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ASAHI KASEI
[AK4181A]
AK4181A
Features: Sampling Frequency: 125kHz(max) Pen Pressure Measurement On-Chip Thermo Sensor Two Auxiliary Analog Inputs Direct Battery Measurement 4-wire I/F On-Chip Voltage Reference (2.5V) 12 bit SAR type A/D Converter with S/H circuit Low Power Consumption (250A) Low Voltage Operation (2.7V - 3.6V) Package 16pin TSSOP
Touch Screen Controller
General Description: The AK4181A is a 4-wire touch screen controller that incorporates a 12-bit 125kHz sampling SAR A/D converter. The AK4181A can detect the pressed screen location by performing two A/D conversions. In addition to location, the AK4181A also measures touch screen pressure. On-chip VREF can be utilized for two analog auxiliary inputs and battery monitoring, with the ability to measure voltages from 0V to 5V. The AK4181A also has an on-chip temperature sensor.
DCLK XP CSN YP DIN XN Control Logic
DOUT BUSY
YN
IN1
Internal VREF(2.5V)
IN2 VBAT R1
VREF+ AIN+ AINVREF-
VREF
R2
12bit ADC (SAR type)
PENIRQN PEN INTERRUPT
Temp. Sensor
VCC
GND
Block Diagram
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Ordering Guide AK4181AVT -20C +70C 16pinTSSOP
Pin Layout
VCC XP YP XN YN GND VBAT IN1 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 DCLK CSN DIN BUSY DOUT PENIRQN IN2 VREF
Top View
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Pin/Function
No. 1 2 Signal Name VCC XP I/O I/O Description Power Supply Touch Screen X+ plate Voltage supply X axis Measurement: Supplies the voltage to X+ position input Y axis Measurement: This pin is used as the input for the A/D converter Pen Pressure Measurement: This pin is the input for the A/D converter at Z1 measurement. Temperature/VBAT/IN1/IN2 Measurement: OPEN state Pen Waiting State: Pulled up by an internal resistor (typ.50k ohm). Touch Screen Y+ plate Voltage supply Y axis Measurement: Supplies the voltage to Y+ position input X axis Measurement: This pin is used as the input for the A/D converter Pen Pressure Measurement: Supplies the voltage. Temperature/VBAT/IN1/IN2 Measurement: OPEN state Touch Screen X- plate Voltage supply X axis Measurement: Supplies the voltage to X- position input Y axis Measurement: OPEN state Pen Pressure Measurement: Supplies the voltage. Temperature/VBAT/IN1/IN2 Measurement: OPEN state Touch Screen Y- plate Voltage supply Y axis Measurement: Supplies the voltage to Y- position input X axis Measurement: OPEN state Pen Pressure Measurement: This pin is the input for the A/D converter at Z2 measurement. Temperature/VBAT/IN1/IN2 Measurement: OPEN state Pen Waiting State: connected to GND. Ground Analog Input for Battery Monitor Auxiliary 1 Analog Input Voltage Reference Input/Output Outputs 2.5V Auxiliary 2 Analog Input Pen Interrupt Output This pin should be pulled up via a 100k-ohm resistor. This pin is "L" during the pen down on pen interrupt enable state with CSN ="H" otherwise this pin is "H". This pin is "H" during pen interrupt disable state with the CSN = "H" regardless pen touch. See Power-down Control and Pen Interrupt for the reference. Serial A/D Data Output Output A/D data serially at the falling edge of DCLK. MSB is output at the falling edge of BUSY signal. Output "L" at CSN= "L" during A/D data does not output. This pin is Hi-Z state at CSN="H" BUSY Output This pin goes to low at CSN = "L". BUSY signal is "H" only for the period between the falling edge of 8th DCLK and the falling edge of 9th DCLK. This pin is Hi-Z state at CSN= "H" Serial Data Input Inputs 8-bit control command data serially when CSN= "L" AK4181A latches at the rising edge of DCLK. Must keep "L" while not issuing commands. Chip Select Input Enables writing data to the registers when CSN= "L". External Clock Input
3
YP
I/O
4
XN
I/O
5
YN
I/O
6 7 8 9 10 11
GND VBAT IN1 VREF IN2 PENIRQN
I I I/O I O
12
DOUT
O
13
BUSY
O
14
DIN
I
15 16
CSN DCLK
I I
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Absolute Maximum Ratings
GND=0V (Note 1) Parameter Power Supplies Input Current (any pins except for supplies) Input Voltage Touch Panel Drive Current Ambient Temperature (power supplied) Storage Temperature Note 1.All voltages with respect to ground. Symbol VCC IIN VIN IOUTDRV Ta Tstg Min -0.3 -0.3 -20 -65 max 6.0 10 6.0(VCC+0.3) 50 70 150 Units V mA V mA C C
WARNING: Operation at or beyond these limits may result in permanent damage to the device. Normal operation is not guaranteed at these extremes.
