LTC1327
3.3V Micropower EIA/TIA-562
Transceiver
FEATURES
s
s
s
s
s
s
s
s
DESCRIPTIO
s
s
Low Supply Current
300µA
0.2µA Supply Current in SHUTDOWN
ESD Protection
±10kV
Operates From a Single 3.3V Supply
Uses Small Capacitors
0.1µF
Operates To 120k Baud
Three-State Outputs are High Impedance When Off
Output Overvoltage Does Not Force Current Back
Into Supplies
EIA/TIA-562 I/O Lines Can Be Forced to
±25V
Without Damage
Flowthrough Architecture
The LTC1327 is an advanced low power, three-driver/five-
receiver EIA/TIA-562 transceiver. In the no load condition,
the supply current is only
300µA.
The charge pump only
requires four 0.1µF capacitors.
In SHUTDOWN mode, the supply current is further re-
duced to 0.2µA. All EIA/TIA-562 outputs assume a high
impedance state in SHUTDOWN and with the power off.
The LTC1327 is fully compliant with all data rate and
overvoltage EIA/TIA-562 specifications. The transceiver
can operate up to 120k Baud 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.
APPLICATI
s
s
S
Notebook Computers
Palmtop Computers
TYPICAL APPLICATI
V
+
C1
0.1µF
C2
0.1µF
DR1 OUT
RX1 IN
DR2 OUT
RX2 IN
RX3 IN
RX4 IN
DR4 OUT
RX5 IN
ON/OFF
V
CC
1
2
3
4
5
6
7
8
9
10
11
12
13
14
LTC1327
3-Drivers/5-Receivers with SHUTDOWN
28
27
26
25
24
23
22
21
20
19
18
17
16
15
1327 TA01
Supply Current vs Temperature
600
C4
0.1µF
V
–
C3
0.1µF
DR1 IN
RX1 OUT
DR2 IN
RX2 OUT
RX3 OUT
RX4 OUT
DR3 IN
RX5 OUT
GND
500
QUIESCENT CURRENT (µA)
V
CC
= 3.3V
ALL DRIVERS INPUTS TIED TO V
CC
400
300
200
100
0
–20
U
1.2
1.0
SHUTDOWN CURRENT (µA)
UO
UO
QUIESCENT
CURRENT
0.8
0.6
SHUTDOWN
CURRENT
0.4
0.2
0
20
40
60
TEMPERATURE (°C)
80
LTC1327 • TA02
1
LTC1327
ABSOLUTE
AXI U
RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW
V
+
1
V
CC
2
C1
+
3
C1
–
4
DR1 OUT 5
RX1 IN 6
DR2 OUT 7
RX2 IN 8
RX3 IN 9
RX4 IN 10
DR3 OUT 11
RX5 IN 12
ON/OFF 13
NC 14
G PACKAGE
28-LEAD SSOP
28 V
–
27 C2
+
26 C2
–
25 DR1 IN
24 RX1 OUT
23 DR2 IN
22 RX2 OUT
21 RX3 OUT
20 RX4 OUT
19 DR3 IN
18 RX5 OUT
17 GND
16 NC
15 NC
N PACKAGE
28-LEAD PLASTIC DIP
Supply Voltage (V
CC
) ................................................. 5V
Input Voltage
Driver ...................................... – 0.3V to (V
CC
+ 0.3V)
Receiver ................................................ – 25V to 25V
On/Off Pin ............................... –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
Commercial LTC1327C .......................... 0°C to 70°C
Storage Temperature Range ................. – 65°c to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
ORDER PART
NUMBER
LTC1327CG
LTC1327CN
LTC1327CS
S PACKAGE
28-LEAD PLASTIC SOL
T
JMAX
= 125°C,
θ
JA
= 96°C/ W (G)
T
JMAX
= 125°C,
θ
JA
= 56°C/ W (N)
T
JMAX
= 125°C,
θ
JA
= 85°C/ W (S)
Consult factory for Industrial and Military grade parts.
