TECHNICAL DATA
Low-Power, Slew-Rate-Limited RS-485/RS-422
Transceivers
General Description
The
KKX485
is low-power transceivers for RS-485 and RS-
422 communication. IC contains one driver and one receiver.
The driver slew rates of the
KKX485
is not limited, allowing
them to transmit up to 2.5Mbps.
These transceivers draw between 120µA and 500µA of
supply current when unloaded or fully loaded with disabled
drivers. All parts operate from a single 5V supply. Drivers are
short-circuit current limited and are protected against
excessive power dissipation by thermal shutdown circuitry
that places the driver outputs into a high-impedance state.
The receiver input has a fail-safe feature that guarantees a
logic-high output if the input is open circuit. The
KKX485
is
designed for half-duplex applications.
KKX485
ORDERING INFORMATION
KKX485N
Plastic
KKX485D
SOIC
Features
Low Quiescent Current: 300µA
-7V to +12V Common-Mode Input Voltage Range
Three-State Outputs
30ns Propagation Delays, 5ns Skew
Full-Duplex and Half-Duplex Versions Available
Operate from a Single 5V Supply
Allows up to 32 Transceivers on the Bus
Data rate: 2,5 Mbps
Current-Limiting and Thermal Shutdown for Driver Overload Protection
1
KKX485
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (V
CC
) 12V
Control Input Voltage -0.5V to (V
CC
+ 0.5V)
Driver Input Voltage (DI) -0.5V to (V
CC
+ 0.5V)
Driver Output Voltage (A, B) -8V to +12.5V
Receiver Input Voltage (A, B) -8V to +12.5V
Receiver Output Voltage (RO) -0.5V to (V
CC
+0.5V)
Continuous Power Dissipation (T
A
= +70°C)
8-Pin Plastic DIP (derate 9.09mW/°C above
+70°C) 727mW
8-Pin SOP (derate 5.88mW/°C above +70°C)
471mW
Operating Temperature Ranges 0°C to +70°C
Storage Temperature Range -65°C to +160°C
Lead Temperature (soldering, 10sec) +300°C
DC ELECTRICAL CHARACTERISTICS
(V
CC
= 5V ±5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Notes 1, 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TY
P
MAX
UNITS
Differential Driver Output (no
load)
Differential Driver Output
(with load)
Change in Magnitude of Driver
Differential Output Voltage for
Complementary Output States
Driver Common-Mode Output
Voltage
Change in Magnitude of Driver
Common-Mode Output Voltage for
Complementary Output States
Input High Voltage
Input Low Voltage
Input Current
Input Current
(A, B)
Receiver Differential Threshold
Voltage
Receiver Input Hysteresis
Receiver Output High Voltage
Receiver Output Low Voltage
Three-State (high impedance)
Output Current at Receiver
Receiver Input Resistance
V
OD1
V
OD2
∆V
OD
R = 50Ω (RS-422)
R = 27Ω (RS-485), Figure 4
R = 27Ω or 50Ω, Figure 4
2
1.5
5
V
V
5
0.2
V
V
OC
∆V
OD
R = 27Ω or 50Ω, Figure 4
R = 27Ω or 50Ω, Figure 4
3
0.2
V
V
V
IH
V
IL
I
IN1
I
IN2
V
TH
∆V
TH
V
OH
V
OL
I
OZR
R
IN
DE, DI,
RE
DE, DI,
RE
DE, DI,
RE
DE = 0V;
V
CC
= 0V or 5.25V,
-7V
≤
V
CM
≤12V
V
IN
= 12V
V
IN
= -7V
2.0
0.8
±2
1.0
-0.8
0.2
70
3.5
0.4
±1
V
V
µA
mA
V
mV
V
V
µA
kΩ
-0.2
V
CM
= 0V
I
O
= -4mA, VID = 200mV
I
O
= 4mA, VID = -200mV
0.4V
≤
V
O
≤
2.4V
-7V
≤
V
CM
≤
12V
2
KKX485
DC ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 5V ±5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Notes 1, 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TY
P
MAX
UNITS
No-Load Supply Current
(Note 3)
Driver Short-Circuit Current,
I
CC
DE = V
CC
RE
= 0V or V
CC
DE = 0V
I
OSD1
-7V
≤
V
O
≤
12V (Note 4)
35
500
300
900
500
µA
250
mA
V
O
= High
Driver Short-Circuit Current,
I
OSD2
V
O
= Low
Receiver Short-Circuit Current
I
OSR
-7V
≤
V
O
≤12V
(Note 4)
0V
≤
V
O
≤
V
CC
35
7
250
95
mA
mA
SWITCHING CHARACTERISTICS
(V
CC
= 5V ±5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Notes 1, 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Driver Input to Output
Driver Output Skew to Output
Driver Enable to Output High
Driver Enable to Output Low
Driver Disable Time from Low
Driver Disable Time from High
| tPLH - tPHL | Differential
Receiver Skew
Receiver Enable to Output Low
Receiver Enable to Output High
Receiver Disable Time from
Low
Receiver Disable Time from
High
Maximum Data Rate
t
PLH
t
PHL
t
SKEW
t
ZH
t
ZL
t
LZ
t
HZ
t
SKD
t
ZL
t
ZH
t
LZ
t
HZ
f
MAX
R
DIFF
= 54Ω
C
L1
= C
L2
= 100pF
R
DIFF
= 54Ω, CL1 = CL2 = 100pF
C
L
= 100pF, S2 closed
C
L
= 100pF, S1 closed
C
L
= 15pF, S1 closed
C
L
= 15pF, S2 closed
R
DIFF
= 54Ω
C
L1
= C
L2
= 100pF
C
RL
= 15pF, S1 closed
C
RL
= 15pF, S2 closed
C
RL
= 15pF, S1 closed
C
RL
= 15pF, S2 closed
10
10
30
30
5
40
40
40
40
13
20
20
20
20
60
60
10
70
70
70
70
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Mbps
50
50
50
50
2.5
3
KKX485
Operation timing diagrams of ILX 485
Table of ILX 485 operation
Transmitting
RE
X
X
0
1
Inputs
DE
1
1
0
0
DI
1
0
X
X
Outputs
X
Z
Y
0
1
1
0
Z
Z
Z
Z
RE
0
0
0
1
Receiving
Inputs
DE
A-B
0
+0.2V
0
-0.2V
0
open
0
X
Outputs
RO
1
0
1
Z
X-don’t care
Z-high impedance
5
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