AK4183_08 Datasheet, PDF (12/18 Pages) Asahi Kasei Microsystems – I2C Touch Screen Controller

[AK4183]
■ Sleep Mode
AK4183 supports the sleep mode that enables touch panel interface to put open state and disables pen interrupt function.
AK4183 goes into the sleep mode when control command is sent to AK4183 as shown Table 2. The selection of the
sleep mode is set by “MODE” bit of the control command. The state of both the output of PENIRQN pin and the
connection with touch panel interface (XP, YP, XN, and YN) are the following Table 2. AK4183 keeps the sleep mode
until next control command is sent.
Command
0111XX1X
0111XX0X
MODE bit PENIRQN
1
Hi-z
0
“H” output
Table 2 Sleep Command Setting
Touch panel
Open
Open
The timing of going into the sleep mode is the rising edge of the 16^th SCL of the write operation. A/D conversion does
not execute when the sleep command is sent. SDA pin is “H” since SDA is pull up.
In order for going to normal mode from sleep mode the command (S= “1”) is sent. The timing of going back to normal
mode is the rising edge of the 16^thSCL. When the sleep command is sent again under the sleep mode the mode
continues the same as before. The initial state after power up is in normal mode.
■ Control Command
The control command, 8 bits, provided to the AK4183 via SDA, is shown in the following table. This command
includes start bit, channel selection bit, power-down bit and resolution bit. The AK4183 latches the serial command at
the rising edge of SCL. Refer to the detailed information regarding the bit order, function, the status of driver switch,
ADC input as shown in Table 3.
BIT Name
Function
7
S
Start Bit. “1” Accelerate and Axis Command, “0”: Sleep mode Command
6-4 A2-A0 Channel Selection Bits. Analog inputs to the A/D converter and the activated driver switches
are selected. Please see the following table for the detail.
3
X1
Don’t care
2
PD0 Power down bit (refer to power-down control)
1 MODE Resolution of A/D converter. “0”: 12 bit output “1”: 8 bit output
0
X2
Don’t care
Input
Status of Driver Switch
ADC input (ΔAIN) Reference Voltage
(ΔVREF)
S A2 A1 A0 XP XN YP YN AIN+ AIN- VREF+ VREF- Note
011
1
Sleep
100
0 ON ON OFF OFF YP
XN
XP
XN Accelerate X-Driver
100
1 OFF OFF ON ON
XP
YN
YP
YN Accelerate Y-Driver
101
0 OFF ON ON OFF XP
XN
YP
XN Accelerate Y+,X-
101
1 OFF ON ON OFF YN
XN
YP
XN Driver
110
0 ON ON OFF OFF YP
XN
XP
XN X-axis
110
1 OFF OFF ON ON
XP
YN
YP
YN Y-axis
111
0 OFF ON ON OFF XP(Z1) XN
YP
XN Z1 (Pen Pressure)
111
1 OFF ON ON OFF YN(Z2) XN
YP
XN Z2 (Pen Pressure)
Table 3 Control Command List
MS0500-E-01
12
2008/12