LTC1544
Software-Selectable
Multiprotocol Transceiver
FEATURES
s
s
DESCRIPTIO
s
s
s
s
Software-Selectable Transceiver Supports:
RS232, RS449, EIA530, EIA530-A, V.35, V.36, X.21
TUV/Detecon Inc. Certified NET1 and NET2
Compliant (Test Report No. NET2/102201/97)
TBR2 Compliant (Test Report No. CTR2/022701/98)
Software-Selectable Cable Termination Using
the LTC1344A
Complete DTE or DCE Port with LTC1543, LTC1344A
or LTC1546 with Integrated Termination
Operates from Single 5V Supply with LTC1543
APPLICATIO S
s
s
s
The LTC
®
1544 is a 4-driver/4-receiver multiprotocol trans-
ceiver. The LTC1544 and LTC1543 form the core of a
complete software-selectable DTE or DCE interface port that
supports the RS232, RS449, EIA530, EIA530-A, V.35, V.36
or X.21 protocols. Cable termination for the LTC1543 may be
implemented using the LTC1344A software-selectable cable
termination chip or by using existing discrete designs. The
LTC1546 includes software-selectable cable termination on-
chip.
The LTC1544 runs from a 5V supply and the charge pump on
the LTC1543 or LTC1546. The part is available in a 28-lead
SSOP surface mount package.
Data Networking
CSU and DSU
Data Routers
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
LL
CTS
DSR
DTE or DCE Multiprotocol Serial Interface with DB-25 Connector
DCD
DTR
RTS
RXD
RXC
TXC
SCTE
TXD
LTC1544
D4
R4
R3
R2
R1
D3
D2
D1
R3
R2
R1
LTC1543
D3
D2
D1
18
LL A (141)
13 5
DSR B
CTS B
CTS A (106)
22 6
DSR A (107)
10 8
DCD B
DCD A (109)
23 20 19 4
DTR B
DTR A (108)
RTS B
RTS A (105)
SHIELD (101)
1
SG (102)
7
16 3
RXD B
RXD A (104)
9
RXC B
17
RXC A (115)
12 15 11 24 14
SCTE B
SCTE A (113)
TXD B
TXD A (103)
TXC B
TXC A (114)
DB-25 CONNECTOR
U
LTC1344A
2
1544 TA01
U
U
1
LTC1544
ABSOLUTE
(Note 1)
AXI U
RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW
V
CC
V
DD
D1
D2
D3
R1
R2
R3
D4
1
2
3
D1
4
5
6
7
8
9
R1
R2
R3
D4
R4
D2
D3
25 D1 B
24 D2 A
23 D2 B
22 D3/R1 A
21 D3/R1 B
20 R2 A
19 R2 B
18 R3 A
17 R3 B
16 D4/R4 A
15 INVERT
G PACKAGE
28-LEAD PLASTIC SSOP
28 V
EE
27 GND
26 D1 A
Supply Voltage, V
CC
................................................ 6.5V
Input Voltage
Transmitters ........................... – 0.3V to (V
CC
+ 0.3V)
Receivers ............................................... – 18V to 18V
Logic Pins .............................. – 0.3V to (V
CC
+ 0.3V)
Output Voltage
Transmitters .................. (V
EE
– 0.3V) to (V
DD
+ 0.3V)
Receivers ................................ – 0.3V to (V
CC
+ 0.3V)
V
EE
........................................................ – 10V to 0.3V
V
DD
....................................................... – 0.3V to 10V
Short-Circuit Duration
Transmitter Output ..................................... Indefinite
Receiver Output .......................................... Indefinite
V
EE
.................................................................. 30 sec
Operating Temperature Range
LTC1544CG ............................................. 0°C to 70°C
LTC1544IG ........................................ – 40°C to 85°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
ORDER PART
NUMBER
LTC1544CG
LTC1544IG
R4 10
M0 11
M1 12
M2 13
DCE/DTE 14
T
JMAX
= 150°C,
θ
JA
= 65°C/ W
Consult factory for Military grade parts.