Recommended Operating Conditions
GND=0V (Note 1) Parameter Power Supplies Note 1. All voltages with respect to ground. Symbol VCC Min 2.7 typ 3.3 max 3.6 Units V
WARNING: AKM assumes no responsibility for the usage beyond the conditions in this datasheet.
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Analog Characteristics
Ta=-20C to 70C, VCC=2.7V, External Vref =2.5V, fs=125kHz, fDCLK=16*fs, 12bit mode Parameter min ADC for Touch Screen Resolution No Missing Codes 11 Integral Linearity Error DNL Analog Input Voltage Range 0 Offset Error Gain Error Touch Panel Driver XP, YP, RL=300 XN, YN, RL=300 XP Pull Up Register (when pen interrupt enable) PSRR (10KHz 100mVpp) Reference Output Internal Reference 2.45 Drift Load Capacitance 0.1 Reference Input Input Voltage Range Battery Monitor Input Voltage Range Input Impedance (Battery Measure Mode) 5 Accuracy (Note 2) External VREF = 2.5V is used Accuracy (Note 2) Internal Reference is used. Temperature Measurement Temperature Range -20 Resolution (Note 3) Accuracy (Note 4) Power Supply Current Normal Mode (Internal Reference OFF) Normal Mode (Internal Reference ON) Full Power Down(when writing control command with PD1=PD0= "0") typ 12 12 2 1 Vref 6 4 5 5 50 70 2.50 30 2.55 max Units Bits Bits LSB LSB V LSB LSB K dB V ppm/C F V V K % % C C C A A A
VCC 5.0 10 2 3 70 1.6 3 250 520 0 500 800 3
Note 2. Accuracy is the difference between the output code when 5 volts is input to the VBAT pin and the "ideal" code at 1.25 volts. Note 3. "ideal" value derived from theory Note 4. Accuracy is defined as the difference between the voltage measured by two current sources, and the ideal voltage derived from theory at specific temperatures.
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DC Characteristics (Logic I/O)
Ta=-20 to 70C, VCC=2.7V to 3.6V Parameter "H" level input voltage "L" level input voltage Input Leakage Current "H" level output voltage (@ Iout = -250uA) "L" level output voltage (@ Iout= 250uA) Tri-state Leakage Current All pins except for XP, YP, XN, YN pins XP, YP, XN, YN pins PENIRQN "L" level output voltage (100K Pull-Up) Symbol VIH VIL IILK VOH VOL IOLK min 0.8xVCC -10 VCC-0.4 -10 -50 VOLP typ max 0.2xVCC 10 0.4 10 50 0.8 Units V V A V V A A V
Switching Characteristics
Ta=-20C to 70C, VCC=2.7V to 3.6V Parameter Touch Panel (A/D Converter) Throughput Rate DCLK frequency duty Tracking Time (Rin=600) (Note 5) Conversion Time CSN "" to First DCLK "" CSN "" to BUSY Tri-State Disabled CSN "" to DOUT Tri-State Disabled DCLK High Pulse Width DCLK Low Pulse Width DCLK "" to BUSY "" Data Setup Time Data Valid to DCLK Hold Time Data Access Time after DCLK "" CSN "" to DCLK Ignored CSN "" to BUSY High-Z state CSN "" to DOUT High-Z state Symbol Fs fDCLK duty tTRK tCONV t1 t2 t3 t4 t5 t6 t7 t8 t9 t10 t11 t12 10 40 1.428 100 200 200 190 190 160 100 10 160 0 200 200 min typ max 125 2100 60 12 Units kHz kHz % s 1/fDCLK ns ns ns ns ns ns ns ns ns ns ns ns
50
Note 5. The actual tracking periods are 3tDCLK. (tDCLK=1/fDCLK)
CSN t5 t1 DCLK t8 t7 DIN PD0 50%VCC t4 t6 t6 t9 t10 50%VCC
50%VCC
t2 BUSY
t11
VOH VOL t12
t3 DOUT D11 D10 D0
VOH VOL
Figure 1 AK4181A Timing Diagram
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A/D Converter for Touch Screen
