MAX1044/ICL7660
Switched-Capacitor Voltage Converters
Paralleling Devices
+
1
2
C1
3
4
8
V+
MAX1044
ICL7660
7
6
Paralleling multiple MAX1044/ICL7660s reduces output
resistance and increases current capability. As illustrated
in Figure 13, each device requires its own pump capacitor
C1, but the reservoir capacitor C2 serves all devices. The
equation for calculating output resistance is:
R
OUT
=
R
OUT
(of MAX1044 or ICL7660)
n (number of devices)
1
+
5
Shutdown Schemes
8
1
2
C1
3
4
MAX1044
ICL7660
7
6
V
OUT
= -(V+)
C2
n
5
Figures 14a–14c illustrate three ways of adding shutdown
capability to the MAX1044/ICL7660. When using these
circuits, be aware that the additional capacitive loading
on the OSC pin will reduce the oscillator frequency. The
first circuit has the least loading on the OSC pin and has
the added advantage of controlling shutdown with a high
or low logic level, depending on the orientation of the
switching diode.
Figure 13. Paralleling MAX1044/ICL7660 to Reduce Output
Resistance
Ordering Information
PART
TEMP. RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
-55°C to +125°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
-55°C to +125°C
-55°C to +125°C
PIN-PACKAGE
8 Plastic DIP
8 SO
Dice*
8 Plastic DIP
8 SO
8 CERDIP**
8 Plastic DIP
8 SO
8 μMAX
Dice*
8 Plastic DIP
8 SO
8 CERDIP**
8 TO-99**
MAX1044CPA
MAX1044CSA
MAX1044C/D*
MAX1044EPA
MAX1044ESA
MAX1044MJA
ICL7660CPA
ICL7660CUA
V+
+
1
2
10µF
3
4
8
10kΩ REQUIRED FOR TTL
V+ CMOS or
TTL GATE
MAX1044
ICL7660
1N4148
7
6
5
V
OUT
= -(V+)
10µF
a)
V+
MAX1044
ICL7660
b)
7
74HC03
OPEN-DRAIN OR
74LS03
OPEN-COLLECTOR
NAND GATES
ICL7660C/D
ICL7660EPA
ICL7660ESA
ICL7660AMJA
†
ICL7660AMTV
†
V+
MAX1044
7
ICL7660
c)
OUTPUT
ENABLE
74HC126 OR
74LS126
TRI-STATE BUFFER
*Contact factory for dice specifications. Dice are not tested
**Contact factory for availability.
†
The
Maxim ICL7660 meets or exceeds all “A” and “S”
specifications.
Figure 14a-14c. Shutdown Schemes for MAX1044/ICL7660
www.maximintegrated.com
Maxim Integrated
│
12
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
