Datasheet

EVAL-ADP5020
Rev. 0 | Page 15 of 24
Quiescent Current Measurement
The ADP5020 has separated supply lines for Buck 1 (V
DD1
), Buck 2
(V
DD2
) and LDO (V
DD3
), in addition to the analog circuit supply
(V
DDA
). The I
DD1
current can be measured using a current loop
across LK12. I
DD2
can be measured using a current loop across
JP3 Position 1 to JP3 Position 2. I
DD3
can be measured using a
current loop across JP5 Position 1 to JP5 Position 2. I
DDA
can be
measured using a current loop across JP10. R4 must be removed.
Regulator Switching Nodes
The Buck 1 switching frequency can be measured on TP25 (SW1).
TP21 is a local power ground that can be used to con-nect the
scope probe to minimize the switching noise pickup.
Buck 2 switching frequency can be measured on TP22. TP24 is a
local power ground that can be used to connect the scope probe to
minimize the switching noise pickup.
Kelvin Measurements
The input and output voltages are routed to Connector J6 using
Kelvin connections, meaning that the point of measurement is
directly on the capacitor pads. This minimizes the measurement
error due to IR drop from the trace resistance. Table 2 and Table 3
show the signals available on Connector J6 and Connector J5,
respectively.
Power Board from USB Port Only
To power the board via the USB without using an external
supply, short Jumper LK10 on the motherboard (USB position).
Avoid exceeding the 500 mA current limit of the USB.
Table 2. Measurement Signals on J6
Signal J6 Pins Description
EN/GPIO 20 EN/GPIO pin from IC
VDDIO 19 ADP5020 logic supply
SYNC 18 External frequency
SDA 17 I
2
C bidirectional line
SCL 16 I
2
C clock line
XSHTDWN 15 XSHTDN pin from IC
+VO2S, VO2S 14, 13 Buck 2 output voltage (+/−)
+VD2S, −VD2S 12, 11 Buck 2 input voltage (+/−)
+VD1S,−VD1S 10, 9 Buck 1 input voltage (+/−)
+VO3S, −VO3S 8, 7 LDO output voltage (+/−)
+VD3S, −VD3S 6, 5 LDO input voltage (+/−)
+VO1S, −VO1S 4, 3 Buck 1 output voltage (+/−)
GND
2
Ground plane and digital grounds
Table 3. Measurement Signals on J5
Signal J5 Pins Description
VDDA 20 Analog supply input
+VDA, −VDA 19, 13 VDDA input voltage (+/−)
+VO2 18, 17 Buck 2 output positive voltage
−VO2 16, 15 Buck 2 output negative voltage
VDD2 14 Buck 2 input voltage
VDD1A, VDD1B 12, 11 Buck 1 input voltage
+VO3
10, 9
LDO output voltage (+)
−VO3 8 LDO output voltage (−)
−VO1
6, 5
Buck 1 output voltage (−)
+VO1
4, 3
Buck 1 output voltage (+)
VDD3 2 LDO input voltage
GND
7, 1
Ground plane and digital grounds