LTC2844
3.3V Software-Selectable
Multiprotocol Transceiver
U
FEATURES
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DESCRIPTIO
The LTC®2844 is a 4-driver/4-receiver multiprotocol transceiver. The LTC2844 and LTC2846 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.
The LTC2844 operates from a 3.3V supply and supplies
provided by the LTC2846. The part is available in a 28-lead
SSOP surface mount package.
Software-Selectable Transceiver Supports:
RS232, RS449, EIA530, EIA530-A, V.35, V.36, X.21
Operates from Single 3.3V Supply with LTC2846
TUV Rheinland of North America Inc. Certified NET1,
NET2 and TBR2 Compliant,
Report No.: TBR2/051501/02
Complete DTE or DCE Port with LTC2846
28-Lead SSOP Surface Mount Package
U
APPLICATIO S
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Data Networking
CSU and DSU
Data Routers
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, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
DTE or DCE Multiprotocol Serial Interface with DB-25 Connector
LL
CTS
DSR
DCD
DTR
RTS
RXD
TXC
D3
R4
18
R3
R2
13 5
22 6
TXD
D3
D2
D1
T
T
T
12
15 11
24 14
LTC2846
LTC2844
D4
SCTE
RXC
D2
D1
R1
10 8
23 20 19 4
1
7
R3
R2
T
T
16
3
9
R1
17
2
TXD A (103)
TXD B
SCTE A (113)
SCTE B
TXC A (114)
TXC B
RXC A (115)
RXC B
RXD A (104)
RXD B
SG (102)
SHIELD (101)
RTS A (105)
RTS B
DTR A (108)
DCD A (109)
DTR B
DCD B
DSR A (107)
CTS A (106)
DSR B
CTS B
LL A (141)
DB-25 CONNECTOR
2844 TA01
sn2844 2844fs
1
LTC2844
W W
W
AXI U
U
ABSOLUTE
RATI GS
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U
W
PACKAGE/ORDER I FOR ATIO
(Note 1)
Supply Voltage
VCC ....................................................... –0.3V to 6.5V
VIN ..................................................................... – 0.3V to 6.5V
VEE ...................................................................... –10V to 0.3V
VDD ..................................................................... – 0.3V to 10V
Input Voltage
Transmitters ............................ – 0.3V to (VCC + 0.3V)
Receivers ................................................– 18V to 18V
Logic Pins ............................... – 0.3V to (VCC + 0.3V)
Output Voltage
Transmitters .................. (VEE – 0.3V) to (VDD + 0.3V)
Receivers ................................. – 0.3V to (VIN + 0.3V)
Short-Circuit Duration
Transmitter Output ...................................... Indefinite
Receiver Output ........................................... Indefinite
VEE ................................................................... 30 sec
Operating Temperature Range
LTC2844CG ............................................. 0°C to 70°C
LTC2844IG ......................................... – 40°C to 85°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
ORDER PART
NUMBER
TOP VIEW
VCC
1
28 VEE
VDD
2
27 GND
D1
3
D2
4
D3
5
R1
6
R2
7
R3
8
D4
9
LTC2844CG
LTC2844IG
26 D1 A
D1
25 D1 B
D2
24 D2 A
23 D2 B
D3
