TC1121_06 MICROCHIP [Microchip Technology], TC1121_06 Datasheet - Page 7

• Manufacturer Part Number: TC1121_06
• Description: 100mA Charge Pump Voltage Converter with Shutdown
• Manufacturer: MICROCHIP [Microchip Technology]

3.6
Figure 3-4 shows this dual function circuit, in which
capacitors C1 and C2 perform pump and reservoir
functions to generate negative voltage. Capacitors C3
and C4 are the respective capacitors for multiplied
positive voltage. This particular configuration leads to
higher source impedances of the generated supplies
due to the finite impedance of the common
charge-pump driver.
FIGURE 3-4:
© 2006 Microchip Technology Inc.
Combined Positive Supply
Multiplication and Negative
Voltage Conversion
Combined Positive Multiplier and Negative Converter
*SHDN should be tied to V
C1
+
2
3
4
FC
CAP
GND
CAP
TC1121
+
–
C3
+
SHDN
V
OSC
OUT
IN
V
IN
if
not used.
8
5
6
V
IN
+
SHDN*
D1, D2 = 1N4148
D1
D2
+
C4
+
C2
V
V
(V
OUT
OUT = (
FD1
= V
) – (V
2V
IN
–
IN
FD2
) –
)
TC1121
DS21358C-page 7