LTC1386
3.3V Low Power
EIA/TIA562 Transceiver
FEATURES
■
■
■
■
■
■
■
DESCRIPTIO
■
■
Operates from a Single 3.3V Supply
Low Supply Current: I
CC
= 200µA
ESD Protection Over
±10kV
Available in 16-Pin SOIC Narrow Package
Uses Small Capacitors: 0.1µF
Operates to 120kBaud
Output Overvoltage Does Not Force Current
Back into Supplies
EIA/TIA562 I/O Lines Can Be Forced to
±25V
Without Damage
Pin Compatible with LT1181A
The LTC
®
1386 is an ultra-low power 2-driver/2-re-
ceiver EIA/TIA562 transceiver that operates from a
single 3.3V supply. The charge pump requires only four
space-saving 0.1µF capacitors. The supply current
(I
CC
) of the transceiver is only 200µA with driver out-
puts unloaded.
The LTC1386 is fully compliant with all data rate and
overvoltage EIA/TIA562 specifications. The transceiver
can operate up to 120kbaud with a 1000pF, 3kΩ load.
Both driver outputs and receiver inputs can be forced to
±25V
without damage and can survive multiple
±10kV
ESD strikes.
APPLICATIO S
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■
Notebook Computers
Palmtop Computers
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
1
0.1µF
3
4
0.1µF
5
11
V
CC
300k
LOGIC INPUT
LOGIC OUTPUT
10
12
5k
LTC1386
V
CC
300k
Quiescent Supply Current vs Temperature
16
2
6
0.1µF
0.1µF
QUIESCENT CURRENT (µA)
600
V
CC
= 3.3V
500
400
TEST CONDITION: V
CC
= 3.3V
LOGIC INPUT
14
300
200
100
0
–20
562 OUTPUT
7
13
562 OUTPUT
562 INPUT
0
LOGIC OUTPUT
9
5k
8
15
562 INPUT
LTC1386 • TA01
U
QUIESCENT
CURRENT
20
40
TEMPERATURE (°C)
60
80
LTC1386 • TA02
U
U
1386fa
1
LTC1386
ABSOLUTE
AXI U
RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW
C1
+
V
+
C1
–
C2
+
C2
–
V
–
TR2 OUT
RX2 IN
1
2
3
4
5
6
7
8
16 V
CC
15 GND
14 TR1 OUT
13 RX1 IN
12 RX1 OUT
11 TR1 IN
10 TR2 IN
9
RX2 OUT
Supply Voltage (V
CC
) ................................................ 5V
Input Voltage
Driver ....................................... – 0.3V to V
CC
+ 0.3V
Receiver ............................................... – 25V to 25V
Digital Input ............................... – 0.3V to V
CC
+ 0.3V
Output Voltage
Driver .................................................... – 25V to 25V
Receiver .................................... – 0.3V to V
CC
+ 0.3V
Short-Circuit Duration
V
+
................................................................... 30 sec
V
–
................................................................... 30 sec
Driver Output .............................................. Indefinite
Receiver Output .......................................... Indefinite
Operating Temperature Range
LTC1386C ............................................... 0°C to 70°C
LTC1386I ............................................ – 40°C to 85°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
ORDER PART
NUMBER
LTC1386CS
LTC1386IS
S PACKAGE
16-LEAD PLASTIC SO
T
JMAX
= 125°C,
θ
JA
= 95°C/W
Consult LTC Marketing for parts specified with wider operating temperature
ranges.
DC ELECTRICAL CHARACTERISTICS
PARAMETER
Any Driver
Output Voltage Swing
Logic Input Voltage Level
Logic Input Current
Output Short-Circuit Current
Any Receiver
Input Voltage Thresholds
Hysteresis
Input Resistance
Output Voltage
Output Short-Circuit Current
Power Supply Generator
V
+
Output Voltage
V
–
Output Voltage
Power Supply
V
CC
Supply Current
CONDITIONS
3k to GND
The
●
denotes specifications which apply over the full operating
temperature range. V
CC
= 3.3V, C1 = C2 = C3 = C4 = 0.1µF, unless otherwise noted.
