TPS55288: TPS55288

Hi Nick,

TPS55288 minimum output voltage is 0.8V. So you cannot set the Vout to 0V or 0.1V.

Our cases is:

A. First case, result - good work:

(Vin ≈12.5 – 13.5V in the all cases)

1. Setting registers (Vout ~1V)

2. Then after 0.1 us

Address	Data
0х06	F0

3. Then after 0.2 us (Setting 12V)

Address	Data
0х00	30
0х01	02
0х04	03

B. Second case: ripple on Vout and high power consumption (~ 4 Wt), heating IC and L, result - bad work:

1. Setting registers (Vout ~1V)

Address	Data
0х00	00
0х01	00
0х04	00

2. Then after 0.1 us

0х06

F0

3. Then after 0.2 us (Setting 12V)

Address	Data
0х00	30
0х01	02
0х04	03

C. Third case: ripple on Vout and high power consumption (~ 4 Wt), heating IC and L, result - bad work just after On:

1. Setting registers (Vout 12V)

Address	Data
0х00	F7
0х01	02
0х04	02
0х06	F0

And What correct algorithm of setting registers to set and change Vout?

Hi Nick,

Please share the full schematic and layout first. In most cases the issue is related to the schematic and layout.

Could you share the waveform when you said Vout has ripple? What kind of ripple do you mean?

To set Vout, you need to configure the register 0H,01h REF and 03h VOUT_SR. VOUT=VREF/INTFB

tps55288-pcb.PDFTPS55288 Design Calculation V1.0-12V-from-comp-change.xlsxTPS55288 Design Calculation V1.0-tps55288.xlsx

We change "R3" (our  R16) from 93.4k to 10k and "ripple" (unstable behavior?) end off.

Ok, thanks.