Describe the connection required to program the device gain to 46dB. Hence determine the bandwidth at this setting given the Unity-Gain Frequency of the device is 25MHz in ad624.

1 answer

To program the device gain to 46dB in ad624, the device needs to be connected according to the following specifications:

1. Connect Pin 5 (GAIN) to the positive supply voltage (V+) to set the gain to 1000.
2. Connect Pin 6 (REF) to GND to set the reference voltage to the inverting input voltage.
3. Connect Pin 7 (IN+) to the signal source.
4. Connect Pin 8 (IN-) to the input voltage reference.
5. Connect Pin 9 (OUT) to the load resistor or amplifier circuit.

To determine the bandwidth at this setting, we need to use the formula:

Unity-Gain Frequency = (Gain x Bandwidth) / (2 x π x Capacitance)

Rearranging the formula, we get:

Bandwidth = (Unity-Gain Frequency x 2 x π x Capacitance) / Gain

Substituting the given values, we get:

Bandwidth = (25MHz x 2 x π x 20pF) / 1000

Bandwidth = 1.57MHz

Therefore, the bandwidth at the setting of 46dB gain is 1.57MHz.