MAX1748 Maxim, MAX1748 Datasheet - Page 6

• Manufacturer Part Number: MAX1748
• Description: Triple-Output TFT LCD DC-DC Converter
• Manufacturer: Maxim

Triple-Output TFT LCD DC-DC Converter
(Circuit of Figure 5, V
6
-10
-11
24
22
20
18
16
14
12
10
-3
-4
-5
-6
-7
-8
-9
MAXIMUM POSITIVE CHARGE-PUMP OUTPUT
8
_______________________________________________________________________________________
OUTPUT VOLTAGE vs. SUPPLY VOLTAGE
5
5
V
V
V
MAXIMUM NEGATIVE CHARGE-PUMP
V
MAIN
NEG
POS
POS
I
I
POS
NEG
VOLTAGE vs. SUPPLY VOLTAGE
= -5V, I
= 15V, I
= 22V
= 10V, I
6
6
= 1mA
= 1mA
RIPPLE WAVEFORMS
NEG
POS
I
NEG
7
MAIN
7
I
POS
= 10mA,
= 10mA
= 10mA
= 200mA,
= 10mA
V
V
8
8
SUPN
SUPP
1µs/div
IN
I
(V)
(V)
I
POS
9
NEG
9
= 3.3V, T
= 20mA
= 20mA
10
V
10
NEG
= -10mA
MAX1748toc13
11
11
A
= +25°C, unless otherwise noted.)
12
12
V
10mV/div
V
10mV/div
V
10mV/div
MAIN
NEG
POS
15.3
15.2
15.1
15.0
14.9
14.8
14.7
14.6
14.5
14.4
1.20
1.15
1.10
1.05
1.00
0.95
0.90
0.85
0.80
Typical Operating Characteristics (continued)
2.5
0
V
R
MEASURED FROM THE
FALLING EDGE OF LX
V
I
IN
MAIN
MAIN
MAIN
POSITIVE CHARGE-PUMP OUTPUT
= 3.3V, V
2
= 500Ω TO 50Ω (20mA TO 200mA)
VOLTAGE vs. LOAD CURRENT
LOAD-TRANSIENT RESPONSE
= 100mA
3.0
= 10V
4
SWITCHING FREQUENCY
MAIN
V
vs. INPUT VOLTAGE
SUPN
6
3.5
INPUT VOLTAGE (V)
= 10V,
= 8V
8
100µs/div
I
POS
10
4.0
(mA)
12 14 16 18 20
4.5
V
V
SUPN
SUPN
MAX1748 toc14
5.0
= 12V
= 10V
5.5
I
200mA/div
I
500mA/div
V
200mV/div
MAIN
LX
MAIN
1.254
1.252
1.250
1.248
1.246
1.244
100
90
80
70
60
50
40
0
0
V
R
POSITIVE CHARGE-PUMP EFFICIENCY
V
IN
MAIN
IN
= 3.3V, V
2
vs. REFERENCE LOAD CURRENT
= 3.3V
5
= 500Ω TO 50Ω (20mA TO 200mA)
LOAD-TRANSIENT RESPONSE
10
4
WITHOUT INTEGRATOR
REFERENCE VOLTAGE
MAIN
vs. LOAD CURRENT
15
6
= 10V, INTG = REF,
20
8
I
100µs/div
POS
I
REF
V
V
V
10
25
SUPP
SUPP
SUPP
(mA)
(µA)
12 14 16 18 20
30
= 8V
= 10V
= 12V
35 40 45 50
MAX1748toc15
I
200mA/div
I
500mA/div
V
200mV/div
MAIN
LX
MAIN