TPS2660: Operation when GND potential fluctuates

Hi,

Welcome to E2E!

For the configuration in Figure-2, Can you share VIN-to-GND, VOUT-to-GND voltages and the input current of the eFuse. 

What is the load ?

Best Regards, Rakesh

The eFuse input voltage is 22V and the output voltage is 20.5V.
The load is a full-bridge circuit.

Figure 2a shows a detailed block diagram.
The FPGA is connected to another power system and controls the full-bridge circuit.
Partly, the signal in the full-bridge circuit is passed to the FPGA.
Since the output voltage is low, it will be judged that the FPGA cannot be started normally.

eFuse_Q2.pdf

Supplement.
The waveform load current is 100 mA or less.
Eventually it will flow about 1.2A.

Hi,

Thanks for the details.

The eFuse output voltage should be Vin-I*Ron but I see 1.5V drop. Looks like some other path is getting activated. Is the Vout close to 22V without full-bridge circuit? Can you share the full schematic. 

What is the application use case ?

Best Regards, Rakesh

無負荷の波形を添付しています。
電位は負荷の有無にかかわらず変化しません。
参考までに、eFuseのVINとVOUTをジャンパしたときの波形も添付しています。
この時、正常に動作しています。
波形からわかるように、GNDの電位はVINを基準に変化します。

最初の質問に戻ると、
eFuseはGND電位が移動する電源システムで機能しますか？

フルブリッジ電源を保護するために既存の製品を改善することを検討しています。eFuse_Q3.pdf

Hi, 

Are the measurements referred to IC-ground. ? Can you measure Vin, Vout of eFuse with respect to its ground by connecting probe ground to the IC-ground as shown below.

Regards, Rakesh