ELECTRICAL CHARACTERISTICS
SYMBOL
Supplies
I
CC
V
CC
Supply Current (DCE Mode,
All Digital Pins = GND or V
CC
)
PARAMETER
The
q
denotes specifications which apply over the full operating tempera-
ture range, otherwise specifications are at T
A
= 25°C. V
CC
= 5V, V
DD
= 8V, V
EE
= – 7V for V.28, – 5.5V for V.10, V.11 (Notes 2, 3)
CONDITIONS
RS530, RS530-A, X.21 Modes, No Load
RS530, RS530-A, X.21 Modes, Full Load
V.28 Mode, No Load
V.28 Mode, Full Load
No-Cable Mode
RS530, RS530-A, X.21 Modes, No Load
RS530, X.21 Modes, Full Load
RS530-A, Full Load
V.28 Mode, No Load
V.28 Mode, Full Load
No-Cable Mode
RS530, RS530-A, X.21 Modes, NoLoad
RS530, RS530-A, X.21 Modes, Full Load
V.28 Mode, No Load
V.28 Mode, Full Load
No-Cable Mode
RS530, RS530-A, X.21 Modes, Full Load
V.28 Mode, Full Load
MIN
TYP
2.7
95
1
1
10
2.1
14
25
1
12
10
0.2
0.2
1
12
10
300
54
MAX
UNITS
mA
mA
mA
mA
µA
mA
mA
mA
mA
mA
µA
mA
mA
mA
mA
µA
mW
mW
q
q
q
q
120
2
2
200
I
EE
V
EE
Supply Current (DCE Mode,
All Digital Pins = GND or V
CC
)
V
EE
= – 5.6V (RS530, RS530-A Modes)
V
EE
= – 8.46V (V.28 Mode)
I
DD
V
DD
Supply Current (DCE Mode,
All Digital Pins = GND or V
CC
)
V
DD
= 8.73V
P
D
Internal Power Dissipation (DCE Mode,
(All Digital Pins = GND or V
CC
)
2
U
W
U
U
W W
W
LTC1544
The
q
denotes specifications which apply over the full operating tempera-
ture range, otherwise specifications are at T
A
= 25°C. V
CC
= 5V, V
DD
= 8V, V
EE
= – 7V for V.28, – 5.5V for V.10, V.11 (Notes 2, 3)
SYMBOL
V
IH
V
IL
I
IN
PARAMETER
Logic Input High Voltage
Logic Input Low Voltage
Logic Input Current
D1, D2, D3, D4
M0, M1, M2, DCE, INVERT = GND (LTC1544C)
M0, M1, M2, DCE, INVERT = GND (LTC1544I)
M0, M1, M2, DCE, INVERT = V
CC
I
O
= – 4mA
I
O
= 4mA
0V
≤
V
O
≤
V
CC
M0 = M1 = M2 = V
CC
, 0V
≤
V
O
≤
V
CC
R
L
= 1.95k (Figure 1)
R
L
= 50Ω (Figure 1)
R
L
= 50Ω (Figure 1)
R
L
= 50Ω (Figure 1)
R
L
= 50Ω (Figure 1)
R
L
= 50Ω (Figure 1)
V
OUT
= GND
– 0.25V
≤
V
O
≤
0.25V, Power Off or
No-Cable Mode or Driver Disabled
LTC1544C (Figures 2, 5)
LTC1544I (Figures 2, 5)
LTC1544C (Figures 2, 5)
LTC1544I (Figures 2, 5)
LTC1544C (Figures 2, 5)
LTC1544I (Figures 2, 5)
LTC1544C (Figures 2, 5)
LTC1544I (Figures 2, 5)
(Figures 2, 5)
– 7V
≤
V
CM
≤
7V
– 7V
≤
V
CM
≤
7V
– 10V
≤
V
A,B
≤
10V
– 10V
≤
V
A,B
≤
10V
(Figures 2, 6)
LTC1544C (Figures 2, 6)
LTC1544I (Figures 2, 6)
LTC1544C (Figures 2, 6)
LTC1544I (Figures 2, 6)
LTC1544C (Figures 2, 6)
LTC1544I (Figures 2, 6)
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
ELECTRICAL CHARACTERISTICS
CONDITIONS
q
q
q
q
q
q
q
q
q
MIN
2
TYP
MAX
UNITS
V
Logic Inputs and Outputs
0.8
– 100
– 120
3
– 50
– 50
– 50
4.5
0.3
40
±1
±5
0.5V
ODO
±2
0.67V
ODO
0.2
3
0.2
±150
±
1
2
2
20
20
20
20
0
0
15
15
40
40
40
40
3
3
3
– 0.2
15
15
30
15
50
50
50
50
0
0
4
4
80
90
80
90
16
21
0.2
40
±0.66
±100
25
35
65
75
65
75
12
17
0.8
50
±10
– 30
– 30
±10
V
µA
µA
µA
µA
V
V
mA
µA
V
V
V
V
V
V
mA
µA
ns
ns
ns
ns
ns
ns
ns
ns
ns
V
mV
mA
kΩ
ns
ns
ns
ns
ns
