ZHCSUZ6B February 2024 – May 2024 TLV9051-Q1 , TLV9052-Q1
PRODMIX
The transfer function of the circuit in Figure 7-1 is given in Equation 1.
The load current (ILOAD) produces a voltage drop across the shunt resistor (RSHUNT). The load current is set from 0A to 1A. To keep the shunt voltage below 100mV at maximum load current, the largest shunt resistor is defined using Equation 2.
Using Equation 2, RSHUNT equals 100mΩ. The voltage drop produced by ILOAD and RSHUNT is amplified by the TLV905x-Q1 device to produce an output voltage of approximately 0V to 4.95V. Equation 3 calculates the gain required for the TLV905x-Q1 device to produce the required output voltage.
Using Equation 3, the required gain equals 49.5V/V, which is set with the RF and RG resistors. Equation 4 sizes the RF and RG, resistors to set the gain of the TLV905x-Q1 device to 49.5V/V.
Selecting RF to equal 165kΩ and RG to equal 3.4kΩ provides a combination that equals approximately 49.5V/V. Figure 7-2 shows the measured transfer function of the circuit shown in Figure 7-1.