LTC2872
Typical perForMance characTerisTics
RS485 Receiver Propagation
Delay vs Temperature
RS485 Receiver Output Voltage
vs Load Current
RS232 Receiver Input Threshold
vs Temperature
6
5
4
3
2
1
0
80
70
60
50
40
2.0
1.8
1.6
1.4
1.2
1.0
V
V
V
= 5V
= 3.3V
= 1.7V
L
L
L
V
V
V
V
= 3.3V, V = 1.7V
L
CC
CC
CC
CC
= 5V, V = 1.7V
L
= 3.3V, V = 3.3V
L
= 5V, V = 5V
L
INPUT HIGH
INPUT LOW
V
CC
V
CC
= 5V
= 3.3V
0
2
4
6
8
10
–50
–25
0
25
50
75
100
–50
–25
0
25
50
75
100
OUTPUT CURRENT (mA)
TEMPERATURE (°C)
TEMPERATURE (°C)
2872 G11
2872 G10
2872 G12
RS232 Receiver Output Voltage
vs Load Current
RS485 Termination Resistance
vs Temperature
RS232 Operation at 500kbps
6
5
4
3
2
1
0
130
128
126
124
122
120
118
116
114
112
110
V
V
V
= 5V
= 3.3V
= 1.7V
L
L
L
V
CM
V
CM
V
CM
= –7V
= 2V
= 12V
DY
DZ
Z
5V/DIV
Y
RA
RB
2872 G15
1µs/DIV
WRAPPING DATA
DOUT LOADS: 5kΩ + 50pF
0
2
4
6
8
10
–50
–25
0
25
50
75
100
OUTPUT CURRENT (mA)
TEMPERATURE (°C)
2872 G13
2872 G14
RS232 Driver Outputs Enabling
and Disabling
RS485 Operation at 20Mbps
VDD and VEE Powering Up
DY
5V/DIV
DXEN
2V/DIV
5V/DIV
FEN
Y
Z
FEN = VL
5V/DIV
1V/DIV
5V/DIV
Z
Y
V
DD
Y
FEN = 0V
Z
RA
V
EE
2872 G17
2872 G18
2872 G16
40ns/DIV
100µs/DIV
20ns/DIV
H/F HIGH
Y, Z LOADS: 120Ω (DIFF) + 50pF
2872f
7
Linear Systems [ Linear Systems ]