ns
ns
V
OH
V
OL
I
OSR
I
OZR
V.11 Driver
V
ODO
V
ODL
∆V
OD
V
OC
∆V
OC
I
SS
I
OZ
t
r
, t
f
t
PLH
t
PHL
∆t
t
SKEW
V
TH
∆V
TH
I
IN
R
IN
t
r
, t
f
t
PLH
t
PHL
∆t
Output High Voltage
Output Low Voltage
Output Short-Circuit Current
Three-State Output Current
Open Circuit Differential Output Voltage
Loaded Differential Output Voltage
Change in Magnitude of Differential
Output Voltage
Common Mode Output Voltage
Change in Magnitude of Common Mode
Output Voltage
Short-Circuit Current
Output Leakage Current
Rise or Fall Time
Input to Output
Input to Output
Input to Output Difference,
t
PLH
– t
PHL
Output to Output Skew
Input Threshold Voltage
Input Hysteresis
Input Current (A, B)
Input Impedance
Rise or Fall Time
Input to Output
Input to Output
Input to Output Difference,
t
PLH
– t
PHL
V.11 Receiver
3
LTC1544
The
q
denotes specifications which apply over the full operating tempera-
ture range, otherwise specifications are at T
A
= 25°C. V
CC
= 5V, V
DD
= 8V, V
EE
= – 7V for V.28, – 5.5V for V.10, V.11 (Notes 2, 3)
SYMBOL
V.10 Driver
V
O
V
T
I
SS
I
OZ
t
r
, t
f
t
PLH
t
PHL
V
TH
∆V
TH
I
IN
R
IN
t
r
, t
f
t
PLH
t
PHL
∆t
V.28 Driver
V
O
I
SS
I
OZ
SR
t
PLH
t
PHL
V
THL
V
TLH
∆V
TH
R
IN
t
r
, t
f
t
PLH
t
PHL
Output Voltage
Short-Circuit Current
Output Leakage Current
Slew Rate
Input to Output
Input to Output
Input Low Threshold Voltage
Input High Threshold Voltage
Receiver Input Hysterisis
Receiver Input Impedance
Rise or Fall Time
Input to Output
Input to Output
– 15V
≤
V
A
≤
15V
(Figures 4, 8)
(Figures 4, 8)
(Figures 4, 8)
q
q
ELECTRICAL CHARACTERISTICS
PARAMETER
Output Voltage
Output Voltage
Short-Circuit Current
Output Leakage Current
Rise or Fall Time
Input to Output
Input to Output
Receiver Input Threshold Voltage
Receiver Input Hysteresis
Receiver Input Current
Receiver Input Impedance
Rise or Fall Time
Input to Output
Input to Output
Input to Output Difference,
t
PLH
– t
PHL
CONDITIONS
Open Circuit, R
L
= 3.9k
R
L
= 450Ω (Figure 3)
R
L
= 450Ω (Figure 3)
V
O
= GND
– 0.25V
≤
V
O
≤
0.25V, Power Off or
No-Cable Mode or Driver Disabled
R
L
= 450Ω, C
L
= 100pF (Figures 3, 7)
R
L
= 450Ω, C
L
= 100pF (Figures 3, 7)
R
L
= 450Ω, C
L
= 100pF (Figures 3, 7)
q
q
q
q
q
MIN
±4
±3.6
0.9V
O
TYP
MAX
±6
UNITS
V
V
±150
±0.1
2
1
1
– 0.25
25
15
30
15
55
109
60
q
q
q
q
q
q
q
mA
µA
µs
µs
µs
±100
V.10 Receiver
0.25
50
±0.66
V
mV
mA
kΩ
ns
ns
ns
ns
±10
±150
±1
4
1.3
1.3
1.5
2
0
3
1.6
0.1
5
15
60
150
100
450
0.3
7
±100
30
2.5
2.5
0.8
V
V
mA
µA
V/µs
µs
µs
V
V
V
kΩ
ns
ns
ns
– 10V
≤
V
A
≤
10V
– 10V
≤
V
A
≤
10V
(Figures 4, 8)
(Figures 4, 8)
(Figures 4, 8)
(Figures 4, 8)
Open Circuit
R
L
= 3k (Figure 3)
V
O
= GND
– 0.25V
≤
V
O
≤
0.25V, Power Off or
No-Cable Mode or Driver Disabled
R
L
= 3k, C
L
= 2500pF (Figures 3, 7)
R
L
= 3k, C
L
= 2500pF (Figures 3, 7)
R
L
= 3k, C
L
= 2500pF (Figures 3, 7)
q
q
±5
±8.5
V.28 Receiver
q
q
q
q
Note 1:
Absolute Maximum Ratings are those beyond which the safety of a
device may be impaired.
