Datasheet
LTC2872
6
2872f
Typical perForMance characTerisTics
V
CC
Supply Current
vs RS232 Data Rate
V
CC
Supply Current
vs Supply Voltage for RS485
at Maximum Data Rate
RS485 Driver Differential Output
Voltage vs Temperature
RS485 Driver Propagation Delay
vs Temperature
RS485 Driver Short-Circuit Current
vs Short-Circuit Voltage
RS485 Driver and Receiver Skew
vs Temperature
V
CC
Supply Current vs Supply
Voltage in Shutdown Mode
V
CC
Supply Current vs Supply
Voltage in Fast Enable Mode
V
CC
Supply Current
vs RS485 Data Rate
INPUT VOLTAGE (V)
3
INPUT CURRENET (µA)
30
25
20
15
10
5
0
4.5 53.5
2872 G01
5.54
H/F LOW
H/F HIGH
SUPPLY VOLTAGE (V)
3
SUPPLY CURRENT (mA)
4.6
4.2
3.8
3.4
4.4
4.0
3.6
3.2
3.0
53.5
2872 G02
5.54.54
–40°C
25°C
85°C
DATA RATE (Mbps)
0.1
SUPPLY CURRENT (mA)
200
140
100
60
160
180
120
80
40
20
0
1
2872 G03
10010
DRIVER AND RECEIVER
TERMINATION ENABLED
TERMINATION DISABLED
ALL RS485 DRIVERS AND
RECEIVERS SWITCHING.
Y TIED TO A; Z TIED TO B,
H/F = 0V, C
L
= 100pF
ON Y AND Z TO GND
V
CC
= 5V
V
CC
= 3.3V
DATA RATE (kbps)
0
INPUT CURRENT (mA)
50
45
35
25
40
30
20
15
10
50
2872 G04
500100 150 200 250 300 350 450400
ALL RS232 DRIVERS
AND RECEIVERS
SWITCHING
2.5nF
2.5nF
0.5nF
V
CC
= 5V
V
CC
= 3.3V
0.5nF
0.05nF
0.05nF
SUPPLY VOLTAGE (V)
3
SUPPLY CURRENT (mA)
240
220
180
140
200
160
120
100
80
3.5
2872 G05
5.54 4.5 5
BOTH RS485 DRIVERS AND
RECEIVERS SWITCHING.
Y TIED TO A, Z TIED TO B
H/F = 0V
DRIVER AND RECEIVER
TERMINATION ENABLED
20Mbps, C
L
= 100pF ON
Y AND Z TO GND
85°C
25°C
–40°C
TEMPERATURE (°C)
–50
VOLTAGE (V)
4.5
3.5
2.5
1.5
4.0
3.0
2.0
1.0
0.5
0
50 75–25
2872 G06
100250
R
L
= 100Ω
R
L
= 54Ω
R
L
= 100Ω
R
L
= 54Ω
V
CC
= 5V
V
CC
= 3.3V
TEMPERATURE (°C)
–50
DELAY (ns)
50
40
30
20
10
0
50 75–25
2872 G07
100250
V
CC
= 3.3V, V
L
= 1.7V
V
CC
= 5V, V
L
= 1.7V
V
CC
= 3.3V, V
L
= 3.3V
V
CC
= 5V, V
L
= 5V
SHORT-CIRCUIT VOLTAGE (V)
–10
SHORT-CIRCUIT CURRENT (mA)
150
100
0
50
–50
–100
–150
10–5
2872 G08
1550
OUTPUT LOW
OUTPUT HIGH
V
CC
= 5V
V
CC
= 3.3V
TEMPERATURE (°C)
–50
SKEW (ns)
3.0
2.5
1.5
2.0
1.0
0.5
0
50 75–25
2872 G09
100250
DRIVER
RECEIVER