1
LTC1546
APPLICATIO S
U
FEATURES
TYPICAL APPLICATION
U
DESCRIPTIO
U
, LTC and LT are registered trademarks of Linear Technology Corporation.
Complete DTE or DCE Multiprotocol Serial Interface with DB-25 Connector
Data Networking
CSU and DSU
Data Routers
Software-Selectable Transceiver Supports:
RS232, RS449, EIA530, EIA530-A, V.35, V.36, X.21
TUV Telecom Services Inc. Certified NET1,
NET2 and TBR2 Compliant
On-Chip Cable Termination
Pin Compatible with LTC1543
Complete DTE or DCE Port with LTC1544
Operates from Single 5V Supply
Small Footprint
The LTC
®
1546 is a 3-driver/3-receiver multiprotocol trans-
ceiver with on-chip cable termination. When combined with
the LTC1544, this chip set forms a complete software-
selectable DTE or DCE interface port that supports the
RS232, RS449, EIA530, EIA530-A, V.35, V.36 and X.21
protocols. All necessary cable termination is provided inside
the LTC1546. In most applications, the LTC1546 replaces
both an LTC1543 and an LTC1344A without any changes to
the PC board.
The LTC1546 runs from a single 5V supply using an internal
charge pump that requires only five space-saving surface
mounted capacitors. The LTC1546 is available in a 28-lead
SSOP surface mount package.
Software-Selectable
Multiprotocol Transceiver
with Termination
D2 D1
LTC1544
RTS
DTRDSR DCDCTS
D3
R2 R1R4
R3
LTC1546
LL
TXDSCTETXC
RXCRXD
21424111512179314192062322513 81018 7 16
1546 TA01
D1
SCTE B
SCTE A (113)
TXD B
TXD A (103)
RXC A (115)
RXC B
RXD A (104)
RXD B
RTS A (105)
RTS B
DTR A (108)
DTR B
CTS A (106)
CTS B
LL A (141)
SG (102)
SHIELD (101)
DB-25 CONNECTOR
TXC A (114)
DCD A (109)
DCD B
DSR A (107)
DSR B
D4
D2D3
R1R2R3
TXC B
TTTTT
2
LTC1546
ORDER PART
NUMBER
(Note 1)
Supply Voltage ....................................................... 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
LTC1546C ............................................... 0°C to 70°C
LTC1546I........................................... 40°C to 85°C
Storage Temperature Range ................ 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
LTC1546CG
LTC1546IG
Consult factory for parts specified with wider operating temperature ranges.
T
JMAX
= 150°C, θ
JA
= 90°C/W*
1
2
3
4
5
6
7
8
9
10
11
12
13
14
TOP VIEW
28
27
26
25
24
23
22
21
20
19
18
17
16
15
C1
C1
+
V
DD
V
CC
D1
D2
D3
R1
R2
R3
M0
M1
M2
DCE/DTE
C2
+
C2
V
EE
GND
D1 A
D1 B
D2 A
D2 B
D3/R1 A
D3/R1 B
R2 A
R2 B
R3 A
R3 B
R3
CHARGE PUMP
R1
D2
D1
R2
D3
G PACKAGE
28-LEAD PLASTIC SSOP
T
T
T
T
T
The denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= 5V (Notes 2, 3)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Supplies
I
CC
V
CC
Supply Current (DCE Mode, RS530, RS530-A, X.21 Modes, No Load 14 mA
All Digital Pins = GND or V
CC
) RS530, RS530-A, X.21 Modes, Full Load 100 130 mA
V.35 Mode
126 170 mA
V.28 Mode, No Load 20 mA
V.28 Mode, Full Load 35 75 mA
No-Cable Mode
60 500 µA
P
D
Internal Power Dissipation (DCE Mode) RS530, RS530-A, X.21 Modes, Full Load 410 mW
V.35 Mode, Full Load 625 mW
V.28 Mode, Full Load 150 mW
V
+