22 D3/R1 A
R1
21 D3/R1 B
20 R2 A
R2
R4 10
19 R2 B
R3
M0 11
18 R3 A
D4
M1 12
R4
M2 13
DCE/DTE 14
17 R3 B
16 D4/R4 A
15 VIN
G PACKAGE
28-LEAD PLASTIC SSOP
TJMAX = 125°C, θJA = 90°C/ W, θJC = 35°C/ W
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VCC = 5V, VIN = 3.3V, VDD = 8V, VEE = – 7V for V.28, – 5.5V for V.10, V.11
(Notes 2, 3)
SYMBOL
PARAMETER
CONDITIONS
VCC Supply Current (DCE Mode,
All Digital Pins = GND or VIN)
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
MIN
TYP
MAX
UNITS
2.7
95
1
1
600
120
2
2
1200
mA
mA
mA
mA
µA
Supplies
ICC
●
●
●
●
IEE
VEE Supply Current (DCE Mode Unless
RS530, RS530-A, X.21 Modes, No Load
Otherwise Noted, All Digital Pins = GND or VIN) RS530, X.21 Modes, Full Load (DTE Mode)
RS530-A, Full Load (DTE Mode)
V.28 Mode, No Load
V.28 Mode, Full Load
No-Cable Mode
1.6
14
25
1
7.5
10
mA
mA
mA
mA
mA
µA
IDD
VDD Supply Current (DCE Mode,
All Digital Pins = GND or VIN)
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
0.2
0.2
1
8
10
mA
mA
mA
mA
µA
IVIN
VIN Supply Current (DCE Mode,
All Digital Pins = GND or VIN)
All Modes Except No-Cable Mode
490
µA
sn2844 2844fs
2
LTC2844
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VCC = 5V, VIN = 3.3V, VDD = 8V, VEE = – 7V for V.28, – 5.5V for V.10, V.11
(Notes 2, 3)
SYMBOL
PARAMETER
CONDITIONS
PD
Internal Power Dissipation (DCE Mode,
All Digital Pins = GND or VIN)
RS530, RS530-A, X.21 Modes, Full Load
V.28 Mode, Full Load
MIN
TYP
MAX
UNITS
210
54
mW
mW
Logic Inputs and Outputs
VIH
Logic Input High Voltage
●
VIL
Logic Input Low Voltage
●
IIN
Logic Input Current
2
V
D1, D2, D3, D4
M0, M1, M2, DCE = GND
M0, M1, M2, DCE = VIN
●
●
●
– 30
– 75
2.7
3
VOH
Output High Voltage
IO = –3mA
●
VOL
Output Low Voltage
IO = 1.6mA
●
IOSR
Output Short-Circuit Current
0V ≤ VO ≤ VIN
●
IOZR
Three-State Output Current
M0 = M1 = M2 = VIN, VO = 0V
M0 = M1 = M2 = VIN, VO = VIN
●
●
VODO
Open Circuit Differential Output Voltage
RL = 1.95k (Figure 1)
●
VODL
Loaded Differential Output Voltage
RL = 50Ω (Figure 1)
– 30
0.8
V
±10
–120
±10
µA
µA
µA
V
0.2
0.4
V
±50
mA
– 85
– 160
±10
µA
µA
±5
V
0.67VODO
V
V
V.11 Driver
●
0.5VODO
±2
∆VOD
Change in Magnitude of Differential
Output Voltage
RL = 50Ω (Figure 1)
●
0.2
V
VOC
Common Mode Output Voltage
RL = 50Ω (Figure 1)
●
3
V
∆VOC
Change in Magnitude of Common Mode
Output Voltage
RL = 50Ω (Figure 1)
●
0.2
V
ISS
Short-Circuit Current
VOUT = GND
IOZ
Output Leakage Current
–0.25V ≤ VO ≤ 0.25V, Power Off or
No-Cable Mode or Driver Disabled
●
tr, tf
Rise or Fall Time
LTC2844C (Figures 2, 5)
LTC2844I (Figures 2, 5)
●
●
tPLH
Input to Output
LTC2844C (Figures 2, 5)
LTC28441 (Figures 2, 5)
tPHL
Input to Output
∆t
tSKEW
±150
mA
±1
±100
µA
2
2
15
15
25
35
ns
ns
●
●
20
20
40
40
65
75
ns
ns
LTC2844C (Figures 2, 5)
LTC2844I (Figures 2, 5)
●
●
20
20
40
40
65
75
ns
ns
Input to Output Difference, tPLH – tPHL
LTC2844C (Figures 2, 5)
LTC2844I (Figures 2, 5)
●
●
0
0
3
3
12
17
ns
