MAX1233ETI+T Maxim Integrated Products, MAX1233ETI+T Datasheet - Page 33

• Manufacturer Part Number: MAX1233ETI+T
• Description: IC CNTRLR TOUCH 28-TQFN
• Manufacturer: Maxim Integrated Products
• Type: Resistiver

Specifications of MAX1233ETI+T

• Touch Panel Interface: 4-Wire
• Number Of Inputs/keys: 1, 4 x 4 Keypad
• Resolution (bits): 8, 10, 12 b
• Data Interface: MICROWIRE™, QSPI™, Serial, SPI™
• Data Rate/sampling Rate (sps, Bps): 50k
• Voltage Reference: External, Internal
• Voltage - Supply: 2.7 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-TQFN Exposed Pad
• Applications: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

where:
ΔV = V (I N) - V (I1) (in mV)
T(°K) = 2.68(°K/mV) × ΔV(mV)
T(°C) = [2.68(°K/mV) × ΔV(mV) - 273°K]°C/ °K
This differential conversion method does not require a
test temperature calibration and can provide much
improved absolute temperature measurement. In the
differential conversion method, however, the resolution
Figure 18. Single Temperature Measurement Process
Controllers Include DAC and Keypad Controller
NO
NO
STORE TEMPERATURE INPUT 1 IN
TEMPERATURE INPUT 1
POWER UP REFERENCE
AUTO POWER-DOWN
CONTROL REGISTER
AVERAGING DONE?
TEMP1 REGISTER
REFERENCE IN
HOST WRITES
START CLOCK
POWER UP
CONVERT
SET BUSY
IS DATA
IS ADC
MODE?
ADC
LOW
ADC
YES
______________________________________________________________________________________
YES
±15kV ESD-Protected Touch-Screen
TEMPERATURE INPUT 1
POWER DOWN REFERENCE
TURN OFF CLOCK
SET BUSY HIGH
POWER DOWN
DONE
ADC
is 1.6°C/LSB (2.5V reference) and 0.65°C/LSB (1V ref-
erence) with a typical accuracy of ±3°C. Figure 19
shows the differential temperature measurement-
process.
Note: The bias current for each diode temperature
measurement is only turned ON during the acquisition
and, therefore, does not noticeably increase power
consumption.
Figure 19. Differential Temperature Measurement Process
NO
NO
STORE TEMPERATURE INPUT 1 IN
TEMPERATURE INPUT 1
POWER UP REFERENCE
AUTO POWER-DOWN
CONTROL REGISTER
AVERAGING DONE?
TEMP1 REGISTER
REFERENCE IN
HOST WRITES
START CLOCK
POWER UP
CONVERT
SET BUSY
IS DATA
MODE?
IS ADC
ADC
LOW
ADC
YES
YES
NO
STORE TEMPERATURE INPUT 2 IN
AND TEMPERATURE INPUT 2
TEMPERATURE INPUT 1
POWER DOWN REFERENCE
TEMPERATURE INPUT 2
AVERAGING DONE?
TEMP2 REGISTER
TURN OFF CLOCK
SET BUSY HIGH
POWER DOWN
CONVERT
IS DATA
DONE
ADC
YES
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