Positive Charge Pump Output Voltage V.11 or V.28 Mode, No Load 8.0 9.3 V
V.35 Mode
7.0 8.0 V
V.28 Mode, with Load
8.0 8.7 V
V.28 Mode, with Load, I
DD
= 10mA 6.5 V
V
Negative Charge Pump Output Voltage V.28 Mode, No Load 9.6 V
V.28 Mode, Full Load
7.5 8.5 V
V.35 Mode
5.5 6.5 V
RS530, RS530-A, X.21 Modes, Full Load
4.5 6.0 V
*θ
JA
SOLDERED TO A CIRCUIT BOARD
IS TYPICALLY 60°C/W
ABSOLUTE AXI U RATI GS
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PACKAGE/ORDER I FOR ATIO
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ELECTRICAL CHARACTERISTICS
3
LTC1546
The denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= 5V (Notes 2, 3)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
f
OSC
Charge Pump Oscillator Frequency 500 kHz
t
r
Charge Pump Rise Time No-Cable Mode/Power-Off to Normal Operation 2 ms
Logic Inputs and Outputs
V
IH
Logic Input High Voltage 2V
V
IL
Logic Input Low Voltage 0.8 V
I
IN
Logic Input Current D1, D2, D3 ±10 µA
M0, M1, M2, DCE = GND
120 75 30 µA
M0, M1, M2, DCE = V
CC
±10 µA
V
OH
Output High Voltage I
O
= –3mA 3 4.5 V
V
OL
Output Low Voltage I
O
= 3mA 0.3 0.45 V
I
OSR
Output Short-Circuit Current 0V V
O
V
CC
–50 50 mA
I
OZR
Three-State Output Current M0 = M1 = M2 = V
CC
, 0V V
O
V
CC
±1 µA
V.11 Driver
V
ODO
Open Circuit Differential Output Voltage R
L
= 1.95k (Figure 1) ±5V
V
ODL
Loaded Differential Output Voltage R
L
= 50 (Figure 1) 0.5V
ODO
0.67V
ODO
V
R
L
= 50 (Figure 1) ±2V
V
OD
Change in Magnitude of Differential R
L
= 50 (Figure 1) 0.2 V
Output Voltage
V
OC
Common Mode Output Voltage R
L
= 50 (Figure 1) 3V
V
OC
Change in Magnitude of Common Mode R
L
= 50 (Figure 1) 0.2 V
Output Voltage
I
SS
Short-Circuit Current V
OUT
= GND ±150 mA
I
OZ
Output Leakage Current V
A
and V
B
0.25V, Power Off or ±1 ±100 µA
No-Cable Mode or Driver Disabled
t
r
, t
f
Rise or Fall Time (Figures 2, 13) 21525 ns
t
PLH
Input to Output Rising (Figures 2, 13) 15 40 65 ns
t
PHL
Input to Output Falling (Figures 2, 13) 15 40 65 ns
t Input to Output Difference, t
PLH
– t
PHL
(Figures 2, 13) 0312 ns
t
SKEW
Output to Output Skew (Figures 2, 13) 3 ns
V.11 Receiver
V
TH
Input Threshold Voltage 7V V
CM
7V 0.2 0.2 V
V
TH
Input Hysteresis 7V V
CM
7V 15 40 mV
R
IN
Input Impedance 7V V
CM
7V (Figure 3) 100 103
t
r
, t
f
Rise or Fall Time C
L
= 50pF (Figures 4, 14) 15 ns
t
PLH
Input to Output Rising C
L
= 50pF (Figures 4, 14) 50 90 ns
t
PHL
Input to Output Falling C
L
= 50pF (Figures 4, 14) 50 90 ns
t Input to Output Difference, t
PLH
– t
PHL
C
L
= 50pF (Figures 4, 14) 0425 ns
V.35 Driver
V
OD
Differential Output Voltage Open Circuit, R
L
= 1.95k (Figure 5) ±1.2 V
With Load, –4V V
CM
4V (Figure 6) ±0.44 ±0.55 ±0.66 V
V
OA
, V
OB
Single-Ended Output Voltage Open Circuit, R
L
= 1.95k (Figure 5) ±1.2 V
V
OC
Transmitter Output Offset R
L
= 50 (Figure 5) ±0.6 V
ELECTRICAL CHARACTERISTICS

LTC1546CG#PBF

Mfr. #:
Manufacturer:
Analog Devices Inc.
Description:
RS-232 Interface IC Multiprotocol (LTCK011, 012)
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
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