Hi,
I've been testing DC/DC converter such as TPS63060 and I had some problems with its behavior while there was applied some load to the converter (made of resistors).
My test application was designed with the following parameters (schematic is shown below):
Vin = 5 V, Vout = ~ 4.1 V, Iout(steady) = 0.08 A, Iout(max) in pick = up to 1.5 A
I have choosen following parts:
L1 - WURTH ELEKTRONIK - 744062001 (4.7 A, DCR = 0.014 Ohm)
C34 to C48 - 6.3 V, dielectric: X5R, 0805 and 0603
And, I'm pretty sure that the PCB layout is correctly designed. L1 is soldered about 2 mm from converter pads. Capacitors and resistors are also as close as possible. Power ground node is connected only in one point (under the device) with control ground node - very similar to the one shown in slvu442 (TPS63060 EVM).
Test discription:
There is applied steady load of 0.08 A to the output of the converter and everything is ok. When I increase load, the output voltage falls down and doesn't goes up while the load is applied. When I decrease the load, the Vout goes back to the ~4.1 V. The results are listed below (values are rounded):
Vin = 5.0 V
Iout = 0.08 A --> Vout = 4.1 V
Iout = 0.20 A --> Vout = 4.1 V
Iout = 0.40 A --> Vout = 3.9 V
Iout = 0.80 A --> Vout = 3.6 V
Iout = 1.20 A --> Vout = 3.3 V
I noticed that when I increase Vin to 6 V, the converter works better. The load value that causes Vout drop of ~3.9 V is about 0.80 A. The converter doesn't cope with load of 1.2 A (Vout = 3.6 V) in this case.
From my results I can claim that TPS63060 doesn't maitain output voltage on the designed level during the load addition.
Can someone help me with this problem, please?
