MP230
any parasitic resistances RP, formed by socket and solder joints
as well as internal ampli铿?er losses.The current limiting resistor
may not be placed anywhere in the output circuit except where
shown in Figure 2. The value of the current limit resistor can
be calculated as follows: R
LIM
= .65/I
LIMIT
OPERATING
CONSIDERATIONS
SHUTDOWN
The output stage is turned off by applying a 5V level to HSD
(pin 8) relative to LSD (pin 7). This is a non-latching circuit. As
long as HSD remains high relative to LSD the output stage will
be turned off. LSD will normally be tied to signal ground but
LSD may 铿俹at from -V
B
to +V
B
- 10V. Shutdown can be used
to lower quiescent current for standby operation or as part of
a load protection circuit.
BOOST OPERATION
With the boost feature the small signal stages of the ampli铿乪r
are operated at a higher supply voltages than the ampli铿乪r鈥檚
high current output stage. +V
B
(pin 1) and -V
B
(pin 38) are
connected to the small signal stages. An additional 10V on the
+V
B
and -V
B
pin is suf铿乧ient to allow the small signal stages
to drive the output stage into the triode region and improve
the output voltage swing for extra ef铿乧ient operation when
required. When the boost feature is not needed +V
S
and
-V
S
are connected to +V
B
and -V
B
respectively. +V
B
and -V
B
must not be operated at supply voltages less than +V
S
and
-V
S
respectively.
BIAS CLASS OPTION
Normally pin 5 (Iq) is left open. But when pin 5 is connected
to pin 6 (Cc1) the quiescent current in the output stage is dis-
abled. This results in lower quiescent power, but also class
C operation of the output stage and the resulting crossover
distortion. In many applications, such as driving motors, the
distortion may be unimportant and lower standby power dis-
sipation is an advantage.
This
MICROTECHNOLOGY CORPORATION 鈥?TELEPHONE (520) 690-8600 鈥?FAX (520) 888-3329 鈥?/div>
inaccuracies or omissions. All speci铿乧ations
prodlit@apexmicrotech.com
APEX
data sheet has been carefully checked and is believed to be reliable, however, no responsibility is assumed for possible
ORDERS (520) 690-8601 鈥?EMAIL
are subject to change without notice.
MP230U REV F DECEMBER 2004 漏 2004 Apex Microtechnology Corp.
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