Datasheet

17
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TSC2000
SBAS257
DL1 DL0 DELAY TIME
000µs
0 1 100µs
1 0 500µs
1 1 1000µs
TABLE XVII. Reference Power-Up Delay Settings.
PDN
VALUE DESCRIPTION
0 Internal Reference is Powered at All Times
1 Internal Reference is Powered Down Between Conversions
TABLE XVIII. PDN Bit Operation.
INT PDN REFERENCE BEHAVIOR
0 0 External Reference Used, Internal Reference Powered Down
0 1 External Reference Used, Interenal Reference Powered Down
1 0 Internal Reference Used, Always Powered Up
1 1 Internal Reference Used, Will Power Up During Conversions
and Then Power Down
TABLE XIX. Reference Behavior Possibilities.
MSB LSB
BIT 15 BIT 14 BIT 13 BIT 12 BIT 11 BIT 10 BIT 9 BIT 8 BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0
X X X X X X X X X X PRE2 PRE1 PRE0 SNS2 SNS1 SNS0
TABLE XXI. Configuration Control Register.
PRE[2:0]
PRE2 PRE1 PRE0 TIME
00 020µs
00 184µs
0 1 0 276µs
0 1 1 340µs
1 0 0 1.044ms
1 0 1 1.108ms
1 1 0 1.300ms
1 1 1 1.364ms
TABLE XXII. Precharge Times.
SNS[2:0]
SNS2 SNS1 SNS0 TIME
00 032µs
00 196µs
0 1 0 544µs
0 1 1 608µs
1 0 0 2.080ms
1 0 1 2.144ms
1 1 0 2.592ms
1 1 1 2.656ms
TABLE XXIII. Sense Times.
RFV
VALUE DESCRIPTION
0 1.25V Reference Voltage
1 2.5V Reference Voltage
TABLE XX. RFV Bit Operation.
Bit 1: PDN = Reference Power Down. If a 1 is written to this
bit, the internal reference will be powered down between
conversions. If this bit is a zero, the internal reference will be
powered at all times. The default state is to power down the
internal reference, so this bit will be a 1. This bit is the same
whether reading or writing.
Note that the PDN bit, in concert with the INT
bit, creates a
few possibilities for reference behavior. These are detailed in
Table XIX.
Bit 0: RFV = Reference Voltage control. This bit selects the
internal reference voltage, either 1.25V or 2.5V. The default
value is 1.25V. This bit is the same whether reading or writing.
TSC2000 CONFIGURATION CONTROL REGISTER
(PAGE 1, ADDRESS 05
H
)
This control register controls the configuration of the precharge
and sense times for the touch detect circuit. The register is
formatted as shown in Table XXI.
Bits [5:3]: PRE[2:0] = Precharge Time Selection Bits. These
bits set the amount of time allowed for precharging any pin
capacitance on the touch screen prior to sensing if a screen
touch is happening.
Bits [2:0]: SNS[2:0] = Sense Time Selection Bits. These bits
set the amount of time the TSC2000 will wait to sense a
screen touch between coordinate axis conversions in
PENIRQ -controlled mode.