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2317 Rev 1.1 (17NOV04)
AuthenTec Confidential Information
49
6.1.1.29
Test
Register
1
(TREG1)
(A1h)
Reset
Value
D7
D6
D5
D4
D3
D2
D1
D0
Excit Bias
Unlock
Manual
Excit
Bias[1]
Manual
Excit
Bias[0]
Reserved
Sense
Amp Bias
Unlock
Sense
Amp
Bias[1]
Sense
Amp
Bias[0]
0
0
0
0
0
0
0
0
0
Excit Bias Unlock
1
Unlocks the controlling of excitation bias as a function of measure frequency.
0
Excitation bias changes depending on measure frequency.
Manual Excit Bias[1:0]
Sets the bias level in the excitation drive circuit.
00
0.9
mA
01
1.8
mA
10
3.6
mA
11
7.2
mA
The table below shows the recommended minimum bias settings based on the highest frequency and drive
level being used [assuming a nominal 3.3V power supply].
Frequency
.325 V
.65 V
1.3 V
2.6 V
125
KHz 00b 00b 00b 00b
250
KHz 00b 00b 00b 01b
500
KHz 00b 00b 01b 10b
1
MHz 00b 01b 10b 11b
2
MHz 01b 10b 11b 11b
Sense Bias Unlock
1
Unlocks the controlling of sense amp bias as a function of measure frequency.
0
Sense amp bias changes depending on measure frequency.
Sense Amp Bias[1:0]
Selects the bias current of the sense amplifiers.
00
2.5
uA
01
5
uA
10
8
uA
11
10
uA
The table below shows the recommended minimum bias settings based on the measure frequency.
Frequency
125 KHz
00b
250 KHz
01b
500 KHz
01b
1 MHz
10b
2 MHz
11b