Datasheet

0
2
4
6
8
10
12
14
16
18
20
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
175 kHz
160 kHz
150 kHz
140 kHz
125 kHz
115 kHz
135 kHz
130 kHz
LOAD (A)
V (V)
RECT
Ping voltage
1A load step droop
1A load operating point
V
A
C
B
C
D
C
S
L
S
R
L
V
IN
bq51013B
www.ti.com SLUSB62A –MARCH 2013–REVISED OCTOBER 2013
Figure 43. Load-Line Analysis Test Bench
Where:
• V
IN
is a square-wave power source that should have a peak-to-peak operation of 19V.
• C
P
is the primary series resonant capacitor (i.e. 100 nF for Type A1 coil).
• L
P
is the primary coil of interest (i.e. Type A1).
• L
S
is the secondary coil of interest.
• C
S
is the series resonant capacitor chosen for the receiver coil under test.
• C
D
is the parallel resonant capacitor chosen for the receiver coil under test.
• C
B
is the bulk capacitor of the diode bridge (voltage rating should be at least 25 V and capacitance value of at
least 10µF)
• V is a Kelvin connected voltage meter
• A is a series ammeter
• R
L
is the load of interest
It is recommended that the diode bridge be constructed of Schottky diodes.
The test procedure is as follows
• Supply a 19V AC signal to L
P
starting at a frequency of 210 kHz
• Measure the resulting rectified voltage from no load to the expected full load
• Repeat the above steps for lower frequencies (stopping at 110 kHz)
An example load-line analysis is shown in Figure 44:
Figure 44. Example Load-Line Results
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