TA7259P/F/FG
(3) Connecting condenser for output ringing absorption
We recommend connecting a condenser between each coil and the GND for output ringing absorption .
However, other methods below can be also applied to prevent oscillation and destruction.
ⅰ) Changing capacity.
ⅱ) Delta connection (Fig.6−a)
ⅲ) Connect to VCC, not to the GND. (Fig. 6−b) In this case; take care not to let the IC be destroyed.
If voltage-current locus is beyond the ASO, series resistance or equivalent must be inserted.
ⅳ) Connect to RF pin.
ⅴ) Insert a resistance between condenser and series. (Fig. 6−c)
ⅵ) Combination of ⅰ), ⅱ), ⅲ), and ⅳ).
TA7259
P/F/FG
Use bipolar condenser.
Fig. 6-a
TA7259
P/F/FG
Fig. 6-b
TA7259
P/F/FG
Fig. 6-c
Others
The output transistor of the IC can be destroyed when the capacity of the output condenser or its connection is
not appropriate. To prevent destruction, confirm the voltage-current locus of the output transistor gained from
the test (see the figure below) is within the ASO. It is especially important to measure the output transistor in
SW’s ON/OFF timing and the sequence of normal rotation, reverse rotation, and normal rotation.
Current probe
To Y-axis of oscilloscope
Applying not only La but Lb
and Lc is recommended.
Current- voltage locus
To X-axis of oscilloscope
Fig. 7
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2006-4-14