RHF330 STMICROELECTRONICS [STMicroelectronics], RHF330 Datasheet - Page 14

• Manufacturer Part Number: RHF330
• Description: Rad-hard 1 GHz low noise operational amplifier
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Noise measurements
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Noise measurements
The noise model is shown in
●
●
●
Figure 30. Noise model
The thermal noise of a resistance R is:
where F is the specified bandwidth.
On a 1 Hz bandwidth the thermal noise is reduced to:
where k is the Boltzmann's constant, equal to 1,374.E(-23)J/°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
Equation 1
eNo
eN: input voltage noise of the amplifier
iNn: negative input current noise of the amplifier
iNp: positive input current noise of the amplifier
=
V1
2
+
V2
R3
N3
2
+
R1
V3
2
+
iN
iN
N1
V4
Figure
+
-
Doc ID 15576 Rev 3
N2
2
Equation
+
V5
30.
eN
2
+
V6
1.
+
_
4kTR F
2
4kTR
R2
Output
HP3577
Input noise:
8 nV/ Hz
AM00837
RHF330