SLUSG35 August 2026 TPS12S24F-Q1
ADVANCE INFORMATION
The device features integrated current sense amplifier which is used for monitoring the voltage drop across the external shunt resistor as a sensor for the load current in forward as well as reverse direction. The bi-directional current sense circuit provide a voltage signal that is proportional to the output current of the switch – a voltage signal that is sampled at the input of the integrated ADC is desired and the direction of current information is stored in ISNS_POLARITY_CHx bit in ADC_RESULT_CHx_I register. The voltage-based conversion enables a common-sense voltage for other signals (CSx+/SRCx/TSNSx/TCONT/VDSx) that are converted by the ADC.
Note that the current sense resistor and GAIN setting needs to be chosen by the customer appropriately to get the voltage to ADC input to within the ADC range.
The 10-bit digital current sense output can be read from the ADC_RESULT_CHx_I register. The ISNS_RDY_CHx bit is set if the ADC conversion result is updated in the register from the last time the register was read.
The following factors should be considered when selecting the RSNS value:
Current sense amplifier gain (GAIN)
Largest and smallest diagnosable load current required for application operation
Full-scale voltage of the ADC
Tolerance of the RSNS resistor used
The differential gain of the current sense amplifier is configurable by the configuration bits ISNS_GAIN_CHx in DIAG_CONFIG_CHx register.
| ISNS_GAIN_CHx | CURRENT SENSE AMPLIFIER GAIN (V/V) |
|---|---|
|
0x0 |
15 |
|
0x1 |
30 |
|
0x2 |
50 |
|
0x3 |
65 |
|
0x4 |
85 |
|
0x5 |
100 |
|
0x6 |
120 |
|
0x7 |
135 |
The ADC conversion equation for current sense is shown below in Equation 5