TPS74801: Asking about Current Limit Spec of TPS748

Randy Chen

Part Number: TPS74801

Hi,

In datasheet of TPS748, condition of typical characteristic with VBIAS=5V for testing. However, figure 6-17 which show current limit curves illustrates relationship between ICL and (VBIAS-VOUT), and Vout = 0.8V is noted at chart, and only figure 6-17 notes Vout=0.8V. From my understanding, this mean that the curves Fig 6-17 are following VBIAS range with Vout=0.8V fix, and it’s totally opposite to electrical conditions. Could you help to clarify the exact mean of Fig 6-17 curves? And have any special reason to write Vout = 0.8V in chart? Thank you.

Best regards,

Randy

over 1 year ago

0 Erin Thibeault over 1 year ago

TI__Expert 6570 points

Hi Randy,

In the instance of figure 6-17, Vbias is not a static value. At any point on the x-axis, you can solve for Vbias. For example, at 1.5V on the x-axis, Vbias = 2.3V (1.5 + Vout = Vbias or 1.5V + 0.8V = 2.3V). The plot in figure 6-17 uses a range of values for Vbias to demonstrate that current limit across temperature is not impacted by a lower or higher voltage on Vbias.

BR,

Erin

0 Randy Chen over 1 year ago in reply to Erin Thibeault

TI__Intellectual 2295 points

Hi Erin,

How about the relationship b/w current limit and (Vbias-Vout) with a static value Vbias=5V? Do you have any curve or document for detail?

Customer is looking for OCP value for power rails Vout = 1V, 1.8V and 2.5V with Vbias = 5V.

Best regards,

Randy

0 Erin Thibeault over 1 year ago in reply to Randy Chen

TI__Expert 6570 points

Hi Randy,

We do not have a current limit curve for a static Vbias value.

BR,

Erin

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TPS74801: Asking about Current Limit Spec of TPS748