The AK4181A incorporates a 12-bit successive approximation resistor (SAR) A/D converter for position measurement, temperature, and battery voltage. The architecture is based on capacitive redistribution algorithm, and an internal capacitor array functions as the sample/hold (S/H) circuit. The SAR A/D converter output is a straight binary format as shown below:
Input Voltage Output Code FFFH (VREF-1.5LSB)~ VREF FFEH (VREF-2.5LSB) ~ (VREF-1.5LSB) ----------------0.5LSB ~ 1.5LSB 001H 0 ~ 0.5LSB 000H VREF: (VREF+) - (VREF-) Table 1 Output Code
The full scale (VREF) of the A/D converter depends on the input mode. The AK4181A is controlled by the 8 bit serial command on DIN.
Analog Inputs
Analog input is selected via the A2, A1, A0 and SER/ DFR bits in the control register. If the analog inputs are selected to the X or Y-axis, SER/ DFR = "0", which means differential mode, the full scale (VREF) is the differential voltage between the noninverting terminal and the inverting terminal of the measured axis (e.g. X-axis measurement:(XP) - (XN)). Analog non-inverting input to A/D converter is the non-inverting terminal of the non-measured axis while the inverting input is the inverting terminal of the measured axis. If the SER/ DFR bit is set to "1" which means single-ended mode, the full scale of A/D converter (VREF) is the internal reference voltage or external reference voltage. Note that SER/ DFR bit should be set to "0" if IN2 is selected as analog input; nevertheless, IN2 is actually measured by single-ended mode. Tracking time is the period from the falling edge of 5th DCLK to that of 8th DCLK after the detection of START bit during CSN="L". The required settling time to charge the internal capacitor array depends on the source impedance (Rin). If the source impedance is 600 ohm, the settling time needs at least 1.428s (3tDCLKat 2.1MHz). The maximum throughput of A/D converter is 125 kHz. If the source impedance of analog input or battery input is larger than 600 ohm, longer tracking time is required.
The Position Detection of Touch Screen
The position on the touch screen is detected by taking the voltage of one axis when the voltage is supplied between the two terminals of another axis. At least two A/D conversions are needed to get the two-dimensional (X/Y axis) position.
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ON XP
ON XP
VREF
AIN+ YP
VREF
AIN+ YP
ADC
VREFAIN-
ADC
VREFAIN-
XN
XN
ON
YN ON
YN
a)
X-Position Measurement Differential Mode
b)
Y-Position Measurement Differential Mode
Figure 2 Axis Measurement
The differential mode position detection is typically more accurate than the single-ended mode. As the full scale of single-ended mode is fixed to the internal (or external) reference voltage, input voltage may exceed the full-scale reference voltage. This problem does not occur in differential mode. In addition to this, the differential mode is less influenced by power supply voltage variation due to the ratio-metric measurement. However, note that the touch screen driver switch is still ON and the current flows even for the A/D conversion time. On the other hand, the touch screen driver switch is ON only for the tracking time, 3tDCLK. From the point of power consumption, singleended mode has more advantages.
