DEVICE OVERVIEW
This family offers the advantages of all PIC18 microcontrollers – namely, high computational performance at an economical price – with the addition of high-endurance, Enhanced Flash program memory. On top of these features, the PIC18F2423/2523/4423/4523 family introduces design enhancements that make these microcontrollers a logical choice for many high-performance, power-sensitive applications.

Power Management Features:
• Run: CPU on, Peripherals on
• Idle: CPU off, Peripherals on
• Sleep: CPU off, Peripherals off
• Ultra Low 50 nA Input Leakage
• Run mode Currents Down to 11 μA Typical
• Idle mode Currents Down to 2.5 μA Typical
• Sleep mode Current Down to 100 μA Typical
• Timer1 Oscillator: 900 nA, 32 kHz, 2V
• Watchdog Timer: 1.4 μA, 2V Typical
• Two-Speed Oscillator Start-up

Flexible Oscillator Structure:
• Four Crystal modes, up to 40 MHz
• 4x Phase Lock Loop (PLL) – Available for Crystal and Internal Oscillators
• Two External RC modes, up to 4 MHz
• Two External Clock modes, up to 40 MHz
• Internal Oscillator Block:
   - Fast wake from Sleep and Idle, 1 μs typical
   - 8 user-selectable frequencies, from 31 kHz to 8 MHz
   - Provides a complete range of clock speeds, from 31 kHz to 32 MHz, when used with PLL
   - User-tunable to Compensate for Frequency Drift
• Secondary Oscillator using Timer1 @ 32 kHz
• Fail-Safe Clock Monitor:
   - Allows for safe shutdown if peripheral clock stops
 
Peripheral Highlights:
• 12-Bit, Up to 13-Channel Analog-to-Digital Converter module (A/D):
   - Auto-acquisition capability
   - Conversion available during Sleep mode
• Dual Analog Comparators with Input Multiplexing
• High-Current Sink/Source 25 mA/25 mA
• Three Programmable External Interrupts
• Four Input Change Interrupts
• Up to Two Capture/Compare/PWM (CCP) modules, One with Auto-Shutdown (28-pin devices)
• Enhanced Capture/Compare/PWM (ECCP) module (40/44-pin devices only):
   - One, two or four PWM outputs
   - Selectable polarity
   - Programmable dead time
   - Auto-shutdown and auto-restart
• Master Synchronous Serial Port (MSSP) module Supporting 3-Wire SPI (all four modes) and I2C™ Master and Slave modes
• Enhanced USART module:
   - Support for RS-485, RS-232 and LIN/J2602
   - RS-232 operation using internal oscillator block (no external crystal required)
   - Auto-wake-up on Start bit
   - Auto-Baud Detect (ABD)