MAX1480 Maxim, MAX1480 Datasheet - Page 9

• Manufacturer Part Number: MAX1480
• Description: Complete / Isolated RS-485/RS-422 Data Interface
• Manufacturer: Maxim

________________________________________________________________Pin Description
MAX1480A/B/C MAX1490A/B
PINS ON THE NON-ISOLATED SIDE
PINS ON THE ISOLATED RS-485/RS-422 SIDE
PINS ON THE NON-ISOLATED SIDE
PINS ON THE ISOLATED RS-485/RS-422 SIDE
1, 2, 8, 10
3, 4
11
12
13
14
15
16
17
18
19
20
—
5
6
7
9
PIN
1, 2, 8, 10
_______________________________________________________________________________________
3, 4
11
12
13
14
15
16
—
—
—
—
—
5
6
7
9
ISO RO LED
ISO DE DRV
V
ISO DI DRV
ISO COM2
ISO COM1
ISO V
CC1
Complete, Isolated RS-485/RS-422
D1, D2
NAME
GND1
GND2
V
RO
RO
SD
DE
FS
DI
CC5
–V
CC2
CC4
Logic-Side (non-isolated side) +5V Supply Voltages
Internal Connections. Leave these pins unconnected.
Logic-Side Ground. Connect to GND2 (pin 12).
Frequency Select Input. If FS = V
= GND, switch frequency is low. For optimal performance and minimal supply
current, connect FS to V
Shutdown Input. Ground for normal operation. When high, the power oscillator is
disabled.
Driver Input. With DE
low and output B high. Similarly, a high on DI
B low. Drives internal LED cathode through a resistor (Table 1 of Figure 1 for
MAX1480A/B/C, Table 2 of Figure 2 for MAX1490A/B).
Driver-Enable Input. The driver outputs, A and B, are enabled by bringing DE
high. The driver outputs are high impedance when DE
puts are enabled, the device functions as a line driver. While the driver outputs
are high impedance, the device functions as a line receiver. Drives internal
LED cathode through a resistor (Table 1 of Figure 1).
Receiver Output. If A > B by 200mV, RO will be high; if A < B by 200mV, RO
will be low. Open collector; must have pull-up to V
Logic-Side Ground. Connect to GND1 (pin 5).
Receiver Output. If A > B by 200mV, RO will be low; if A < B by 200mV, RO will
be high. Open collector; must have pull-up to V
Logic-Side (non-isolated side) +5V Supply Voltage
Isolated Receiver Output LED. Internal LED anode in MAX1480A/B/C and LED
cathode in MAX1490A/B. Connect to ISO RO DRV through a resistor (Table 1 of
Figure 1 for MAX1480A/B/C; Table 2 of Figure 2 for MAX1490A/B).
Isolated Common. Connect to ISO COM1 (pin 20).
Isolated Driver-Enable Drive. The driver outputs, A and B, are enabled by bring-
ing DE
er outputs are enabled, the device functions as a line driver. While the driver
outputs are high impedance, the device functions as a line receiver. Open-
collector output; must have pull-up to ISO VCC_ and be tied to ISO DE IN for
normal operation (Table 1 of Figure 1).
Isolated Supply Voltage. Connect to ISO V
pin 22 for MAX1490A/B).
Isolated Driver-Input Drive. With DE
forces output A low and output B high. Similarly, a high on DI
high and output B low. Connect to ISO DI IN (on the MAX1480A/B/C only) for
normal operation. Open-collector output; connect a pull-up resistor to ISO V
(Table 1 of Figure 1 for MAX1480A/B/C; Table 2 of Figure 2 for MAX1490A/B).
Isolated Common. For MAX1480A/B/C, connect to ISO COM2 (pin 16)
(Figures 1 and 2).
´
high. The driver outputs are high impedance when DE
´
high (MAX1480A/B/C only), a low on DI
CC_
or leave unconnected.
CC_
FUNCTION
´
high (MAX1480A/B/C only), a low on DI
or is open, switch frequency is high; if FS
Data Interface
CC1
´
forces output A high and output
CC_
(pin 26 for MAX1480A/B/C, or
CC
(Table 1 of Figure 1).
(Table 2 of Figure 2).
´
is low. If the driver out-
´
´
´
is low. If the driv-
forces output A
forces output A
CC_
´
´
9