LTC2872 Datasheet, PDF (3/28 Pages) –

LTC2872
Electrical Characteristics The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C. V_CC = V_L = 3.3V, TE485_1 = TE485_2 = 0V, LB = 0V unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN TYP MAX UNITS
Power Supply
V_CC
Supply Voltage Operating Range
V_L
Logic Supply Voltage Operating Range
V_CC Supply Current in Shutdown Mode
V_L ≤ V_CC
RXEN1 = RXEN2 = V_L,
DXEN1 = DXEN2 = FEN = H/F = 0V
l3
5.5
V
l 1.7
V_CC
V
l
8
60
µA
V_CC Supply Current in RS485 Transceiver Mode 485/232_1 = 485/232_2 = DXEN1 =
l
(Outputs Unloaded) (Note 3)
DXEN2 = V_L, RXEN1 = RXEN2 = 0V
V_CC Supply Current in RS232 Transceiver Mode DXEN1 = DXEN2 = V_L; 485/232_1 =
l
(Outputs Unloaded) (Note 3)
485/232_2 = RXEN1 = RXEN2 = 0V
4.5
7
mA
5.5
8
mA
V_L Supply Current in RS485 or RS232 Transceive DXEN1 = DXEN2 = V_L, RXEN1 = RXEN2 = 0V l
Mode (Outputs Unloaded)
0
5
µA
RS485 Drivers
|V_OD|
∆|V_OD|
V_OC
∆|V_OC|
Differential Output Voltage
Difference in Magnitude of Differential Output
Voltage for Complementary Output States
Common Mode Output Voltage
Difference in Magnitude of Common Mode
Output Voltage for Complementary Output States
R_L = ∞, V_CC = 3V (Figure 1)
R_L = 27Ω, V_CC = 4.5V (Figure 1)
R_L = 27Ω, V_CC = 3V (Figure 1)
R_L = 50Ω, V_CC = 3.13V (Figure 1)
R_L = 27Ω, V_CC = 3V (Figure 1)
R_L = 50Ω, V_CC = 3.13V (Figure 1)
R_L = 27Ω or 50Ω (Figure 1)
R_L = 27Ω or 50Ω (Figure 1)
l
l 2.1
l 1.5
l2
l
l
l
l
6
V
V_CC
V
V_CC
V
V_CC
V
0.2
V
0.2
V
3
V
0.2
V
I_OZD485 Three-State (High Impedance) Output Current
I_OSD485 Maximum Short-Circuit Current
RS485 Receiver
V_OUT = 12V or –7V,
V_CC = 0V or 3.3V (Figure 2)
–7V ≤ V_OUT ≤ 12V (Figure 2)
l –100
l –250
125
µA
250
mA
I_IN485
Input Current
V_IN = 12V or –7V, V_CC = 0V or 3.3V
(Figure 3) (Note 5)
l –100
125
µA
R_IN485 Input Resistance
V_IN = 12V or –7V, V_CC = 0V or 3.3V
(Figure 3) (Note 5)
125
kΩ
Differential Input Signal Threshold Voltage (A–B) –7V ≤ (A or B) ≤ 12 (Note 5)
l
±200
mV
Differential Input Signal Hysteresis
B = 0V (Notes 3, 5)
190
mV
Differential Input DC Failsafe Threshold Voltage –7V ≤ (A or B) ≤ 12 (Note 5)
(A–B)
l –200 –65
0
mV
Differential Input DC Failsafe Hysteresis
B = 0V (Note 5)
30
mV
V_OL
V_OH
R_TERM
Output Low Voltage
Output High Voltage
Three-State (High Impedance) Output Current
Short-Circuit Output Current
Terminating Resistor
Output Low, I(RA) = 3mA (Sinking),
3V ≤ V_L ≤ 5.5V
Output Low, I(RA) = 1mA (Sinking),
1.7V ≤ V_L < 3V
Output High, I(RA) = –3mA (Sourcing),
3V ≤ V_L ≤ 5.5V
Output High, I(RA) = –1mA (Sourcing),
1.7V ≤ V_L < 3V
0V ≤ RA ≤ V_L, V_L = 5.5V
0V ≤ RA ≤ V_L, V_L = 5.5V
TE485 = V_L, A–B = 2V, B = –7V, 0V, 10V
(Figure 8) (Note 5)
l
0.4
V
l
0.4
V
l V_L – 0.4
V
l V_L – 0.4
V
l
0
±5
μA
l
±135
mA
l 108
120
156
Ω
2872f
3