AN836

Rev. 1.0

5

2.2. Performance Comparison Results

The results are shown in Table 2 where VSENSE, ILOAD, and VOUT were measured for both devices.

2.3. Parasitic Resistance Considerations

Because the RSENSE resistor and trace resistances can vary from board to board, each demo board’s ILOAD was

adjusted using its own active load in order to equalize the VSENSE voltage. In a design, it is important to measure

the exact sense resistor value and then calculate the necessary load current while taking into account any small

trace resistances that can affect the load current measurement.

3. Conclusion

Because its input offset voltage is 3 times lower than the MAX9634, the TS1100 exhibits an improved load current

sense accuracy by a factor of 2 over the MAX9634. Available in a pcb-space saving SOT23-5 package, the

TS1100 consumes less than 1µA of supply current, can be used in applications that operate from 2 V to 25 V, and

is available in four gain options: 25, 50, 100, and 200. This makes the TS1100 an ideal solution for load current

measurement in power conscious applications. See documentation on the TS1100 Current-Sense Amplifier and

TS9634 Current-Sense Amplifier. For additional information, contact Silicon Labs.

Table 2. TS1100 and MAX9634 Data Sheet Specifications

TS1100-50

MAX9634F

%error = 0.64%

%error = 1.28%