CMOS Monolithic Voltage Converter
MAX660
The following is a list of manufacturers who provide
low-ESR electrolytic capacitors:
Manufacturer/
Series
AVX TPS Series
AVX TAG Series
Phone
(803) 946-0690
(803) 946-0690
Fax
(803) 626-3123
(803) 626-3123
(714) 960-6492
(603) 224-1430
(619) 661-1055
(619) 661-1055
(847) 843-2798
(847) 696-9278
(847) 390-4428
Comments
Low-ESR
tantalum SMT
Low-cost
tantalum SMT
Low-cost
tantalum SMT
Aluminum elec-
trolytic thru-hole
Aluminum elec-
trolytic SMT
Aluminum elec-
trolytic thru-hole
Low-ESR
tantalum SMT
Ceramic SMT
Ceramic SMT
Cascading Devices
To produce larger negative multiplication of the initial
supply voltage, the MAX660 may be cascaded as
shown in Figure 3. The resulting output resistance is
approximately equal to the sum of the individual
MAX660 R
OUT
values. The output voltage, where n is
an integer representing the number of devices cascad-
ed, is defined by V
OUT
= -n (V
IN
).
Paralleling Devices
Paralleling multiple MAX660s reduces the output resis-
tance. As illustrated in Figure 4, each device requires
its own pump capacitor C1, but the reservoir capacitor
C2 serves all devices. The value of C2 should be
increased by a factor of n, where n is the number of
devices. Figure 4 shows the equation for calculating
output resistance.
Matsuo 267 Series (714) 969-2491
Sprague 595
Series
Sanyo MV-GX
Series
Sanyo CV-GX
Series
Nichicon PL
Series
(603) 224-1961
(619) 661-6835
(619) 661-6835
(847) 843-7500
United Chemi-Con
(847) 696-2000
(Marcon)
TDK
(847) 390-4373
R
OUT
=
R
OUT
(of MAX660)
n (NUMBER OF DEVICES)
+V
IN
+V
IN
8
8
2
3
4
2
8
2
3
4
5
C2n
C2
V
OUT
= -nV
IN
C2
V
OUT
2
8
R
L
C1
MAX660
"1"
5
C1n
3
4
MAX660
"n"
C1
MAX660
"1"
C1n
5
3
4
MAX660
"n"
5
Figure 3. Cascading MAX660s to Increase Output Voltage
Figure 4. Paralleling MAX660s to Reduce Output Resistance
8
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