Note 2:
All currents into device pins are positive; all currents out of device
are negative. All voltages are referenced to device ground unless otherwise
specified.
Note 3:
All typicals are given for V
CC
= 5V, V
DD
= 8V, V
EE
= – 7V for V.28,
– 5.5V for V.10, V.11 and T
A
= 25°C.
4
LTC1544
PI FU CTIO S
V
CC
(Pin 1):
Positive Supply for the Transceivers. 4.75V
≤
V
CC
≤
5.25V. Connect a 1µF capacitor to ground.
V
DD
(Pin 2):
Positive Supply Voltage for V.28. Connect to
V
DD
Pin 3 on LTC1543 or 8V supply. Connect a 1µF
capacitor to ground.
D1 (Pin 3):
TTL Level Driver 1 Input.
D2 (Pin 4):
TTL Level Driver 2 Input.
D3 (Pin 5):
TTL Level Driver 3 Input.
R1 (Pin 6):
CMOS Level Receiver 1 Output.
R2 (Pin 7):
CMOS Level Receiver 2 Output.
R3 (Pin 8):
CMOS Level Receiver 3 Output.
D4 (Pin 9):
TTL Level Driver 4 Input.
R4 (Pin 10):
CMOS Level Receiver 4 Output.
M0 (Pin 11):
TTL Level Mode Select Input 0 with Pull-Up
to V
CC
.
M1 (Pin 12):
TTL Level Mode Select Input 1 with Pull-Up
to V
CC
.
M2 (Pin 13):
TTL Level Mode Select Input 2 with Pull-Up
to V
CC
.
DCE/DTE (Pin 14):
TTL Level Mode Select Input with
Pull-Up to V
CC
.
INVERT (Pin 15):
TTL Level Mode Select Input with Pull-
Up to V
CC
.
D4/R4 A (Pin 16):
Receiver 4 Inverting Input and Driver 4
Output.
R3 B (Pin 17):
Receiver 3 Noninverting Input.
R3 A (Pin 18):
Receiver 3 Inverting Input.
R2 B (Pin 19):
Receiver 2 Noninverting Input.
R2 A (Pin 20):
Receiver 2 Inverting Input.
D3/R1 B (Pin 21):
Receiver 1 Noninverting Input and
Driver 3 Noninverting Output.
D3/R1 A (Pin 22):
Receiver 1 Inverting Input and Driver 3
Inverting Output.
D2 B (Pin 23):
Driver 2 Noninverting Output.
D2 A (Pin 24):
Driver 2 Inverting Output.
D1 B (Pin 25):
Driver 1 Noninverting Output.
D1 A (Pin 26):
Driver 1 Inverting Output.
GND (Pin 27):
Ground.
V
EE
(Pin 28):
Negative Supply Voltage. Connect to V
EE
Pin
26 on LTC1543 or to – 8V supply. Connect a 1µF capacitor
to ground.
TEST CIRCUITS
A
R
L
50Ω
V
OD
R
L
50Ω
B
V
OC
Figure 1. V.11 Driver Test Circuit
U
U
U
B
A
R
L
100Ω
C
L
100pF
C
L
100pF
B
A
R
15pF
1544 F01
1544 F02
Figure 2. V.11 Driver/Receiver AC Test Circuit
5
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