TLC876M_07 Datasheet, PDF (18/22 Pages) Texas Instruments – 10-BIT 20 MSPS PARALLEL OUTPUT CMOS ANALOG-TO-DIGITAL CONVERTERS

TLC876M, TLC876I, TLC876C
10-BIT 20 MSPS PARALLEL OUTPUT CMOS
ANALOG-TO-DIGITAL CONVERTERS
SLAS140E – JULY 1997 – REVISED OCTOBER 2000
PRINCIPLES OF OPERATION
ac considerations (continued)
REFT
REFB
5V
_
+
C2
0.1 µF
C3
0.1 µF
C4
_
0.1 µF
+
C1
0.1 µF
TLC876
REFTS
REFTF
REFBS
REFBF
Figure 20. Kelvin Connection Reference Using an Operational Amplifier
With Unlimited Capacitive Load Drive Capability
Figure 21 shows a circuit using a dual operational amplifier with unlimited capacitive load drive. The operational
amplifier should provide stable 3.6 V and 1.6 V reference voltages for REFTF and REFBF, respectively. The
amplifier must be able to maintain stability while driving unlimited capacitive loads, so the 0.1 µF capacitors C1
and C2 can connect directly to the outputs of the operational amplifiers, which reduces high frequency
transients. Capacitors C3 and C4 shunt across the internal resistors of the force-sense connections and prevent
instability. The stability of any operational amplifier used must be examined closely when driving capacitive
loads.
10 kΩ
REFT
10 kΩ
0.1 µF
_
10 Ω
A†
+
1 µF
TLC876
REFTS
0.1 µF
REFTF
10 kΩ
REFB
10 kΩ
0.1 µF
_
10 Ω
A†
+
1 µF
REFBS
0.1 µF
REFBF
† _{This device is 1/2 of a TLV2442. The TLV2442 is a rail-to-rail output dual operational}
amplifier.
Figure 21. Kelvin Connection Reference Using an Operational Amplifier
With Unlimited Capacitive Load Drive Capability
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