2 Compatibility Across Silicon Versions

The TPS272C45EVM is compatible across all versions of the TPS272C45. This compatibility includes the TPS272C45A with the external Vdd rail (A version), the TPS272C45B version without the Vdd rail (B version), the TPS272C45C with support for the external inductive loading diode (C version), and the TPS272C45D with fault output for individual channel (D version). By default, the A version of the silicon is populated on the EVM. The footprints among the A, B, C, and D versions of the TPS272C45 silicon are footprint compatible and can be interchanged by unpopulating the A version that ships default on the EVM and soldering, populating the desired version of the silicon.

The A, C and D version of the device includes the ability to power the digital logic of the TPS272C45 from an external Vdd pin. While the Vdd input pin exists on the A version of the TPS272C45 it does not exist in the B versions. When using the B versions of silicon on this EVM, disconnect the Vdd line (and associated jumper, J17) and ground the pin as this pin is classified as GND for B versions of the TPS272C45. Additionally with the A, C and D version of the silicon it is possible to solder a TVS diode to D6 to filter out transients to the Vdd line. This TVS diode must have a reverse standoff voltage equal to the logic level of the voltage rail being fed into Vdd. For example, if the logic level is 5 V, then a SMAJ5.0CA diode is appropriate to filter any transients above 5 V.

When using the C version of the device, populate D2, D3, D8, and D9 with the relevant diodes required for inductive loading. TI recommends the SMC series of diodes due to their ability to dissipate large energies and handle current required for discharging charged inductors during switch turn-off. These diodes must be chosen so that reverse standoff voltage falls within the nominal operating supply voltage of the device and anything above the breakdown voltage is considered a transient. The SMCJ48A-TR, for example, is able the absolute device max rating of 48 V and filter any transients above this level. More information about the transient protections provided by the EVM can be found in Transient Protection.

When using the D version of the device, make sure jumper J23 is connected to the FLT1_IC position to get the Fault output for each channel.

A table of the versions of TPS272C45 and considerations that have to be taken can be found in Table 2-1.