LM8323
Description
The LM8323 key-scan controller is a dedicated device to unburden a host from scanning a matrixaddressed keypad. In addition, the LM8323 provides general-purpose I/O expansion, a rotary encoder interface and PWM outputs useful f.
Key Features
- 2 Key Features - Supports Keypad Matrices of up to 8 × 12 Keys Plus 8 Special-function (SF) Keys for a Total of 104 Keys. SF Keys Pull Keypad Scan Inputs Directly to Ground, Rather than Connecting to a Keypad Scan Output. - Supports I2C-compatible Interface in Slave Mode up to 400 kHz (Fast-mode). - Three Host-programmable PWM Outputs Useful for Smooth LED Brightness Modulation. - Supports General-purpose I/O Expansion on Pins Not Otherwise Used for Keypad or Rotary Encoder Interface. - Key-scan Event Storage in a FIFO Buffer for up to 15 Events. - Key Events, Errors, and Dedicated Hardware Interrupts Request Host Service by Asserting the IRQ Output. - The Correct Reception of a Command May be Assumed, if No Error is Reported from the LM8323 After Receiving it. - Wake-up from Halt Mode on any Matrix Key-scan Event, any Use of the SF Keys, or Any Activity on the Interface, or Any Change in the Rotary Encoder Counter Value (if Enabled).
- Host-Controlled Functions - Three PWM Outputs - Period of Inactivity that Triggers Entry into Halt Mode - Debounce Time for Reliable Key Event Polling - Configuration of General-purpose I/O Ports - Various Initialization Options (Keypad Size, etc.)
- Key Device Characteristics - 1.8V ± 180 mV Single-supply Operation - On-chip Power-on Reset (POR) - Watchdog Timer - Dedicated Slow Clock Input for 32 kHz - -40°C to +85°C Industrial Temperature Range - 36-pin csBGA Package
