LM82CIMQA National Semiconductor, LM82CIMQA Datasheet - Page 7

• Manufacturer Part Number: LM82CIMQA
• Description: IC,SSOP,16PIN
• Manufacturer: National Semiconductor

Specifications of LM82CIMQA

• Rohs Compliant: NO

Other Applications
Combined Doubler and Inverter
In Figure 5, the LM828 is used to provide a positive voltage
doubler and a negative voltage converter. Note that the total
current drawn from the two outputs should not exceed 40
mA.
Regulating V
It is possible to regulate the negative output of the LM828 by
use of a low dropout regulator (such as the LP2980). The
whole converter is depicted in Figure 6. This converter can
give a regulated output from −1.8V to −5.5V by choosing the
proper resistor ratio:
OUT
FIGURE 6. Combining LM828 with LP2980 to Make a Negative Adjustable Regulator
V
where, V
out
= V
ref
ref
(1 + R
= 1.23V
(Continued)
1
FIGURE 5. Combined Voltage Doubler and Inverter
/R
2
)
7
Note that the following conditions must be satisfied simulta-
neously for worst case design:
V
V
in_max
in_min
+ I
+ I
out_max
<
>
out_min
V
V
out_min
out_max
x R
x R
+V
out_max
out_min
+V
DS100137-11
drop_max
drop_min
DS100137-12
(LM828)
(LM828)
(LP2980)
(LP2980)
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