The Pen Pressure Measurement
The touch screen pen pressure can be derived from the measurement of the contact resistor between two plates. The contact resistance depends on the size of the depressed area and the pressure. The area of the spot is proportional to the contact resistance. This resistance (Rtouch) can be calculated using two different methods. The first method is that when the total resistance of the X-plate sheet is already known. The resistance, Rtouch, is calculated from the results of three conversions, X-position, Z1-Position, and Z2-Position, and then using the following formula: Rtouch = (Rxplate) * (Xposition/4096) * [ (Z2/Z1) - 1] The second method is that when both the resistances of the X-plate and Y-plate are known. The resistance, Rtouch, is calculated from the results of three conversions, X-position, Y-Position, and Z1-Position, and then using the following formula: Rtouch = (Rxplate*Xposition/4096)*[(4096/Z1) - 1] - Ryplate*[1 - (Yposition/4096)]
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ON YP
ON YP
XP
VREF+ AIN+
touch
VREF+ AIN+
XP
touch
ADC
VREFAIN-
ADC
VREFAIN-
XN
XN
ON YN
ON YN
a)
Z1-Position Measurement Differential Mode
b)
Z2-Position Measurement Differential Mode
Figure 3 Pen Pressure Measurements
Voltage Reference
The AK4181A has an internal 2.5V voltage reference. This reference can be turned ON when PD1 = "1", and OFF when PD1 = "0". This reference is used in the single-ended mode for the battery monitoring, temperature measurement, or for auxiliary input. A 0.1F or larger capacitor should be connected for stable operation of the VREF circuit. Settling time depends on this external capacitance, but 400s or longer time is required if the external capacitance is 0.1F. If an external voltage reference is used, PD1 bit should be set to "0".
Battery Measurement
The AK4181A can directly measure the battery voltage up to 5V while the AK4181A operates at 2.7V to 3.3V. The input voltage is internally divided down by 4 and applied to the input of AD converter (AIN+). Minimum 5s is required as tracking time. If the source impedance is larger, more tracking time is required.
VREF PD1 Internal VREF(2.5V) VBAT R0 R1=7.5K AINR2=2.5K AIN+ ADC VREFVREF+
Enable
Figure 4 Battery Monitoring
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Temperature Measurement
Equation <1> describes the forward characteristics of the diode. iD=I0exp(vD/VT) ( VT = kT/q) <1> I0: reverse saturation current q : 1.602189x10-19 (electron charge) k : 1.38054x10-23 (Boltzmann's constant) vD: voltage across diode T: absolute temperature K The diode characteristic is approximately shown as a diode junction voltage. That is theoretically proportional to the temperature; the ambient temperature can be predicted by knowing this voltage.
I
Temp. Sensor
82I
TEMP0
TEMP1
Figure 5 Temperature Measurement
As the AK4181A has two different fixed current circuits and a diode (temperature sensor), the temperature can be measured by using two different methods. The first method needs two conversions, but can derive the temperature directly without knowing the voltage at a specific temperature. From equation <1> (iD2 / iD1) = exp{(v(NI) - v(I))/VT}
N = (iD2 / iD1) = 82 (ratio of the current)
TC = (Vbe * q)/(k * ln N) - 273 Vbe = V(82I) - V(I) TC = 2.63x103 x Vbe - 273
The second method needs only one conversion as the following equation, but requires knowing the junction voltage at the specific temperature. T = (k/q)* vD/ln(iD/I0) <2>
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Control Command
The control command, 8 bits, provided to the AK4181A via DIN is shown in the following table. This command includes start bit, channel selection, resolution, measurement configuration, and power-down mode. The AK4181A latches the serial command at the rising edge of DCLK. Table 2 gives detailed information regarding the bit order, function, the status of driver switch, ADC input, reference voltage. D7 S D6 A2 D5 A1 D4 A0 D3 MODE D2 SER/ DFR D1 PD1 D0 PD0