DC ELECTRICAL CHARACTERISTICS
PARAMETER
Any Driver
Output Voltage Swing
Logic Input Voltage Level
Logic Input Current
Output Short-Circuit Current
Output Leakage Current
Any Receiver
Input Voltage Thresholds
Hysteresis
Input Resistance
Output Voltage
Output Short-Circuit Current
Output Leakage Current
V
IN
=
±10V
Input Low Threshold
Input High Threshold
Positive
Negative (3k to GND)
CONDITIONS
V
CC
= 3.3V, C1 to C4 = 0.1µF, unless otherwise noted.
MIN
q
q
q
q
q
q
TYP
4.5
– 4.5
1.4
1.4
MAX
UNITS
V
V
3.7
– 3.7
2
Input Low Level (V
OUT
= High)
Input High Level (V
OUT
= Low)
V
IN
= 3.3
V
IN
= 0
V
OUT
= 0V
SHUTDOWN (Note 3), V
OUT
=
±20V
0.8
5
–5
±7
±10
q
q
q
mA
±500
µA
V
V
V
kΩ
V
V
mA
10
µA
0.8
0.1
3
1.3
1.7
0.4
5
0.2
3.2
– 10
1
2.4
1
7
0.4
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
SHUTDOWN (Note 3), 0
≤
V
OUT
≤
V
CC
q
q
3
–2
q
2
U
V
V
µA
µA
W
U
U
W W
W
LTC1327
DC ELECTRICAL CHARACTERISTICS
PARAMETER
Power Supply Generator
V
+
Output Voltage
V
–
Output Voltage
Supply Rise Time
Power Supply
V
CC
Supply Current
Supply Leakage Current (V
CC
)
On/Off Threshold Low
On/Off Threshold High
No Load (Note 2)
SHUTDOWN (Note 3)
q
q
q
q
V
CC
= 3.3V, C1 to C4 = 0.1µF, unless otherwise noted.
MIN
TYP
5.7
5.5
– 5.3
– 5.0
0.2
0.3
0.2
1.4
2
1.4
0.5
10
0.8
MAX
UNITS
V
V
V
V
ms
mA
µA
V
V
CONDITIONS
I
OUT
= 0mA
I
OUT
= 5mA
I
OUT
= 0mA
I
OUT
= – 5mA
SHUTDOWN to Turn-On
AC CHARACTERISTICS
Slew Rate
Driver Propagation Delay
(TTL to EIA/TIA-562)
Receiver Propagation Delay
(EIA/TIA-562 to TTL)
R
L
= 3k, C
L
= 51pF
R
L
= 3k, C
L
= 1000pF
t
HLD
t
LHD
t
HLR
t
LHR
q
q
q
q
3
6
5
2
2
0.3
0.2
30
3.5
3.5
0.8
0.8
V/µs
V/µs
µs
µs
µs
µs
The
q
denotes specifications which apply over the operating temperature
(0°C
≤
T
A
≤
70°C).
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 output
unloaded and driver inputs tied high.
Note 3:
Supply current measurement in SHUTDOWN mode is performed
with V
ON/OFF
= 0V.
