SLUSDP0A August 2019 – May 2021 TPS53676
PRODUCTION DATA
The VIN_CSNIN and CSP pins are internally connected to a high-side current sense amplifier. Kelvin connect these pins to the external sense element RSENSE as shown in Figure 7-3,and route back to the controller as a tightly coupled differential pair. RSENSE may be a precision current sense shunt resistor or an input inductor DCR, with an associated temperature compensation network. TI recommends adding common-mode filtering capacitors, shown as CCMFILT, and a differential-mode filtering capacitor CDMFILT to reduce measurement noise. A typical value for these capacitors is 1.0 µF.
For designs that do not use input current sensing, connect VIN_CSNIN and CSPIN together, and to the input voltage supply. The controller requires input voltage sense for proper on-time generation. Ensure the VIN_CSNIN and CSPIN pins remain within ± 300 mV due to internal ESD protection structures on these pins.
Once properly calibrated, the READ_IIN command returns measured input current data in real time. Section 7.5.3 describes the process and equations for input current calibration.