TPS62740: power saving

GARETH OU

Part Number: TPS62740

Currently tuning low power saving
U5 TPS62740DSS PIN5 (VOUT 3.3V) connect to low power MCU,
Other loads are connected to PIN6 (LOAD), PIN4 (CTRL) is controlled by MCU, set to LOW, no power supply
Powered by BATT_SYS-1 DC 3.8V to U5 (TPS62740DSS), MCU enters Shutdown mode, about, this is a series of ammeter on the power supply terminal of U5 measured 130uA
Theoretically, MCU enters shutdown only 1uA, but now it is 130uA

Do you have any suggestions to improve the current consumption of TPS62740DSS at light load?

over 4 years ago

0 Excel Regidor over 4 years ago

TI__Mastermind 31201 points

Hi Gareth,

Just to clarify. The CTRL pin is Low and MCU is at shutdown mode but the current consumption of TPS62740 was 130uA. Is it right? What equipment the customer used in measuring the current consumption? Can you provide the test setup as well?

In addition, please provide the waveforms with the following items: VIN, VOUT, inductor current (L3), load current on VDDS.

Best regards,

Excel

0 Excel Regidor over 4 years ago in reply to Excel Regidor

TI__Mastermind 31201 points

Hi Gareth,

Just a soft reminder. Kindly respond to my queries on my previous post.

Best regards,

Excel

0 GARETH OU over 4 years ago in reply to Excel Regidor

Mastermind 9945 points

Thank you very much

We found the problem. There are two shottkey diodes on the board. The IR is relatively large.

The reverse current causes 100uA current consumption. If we remove the diode, there will be no 100uA power consumption.

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TPS62740: power saving