differentiators
- 12-bit ADC precision at 40 MHz / 32 KB flash / 5V operation in a single PIC18 chip (vs PIC18F4520-I/ML)
- TQFP-44 (ML) with exposed thermal pad for better thermal performance (vs PIC18F4523T-I/PT)
- Drop-in upgrade path to USB 2.0 with PIC18F4550/PIC18F4458 family (vs PIC18F4423-I/ML)
- Dual USART for simultaneous Modbus + diagnostic port (vs PIC18F44J10-I/ML)
Design Notes
Place a 100 nF decoupling capacitor within 5 mm of each VDD/VSS pair (pins 12-13 and 32-33) and a single 10 uF bulk capacitor near the MCU. For AVDD (pin 43) and AVSS (pin 42) add a separate 100 nF + 10 uF filter pair to keep digital switching noise out of the ADC reference. The 5V supply tolerance handles 24V-bus rectified/regulated rails but the MCU draws roughly 16 mA at 40 MHz in Run mode, so ensure the regulator can supply at least 25 mA with adequate thermal margin.
The TQFP-44 (ML) package exposes the central pad beneath the die for thermal dissipation. Per datasheet section 2.4, solder this pad to a PCB ground plane of at least 1 square inch to keep junction temperature within limits at 40 MHz / 5V operation. The PT package variant lacks this pad and has approximately 30% higher thermal resistance, derating maximum operating temperature by 5-10 C in enclosed industrial cabinets. Always cross-check Microchip's Package Thermal Data document for theta_JA under specific PCB copper area assumptions before deployment.
Route the crystal traces (OSC1/OSC2, pins 14-15) as short as possible and guard them with a ground pour to minimize EMI pickup. Keep analog input traces (RA0-RA5) away from digital switching lines (RC2/CCP1 PWM, RB7 ICSP) by at least 3x the trace width or use a ground trace between them. Place the MCLR pull-up (typically 10 kohm to VDD) close to pin 44 and add a 100 nF cap to VSS for noise immunity; missing this capacitor can cause spurious resets in noisy industrial environments.
For 12-bit ADC accuracy, drive analog inputs through a source impedance under 2 kohm. Higher source impedance increases acquisition time and may exceed the minimum TACQ specified in datasheet section 17. If the source impedance is unavoidable (e.g., a resistive divider), insert a low-leakage op-amp buffer (MCP6001 or similar) between the source and the ANx pin. For temperature measurement with NTC thermistors, configure the ADC in differential mode and use the internal fixed voltage reference (1.024V or 2.048V) for ratiometric readings.
Do not forget to configure CONFIG words (fuses) for the oscillator source, watchdog timer, low-voltage programming, and code protection. A common production failure is leaving the watchdog enabled by default and tripping it before firmware configures CLRWDT. Also, the ICSP pins (RB6/RB7) must be released from programming mode by clearing the appropriate LVP bit, otherwise the MCU will not boot from internal flash on subsequent power-ups. Refer to Microchip application note AN1106 for production-line programming guidance.
Compliance Information
RoHS compliant per Microchip product page. Industrial temperature grade -40C to +85C. Not AEC-Q100 qualified - choose PIC18F4523-I/ML automotive variants (with -CV/-Q suffix) for automotive applications. Lead-free terminations per JEDEC J-STD-020 MSL-3.