ns
Output to Output Skew
(Figures 2, 5)
3
ns
V.11 Receiver
VTH
Input Threshold Voltage
–7V ≤ VCM ≤ 7V
●
∆VTH
Input Hysteresis
–7V ≤ VCM ≤ 7V
●
IIN
Input Current (A, B)
–10V ≤ VA,B ≤ 10V
●
RIN
Input Impedance
–10V ≤ VA,B ≤ 10V
●
tr, tf
Rise or Fall Time
(Figures 2, 6)
tPLH
Input to Output
LTC2844C CL = 50pF (Figures 2, 6)
LTC2844I CL = 50pF (Figures 2, 6)
– 0.2
0.2
15
15
40
mV
±0.66
mA
30
kΩ
15
●
●
50
50
V
ns
80
90
ns
ns
sn2844 2844fs
3
LTC2844
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VCC = 5V, VIN = 3.3V, VDD = 8V, VEE = – 7V for V.28, – 5.5V for V.10, V.11
(Notes 2, 3)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
tPHL
Input to Output
LTC2844C CL = 50pF (Figures 2, 6)
LTC2844I CL = 50pF (Figures 2, 6)
●
●
50
50
80
90
ns
ns
∆t
Input to Output Difference, tPLH – tPHL
LTC2844C CL = 50pF (Figures 2, 6)
LTC2844I CL = 50pF (Figures 2, 6)
●
●
0
0
4
4
16
21
ns
ns
VO
Output Voltage
Open Circuit, RL = 3.9k
●
±4
±6
V
VT
Output Voltage
RL = 450Ω (Figure 3)
RL = 450Ω (Figure 3)
●
ISS
Short-Circuit Current
VO = GND
IOZ
Output Leakage Current
–0.25V ≤ VO ≤ 0.25V, Power Off or
No-Cable Mode or Driver Disabled
tr, tf
Rise or Fall Time
RL = 450Ω, CL = 100pF (Figures 3, 7)
2
µs
tPLH
Input to Output
RL = 450Ω, CL = 100pF (Figures 3, 7)
1
µs
tPHL
Input to Output
RL = 450Ω, CL = 100pF (Figures 3, 7)
1
µs
V.10 Driver
±3.6
0.9VO
V
±0.1
●
±150
mA
±100
µA
V.10 Receiver
VTH
Receiver Input Threshold Voltage
∆VTH
Receiver Input Hysteresis
IIN
Receiver Input Current
–10V ≤ VA ≤ 10V
●
RIN
Receiver Input Impedance
–10V ≤ VA ≤ 10V
●
tr, tf
Rise or Fall Time
tPLH
Input to Output
tPHL
∆t
●
–0.25
0.25
25
●
15
V
50
mV
±0.66
mA
30
kΩ
CL = 50pF (Figures 4, 8)
15
ns
CL = 50pF (Figures 4, 8)
55
ns
Input to Output
CL = 50pF (Figures 4, 8)
109
ns
Input to Output Difference, tPLH – tPHL
CL = 50pF (Figures 4, 8)
60
ns
VO
Output Voltage
Open Circuit
RL = 3k (Figure 3)
●
●
ISS
Short-Circuit Current
VO = GND
●
IOZ
Output Leakage Current
–0.25V ≤ VO ≤ 0.25V, Power Off or
No-Cable Mode or Driver Disabled
●
SR
Slew Rate
RL = 3k, CL = 2500pF (Figures 3, 7)
●
tPLH
Input to Output
RL = 3k, CL = 2500pF (Figures 3, 7)
●
tPHL
Input to Output
RL = 3k, CL = 2500pF (Figures 3, 7)
●
V.28 Driver
±5
±8.5
±1
4
±10
V
V
±150
mA
±100
µA
30
V/µs
1.3
2.5
µs
1.3
2.5
µs
0.8
V
0.1
0.3
V
5
7
kΩ
V.28 Receiver
VTHL
Input Low Threshold Voltage
●
VTLH
Input High Threshold Voltage
●
∆VTH
Receiver Input Hysterisis
●
RIN
Receiver Input Impedance
–15V ≤ VA ≤ 15V
tr, tf
Rise or Fall Time
CL = 50pF (Figures 4, 8)
tPLH
Input to Output
CL = 50pF (Figures 4, 8)
●
60
100
ns
tPHL
Input to Output
CL = 50pF (Figures 4, 8)
●
150
500
ns
●
2
3
V
15
ns
sn2844 2844fs
4
LTC2844
ELECTRICAL CHARACTERISTICS
Note 1: Absolute Maximum Ratings are those values beyond which the life
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 VCC = 5V, VIN = 3.3V, VDD = 8V, VEE = – 7V
for V.28, – 5.5V for V.10, V.11 and TA = 25°C.