BIT 7 6-4 3 2 3
Name S A2-A0 MODE SER/ DFR PD1-PD0
Function Start Bit. This bit must be "H" because the AK4181A initiates the command recognition 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. Resolution of A/D converter. "L": 12 bit output "H": 8 bit output Measurement Mode (Single-Ended/Differential) Power-down Mode (reference to " Power-down Control")
Control Command A2 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 A1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 A0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 SER/ DFR 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0
Status of Driver Switch XP OFF OFF OFF OFF OFF ON OFF OFF OFF OFF OFF ON OFF XN OFF OFF OFF ON ON ON OFF OFF OFF ON ON ON OFF YP OFF ON OFF ON ON OFF OFF OFF ON ON ON OFF OFF YN OFF ON OFF OFF OFF OFF OFF OFF ON OFF OFF OFF OFF
ADC input (AIN) AIN+ TEMP0 XP VBAT XP(Z1) YN(Z2) YP IN1 TEMP1 XP XP(Z1) YN(Z2) YP IN2 AINGND GND GND GND GND GND GND GND YN XN XN XN GND
Reference Voltage (VREF) VREF+ VREFVREF VREF VREF VREF VREF VREF VREF VREF YP YP YP XP VREF GND GND GND GND GND GND GND GND YN XN XN XN GND
Note TEMP0 Y-axis Battery Monitor Z1 (Pen Pressure) Z2 (Pen Pressure) X-axis IN1 TEMP1 NA Y-axis NA Z1 (Pen Pressure) Z2 (Pen Pressure) X-axis IN2 (Note 6) NA
Note 6. Note that IN2 auxiliary input is measured by single-ended mode although SER/ DFR bit is "0".
Table 2 Control Command List
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Power-down Control
Power-down is controlled by two bits, PD0 bit and PD1 bit. The power-down state of internal voltage reference is controlled by PD1 bit, and is updated at the rising edge of 7th DCLK with CSN = "L". The power-down state of A/D converter, and touch screen driver switches is controlled by PD0 bit, and is updated at the rising edge of 8th DCLK with CSN = "L". If PD0 bit is set to "1", the state of the driver switches is maintained until the 5th DCLK of the next conversion if CSN is "L". If CSN is "H", all driver switches except for YN switch switches are turned off and are open states. Only YN driver switch is turned ON and YN pin is forced to the ground in this case. PD1 0 PD0 0 PENIRQN Enabled Function Auto Power-down Mode. A/D converter is automatically powered up at the start of the conversion, and goes to power- down state automatically at the end of the conversion. And the AK4181A is always powered down at this mode if CSN= "H". All touch screen driver switches except for YN switch are turned off and relative pins are open state. Only YN driver switch is turned ON and YN pin is forced to the ground in this case. PEN interrupt function is enabled except for the tracking time and conversion time even CSN= "L". Please see " PEN Interrupt" for the detail. The internal voltage reference is always power-down state. ADC ON Mode A/D converter is always powered up while CSN = "L". The internal voltage reference is always power-down state. If X-axis or Y-axis is selected as analog input, touch screen driver switches are always turned ON and the current flows through the touch plate if CSN= "L". This is effective if more settling time is required to suppress the electrical bouncing of touch plate. VREF ON Mode The internal voltage reference is always powered up regardless of CSN state. ADC is auto powerdown mode. PEN interrupt function is enabled at all the period except for the period from the 5DCLK to 20DCLK regardless of CSN state. ADC and VREF ON Mode A/D converter and the internal voltage reference is power-up state PEN interrupt function is disabled and PENIRQN is forced to "H" state if CSN= "H". The behavior of PENIRQN is the same as "ADC ON Mode" Table 3 Power-down Control
0
1
Enabled
1
0
Enabled
1
1
Disabled
Serial Interface
The AK4181A is controlled via 4-wire serial interface, CSN, DCLK, DIN, DOUT. Please see " Switching Characteristics" for the detail.
