LM8333

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SNLS246K – SEPTEMBER 2006 – REVISED MAY 2013

LM8333 Mobile I/O Companion Supporting Key-Scan, I/O Expansion, PWM, and

ACCESS.bus Host Interface

Check for Samples: LM8333

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FEATURES

DESCRIPTION

The LM8333 Mobile I/O Companion offloads the

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•

8 × 8 Standard Keys

burden of keyboard scanning from the host, while

•

8 Special Function Keys (SF Keys) Providing a

providing extremely low power consumption in both

Total of 72 Keys for the Maximum Keyboard

operational and standby modes. It supports keypad

Matrix

matrices up to 8 × 8 in size (plus another 8 special-

function keys), for portable applications such as

•

ACCESS.Bus (I2C-compatible) Communication

cellphones,

PDAs,

games,

and

other

handheld

Interface to the Host

applications.

•

Four General Purpose Host Programmable I/O

Pins with Two Optional (Slow) External

Key press and release events are encoded into a

byte format and loaded into a FIFO buffer for retrieval

Interrupts

by the host processor. An interrupt output (IRQ) is

•

15-byte FIFO Buffer to Store Key Pressed and

used to signal events such as keypad activity, a state

Key Released Events

change on either of two interrupt-capable general-

•

Error Control with Error Reports on (FIFO

purpose I/O pins, or an error condition. Interrupt and

Overrun, Keypad Overrun, Invalid Command)

error codes are available to the host by reading

dedicated registers.

•

Host Programmable PWM

•

Host Programmable Active Time and

Four general-purpose I/O pins are available, two of

which

have

interrupt

capability.

A

pulse-width

Debounce Time

modulated output based on a host-programmable

internal timer is also available, which can be used as

APPLICATIONS

a general-purpose output if the PWM function is not

•

Mobile Phones

required.

•

Personal Digital Assistants (PDAs)

To minimize power, the LM8333 automatically enters

•

Smart Handheld Devices

a low-power standby mode when there is no keypad,

I/O, or host activity.

•

Personal Media Players

The device is packaged in a 32–pin WQFN and a

49-pin csBGA. Both are chip-scale packages.

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PRODUCTION DATA information is current as of publication date.

Copyright © 2006–2013, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.