ak4184a AKM Semiconductor, Inc., ak4184a Datasheet - Page 9

• Manufacturer Part Number: ak4184a
• Description: Tsc With Keypad Scanner And Gpio Expander
• Manufacturer: AKM Semiconductor, Inc.

The AK4184A consists of the following blocks:
AK4184A interfaces to the host processor through standard SPI™ serial interface.
SPI™ is the trademark of Motorola.
■
The AK4184A 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:
MS0947-E-00
Touch Screen A/D Converter
4-wire resistive touch screen controller interface
6 columns by 5 rows keypad interface
8 GPIO pins
PWM control circuit for LED bias control
Successive approximation resister (SAR) A/D converter
Pen interrupt and key interrupt circuit
Oscillation circuit
(ΔVREF - 2.5LSB) ~ (ΔVREF - 1.5LSB)
(ΔVREF - 1.5LSB) ~ ΔVREF
0.5LSB ~ 1.5LSB
Input Voltage
0 ~ 0.5LSB
ΔVREF: (VREF+) – (VREF-)
OPERATION OVERVIEW
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Table 1. Output Code
- 9 -
Output Code
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FFFH
FFEH
001H
000H
[AK4184A]
2008/04