U W
TYPICAL PERFOR A CE CHARACTERISTICS
26
TA = 25°C
120
110
IEE (mA)
ICC (mA)
115
105
100
95
90
10
TA = 25°C
24
9
22
8
IDD (mA)
125
V.28 in DCE Mode
(Three V.28 Drivers with Full
Load) IDD vs Data Rate
RS530-A in DTE Mode
(Two V.10 Drivers with Full Load)
IEE vs Data Rate
RS530, X.21 in DCE Mode
(Three V.11 Drivers with Full
Load) ICC vs Data Rate
20
100
1000
DATA RATE (kBd)
7
18
6
16
5
14
10
10
10000
4
20
30 40 50 60 70 80 100
DATA RATE (kBd)
TA = 25°C
10
20
30 40 50 60 70 80 100
DATA RATE (kBd)
2844 G02
2844 G01
2844 G03
RS530-A in DTE Mode
(Two V.10 Drivers with Full Load)
IEE vs Temperature
RS530, X.21 in DCE Mode
(Three V.11 Drivers with Full
Load) ICC vs Temperature
105
100
V.28 in DCE Mode
(Three V.28 Drivers with Full
Load) IDD vs Temperature
23.5
8.20
25.4
8.15
25.3
8.10
90
25.1
IDD (mA)
95
IEE (mA)
ICC (mA)
25.2
25.0
24.9
7.90
24.7
7.85
24.6
80
–40 –20
8.00
7.95
24.8
85
8.05
0
40
20
60
TEMPERATURE (°C)
80
100
2844 G04
24.5
–40 –20
0
20
40
60
TEMPERATURE (°C)
80
100
2844 G05
7.80
–40 –20
0
20
40
60
TEMPERATURE (°C)
80
100
2844 G06
sn2844 2844fs
5
LTC2844
U
U
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PI FU CTIO S
VCC (Pin 1): Positive Supply for the Transceivers. Connect
to VCC Pin 8 on LTC2846 or to 5V supply. Connect a 1µF
capacitor to ground.
VDD (Pin 2): Positive Supply Voltage for V.28. Connect to
VDD Pin 7 on LTC2846 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. Receiver
outputs have a weak pull up to VIN when high impedance.
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. Mode select
inputs pull up to VIN.
M1 (Pin 12): TTL Level Mode Select Input 1.
M2 (Pin 13): TTL Level Mode Select Input 2.
DCE/DTE (Pin 14): TTL Level Mode Select Input.
VIN (Pin 15): Positive Supply for the Receiver Outputs.
3V ≤ VIN ≤ 3.6V. Connect a 1µF capacitor to ground.
D4/R4 A (Pin 16): Receiver 4 Inverting Input and Driver 4
Inverting 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.
VEE (Pin 28): Negative Supply Voltage. Connect to VEE
Pin␣ 31 on LTC2846 or to – 7V supply. Connect a 1µF
capacitor to ground.
sn2844 2844fs
6
LTC2844
W
BLOCK DIAGRA
TEST CIRCUITS
VCC 1
28 VEE
VDD 2
27 GND
A
RL
26 D1A
D1 3
VOD
D1
B
24 D2A
D2 4
VOC
RL
25 D1B
2844 F01
Figure 1. V.11 Driver Test Circuit
D2
23 D2B
25 D3/R1 A
D3
5
D3
10k
20k
6k
B
RL
100Ω
S3
A
10k
CL
100pF
B
CL
100pF
A
R
CL
20k
21 D3/R1 B
R1
6
R1
2844 F02
20 R2A
20k
Figure 2. V.11 Driver/Receiver AC Test Circuit
6k
10k
R2 7
S3
R2
10k
D
A
19 R2B
20k
RL
CL
18 R3A
20k
6k
2844 F03
10k
R3
8
S3
R3
Figure 3. V.10/V.28 Driver Test Circuit
10k
17 R3B
20k
D4
9
D4
16 D4/R4 A
10k
R4 10
20k
D
A
A
R
CL
6k
R4
S3
2844 F04
Figure 4. V.10/V.28 Receiver Test Circuit
M0 11
M1 12
MODE
SELECTION
LOGIC
M2 13
DCE/DTE 14
15 VIN
2844 BD
sn2844 2844fs
7
LTC2844
U
W
ODE SELECTIO
MODE NAME
Not Used
(Default V.11)
RS530A
RS530
X.21
V.35
RS449/V.36
V.28/RS232
No Cable
Not Used
(Default V.11)
RS530A
RS530
X.21
V.35
RS449/V.36
V.28/RS232
No Cable
M2
M1
M0
DCE
/DTE
(Note 1) (Note 1) (Note 1)
D1
D3
D4
D2
D1
D2
D3
D4A
A
B
A
B
A
B
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
0
0
0
0
0
0
0
TTL
TTL
TTL
TTL
TTL
TTL
TTL
X
X
X
X
X
X
X
X
X
TTL
TTL
TTL
TTL
TTL
TTL
TTL
X
V.11
V.11
V.11
V.11
V.28
V.11
V.28
Z
V.11
V.11
V.11
V.11
Z
V.11
Z
Z
V.11
V.10
V.11
V.11
V.28
V.11
V.28
Z
V.11
Z
V.11
V.11
Z
V.11
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
V.10
V.10
V.10
V.10
V.28
V.10
V.28
Z
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
1
1
1
1
1
1
1
1
TTL
TTL
TTL
TTL
TTL
TTL
TTL
X
TTL
TTL
TTL
TTL
TTL
TTL
TTL
X
X
X
X
X
X
X
X
X
V.11
V.11
V.11
V.11
V.28
V.11
V.28
Z
V.11
V.11
V.11
V.11
Z
V.11
Z
Z
V.11
V.10
V.11
V.11
V.28
V.11
V.28
Z
V.11
Z
V.11
V.11
Z
V.11
Z
Z
V.11
V.11
V.11
V.11
V.28
V.11
V.28
Z
V.11
V.11
V.11
V.11
Z
V.11
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
Note 1: Driver inputs are TTL level compatible.