TYPICAL PERFOR A CE CHARACTERISTICS
Driver Output Voltage vs
Temperature
5
4
DRIVER OUTPUT VOLTAGE (V)
2.2
THRESHOLD VOLTAGE (V)
3
2
1
0
–1
–2
–3
–4
–5
0
10
V
CC
= 3.3V
OUTPUT HIGH
SUPPLY CURRENT (mA)
ALL DRIVERS WITH LOAD R
L
= 3k
V
CC
= 3.3V
OUTPUT LOW
40
30
20
50
TEMPERATURE (°C)
U W
60
1327 G01
Receiver Input Thresholds vs
Temperature
45
40
2.0
Supply Current vs Data Rate
V
CC
= 3.3V
R
L
= 3k
C
L
= 1000pF
3 DRIVERS ACTIVE
35
30
25
20
15
10
5
0
1.8
1.6
1.4
1.2
1.0
V
TH+
V
TH–
70
0
10
40
30
50
20
TEMPERATURE (°C)
60
70
0
20
40
60
80
100
DATA RATE (k BAUD)
120
140
1327 G02
1327 G03
3
LTC1327
TYPICAL PERFOR A CE CHARACTERISTICS
V
CC
Supply Current vs Data Rate
45
40
SUPPLY CURRENT (mA)
35
30
25
20
15
10
5
0
0
20
40
60
80 100
DATA RATE (k BAUD)
120
140
V
CC
= 3.3V
R
L
= 3k
C
L
= 1000pF
3 DRIVERS ACTIVE
45
40
SHORT-CIRCUIT CURRENT (mA)
LEAKAGE CURRENT (µA)
Receiver Short-Circuit Current
vs Temperature
40
35
30
25
20
15
INPUT
DRIVER
OUTPUT
R
L
= 3k
C
L
= 1000pF
DRIVER
OUTPUT
R
L
= 3k
SHORT-CIRCUIT CURRENT (mA)
I
SC
–
10
5
0
0
10
I
SC
+
1327 G08
1327 G09
20
30
40
50
TEMPERATURE (°C)
1327 G07
PI FU CTIO S
V
CC
:
3.3V Input Supply Pin. Supply current 0.2µA in the
SHUTDOWN mode. This pin should be decoupled with a
0.1µF ceramic capacitor.
GND:
Ground Pin.
ON/OFF:
TTL/CMOS Compatible Shutdown Pin. A logic
low puts the device in SHUTDOWN mode which reduces
the supply current to 0.2µA and places all drivers and
receivers in high impedance state. This pin cannot float.
V
+
:
Positive Supply Output (EIA/TIA-562 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 3.3V. With multiple devices, the V
+
and V
–
pins
may be paralleled into common capacitors. For large
numbers of devices, increasing the size of the shared
common storage capacitors is recommended to reduce
ripple.
V
–
:
Negative Supply Output (EIA/TIA-562 Drivers).
V
–
≅
– (2V
CC
– 1.3). This pin requires an external capacitor
C = 0.1µF for a charge storage.
4
U W
1327 G03
Driver Leakage in SHUTDOWN
vs Temperature
14
12
10
8
6
4
2
0
0
10
30
20
40
50
TEMPERATURE (°C)
60
70
Driver Short-Circuit Current vs
Supply Voltage
35
30
25
20
15
10
5
0
V
OUT
= 20V
V
OUT
= –20V
I
SC
–
I
SC
+
0
10
40
30
50
20
SUPPLY VOLTAGE (V)
60
70
1327 G05
1327 G06
Driver Output Waveform
RECEIVER
OUTPUT
C
L
= 50pF
Receiver Output Waveform
INPUT
60
70
U
U
U
LTC1327
PI FU CTIO S
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 20Ω.
DR IN:
EIA/TIA-562 Driver Input Pins. Inputs are TTL/
CMOS compatible. Inputs should not be allowed to float.
Tie unused inputs to V
CC
.
DR OUT:
Driver Outputs at EIA/TIA-562 Voltage Levels.
Outputs are in a high impedance state when in SHUT-
DOWN mode or V
CC
= 0V. 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 Lev-
els. Outputs are in a high impedance state when in SHUT-
DOWN mode to allow data line sharing.
TEST CIRCUITS
ESD Test Circuit
V
+
C1
0.1µF
C2
0.1µF
DR1 OUT
RX1 IN
EIA/TIA 562
LINE PINS
PROTECTED
TO ±10kV
DR2 OUT
RX2 IN
RX3 IN
RX4 IN
DR3 OUT
RX5 IN
ON/OFF
NC
V
CC
1
2
3
4
5
6
7
8
9
10
11
12
13
14
LTC1327
28
27
26
25
24
23
22
21
20
19
18
17
16
15
LT1327 • TC01
U
U
U
Driver Timing Test Load
V
–
C3
0.1µF
DR1 IN
RX1 OUT
DR2 IN
RX2 OUT
RX3 OUT
RX4 OUT
DR3 IN
RX5 OUT
GND
RX IN
RX
51pF
RX
OUTPUT
1327 TC02
C4
0.1µF
DRIVER
INPUT
DRIVER
OUTPUT
DR
51pF
3k
Receiver Timing Test Load
1327 TC03
5
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