LTC1690
Differential Driver and
Receiver Pair with Fail-Safe
Receiver Output
FEATURES
s
DESCRIPTIO
s
s
s
s
s
s
s
s
s
s
No Damage or Latchup to
±
15kV ESD (Human Body
Model), IEC1000-4-2 Level 4 (
±
8kV) Contact and
Level 3 (
±
8kV) Air Discharge
Guaranteed High Receiver Output State for
Floating, Shorted or Terminated Inputs with No
Signal Present
Drives Low Cost Residential Telephone Wires
I
CC
= 600µA Max with No Load
Single 5V Supply
–7V to 12V Common Mode Range Permits
±7V
Ground Difference Between Devices on the Data Line
Power-Up/Down Glitch-Free Driver Outputs Permit
Live Insertion or Removal of Transceiver
Driver Maintains High Impedance with the Power Off
Up to 32 Transceivers on the Bus
Pin Compatible with the SN75179 and LTC490
Available in SO,
MSOP
and PDIP Packages
The LTC
®
1690 is a low power receiver/driver pair that is
compatible with the requirements of RS485 and RS422.
The receiver offers a fail-safe feature that guarantees a
high receiver output state when the inputs are left open,
shorted together or terminated with no signal present. No
external components are required to ensure the high
receiver output state.
Separate driver output and receiver input pins allow full
duplex operation. Excessive power dissipation caused by
bus contention or faults is prevented by a thermal shut-
down circuit which forces the driver outputs into a high
impedance state.
The LTC1690 is fully specified over the commercial and
industrial temperature ranges. The LTC1690 is available in
8-Pin SO, MSOP and PDIP packages.
, LTC and LT are registered trademarks of Linear Technology Corporation.
APPLICATIO S
s
s
s
s
Battery-Powered RS485/RS422 Applications
Low Power RS485/RS422 Transceiver
Level Translator
Line Repeater
TYPICAL APPLICATIO
LTC1690
5
D1
3
DRIVER
6
Z1
Y1
120Ω
LTC1690
A2
120Ω
7
B2
8
RECEIVER
2
R2
B2
D1
7
R1
2
RECEIVER
8
B1
120Ω
A1
Z2
120Ω
6
5
DRIVER
3
D2
Y2
1690 TA01
U
Driving a 1000 Foot STP Cable
A2
R2
1690 TA01a
U
U
1
LTC1690
ABSOLUTE
MAXIMUM
RATINGS
Supply Voltage (V
CC
) .............................................. 6.5V
Driver Input Voltage ..................... –0.3V to (V
CC
+ 0.3V)
Driver Output Voltages ................................. –7V to 10V
Receiver Input Voltages .........................................
±14V
Receiver Output Voltage .............. –0.3V to (V
CC
+ 0.3V)
Junction Temperature ........................................... 125°C
PACKAGE/ORDER INFORMATION
ORDER PART
NUMBER
TOP VIEW
V
CC
R
D
GND
1
2
3
4
8
7
6
5
A
B
Z
Y
TOP VIEW
V
CC
1
R 2
D 3
GND 4
D
5
R
8
7
6
A
B
Z
Y
LTC1690CMS8
MS8 PACKAGE
8-LEAD PLASTIC MSOP
T
JMAX
= 125°C,
θ
JA
= 200°C/W
MS8 PART MARKING
LTDA
Consult factory for Military Grade Parts
DC ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
V
OD1
V
OD2
V
OD3
∆V
OD
V
OC
∆|V
OC
|
V
IH
V
IL
I
IN1
I
IN2
V
TH
∆V
TH
Differential Driver Output Voltage (Unloaded)
Differential Driver Output Voltage (with Load)
Differential Driver Output Voltage (with Common Mode)
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)
Differential Input Threshold Voltage for Receiver
Receiver Input Hysteresis
The
q
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= 5V
±5%
(Notes 2, 3)
CONDITIONS
I
O
= 0
R = 50Ω; (RS422)
R = 22Ω or 27Ω; (RS485), Figure 1
V
TST
= –7V to 12V, Figure 2
R = 22Ω, 27Ω or 50Ω, Figure 1
V
TST
= –7V to 12V, Figure 2
R = 22Ω, 27Ω or 50Ω, Figure 1
R = 22Ω, 27Ω or 50Ω, Figure 1
Driver Input (D)
Driver Input (D)
Driver Input (D)
V
CC
= 0V or 5.25V, V
IN
= 12V
V
CC
= 0V or 5.25V, V
IN
= –7V
–7V
≤
V
CM
≤
12V
V
CM
= 0V
q
q
q
q
q
q
q
q
q
q
q
q
2
U
U
W
W W
U
W
(Note 1)
