Rainbow Electronics MAX1748 - Manual (Page 10)

MAX1748
Triple-Output TFT LCD DC-DC Converter
10 ______________________________________________________________________________________
GND PGND
R6
C REF
0.22 µF
V SUPN = 2.7V TO 13V
V POS = (R5 / R6) x V
REF
V REF = 1.25V
SUPN
OSC
R5 V NEG
C5
C6
D5
D4
+
-
DRVN
FBN
REF MAX1748
+
- V REF
1.25V
Figure 2. Negative Charge-Pump Block Diagram
GND PGND
V
REF
1.25V
R4
V
SUPP
= 2.7V TO 13V
V POS = [1 + (R3 / R4)] x V REF
V
REF
= 1.25V
SUPP
OSC
R3 V POS
C3
C4
D3
D2
+
-
DRVP
FBP
MAX1748
+
-
Figure 3. Positive Charge-Pump Block Diagram