MAX1490EBCPG+ Maxim Integrated Products, MAX1490EBCPG+ Datasheet - Page 10

• Manufacturer Part Number: MAX1490EBCPG+
• Description: IC RS485/RS422 DATA INTRFC 24DIP
• Manufacturer: Maxim Integrated Products
• Type: Transceiverr

Specifications of MAX1490EBCPG+

• Number Of Drivers/receivers: 1/1
• Protocol: RS422, RS485
• Voltage - Supply: 4.5 V ~ 5.5 V
• Mounting Type: Through Hole
• Package / Case: 24-DIP (0.600", 15.24mm)
• Data Rate: 250 Kbps
• Operating Supply Voltage: 5 V
• Supply Current: 130 mA
• Operating Temperature Range: 0 C to + 70 C
• Maximum Power Dissipation: 696 mW
• Mounting Style: Through Hole
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The high-speed optocouplers on the MAX1480EA/
MAX1480EC/MAX1490EA consume an additional 10mA
through V
completely shut down these devices, use an external P-
channel MOSFET as shown in Figure 3. In normal opera-
tion, SD is low, turning the MOSFET on and thereby
providing power to all the V
high, the power oscillator is disabled and the switch is
turned off, disconnecting power from the DI and DE opto-
±15kV ESD-Protected, Isolated RS-485/RS-422
Data Interfaces
Figure 1. MAX1480EA/MAX1480EC Detailed Block Diagram and Application Circuit
Table 1. Pullup and LED Drive Resistors for Figure 1
10
MAX1480EA
MAX1480EC
______________________________________________________________________________________
DE
RO
FS
DI
PART
CC5
*SEE TABLE 1.
OR EQUIVALENT
74HC86
1.07MHz/
1.45MHz
(V
OSC
+5V
V
IN
CC4
RECEIVER OUTPUT
DRIVER ENABLE
DRIVER INPUT
V
CC3
for the MAX1490EA). Therefore, to
C1
22µF
T F/F
Q
Q
LOGIC GROUND
DE
CC
DI
C2
0.1µF
SD
´
´
R1 (Ω)
200
200
R3*
R1*
R2*
pins. When SD is pulled
MAX845E
GND1
GND2
V
V
V
V
V
CC1
CC2
CC3
CC4
CC5
D1
D2
SD
DE
RO
FS
DI
GND1
N
N
10
11
12
13
14
1
2
3
4
5
6
7
8
9
R2 (Ω)
200
200
D1
D2
MAX845E
ISOLATION BARRIER
MAX1480EA
MAX1480EC
270pF
4kV
MAX1487E
MAX487E
R3 (Ω)
28
27
26
25
24
23
22
21
20
19
18
17
16
ISO RO DRV
15
1000
3000
couplers. In normal operating mode, the switch carries
only the optocoupler currents, so an on-resistance of sev-
eral ohms does not significantly degrade efficiency.
ISO DE IN
ISO DI IN
AC1 (MAKE NO CONNECTION)
AC2 (MAKE NO CONNECTION)
ISO V
B
ISO RO DRV
A
ISO DI IN
ISO DE IN
ISO COM1
ISO DI DRV
ISO V
ISO DE DRV
ISO COM2
ISO RO LED
CC1
CC2
ISOLATED COMMON
D
ISO COM1
ISO V
RE
R6*
R4 (Ω)
R
R4*
R5*
CC1
MAX1480EA: MAX1487E
4300
3000
MAX1480EC: MAX487E
SH
B
A
EXTERNAL RS-485/RS-422 WIRING
100Ω
R7
B
A
NOTE: RESISTOR R7 PROTECTS
THE MAX1480EA FROM TRANSIENT
CURRENTS BETWEEN SHIELD AND
TRANSMISSION LINES.
R5 (Ω)
(ONE RESISTOR ON EACH END)
TO OTHER TRANSCEIVERS
TO OTHER TRANSCEIVERS
1000
3000
TERMINATING RESISTOR
SHIELD (OPTIONAL)
SHIELD (OPTIONAL)
TWISTED PAIR
TWISTED PAIR
R6 (Ω)
200
200
R
R
L
L