Manual

MAX1747
Triple Charge-Pump TFT LCD
DC-DC Converter
6 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(Circuit of Figure 1, V
IN
= V
SUPM
= +3.3V, T
A
= +25°C, unless otherwise noted.)
0
2
4
6
8
10
12
14
16
0 0.5 1.0 1.5 2.0
NO-LOAD SUPPLY CURRENT
vs. SWITCHING FREQUENCY
MAX1747 toc04
FREQUENCY (MHz)
I
CC
+ I
IN
(mA)
0
0.4
1.2
0.8
1.6
2.0
02010 30 40 50
SWITCHING FREQUENCY
vs. I
SHDN
MAX1747 toc05
I
SHDN
(mA)
FREQUENCY (MHz)
9.0
10.0
9.5
11.0
10.5
11.5
12.0
-40 10-15 35 60 85
MAX1747 toc06
TEMPERATURE (
°
C)
I
IN
+ I
SUPM
(mA)
NO-LOAD SUPPLY CURRENT
vs. TEMPERATURE
V
ON
= 3.3V
R
FREQ
= 120k
Ω
0.85
0.95
0.90
1.05
1.00
1.10
1.15
-40 10-15 356085
MAX1747 toc07
TEMPERATURE (
°
C)
FREQUENCY (MHz)
SWITCHING FREQUENCY
vs. TEMPERATURE
V
ON
= 3.3V
R
FREQ
= 120k
Ω
20
30
40
50
60
70
80
90
100
0 10203040
NEGATIVE LOW-POWER CHARGE-PUMP
EFFICIENCY vs. LOAD CURRENT
MAX1747 toc08
I
NEG
(mA)
EFFICIENCY (%)
V
SUPN
= 6V
V
SUPN
= 5V
V
SUPN
= 7V
V
NEG
= -7V
-7.1
-7.0
-6.9
-6.8
-6.7
-6.6
-6.5
-6.4
-6.3
0 10203040
NEGATIVE LOW-POWER CHARGE-PUMP
OUTPUT VOLTAGE vs. LOAD CURRENT
MAX1747 toc09
I
NEG
(mA)
V
NEG
(V)
V
SUPN
= 5V
V
SUPN
= 6V
V
SUPN
= 7V
-22
-18
-10
-14
-6
-2
37591113
MAXIMUM NEGATIVE CHARGE-PUMP
OUTPUT VOLTAGE vs. SUPPLY VOLTAGE
MAX1747 toc10
V
SUPN
(V)
V
NEG
(V)
I
NEG
= 10mA
I
NEG
= 1mA
V
NEG(NOMINAL)
= -20V
11.4
11.5
11.6
11.7
11.8
11.9
12.0
12.1
12.2
0 10203040
POSITIVE LOW-POWER CHARGE-PUMP
OUTPUT VOLTAGE vs. LOAD CURRENT
MAX1747 toc12
I
POS
(mA)
V
POS
(V)
V
SUPP
= 7V
V
SUPP
= 6V
V
SUPP
= 5V
20
30
40
50
60
70
80
90
100
0 10203040
POSITIVE LOW-POWER CHARGE-PUMP
EFFICIENCY vs. LOAD CURRENT
MAX1747 toc11
I
POS
(mA)
EFFICIENCY (%)
V
SUPP
= 6V
V
SUPP
= 5V
V
POS
= 12V
V
SUPP
= 7V