1FEATURES
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 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. matrix–
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, keyor
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

APPLICATIONS
• Cordless Phones
• Smart Handheld Devices

DESCRIPTION
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 keyor
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.