XTR108EA-2K5 BURR-BROWN [Burr-Brown Corporation], XTR108EA-2K5 Datasheet - Page 14

• Manufacturer Part Number: XTR108EA-2K5
• Manufacturer: BURR-BROWN [Burr-Brown Corporation]

TABLE VII. Register 5, Over-Scale Threshold.
Address = 4: Control Register 2
If the RBD bit is set to ‘1’, the automatic read-back from the
EEPROM will be disabled after a valid checksum byte is
received in Register 15. This bit is read from the EEPROM
during a read-back by the XTR108 and allows the user to
program the XTR108 to read the EEPROM data once
(instead of continuously), and then disables the automatic
read-back function. The XTR108 will continuously read the
EEPROM if RBD is set to ‘0’. The remaining bits in this
register must be set to ‘0’.
Address = 5: Over- and Under-Scale Register
This register sets the magnitude of the over-scale current
limit and the magnitude of the under-scale current limit. The
threshold level, as shown in Table VII and VIII, is the
normal analog (no error condition) output limit. If an input
voltage to the PGA exceeds the linear operation range, the
output will be programmed to either the over-scale error
level or the under-scale error level. The over-scale error
level is 10mA greater than the over-scale threshold level.
The under-scale error level is 0.4mA less than the under-
scale threshold level. The FD bit will disable the over-scale
and under-scale limiting function as well as the PGA fault
indication error levels.
Address = 6: PGA Gain Register
This register sets the gain of the programmable-gain ampli-
fier. The unused bits must always be set to ‘0’. The gain step
to register content is given in Table IX.
Address = 7: Alarm Configuration Register
This register configures whether the XTR108 will go over-
scale or under-scale for various detected fault conditions at
the input of the PGA. Table X defines each of the bits.
If a bit corresponding to the particular error is set to ‘1’, the
output will go over-scale when it occurs and if a bit corre-
sponding to the particular error is set to ‘0’, the output will
go under-scale.
14
OS3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
OS2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
OS1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
OS0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
V
O
THRESHOLD
OVER-SCALE
2.6875V
2.8125V
2.9375V
3.0625V
3.1875V
3.3125V
3.4375V
3.5625V
2.625V
2.875V
3.125V
3.375V
2.75V
3.25V
3.0V
3.5V
I
O
THRESHOLD
R
OVER-SCALE
VI
20.7mA
21.2mA
21.7mA
22.2mA
22.7mA
23.2mA
23.7mA
24.2mA
24.6mA
25.1mA
25.6mA
26.1mA
26.6mA
27.1mA
27.6mA
28.1mA
= 6.34k
www.ti.com
TABLE VIII. Register 5, Under-Scale Threshold.
TABLE XII. Register 8, PGA Negative Input Selection.
TABLE XI. Register 8, PGA Positive Input Selection.
TABLE IX. Register 6, PGA Gains.
TABLE X. Register 7, Alarm Configuration Register.
Address = 8: PGA Input Configuration Register
This register connects the inputs of the PGA to the various
multiplexed input pins. Tables XI and XII show the relation-
ship between register, contents, and PGA inputs.
US2
VN2
NOTES: ‘h’ = input exceeds positive common-mode range, ‘l’ = input exceeds
negative common-mode range, and ‘n’ = input pin is within the CM range.
VP2
V
V
G2
BIT
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
#
INN
INP
US1
VP1
VN1
G1
0
0
1
1
0
0
1
1
AC
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
7
h
l
US0
VP0
VN0
G0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
AC
6
h
l
V
O
VOLTAGE GAIN
AC
5
THRESHOLD
l
l
UNDER-SCALE
Reserved
450mV
425mV
400mV
375mV
350mV
325mV
300mV
275mV
6.25V/V
12.5V/V
100V/V
200V/V
400V/V
25V/V
50V/V
PGA
PGA V
PGA V
PGA V
PGA V
PGA V
PGA V
PGA V
PGA V
PGA V
PGA V
PGA V
PGA V
AC
PGA NEGATIVE INPUT
PGA POSITIVE INPUT
4
h
h
IN+
IN+
IN+
IN+
IN+
IN+
IN–
IN–
IN–
IN–
IN–
IN–
Reserved
Reserved
Reserved
Reserved
Connected to V/ I-0
Connected to V/ I-1
Connected to V/ I-2
Connected to V/ I-3
Connected to V/ I-4
Connected to V/ I-5
Connected to V/ I-0
Connected to V/ I-1
Connected to V/ I-2
Connected to V/ I-3
Connected to V/ I-4
Connected to V/ I-5
AC
3
n
l
TRANSCONDUCTANCE
I
O
AC
SIGNAL PATH
2
n
h
THRESHOLD
UNDER-SCALE
R
R
VI
VI
1577mA/V
3155mA/V
197mA/V
394mA/V
789mA/V
3.55mA
3.35mA
3.15mA
2.96mA
2.76mA
2.56mA
2.37mA
2.17mA
49mA/V
99mA/V
= 6.34k
= 6.34k
AC
XTR108
1
n
l
SBOS187C
AC
0
h
n