TSH310 STMicroelectronics, TSH310 Datasheet - Page 12

• Manufacturer Part Number: TSH310
• Description: Ultra low consumption high-speed op-amp
• Manufacturer: STMicroelectronics

Specifications of TSH310

• Bandwidth: 120MHz (Gain=2)
• Slew Rate: 115V/μs
• Input Noise: 7.5nV/√Hz

TSH310
5 Noise Measurements
The noise model is shown in
Figure 28: Noise model
The thermal noise of a resistance R is:
where F is the specified bandwidth.
On a 1Hz bandwidth the thermal noise is reduced to
where k is the Boltzmann's constant, equal to 1,374.10-23J/°K. T is the temperature (°K).
The output noise eNo is calculated using the Superposition Theorem. However eNo is not the simple sum
of all noise sources, but rather the square root of the sum of the square of each noise source, as shown
in
12/19
Equation
eNo
eN: input voltage noise of the amplifier
iNn: negative input current noise of the amplifier
iNp: positive input current noise of the amplifier
2
=
1:
eN
2
g
2
+
iNn
2
eNo
R3
R3
N3
N3
R 2
Figure
2
R1
R1
=
+
iNp
V 1
28, where:
iN+
iN+
iN-
iN-
N1
N1
2
2
N2
N2
+
R 3
V2
2
eN
eN
2
+
g
V3
4kTR F
2
+
+
_
_
4kTR
+
2
+
R 2
-------
R 1
V4
R2
R2
2
2
4 kTR 1
+
V5
2
+
+
V6
4 kTR 2
output
output
2
HP3577
HP3577
Input noise:
Input noise:
8nV/ Hz
8nV/ Hz
+
1
+
R 2
-------
R 1
Noise Measurements
2
4 kTR 3
Equation 1
Equation 2