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Validation Result

Validation Result

Owned by Jerry Tian
Last updated: 2024-08-15 by Anthony Lazar
5 min read

Buck converter:

 

 

Load regulation

Vin = 50V, Iout = 1A

 

Vin = 50V, Iout = 2A

 

Vin = 50V, Iout = 3A

 

Vin = 50V, Iout = 4A

 

 

Vin = 22V, Iout = 0A

 

Vin = 22V, Iout = 1A, efficiency = 94.16%

 

Vin = 22V, Iout = 2A, efficiency = 93.48%
Vin = 22V, Iout = 3A, efficiency = 92.31%
Vin = 22V, Iout = 4A, Efficiency = 90.78%

 

Load transient

 

 

Iout from 1A to 3A

Iout from 3A to 1A

 

Vout ripple

 

Set up: Oscilloscope AC coupled, 1GHz bandwidh

 

Vin = 55V, Iout = 0A, Vpp = 1.4V
Vin = 55V, Iout = 1A, Vpp = 326mV
Vin = 55V, Iout = 2A, Vpp = 211mV

 

Vin = 55V, Iout = 3A, Vpp = 173mV

 

Vin = 55V, Iout = 4A, Vpp = 163mV

 

Over current protection

 

The video below is testing the over current protection feature of the buck chip only, the PCB only has the buck circuit assembled at this point. The e-fuse chips and pwm buffer are not populated at this point yet.

 

Efuses

Setup:

 

IMG_20240711_152503.jpg
Setup
IMG20240711160155.jpg
R_L = 1.25Omhs

 

With 47 Omhs connected, For U4, U3, U2 Measured Vout on board to be roughly 5.95V, U5 was roughly 0V

Over Current Test. Used 8, 10Omh Resistors in parallel, R_L = 1.25Omh, Current Loaded (ideal) = 4.8A

With 1.25Omhs connected For U4, U3, U2 Measured with DMM Vout on board to be 1.9V and steady decline till 1.3V, U5 was roughly 0V

 

EFuse U5: (At 4.8A Unresponsive)

 

IMG20240711153208.jpg
Iout = 40.0mA, Vout=80mV, Vin = 6.16V

 

EFuse U4 (4.8A):

 

IMG20240711155801.jpg
Vout_Max = 1.44V(Voltage Drop in Wires), Iout Latched = 1.16, Vin_Max = 6.16, Vin_Min = 6V

 

EFuse U3 (4.8A):

 

IMG20240711155832.jpg
Vout_Max = 1.44V(Voltage Drop in Wires), Iout Latched = 1.12, Vin_Max = 6.16, Vin_Min = 6V

EFuse U2 (4.8A):

 

IMG20240711155852.jpg
Vout_Max = 1.44V(Voltage Drop in Wires), Iout Latched = 1.12, Vin_Max = 6.16, Vin_Min = 6V

Short-to-ground Test

EFuse U5: (Taken on Different Day)

 

IMG20240805195642.jpg
VoutMax = 720mV, Iout Latched = 1.20, Vin_Max = 6.24, Vin_Min = 5.76V

 

Efuse U4:

IMG20240711162529.jpg
Vout = 80mV, Iout Latched = 1.16, Vin_Max = 6.16, Vin_Min = 6V

Efuse U3:

IMG20240711162505.jpg
Vout = 80mV, Iout Latched = 1.16, Vin_Max = 6.16, Vin_Min = 6V

Efuse U2 :

IMG20240711162412.jpg
Vout = 80mV, Iout Latched = 1.16, Vin_Max = 6.16, Vin_Min = 6V

 

 

Battery Inrush Test

Used 8, 10Omh Resistors in parallel, R_L = 1.25Omh, Current Loaded (ideal) = 4.8A

Channel 1 is Iout, Channel 2 is Vin after the filter, Channel 3 is Vout of the U2 efuse.

 

1.25OhmInrush.jpg
Iout Steady = 0A, Iout Max = 1.40A, Vin Filtered = 23.6V, Vout Steady @ 0.24V

 

Compared to using 22K Resistor, Ideal current 0.27mA

Channel 1 is Iout, Channel 2 is Vin after the filter, Channel 3 is Vout of the U2 efuse.

 

22K Inrush.jpg
Iout Steady = 55mA, Iout Max = ?1.0A, Vin Filtered = 28.4V, Vout Steady @ 0.24V

Vout should increase to 6V to match the load. It’s a bit strange that there is no change once power ris connected.

 

 

PWM buffer

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