Operating Temperature Range
LTC1690C ........................................ 0°C
≤
T
A
≤
70°C
LTC1690I ..................................... – 40°C
≤
T
A
≤
85°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
ORDER PART
NUMBER
LTC1690CN8
LTC1690IN8
LTC1690CS8
LTC1690IS8
S8 PART MARKING
1690
1690I
S8 PACKAGE
8-LEAD PLASTIC SO
N8 PACKAGE
8-LEAD PLASTIC DIP
T
JMAX
= 125°C,
θ
JA
= 130°C/W (N)
T
JMAX
= 125°C,
θ
JA
= 135°C/W (S)
MIN
2
1.5
1.5
TYP
MAX
V
CC
5
5
0.2
3
0.2
UNITS
V
V
V
V
V
V
V
V
2
0.8
±2
1
–0.8
– 0.20
±30
– 0.01
V
µA
mA
mA
V
mV
LTC1690
DC ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
V
OH
V
OL
R
IN
I
CC
I
OSD1
I
OSD2
I
OZ
I
OSR
t
PLH
t
PHL
t
SKEW
t
r
, t
f
t
PLH
t
PHL
t
SKD
f
MAX
Receiver Output High Voltage
Receiver Output Low Voltage
Receiver Input Resistance
Supply Current
Driver Short-Circuit Current, V
OUT
= HIGH
Driver Short-Circuit Current, V
OUT
= LOW
Driver Three-State Current (Y, Z)
Receiver Short-Circuit Current
Driver Input to Output, Figure 3, Figure 4
Driver Input to Output, Figure 3, Figure 4
Driver Output to Output, Figure 3, Figure 4
Driver Rise or Fall Time, Figure 3, Figure 4
Receiver Input to Output, Figure 3, Figure 5
Receiver Input to Output, Figure 3, Figure 5
|t
PLH
– t
PHL
|, Differential Receiver Skew, Figure 3, Figure 5
Maximum Data Rate, Figure 3, Figure 5
The
q
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= 5V
±5%
(Notes 2, 3)
CONDITIONS
I
O
= – 4mA, V
ID
= 200mV
I
O
= 4mA, V
ID
= – 200mV
–7V
≤
V
CM
≤
12V
No Load
–7V
≤
V
O
≤
10V
–7V
≤
V
O
≤
10V
–7V
≤
V
O
≤
10V, V
CC
= 0V
0V
≤
V
O
≤
V
CC
R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF
R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF
R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF
R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF
R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF
R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF
R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF
R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF
q
q
q
q
q
q
q
q
q
q
q
q
q
MIN
3.5
TYP
MAX
0.4
UNITS
V
V
kΩ
µA
mA
mA
µA
mA
ns
ns
ns
ns
ns
ns
ns
Mbps
12
35
35
22
260
600
250
250
5
200
85
22.5
25
2.5
13
94
89
5
60
60
15
40
160
160
7
10
10
2
30
30
5
Note 1:
Absolute Maximum Ratings are those values beyond which the life
of the device may be impaired.
Note 2:
All currents into device pins are positive; all currents out of device
pins are negative. All voltages are referenced to device ground unless
otherwise specified.
Note 3:
All typicals are given for V
CC
= 5V and T
A
= 25°C.
TYPICAL PERFOR A CE CHARACTERISTICS
Receiver Input Threshold Voltage
(Output High) vs Temperature
RECEIVER INPUT THRESHOLD VOLTAGE (mV)
RECEIVER INPUT THRESHOLD VOLTAGE (mV)
0
–20
–40
–60
–80
–100
–120
–140
–160
–180
–200
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
1690 G01
V
CM
= 12V
V
CM
= 0V
V
CM
= –7V
–60
–80
–100
–120
–140
–160
–180
–200
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
1690 G02
RECEIVER HYSTERESIS (mV)
U W
V
CC
= 5V
Receiver Input Threshold Voltage
(Output Low) vs Temperature
0
–20
–40
V
CM
= 12V
V
CM
= 0V
V
CC
= 5V
100
90
80
70
60
50
40
30
20
10
Receiver Hysteresis vs
Temperature
V
CC
= 5V
V
CM
= 12V
V
CM
= 0V
V
CM
= –7V
V
CM
= –7V
0
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
1690 G03
3
LTC1690
TYPICAL PERFOR A CE CHARACTERISTICS
Receiver Input Offset Voltage vs
Temperature
RECEIVER INPUT OFFSET VOLTAGE (mV)
–40
–60
–80
–100
–120
–140
–160
–180
–200
–55 –35 –15
–60
–80
–100
–120
–140
–160
4.5
V
CM
= 0V
V
CM
= –7V
OUTPUT HIGH
RECEIVER OUTPUT CURRENT (mA)
–20
V
