TLV757P: About VDO

Hi Nishie,

Yuta Nishie said:

1) The TEST CONDITION of the VDO lists the range of each Vout. Is it correct to understand that the VDO is fixed for each voltage of the output voltage fixing device?

The VDO for each fixed output voltage device will follow the behavior found in the EC table. The "typical" value is given for spec'd VDO at 25C junction temperature, whereas the "MAX" value is the maximum VDO across the temperature range and at the load current listed in the corresponding "Test Conditions" section of the EC table.

For example, at 25C and 1A of output current, you can expect TLV757P with 0.9V fixed Vout to have a VDO of 1200mV. For the same device at the same load current, but across the full temperature range -40 to 125C, the maximum VDO would be 1350mV.

VDO is most impacted by Vout, load current, and temperature, and for any given LDO, VDO will vary based on any changes in these. The graphs we have in the datasheet related to VDO cover of a variety of scenarios to help you best plan for the conditions expected in your specific design.

Yuta Nishie said:

2) Figure 5-15 shows a 5.0 V graph. But there is not device have 5.0V output voltage(fix). What does this 5.0 V represent?

You're correct, Figure 5-15 shows a graph for a 5V fixed output version of TLV757P. While the 5V fixed version of this device is not currently available to order, TLV757P is designed such that a 5V option is possible, and Graph 5-15 shows the VDO behavior that would be guaranteed by the design of the die.

In general, we have more information in the datasheet than devices that are currently available for purchase. Another example is VDO being spec'd in the EC table for Vout between 0.6V and 0.8V. Even though no OPN with Vout <0.9V exists today, the VDO given in the EC table is guaranteed by the design of the die.

The reason this graph is included is because it provides a reference point for expected VDO; not all fixed Vout options have their own graph in the datasheet. VDO graphs for 3.3V and 5V were chosen as benchmarks from which other output voltage options can be extrapolated.

Regards,

Kelsey