MAX1234ETI+T Maxim Integrated Products, MAX1234ETI+T Datasheet - Page 21

• Manufacturer Part Number: MAX1234ETI+T
• Description: IC CNTRLR TOUCH 28-TQFN
• Manufacturer: Maxim Integrated Products
• Type: Resistiver

Specifications of MAX1234ETI+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: Internal
• Voltage - Supply: 4.75 V ~ 5.25 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

These bits are used to control or monitor ADC scans.
These bits control which input to convert and which con-
verter mode is used. The bits are identical regardless of a
read or write. See Table 7 for details about using these bits.
These bits specify the ADC resolution and are identical
regardless of read or write. Table 8 shows how to use
these bits to set the resolution.
Table 5. ADC Control Register Bit Descriptions (Write 0x0040/Read 0x8040)
Table 6. ADSTS Bit Operation
Controllers Include DAC and Keypad Controller
15 (MSB)
PENSTS
0 (LSB)
BIT
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
1
0
1
PENSTS
ADSTS
NAME
AVG1
AVG0
CNR1
CNR0
ADSTS
RES1
RES0
A/D3
A/D2
A/D1
A/D0
Bits 14-15: Pen Interrupt Status and
ST2
ST1
ST0
RFV
______________________________________________________________________________________
0
0
1
1
Bits 8-9: ADC Resolution Control
Bits 10-13: ADC Scan Select
Read: pen interrupt status; Write: sets interrupt initiated touch-screen scans
Read: ADC status; Write: stops ADC
Selects ADC scan functions
Selects ADC scan functions
Selects ADC scan functions
Selects ADC scan functions
Controls ADC resolution
Controls ADC resolution
Controls ADC result averaging
Controls ADC result averaging
Controls ADC conversion rate
Controls ADC conversion rate
Controls touch-screen settling wait time
Controls touch-screen settling wait time
Controls touch-screen settling wait time
Chooses 1.0V or 2.5V reference
No screen touch detected;
scan or conversion in progress
Screen touch detected;
scan or conversion in progress
No screen touch detected;
data available
Screen touch detected;
data available
±15kV ESD-Protected Touch-Screen
READ FUNCTION
ADC Status Bits
Performs one scan and waits to detect a screen touch. Upon
detection, issues an interrupt and waits until told to scan by the
host controller.
Stops any ongoing scan and waits to detect a screen touch. Upon
detection, issues an interrupt and performs a scan.
Stops any ongoing scan and waits to detect a screen touch. Upon
detection, issues an interrupt and waits until told to scan by the
host controller.
Stops any ongoing scan and powers down the screen touch
detection circuit. No screen touches are detected in this mode.
These bits specify the number of data averages the
converter performs. Table 9 shows how to program for
the desired number of averages. When averaging is
used, ADSTS and BUSY indicate the converter is busy
until all conversions needed for the averaging finish.
These bits are identical, regardless of read or write.
These bits specify the internal conversion rate, which
the ADC uses to perform a single conversion, as shown
in Table 10. Lowering the conversion rate also reduces
power consumption. These bits are identical, regard-
less of read or write.
DESCRIPTION
Bits 4-5: ADC Conversion Rate Control
Bits 6-7: Converter Averaging Control
WRITE FUNCTION
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