LM8323是TI公司的一款I2C特殊功能产品，LM8323是移动 I/O 配套支持 Keyscan、I/O 扩展、PWM 和 ACCESS.bus 主机接口，本页介绍了LM8323的产品说明、应用、特性等，并给出了与LM8323相关的TI元器件型号供参考。
LM8323 - 移动 I/O 配套支持 Keyscan、I/O 扩展、PWM 和 ACCESS.bus 主机接口 - I2C特殊功能 - I2C - TI公司（Texas Instruments，德州仪器）
The LM8323 key-scan controller is a dedicated device to unburden a host from scanning a matrix-addressed keypad. In addition, the LM8323 provides general-purpose I/O expansion, a rotary encoder interface and PWM outputs useful for dynamic LED brightness modulation.
It communicates with the host through an I2C-compatible ACCESS.bus interface. An interrupt output is available for signaling key-press and key-release events. Communication frequencies up to 400 kHz (Fast-mode) bus speed are supported. The LM8323 supports a predefined set of commands. These commands enable a host device to keep control over all functions.
- 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 ACCESS.bus 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 ACCESS.bus 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
