MAX253ESA-T Datasheet, PDF (4/18 Pages) Maxim Integrated Products – MAX253 Transformer Driver for Isolated RS-485 Interface

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