CC
= 5V
RECEIVER INPUT THRESHOLD VOLTAGE (mV)
0
V
CM
= 12V
5 25 45 65 85 105 125
TEMPERATURE (°C)
1690 G04
Receiver Output Low Voltage vs
Output Current
40
4.8
RECEIVER OUTPUT HIGH VOLTAGE (V)
RECEIVER OUTPUT CURRENT (mA)
35
30
25
20
15
10
5
0
0
4.6
4.4
4.2
4.0
3.8
3.6
3.4
3.2
RECEIVER OUTPUT LOW VOLTAGE (V)
T
A
= 25°C
V
CC
= 4.75V
0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8
RECEIVER OUTPUT LOW VOLTAGE (V)
Receiver Propagation Delay vs
Temperature
120
RECEIVER PROPAGATION DELAY (ns)
V
CC
= 5V
110
RECEIVER SKEW (ns)
100
90
t
PHL
80
70
60
–55 –35 –15
t
PLH
10
9
8
7
6
5
4
3
5 25 45 65 85 105 125
TEMPERATURE (°C)
1690 G10
RECEIVER PROPAGATION DELAY (ns)
4
U W
1690 G07
Receiver Input Threshold Voltage
vs Supply Voltage
–40
T
A
= 25°C
Receiver Output High Voltage vs
Output Current
–25
T
A
= 25°C
V
CC
= 4.75V
–20
–15
OUTPUT LOW
–10
–5
0
4.75
5
5.25
SUPPLY VOLTAGE (V)
5.5
1690 G05
5
3
2.5
3.5
RECEIVER OUTPUT HIGH VOLTAGE (V)
4.5
4
2
1690 G06
Receiver Output High Voltage vs
Temperature
0.7
I = 8mA
V
CC
= 4.75V
Receiver Output Low Voltage vs
Temperature
I = 8mA
V
CC
= 4.75V
0.6
0.5
0.4
0.3
0.2
0.1
2
3.0
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
1690 G08
0
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
1690 G09
Receiver Skew
t
PLH
– t
PHL
vs
Temperature
110
V
CC
= 5V
100
90
80
70
60
50
Receiver Propagation Delay vs
Supply Voltage
t
PLH
t
PHL
2
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
1690 G11
4.5 4.6 4.7 4.8 4.9 5 5.1 5.2 5.3 5.4 5.5
SUPPLY VOLTAGE (V)
1690 G12
LTC1690
TYPICAL PERFOR A CE CHARACTERISTICS
Receiver Short-Circuit Current vs
Temperature
70
SHORT-CIRCUIT
CURRENT (mA)
V
CC
= 5.25V
60
50
40
30
20
10
0
–55 –35 –15
OUTPUT HIGH
OUTPUT LOW
SUPPLY CURRENT (µA)
340
320
300
280
260
240
220
200
180
160
140
5 25 45 65 85 105 125
TEMPERATURE (°C)
1690 G13
LOGIC INPUT THRESHOLD VOLTAGE (V)
Driver Differential Output Voltage
vs Temperature
DRIVER DIFFERENTIAL OUTPUT VOLTAGE (V)
DRIVER DIFFERENTIAL OUTPUT VOLTAGE (V)
2.9
R
L
= 44Ω
2.7
2.5
2.3
2.1
1.9
V
CC
= 4.5V
1.7
1.5
–55 –35 –15
V
CC
= 4.75V
5 25 45 65 85 105 125
TEMPERATURE (°C)
1690 G16
2.7
2.5
2.3
2.1
V
CC
= 5.25V
V
CC
= 5V
R
L
= 54Ω
DRIVER DIFFERENTIAL OUTPUT VOLTAGE (V)
V
CC
= 5.25V
V
CC
= 5V
Driver Common Mode Output
Voltage vs Temperature
DRIVER COMMON MODE OUTPUT VOLTAGE (V)
DRIVER COMMON MODE OUTPUT VOLTAGE (V)
3.0
2.5
V
CC
= 5.25V
2.0
1.5
1.0
0.5
R
L
= 44Ω
0
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
1690 G19
2.5
V
CC
= 5.25V
2.0
1.5
1.0
0.5
R
L
= 54Ω
0
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
1690 G20
DRIVER COMMON MODE OUTPUT VOLTAGE (V)
V
CC
= 5V
V
CC
= 4.75V
V
CC
= 4.5V
U W
Supply Current vs Temperature
1.75
Logic Input Threshold Voltage vs
Temperature
1.70
V
CC
= 5.25V
V
CC
= 5.25V
1.65
V
CC
= 5V
1.60
V
CC
= 4.75V
V
CC
= 5V
1.55
V
CC
= 4.75V
120
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
1690 G14
1.50
–55 –35 –15
5 25 45 65 85 105 125
TEMPERATURE (°C)
1690 G15
Driver Differential Output Voltage
vs Temperature
2.9
3.4
Driver Differential Output Voltage
vs Temperature
R
L
= 100Ω
3.2
3.0
2.8
2.6
2.4
2.2
–55 –35 –15
V
CC
= 5.25V
V
CC
= 5V
V
CC
= 4.75V
V
CC
= 4.5V
V
CC
= 4.5V
1.9
1.7
1.5
–55 –35 –15
V
CC
= 4.75V
5 25 45 65 85 105 125
TEMPERATURE (°C)
1690 G17
5 25 45 65 85 105 125
TEMPERATURE (°C)
1690 G18
Driver Common Mode Output
Voltage vs Temperature
3.0
3.0
2.5
Driver Common Mode Output
Voltage vs Temperature
V
CC
= 5V
V
CC
= 4.75V
V
CC
= 4.5V
V
CC
= 5.25V
2.0
1.5
1.0
0.5
R
L
= 100Ω
0
–55 –35 –15
V
CC
= 5V
V
CC
= 4.75V
V
CC
= 4.5V
5 25 45 65 85 105 125
TEMPERATURE (°C)
1690 G21
5