CSN 1 DCLK
S
A2 A1 A0 MO SER/ DFR PD1 PD0 S A2 A1 A0 MO SER/ DFR PD1 PD0
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
DIN Hi-Z BUSY Hi-Z DOUT Driver SW
SER/ DFR ="1"
11
10
9
8
7
6
5
4
3
2
1
0
11
10
Driver SW
SER/ DFR ="0"
Figure 6 Serial Interface
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BUSY and DOUT goes to "L" from Hi-Z state at the falling edge of CSN. The AK4181A latches the 8bit control word serially via DIN at the rising edge of DCLK. As the AK4181A starts the command decoding at the first "H" bit after CSN= "", MSB (S bit) of the command must be "H". Tracking time is the period from the falling edge of 5th DCLK to the falling edge of 8th DCLK. If SER/ DFR = "1", PD0= "0", and if analog input is X-axis or Y-axis (the measurement is the pen position or pen pressure), the touch screen driver switches are turned ON for this 3DCLK period. If SER/ DFR = "0", the switches are turned ON for the period from 5DCLK to 20 DCLK. BUSY is "H" for one DCLK period, which is from 8DCLK to 9DCLK. BUSY is "L" for other period. The AK4181A outputs A/D data with MSB first via DOUT from the falling edge of 9th DCLK. DIN must keep low state for minimum 7 DCLK times (9th-15th DCLK) after command is sent on the DIN. The AK4181A can output one A/D data per 15 DCLK clock cycles for the fastest way as shown in the dotted line of the Figure 6.
Pen Interrupt
The AK4181A has pen interrupt function to detect the pen touch. Pen interrupt function is enabled at power-down state. YN pin is connected to GND at the PEN interrupt enabled state. And XP pin is pulled up via an internal resistor (Ri), typically 50k ohm. PENIRQN pulled up via an external resistor, 100k ohm, is also connected to XP pin. If touch plate is pressed by pen the current flows via - - - - . The resistance of the plate is generally 1k ohm or less, PENIRQN is forced to "L" level. If the pen is released, PENIRQN returns "H" level because two plates are disconnected, and the current doesn't flow via two plates. If the plate is touched with pen or finger, PENIRQN goes to "L" at CSN = "H" unless previous command issued with both PD1 and PD0 is "1". PENIRQN is disabled and keeps "H" level regardless of the touched/non-touched state if CSN = "H". The operation of PENIRQN is related to PD0 bit. PD0 bit is updated at the rising edge of 8th DCLK (please see " Power-down Control" for the detail). Therefore, the last PD0 bit is valid until this timing. (The internal voltage reference is controlled by only PD1 bit regardless of PD0 bit and CSN state.) The period from the 5th DCLK to the 20th DCLK The behavior of PENIRQN is related to the selected analog input. If the X-axis or Y-axis is selected as analog input, PENIRQN is forced to "L" regardless of the touched/non-touched state. If the temperature, VBAT, or auxiliary inputs is selected, PENIRQN is forced to "H" regardless of the touched/non-touched state. ii. The period from CSN to the 5th DCLK. The behavior of PENIRQN is related to the combination of the last selected analog input channel, and the last PD0 bit. If the last PD0 bit was set to "0", PENIRQN is "H" while the plate is not pressed, and "L" while the plate is pressed regardless of the last analog input. If the last PD0 bit was set to "1", the last analog input decides the level of PENIRQN. If the last analog input channel is ether X-axis or Y-axis, PENIRQN is "L" for all the time in this period regardless of the touched/non-touched state. On the other hand, if the last analog input is temperature, VBAT, or auxiliary inputs, PENIRQN is "H" for all the time in this period regardless of the touched/non-touched state. iii. The period from the 20th DCLK to CSN The behavior of PENIRQN is related to the combination of the current selected analog input channel, and the current PD0 bit. If the current PD0 bit is set to "0", PENIRQN is "H" while the plate is not pressed, and "L" while the plate is pressed regardless of the current selected analog input. If the current PD0 bit is set to "1", the current analog input decides the operation of PENIRQN. If the current analog input channel is ether X-axis or Y-axis, PENIRQN is "L" for all the time in this period regardless of the touched/non-touched state. On the other hand, if the current analog input is temperature, VBAT, or auxiliary inputs, PENIRQN is "H" for all the time in this period regardless of the touched/non-touched state. It is recommended that the micro controller mask the pseudo-interrupts while the control command is issued or A/D data is output. Full power down (CSN = "H", DIN = "H", DCLK= "L" or "H") should force internal register to initial value 00H and XP, YP, XN pin to Hi-z state. In addition to this, the current does not flow even if the plate is touched with pen or finger. PENIRQN goes to "H" regardless of pen touch at full power. i.
