TSH350_07 STMICROELECTRONICS [STMicroelectronics], TSH350_07 Datasheet - Page 12

• Manufacturer Part Number: TSH350_07
• Description: 550MHz low noise current feedback amplifier
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Power supply considerations
4
Note:
12/22
Power supply considerations
Correct power supply bypassing is very important for optimizing performance in high-
frequency ranges. Bypass capacitors should be placed as close as possible to the IC pins to
improve high-frequency bypassing. A capacitor greater than 1 F is necessary to minimize
the distortion. For better quality bypassing, a capacitor of 10nF can be added which should
also be placed as close as possible to the IC pins.
Bypass capacitors must be incorporated for both the negative and the positive supply.
On the SO8_SINGLE_HF board, these capacitors are C6, C7, C8, C9.
Figure 30. Circuit for power supply bypassing
Single power supply
In the event that a single supply system is used, biasing is necessary to obtain a positive
output dynamic range between 0V and +V
and V
The amplifier must be biased with a mid-supply (nominally +V
DC component of the signal at this value. Several options are possible to provide this bias
supply, such as a virtual ground using an operational amplifier or a two-resistance divider
(which is the cheapest solution). A high resistance value is required to limit the current
consumption. On the other hand, the current must be high enough to bias the non-inverting
input of the amplifier. If we consider this bias current (35 A maximum) as 1% of the current
through the resistance divider, to keep a stable mid-supply, two resistances of 750 can be
used.
The input provides a high-pass filter with a break frequency below 10Hz which is necessary
to remove the original 0 volt DC component of the input signal, and to fix it at +V
Figure 31
evaluation board (see
OL
, the amplifier will provide an output swing from +0.9V to +4.1V on a 100 load.
illustrates a 5V single power supply configuration for the SO8_S_MULTI
Evaluation boards
+
+
-
-
on page 11).
CC
+V
+V
-V
-V
supply rails. Considering the values of V
CC
CC
CC
CC
+
+
10nF
10nF
10µF
10µF
+
+
10nF
10nF
10µF
10µF
CC
/2), in order to maintain the
CC
/2.
TSH350
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