THS4150CDGN Datasheet, PDF (17/34 Pages) Texas Instruments – HIGH-SPEED DIFFERENTIAL I/O AMPLIFIERS

THS4150
THS4151
www.ti.com........................................................................................................................................................... SLOS321G – MAY 2000 – REVISED MARCH 2009
Input voltage definition
Output voltage definition
Transfer function
VID + ^ǒVI₎^Ǔ – ^ǒVI–^Ǔ
VIC
+
ǒ_VI)Ǔ
)
2
ǒ_VI–Ǔ
VOD + ǒVO₎Ǔ – ǒVO–Ǔ
ǒ Ǔ ǒ Ǔ _{VOC +}
VO₎
)
2
VO–
VOD + VID x A_ǒfǓ
Output common mode voltage VOC + VOCM
Differential Structure Rejects
Coupled Noise at the Input
V_CC+
Differential Structure Rejects
Coupled Noise at the Output
V_IN-
_
+
V_O+
V_IN+
_
+
V_O-
Differential Structure Rejects
Coupled Noise at the Power Supply
V_OCM
V_CC-
Figure 37. Definition of the Fully Differential Amplifier
The following schematics depict the differences between the operation of the THS415x, a fully differential
amplifier, in two different modes. Fully differential amplifiers can work with differential input or can be
implemented as single in/differential out.
V_IN− ^R(g)
Vs
V_IN+
R_(g)
R_f
V_CC+
−+
+−
V_OCM
V_CC−
V_O+
V_O−
R_f
Note: For proper operation, maintain symmetry by setting
R_f1 = R_f2 = R_f and R_(g)1 = R_(g)2 = R_(g) ⇒ A = R_f/R_(g)
Figure 38. Amplifying Differential Signals
V_IN- ^R(g)
V_IN+
R_(g)
Vs
R_f
V_CC+
RECOMMENDED RESISTOR VALUES
-+
V_O+
+-
V_O-
V_OCM
GAIN
1
2
5
10
R_(g) Ω
390
374
402
402
R_f Ω
390
750
2010
4020
V_CC-
R_f
Figure 39. Single In With Differential Out
Copyright © 2000–2009, Texas Instruments Incorporated
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