Datasheet

MAX253
Transformer Driver for
Isolated RS-485 Interface
Maxim Integrated | 4www.maximintegrated.com
10
0
0 40 220
OUTPUT VOLTAGE vs. LOAD CURRENT
(FS = LOW)
2
8
plot10
LOAD CURRENT (mA)
OUTPUT VOLTAGE (V)
80
6
4
1
3
9
7
5
20 60 140
12 0100 160 180 200
CIRCUIT OF FIGURE 6
V
IN
= 5.0V
TURNS RATIO = 1:1
CIRCUIT OF FIGURE 6
V
IN
= 5.0V
TURNS RATIO = 1:1.3
CIRCUIT OF FIGURE 7
V
IN
= 3.3V
TURNS RATIO = 1:2.1
MEASURED AT TP1
10
0
040 220
OUTPUT VOLTAGE vs. LOAD CURRENT
(FS = HIGH)
2
8
plot11
LOAD CURRENT (mA)
OUTPUT VOLTAGE (V)
80
6
4
1
3
9
7
5
20 60 140
12 0100 160 180 200
CIRCUIT OF FIGURE 6
V
IN
= 5.0V
TURNS RATIO = 1:1
CIRCUIT OF FIGURE 6
V
IN
= 5.0V
TURNS RATIO = 1:1.3
CIRCUIT OF FIGURE 7
V
IN
= 3.3V
TURNS RATIO = 1:2.1
MEASURED AT TP1
CIRCUIT OF FIGURE 1
SWITCHING WAVEFORMS
(TWO CYCLES)
D1
D2
CIRCUIT OF FIGURE 1
SWITCHING WAVEFORMS
(BREAK BEFORE MAKE)
D1
D2
CIRCUIT OF FIGURE 6
TIME FROM SHUTDOWN TO POWER-UP
SD
TP1 (OUTPUT VOLTAGE)
Typical Operating Characteristics (continued)
Circuit of Figure 6, V
IN
= 5V ±10%, T
A
= +25°C, unless otherwise noted.)
100
0
0 40 120 200
EFFICIENCY vs. LOAD CURRENT
(FS = HIGH)
20
80
plot09
LOAD CURRENT (mA)
EFFICIENCY (%)
80 160
60
40
10
30
90
70
50
20 60 140100 180
V
IN
= 5.5V
V
IN
= 4.5V