ak4184 AKM Semiconductor, Inc., ak4184 Datasheet - Page 9

• Manufacturer Part Number: ak4184
• Description: Tsc With Keypad Scanner And Gpio Expander
• Manufacturer: AKM Semiconductor, Inc.

The AK4184 consists of the following blocks:
AK4184 interfaces to the host processor through standard SPI™ serial interface.
SPI™ is the trademark of Motorola
L
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:
MS0603-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
( VREF-2.5LSB) ~ ( VREF-1.5LSB)
( VREF-1.5LSB) ~ VREF
0.5LSB ~ 1.5LSB
Input Voltage
0 ~ 0.5LSB
OPERATION OVERVIEW
---------
VREF: (VREF+) – (VREF-)
Table 1. Output Code
9
Output Code
---------
FFFH
FFEH
001H
000H
2007/04
[AK4184]