7
Table 1. Power Supply Schemes
V
cc1
V
cc2a
V
eea
S2a
S3a
D4a/
R7a
V
cc2b
V
eeb
S2b
S3b
D4b/
R7b Remarks
1
+5 V
External
+12V~20V
External
0 V
s/c
s/c
NM
Bootstrapped
from V
cc2a
(+12V~20V)
0 V
s/c
s/c
NM
Default (simplest)
- Two external supplies needed
for V
cc1
and V
cc2a
2
+5 V
External
+12V~20V
External
0 V
s/c
s/c
NM
+12V~20V
External
0 V
s/c
s/c
NM
Higher Power
- Three external supplies needed
for V
cc1
, V
cc2a
and V
cc2b
3
+5 V
External
+15V~24V External
open open 12V/
1k
+15V~24V External
open open 12V/1k V
ee
available
- Three external supplies needed
for V
cc1
, V
cc2a
and V
cc2b
- Virtual gnds V
ea
and V
eb
generated through D4 and R7
12V
-3V~-12V
12V
-3V~-12V
4
+5 V
External
DC/DC
(=V
cc1
/+12V)
0 V
s/c
s/c
NM
Bootstrapped
from V
cc2a
(+12V)
0 V
s/c
s/c
NM
Cheap
- One single output DC/DC
converter for V
cc2a
- Only one external supply is
needed (V
cc1
)
5
+5 V
External
DC/DC
(=V
cc1
/+12V)
0V
s/c
s/c
NM
DC/DC
(=V
cc1
/+12V)
0 V
s/c
s/c
NM
Higher Power
- Two single output DC/DC
converters for V
cc2a
and V
cc2b
- Only one external supply is
needed (V
cc1
)
6
+5 V
External
DC/±DC
(=V
cc1
/±12V) open
s/c
NM
DC/±DC
(=V
cc1
/±12V) open
s/c
NM
V
ee
available
- Two dual output DC/DC
converters for V
cc2a
,V
cc2b
, V
eea
and V
eeb
- Only one external supply is
needed (V
cc1
)
+12V
-12V
+12V
-12V
7
+5 V
External
DC/±DC
(=V
cc1
/±9V)
open open 12V/
1k
DC/±DC
(=V
cc1
/±9V)
open open 12V/1k V
ee
available
- Dual output DC/DC converters
for V
cc2a
and V
cc2b
- only 1 external supply is
needed (V
cc1
)
- Virtual gnds V
ea
and V
eb
generated through D4 and R7
+12V
-6V
+12V
-6V
Note: As TVS D2 voltage is selected at a breakdown voltage of 12.2 V, it is not advised to set both V
cc2
and V
ee
voltage at a voltage beyond ±12 V.
To use a voltage higher than 12 V, please replace D2 with a bigger clamping voltage.