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100k
PENIRQN EN2 50k EN1 Driver OFF XP
YN
Driver ON
Figure 7 PENIRQ Functional Block Diagram
CSN
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
DCLK DIN BUSY
11 10 9 8 7 6 5 4 3 2 1 0 S A2 A1
A0 MO SER/ DFR PD1
PD0
DOUT CONV Internal
AXIS = ((!A2) & (!A1) & (A0)) | ((!A2) & (A1) & (A0)) | ((A2) & (!A1) & (!A0)) | ((A2) & (!A1) & (A0));
/* X-axis Measurement */ /* Z1 Measurement */ /* Z2 Measurement */ /* Y-axis Measurement */
EN1 = ((!CSN) & (!CONV) & AXIS & PD0) /* CSN="L", X/Y/Z1/Z2 Measurement, PD0 = 1, NOT "CONV period" */ | ((!CSN) & AXIS & CONV); /* CSN="L", X/Y/Z1/Z2 Measurement, "CONV period" */ EN2 = ((!CSN) & (!CONV) & (!PD0)) /* CSN="L", PD0 = 1, NOT "CONV period" */ | (CSN & (!(PD1& PD0)); /* CSN="H", (PD0, PD1) is not (1,1) */
Power on Sequence
On the AK4181A first powers up, the register value including power down mode, internal reference (PD1, PD0) holds unfixed before sending first control command. On this condition pen interrupt function may be disable, internal reference may also be ON state ([PD1, PD0] = [1,1]). 8bit control command must be sent as quick as possible when first power up to fix the internal register value. The sequence is that 1) Power On with CSN = "L" or "H" then CSN = "H". 2) Send control command after CSN = "L". 3) CSN = "H" again. Once sending command to fix the internal register after first power up, the state of AK4181A is held on the condition of state as last command issued.
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[AK4181A]
Package
16pin TSSOP (Unit: mm)
5.000.08
16
9 A 4.40.1 6.40.2
1
8
0.220.08 | 0.13|M
0.65 1.07 +0.03 -0.07
0.170.05 0.070.04 Detail A 0.50.2
Seating Plane
Package & Lead frame material
Package molding compound: Epoxy Lead frame material: Cu Lead frame surface treatment: Solder (Pb free) plate
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0-10
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[AK4181A]
Marking
AKM 4181AVT XXYYY
Contents of XXYYY XX: Lot # YYY: Date Code
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ASAHI KASEI
[AK4181A]
IMPORTANT NOTICE * These products and their specifications are subject to change without notice. Before considering any use or application, consult the Asahi Kasei Microsystems Co., Ltd. (AKM) sales office or authorized distributor concerning their current status. * AKM assumes no liability for infringement of any patent, intellectual property, or other right in the application or use of any information contained herein. * Any export of these products, or devices or systems containing them, may require an export license or other official approval under the law and regulations of the country of export pertaining to customs and tariffs, currency exchange, or strategic materials. * AKM products are neither intended nor authorized for use as critical components in any safety, life support, or other hazard related device or system, and AKM assumes no responsibility relating to any such use, except with the express written consent of the Representative Director of AKM. As used here: (a) A hazard related device or system is one designed or intended for life support or maintenance of safety or for applications in medicine, aerospace, nuclear energy, or other fields, in which its failure to function or perform may reasonably be expected to result in loss of life or in significant injury or damage to person or property. (b)A critical component is one whose failure to function or perform may reasonably be expected to result, whether directly or indirectly, in the loss of the safety or effectiveness of the device or system containing it, and which must therefore meet very high standards of performance and reliability. * It is the responsibility of the buyer or distributor of an AKM product who distributes, disposes of, or otherwise places the product with a third party to notify that party in advance of the above content and conditions, and the buyer or distributor agrees to assume any and all responsibility and liability for and hold AKM harmless from any and all claims arising from the use of said product in the absence of such notification.
MS0313-E-00
17
2004/06
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