AKD4184 データシートの表示（PDF） - Asahi Kasei Microdevices

部品番号

コンポーネント説明

メーカー

AKD4184

TSC with Keypad Scanner and GPIO Expander

Asahi Kasei Microdevices 

[AK4184]

OPERATION OVERVIEW

The AK4184 consists of the following blocks:

z 4-wire resistive touch screen controller interface

z 6 columns by 5 rows keypad interface

z 8 GPIO pins

z PWM control circuit for LED bias control

z Successive approximation resister (SAR) A/D converter

z Pen interrupt and key interrupt circuit

z Oscillation circuit

AK4184 interfaces to the host processor through standard SPI™ serial interface.

SPI™ is the trademark of Motorola

■ Touch Screen A/D Converter

The AK4184 incorporates a 12-bit successive approximation resistor (SAR) A/D converter for determining the touch

position and pressure measurement. The architecture is based on a capacitive redistribution algorithm, and an internal

capacitor array functions as the sample/hold (S/H) circuit. The SAR A/D converter output is in straight binary format

as shown below:

Input Voltage

Output Code

(ΔVREF-1.5LSB) ~ ΔVREF

FFFH

(ΔVREF-2.5LSB) ~ (ΔVREF-1.5LSB)

FFEH

---------

---------

0.5LSB ~ 1.5LSB

001H

0 ~ 0.5LSB

000H

ΔVREF: (VREF+) – (VREF-)

Table 1. Output Code

MS0603-E-00

9

2007/04

Share Link: