xDSL/Cable Modem Triple/Quintuple Output
Power Supplies
Typical Operating Characteristics (continued)
(Circuit of Figure 1, V
IN
= 12V, V
OUT
= 3.3V, T
A
= +25°C, unless otherwise noted.)
POSITIVE LINEAR REGULATOR
OUTPUT VOLTAGE vs. SUPPLY VOLTAGE
(Q
LDO
= 2N3905)
MAX18664/65 toc10
MAX1864/65 toc11
MAX1864/MAX1865
POSITIVE LINEAR REGULATOR
OUTPUT VOLTAGE vs. LOAD CURRENT
(Q
LDO
= 2N3905)
2.50
2.50
POSITIVE LINEAR REGULATOR
POWER-SUPPLY REJECTION RATIO
(Q
LDO
= 2N3905)
70
60
PSRR (dB)
50
40
30
MAX1864/65 toc12
80
2.48
OUTPUT VOLTAGE (V)
V
SUP(POS)
= 5.0V
2.46
V
SUP(POS)
= 3.3V
2.44
OUTPUT VOLTAGE (V)
2.48
I
OUT2
= 1mA
2.46
I
OUT2
= 100mA
2.44
20
10
I
OUT2
= 50mA
2.42
0.01
0.1
1
10
100
1000
LOAD CURRENT (mA)
2.42
2
3
4
5
6
7
8
SUPPLY VOLTAGE (V)
0
0.1
1
10
FREQUENCY (kHz)
100
1000
POSITIVE LINEAR REGULATOR
LOAD TRANSIENT
(Q
LDO
= 2W3905)
100mA
MAX1864/65 toc13
MAX1864/65 toc14
A
OUTPUT VOLTAGE (V)
0
2.48
2.46
OUTPUT VOLTAGE (V)
V
SUP(POS)
= 5.0V
2.48
I
OUT2
= 1mA
V
SUP(POS)
= 3.3V
2.46
I
OUT2
= 100mA
2.467V
B
2.457V
2.44
2.44
2.42
10µs/div
A. I
OUTZ
= 1mA TO 100mA, 50mA/div
B. V
OUTZ
= 2.5V, 5mV/div
C
LDO(POS)
= 10µF CERAMIC, V
SUP(POS)
= 3.3V
CIRCUIT OF FIGURE 1
0.01
0.1
1
10
100
1000
LOAD CURRENT (mA)
2.42
2
4
6
8
10
12
SUPPLY VOLTAGE (V)
_______________________________________________________________________________________
7
MAX1864/65 toc15
2.50
POSITIVE LINEAR REGUALTOR
OUTPUT VOLTAGE vs. LOAD CURRENT
(Q
LDO
= TIP30)
2.50
POSITIVE LINEAR REGULATOR
OUTPUT VOLTAGE vs. SUPPLY VOLTAGE
(Q
LDO
= TIP30)
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