MIN
Positive
Negative
●
●
●
●
●
●
TYP
4.5
– 4.5
1.4
1.4
– 20
±10
1.3
1.7
0.4
5
0.2
3.2
– 20
7
5.7
5.5
– 5.3
– 5.0
MAX
UNITS
V
V
V
V
µA
µA
mA
V
V
V
kΩ
V
V
mA
mA
V
V
V
V
3.7
– 3.7
2.0
Input Low Level (V
OUT
= High)
Input High Level (V
OUT
= Low)
V
IN
= V
CC
V
IN
= 0V
V
OUT
= 0V
Input Low Threshold
Input High Threshold
– 10V
≤
V
IN
≤
10V
Output Low, I
OUT
= – 1.6mA (V
CC
= 3.3V)
Output High, I
OUT
= 160µA (V
CC
= 3.3V)
Sinking Current, V
OUT
= V
CC
Sourcing Current, V
OUT
= GND
I
OUT
= 0mA
I
OUT
= 5mA
I
OUT
= 0mA
I
OUT
= – 5mA
No Load (Note 2), 0°C to 70°C
No Load (Note 2), – 40°C to 85°C
0.8
5
– 40
±9
●
●
●
●
●
0.8
0.1
3
3.0
–5
2
2.4
1
7
0.4
●
●
0.2
0.35
0.5
1.0
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2
U
mA
mA
W
U
U
W W
W
LTC1386
AC CHARACTERISTICS
PARAMETER
Slew Rate
Driver Propagation Delay
(TTL to EIA/TIA562)
Receiver Propagation Delay
(EIA/TIA562 to TTL )
The
●
denotes specifications which apply over the full operating temperature range.
V
CC
= 3.3V, C1 = C2 = C3 = C4 = 0.1µF, unless otherwise noted.
CONDITIONS
R
L
= 3k, C
L
= 51pF
R
L
= 3k, C
L
= 1000pF
t
HLD
(Figure 1)
t
LHD
(Figure 1)
t
HLR
(Figure 2)
t
LHR
(Figure 2)
MIN
3
●
●
●
●
TYP
8
5
2
2
0.3
0.3
MAX
30
3.5
3.5
0.8
0.8
UNITS
V/µs
V/µs
µs
µs
µs
µs
Note 1:
Absolute Maximum Ratings are those values beyond which the life
of the device may be impaired.
Note 2:
Supply current is measured with driver and receiver outputs
unloaded.
Note 3:
Measurements made in the shutdown mode are performed
with V
ON/OFF
=OV.
TYPICAL PERFOR A CE CHARACTERISTICS
Driver Output Voltage
vs Temperature
5
4
OUTPUT HIGH
V
CC
= 3.3V
DRIVER OUTPUT VOLTAGE (V)
THRESHOLD VOLTAGE (V)
3
2
1
0
–1
–2
–3
–4
–5
0
10
1.8
1.6
1.4
V
TH+
ALL DRIVERS WITH LOAD
R
L
= 3k
SUPPLY CURRENT (mA)
OUTPUT LOW
V
CC
= 3.3V
40
30
20
50
TEMPERATURE (°C)
V
CC
Supply Current
vs Temperature
4.5
4.0
SUPPLY CURRENT (mA)
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
0
10
2 DRIVERS LOADED
R
L
= 3k
1 DRIVER LOADED
R
L
= 3k
20
30
40
50
TEMPERATURE (°C)
LTC1386 • TPC04
U W
60
70
LTC1386 • TPC01
Receiver Input Thresholds
vs Temperature
2.2
2.0
15
20
Supply Current vs Data Rate
V
CC
= 3.3V
R
L
= 3k
C
L
= 2500pF
ALL DRIVERS ACTIVE
10
V
TH–
1.2
1.0
0
10
40
50
30
20
TEMPERATURE (˚C)
60
70
5
0
0
20
40
80 100
60
DATA RATE (kBAUD)
120
140
LTC1386 • TPC02
LTC1386 • TPC03
Driver Output Waveforms
DRIVER
OUTPUT
R
L
= 3k
C
L
= 1000pF
DRIVER
OUTPUT
R
L
= 3k
Receiver Output Waveforms
RECEIVER
OUTPUT
C
L
= 51pF
INPUT
INPUT
LTC1386 • TPC05
LTC1386 • TPC06
5µs/DIV
60
70
5µs/DIV
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3
LTC1386
PI FU CTIO S
V
CC
:
3.3V Input Supply Pin. This pin should be decoupled
with a 0.1µF ceramic capacitor.
