tc1240a Microchip Technology Inc., tc1240a Datasheet - Page 9

• Manufacturer Part Number: tc1240a
• Description: Positive Doubling Charge Pumps With Shutdown In A Sot-23 Package
• Manufacturer: Microchip Technology Inc.

5.4
The V
reduce AC impedance and minimize noise effects due
to
recommended capacitor should be a large value (at
least equal to C
5.5
The TC1240 and TC1240A are disabled when SHDN is
high, and enabled when SHDN is low. This input cannot
be allowed to float.
FIGURE 5-3:
 2003 Microchip Technology Inc.
TC1240
TC1240A
Device
the
IN
3
4
5
1
Input Supply Bypassing
Shutdown Input
OUT
V
C-
SHDN
switching
input should be capacitively bypassed to
TC1240A
IN
TC1240
1
) connected from the input to GND.
GND
3.3 µF
C
C+
1
internal
C
Test Circuit.
6
2
3
C
+
1
+
3.3 µF
to
C
2
the
+
C
V
2
R
IN
L
device.
3.3 µF
C
3
V
The
OUT
5.6
The most common application for charge pump
devices is the doubler (Figure 5-3). This application
uses two external capacitors – C
supply bypass capacitor, if necessary). The output is
equal to 2 x V
loading. Refer to Table 5-1 and Table 5-2 for capacitor
selection.
Voltage Doubler
TC1240/TC1240A
IN
minus any voltage drops due to
1
and C
DS21516C-page 9
2
(plus a power