LTC2872
elecTrical characTerisTics The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VCC = VL = 3.3V, TE485_1 = TE485_2 = 0V, LB = 0V unless otherwise noted.
SYMBOL PARAMETER
Power Supply
CONDITIONS
MIN
TYP
MAX
UNITS
l
l
l
V
CC
V
L
Supply Voltage Operating Range
3
5.5
V
V
Logic Supply Voltage Operating Range
V ≤ V
±.7
V
CC
L
CC
V
CC
Supply Current in Shutdown Mode
RXEN1 = RXEN2 = V ,
DXEN± = DXEN2 = FEN = H/F = 0V
8
60
µA
L
l
l
l
V
Supply Current in RS485 Transceiver Mode 485/232_± = 485/232_2 = DXEN± =
DXEN2 = V , RXEN1 = RXEN2 = 0V
4.5
5.5
0
7
8
5
mA
mA
µA
CC
(Outputs Unloaded) (Note 3)
L
V
Supply Current in RS232 Transceiver Mode DXEN± = DXEN2 = V ; 485/232_± =
CC
L
(Outputs Unloaded) (Note 3)
485/232_2 = RXEN1 = RXEN2 = 0V
V Supply Current in RS485 or RS232 Transceive DXEN± = DXEN2 = V , RXEN1 = RXEN2 = 0V
Mode (Outputs Unloaded)
L
L
RS485 Drivers
l
l
l
l
|V
|
OD
Differential Output Voltage
R = ∞, V = 3V (Figure ±)
6
V
V
V
V
L
CC
R = 27Ω, V = 4.5V (Figure ±)
2.±
±.5
2
V
L
CC
CC
CC
CC
R = 27Ω, V = 3V (Figure ±)
V
V
L
CC
R = 50Ω, V = 3.±3V (Figure ±)
L
CC
l
l
∆|V |
OD
Difference in Magnitude of Differential Output
Voltage for Complementary Output States
R = 27Ω, V = 3V (Figure ±)
0.2
0.2
V
V
L
CC
R = 50Ω, V = 3.±3V (Figure ±)
L
CC
l
l
V
Common Mode Output Voltage
R = 27Ω or 50Ω (Figure ±)
3
V
V
OC
L
∆|V
|
Difference in Magnitude of Common Mode
Output Voltage for Complementary Output States
R = 27Ω or 50Ω (Figure ±)
L
0.2
OC
l
l
I
I
Three-State (High Impedance) Output Current
V
V
= ±2V or –7V,
OUT
CC
–±00
–250
±25
250
µA
OZD485
= 0V or 3.3V (Figure 2)
Maximum Short-Circuit Current
–7V ≤ V
≤ ±2V (Figure 2)
mA
OSD485
OUT
RS485 Receiver
l
I
Input Current
V
= ±2V or –7V, V = 0V or 3.3V
–±00
±25
µA
IN485
IN
CC
(Figure 3) (Note 5)
R
IN485
Input Resistance
V
= ±2V or –7V, V = 0V or 3.3V
±25
kΩ
IN
CC
(Figure 3) (Note 5)
l
l
Differential Input Signal Threshold Voltage (A–B) –7V ≤ (A or B) ≤ ±2 (Note 5)
±200
0
mV
mV
mV
Differential Input Signal Hysteresis
B = 0V (Notes 3, 5)
±90
–65
Differential Input DC Failsafe Threshold Voltage
(A–B)
–7V ≤ (A or B) ≤ ±2 (Note 5)
–200
Differential Input DC Failsafe Hysteresis
Output Low Voltage
B = 0V (Note 5)
30
mV
V
l
l
l
l
V
V
Output Low, I(RA) = 3mA (Sinking),
0.4
0.4
OL
3V ≤ V ≤ 5.5V
L
Output Low, I(RA) = ±mA (Sinking),
V
V
V
±.7V ≤ V < 3V
L
Output High Voltage
Output High, I(RA) = –3mA (Sourcing),
V – 0.4
L
OH
3V ≤ V ≤ 5.5V
L
Output High, I(RA) = –±mA (Sourcing),
V – 0.4
L
±.7V ≤ V < 3V
L
l
l
l
Three-State (High Impedance) Output Current
Short-Circuit Output Current
0V ≤ RA ≤ V , V = 5.5V
0
±5
μA
mA
Ω
L
L
0V ≤ RA ≤ V , V = 5.5V
±±35
±56
L
L
R
Terminating Resistor
TE485 = V , A–B = 2V, B = –7V, 0V, ±0V
±08
±20
TERM
L
(Figure 8) (Note 5)
2872f
3
Linear Systems [ Linear Systems ]