GND:
Ground Pin.
V
+
:
Positive Supply Output (EIA/TIA562 Drivers). V
+
≅
2V
CC
– 1V. This pin requires an external capacitor C =
0.1µF for charge storage. The capacitor may be tied to
ground or V
CC
. With multiple devices, the V
+
and V
–
pins
may share a common capacitor. For large numbers of
devices, increasing the size of the shared common storage
capacitors is recommended to reduce ripple.
V
–
:
Negative Supply Output (RS232 Drivers). V
–
≅
– (2V
CC
– 1.3V). This pin requires an external capacitor C = 0.1µF
for charge storage.
C1
+
, C1
–
, C2
+
, C2
–
:
Commutating Capacitor Inputs. These
pins require two external capacitors C = 0.1µF: one from
C1
+
to C1
–
and another from C2
+
to C2
–
. To maintain
charge pump efficiency, the capacitor’s effective series
resistance should be less than 2Ω.
TR IN:
EIA/TIA562 Driver Input Pins. Inputs are TTL/
CMOS compatible. The inputs of unused drivers can be left
unconnected since 300k input pull-up resistors to V
CC
are
included on chip.
TR OUT:
Driver Outputs at EIA/TIA562 Voltage Levels.
The driver outputs are protected against ESD to
±10kV
for
human body model discharges.
RX IN:
Receiver Inputs. These pins can be forced to
±25V
without damage. The receiver inputs are protected against
ESD to
±10kV
for human body model discharges. Each
receiver provides 0.4V of hysteresis for noise immunity.
RX OUT:
Receiver Outputs with TTL/CMOS Voltage
Levels.
SWITCHI G TI E WAVEFOR S
DRIVER
INPUT
DRIVER
OUTPUT
t
LHD
V
CC
1.4V
1.4V
0V
V
+
0V
t
HLD
LTC1386 • F01
Figure 1. Driver Propagation Delay Timing
RX
INPUT
RX
OUTPUT
t
LHR
1.7V
Figure 2. Receiver Propagation Delay Timing
4
W
W
U
U
U
U
0V
V
–
V
CC
1.3V
0V
2.4V
0.8V
t
HLR
V
CC
0V
LTC1386 • F02
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LTC1386
TEST CIRCUITS
Driver Timing Test Load
Receiver Timing Test Load
DRIVER
INPUT
DRIVER
OUTPUT
DRIVER
51pF
3k
RX
OUTPUT
RX INPUT
RX
51pF
LTC1386 • TA04
LTC1386 • TA03
ESD Test Circuit
1
0.1µF
0.1µF
LOGIC INPUT
3
4
5 V
CC
11
V
CC
LOGIC INPUT
LOGIC OUTPUT
LOGIC OUTPUT
10
12
9
5k
5k
300k
7
13
8
562 OUTPUT
562 INPUT
562 INPUT
RS562
LINE PINS
PROTECTED
TO
±10kV
300k
14
LTC1386
16
2
6
0.1µF
562 OUTPUT
0.1µF
VCC
15
1386 TA05
1386fa
5
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