LM8322数据手册集成电路（IC）的专用规格书PDF

描述 Description

General Description
The LM8322 Mobile I/O Companion is a dedicated device to unburden a host processor from scanning a matrix-addressed keypad. In addition, the LM8322 provides general-purpose I/O expansion, 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 LM8322 supports a predefined set of commands. These commands enable a host device to keep control over all functions.

特性 Features

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 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 LM8322 after receiving a command.
■ 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.Applications
■ Mobile phones
■ Personal Digital Assistants (PDAs)
■ Smart handheld devices
■ Personal media players