Low-Noise, Dual-Output, Regulated Charge Pump
for GaAsFET, LCD, and VCO Supplies
MAX768
____________________________Typical Operating Characteristics (continued)
(SYNC = IN, T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT
vs. SYNC FREQUENCY
MAX768-TOC04
CHARGE-PUMP FREQUENCY
vs. SUPPLY VOLTAGE
MAX768-TOC05
CHARGE-PUMP FREQUENCY
vs. TEMPERATURE
V
IN
= 3.3V
CHARGE-PUMP FREQUENCY (kHz)
100
80
60
40
SYNC = GND
20
0
SYNC = IN
MAX768-TOC06
4
115
SYNC = IN
CHARGE-PUMP FREQUENCY (kHz)
100
85
70
55
40
SYNC = GND
25
10
120
SUPPLY CURRENT (mA)
3
V
IN
= 5.0V
2
1
V
IN
= 3.3V
0
0
40
80
120 160 200 240 280 320
SYNC FREQUENCY (kHz)
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
-55 -35 -15
5
25
45
65
85 105 125
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
SHDN SUPPLY CURRENT
vs. TEMPERATURE
MAX768-TOC07
SHDN SUPPLY CURRENT
vs. TEMPERATURE
MAX768-TOC08
SUPPLY CURRENT
vs. SUPPLY VOLTAGE (NO LOAD)
1.6
SUPPLY CURRENT (mA)
1.4
1.2
1.0
0.8
f = 25kHz
0.6
0.4
0.2
f = 100kHz
MAX768-TOC09
20
18
SHDN SUPPLY CURRENT (µA)
16
14
12
10
8
6
4
2
0
-40
-15
10
35
60
V
IN
= 3.3V
V
IN
= 5.0V
0.40
0.35
SHDN SUPPLY CURRENT (µA)
0.30
0.25
0.20
0.15
0.10
0.05
0
-0.05
V
IN
= 3.3V
-40
-15
10
35
60
V
IN
= 4.0V
V
IN
= 5.0V
1.8
0
85
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
SUPPLY VOLTAGE (V)
85
TEMPERATURE (°C)
TEMPERATURE (°C)
EFFICIENCY vs. LOAD CURRENT
(NOUT ONLY LOADED)
MAX768 TOC10
EFFICIENCY vs. OUTPUT CURRENT
(POUT ONLY LOADED)
MAX768 TOC11
EFFICIENCY vs. OUTPUT CURRENT
LOAD BETWEEN POUT AND NOUT
80
70
EFFICIENCY (%)
60
50
40
30
20
10
0
V
IN
= 4.0V
MAX768 TOC12
90
80
70
EFFICIENCY (%)
60
50
40
30
20
10
0
0.1
1
10
V
IN
= 4.0V
V
IN
= 3.0V
90
80
70
EFFICIENCY (%)
60
50
40
30
20
10
0
V
IN
= 4.0V
V
IN
= 3.0V
90
V
IN
= 3.0V
100
0.1
1
10
100
0.1
1
10
100
LOAD CURRENT (mA)
OUTPUT CURRENT (mA)
OUTPUT CURRENT (mA)
4
_______________________________________________________________________________________
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
