Rainbow Electronics MAX1865 - Manual (Page 8)

MAX1864/MAX1865
xDSL/Cable Modem Triple/Quintuple Output
Power Supplies
8 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(Circuit of Figure 1, V IN = 12V, V OUT = 3.3V, T A = +25°C, unless otherwise noted.)
-12.00
-12.06
-12.12
-12.18
-12.24
0.01 1 10 100 0.1 1000
NEGATIVE LINEAR REGULATOR
OUTPUT VOLTAGE vs. LOAD CURRENT
(Q
LDO
= TIP29)
MAX1864/65 toc19
LOAD CURRENT (mA)
OUTPUT VOLTAGE (V)
V SUP(NEG) = -15V
V OUT3 = 5V
-12.24
-12.18
-12.12
-12.06
-12.00
-20 -18 -16 -14 -12 -10
NEGATIVE LINEAR REGULATOR
OUTPUT VOLTAGE vs. SUPPLY VOLTAGE
(Q LDO = TIP29)
MAX1864/65 toc20
SUPPLY VOLTAGE (V)
OUTPUT VOLTAGE (V)
I LDO(NEG) = 100mA
I LDO(NEG) = 1mA
80
70
60
50
40
30
20
10
0
0.1 10 100 1 1000
POSITIVE LINEAR REGULATOR
POWER-SUPPLY REJECTION RATIO
(Q LDO = TIP30)
MAX1864/65 toc16
FREQUENCY (kHz)
PSRR (dB)
I OUT2 = 150mA
POSITIVE LINEAR REGULATOR
LOAD TRANSIENT
(Q LDO = TIP30)
MAX1864/65 toc17
250mA
2.453V
2.473V
A. I OUT2 = 10mA TO 250mA, 200mA/div
B. V OUT2 = 2.5V, 10mV/div
C LDO(POS) = 10 µF CERAMIC, V
SUP(POS) = 3.3V
CIRCUIT OF FIGURE 1
0
B
A
10 µs
0
10
5
25
20
15
40
35
30
45
0 4 2 6 8 10
NEGATIVE LINEAR REGULATOR BASE-
DRIVE CURRENT vs. BASE-DRIVE VOLTAGE
MAX1864/65 toc18
V OUT - V B5 (V)
BASE-DRIVE SOURCE CURRENT (mA)
V FB5 = 250mV
V FB5 = 50mV
V OUT = 5.0V
V OUT = 3.3V
B5 (MAX1865) ONLY