REV.-A
The negative terminal of AMP 3
receives VREF (5V)
#’.
Consequently, the voltage applied to the positive terminal is adjusted to 5V. Therefore, based on Figure
%-.
2-23, the output voltage is set to the following value:
~
(R6 + R2) =
~
ohms (9.1 K ohms + 2.4K ohms)
= 23.96 V
OUTPUT
VW
Voltage
A
3. 3K
9R7K
2R5K
$“,:.
Figure 2-23. Constant-Voltage Control (+24 VDC)
AMP 2 operates as follows for over-current control.
+24 V is applied to the negative terminal, and the positive terminal will receive an equal voltage when,
based on Figure 2-24, a negative current of the following value flows.
o“tpu;~o’tage
R9/R3
=
, ,
~~~ms
560 ohms/O.22 ohms
= 5.55 [A]
If the
current exceeds this value, over-current protection is turned on to reduce the output voltage.
OUTPUT
Voltage
+
Figure 2-24. Over-Current Protection (OCP)
Dead-time control has no bearing in this case, because pin 3 of
IC
1 1 is grounded.
2-24