MODE NAME
Not Used
(Default V.11)
RS530A
RS530
X.21
V.35
RS449/V.36
V.28/RS232
No Cable
Not Used
(Default V.11)
RS530A
RS530
X.21
V.35
RS449/V.36
V.28/RS232
No Cable
M2
M1
M0
(Note 2)
R1
(Note 2)
R2
(Note 2)
R3
DCE
/DTE
A
B
A
B
A
B
(Note 2) (Note 3) (Note 3) (Note 3)
R4A
R1
R2
R4
R3
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
0
0
0
0
0
0
0
V.11
V.11
V.11
V.11
V.28
V.11
V.28
30k
V.11
V.11
V.11
V.11
30k
V.11
30k
30k
V.11
V.10
V.11
V.11
V.28
V.11
V.28
30k
V.11
30k
V.11
V.11
30k
V.11
30k
30k
V.11
V.11
V.11
V.11
V.28
V.11
V.28
30k
V.11
V.11
V.11
V.11
30k
V.11
30k
30k
30k
30k
30k
30k
30k
30k
30k
30k
CMOS
CMOS
CMOS
CMOS
CMOS
CMOS
CMOS
Z
CMOS
CMOS
CMOS
CMOS
CMOS
CMOS
CMOS
Z
Z
Z
Z
Z
Z
Z
Z
Z
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
1
1
1
1
1
1
1
1
30k
30k
30k
30k
30k
30k
30k
30k
30k
30k
30k
30k
30k
30k
30k
30k
V.11
V.10
V.11
V.11
V.28
V.11
V.28
30k
V.11
30k
V.11
V.11
30k
V.11
30k
30k
V.11
V.11
V.11
V.11
V.28
V.11
V.28
30k
V.11
V.11
V.11
V.11
30k
V.11
30k
30k
V.10
V.10
V.10
V.10
V.28
V.10
V.28
30k
Z
Z
Z
Z
Z
Z
Z
Z
CMOS
CMOS
CMOS
CMOS
CMOS
CMOS
CMOS
Z
CMOS
CMOS
CMOS
CMOS
CMOS
CMOS
CMOS
Z
Note 2: Unused receiver inputs are terminated with 30k to ground.
Note 3: Receiver outputs are CMOS level compatible and have a weak pull-up to VIN when Z.
sn2844 2844fs
8
LTC2844
U
W
W
SWITCHI G TI E WAVEFOR S
3V
f = 1MHz : t r ≤ 10ns : t f ≤ 10ns
1.5V
D
0V
1.5V
t PHL
t PLH
VO
B–A
–VO
90%
50%
10%
tr
90%
VDIFF = V(A) – V(B)
1/2 VO
50%
10%
tf
A
VO
B
t SKEW
t SKEW
2844 F05
Figure 5. V.11, V.35 Driver Propagation Delays
VOD2
B–A
–VOD2
f = 1MHz : t r ≤ 10ns : t f ≤ 10ns
0V
INPUT
t PLH
0V
t PHL
VOH
R
VOL
1.65V
OUTPUT
1.65V
2844 F06
Figure 6. V.11, V.35 Receiver Propagation Delays
3V
1.5V
1.5V
D
0V
VO
t PHL
t PLH
3V
3V
0V
A
0V
–3V
–VO
2844 F07
–3V
tf
tr
Figure 7. V.10, V.28 Driver Propagation Delays
VIH
RECEIVER THRESHOLD
A
VIL
VOH
R
VOL
t PHL
RECEIVER THRESHOLD
t PLH
1.65V
1.65V
2844 F08
Figure 8. V.10, V.28 Receiver Propagation Delays
sn2844 2844fs
9
LTC2844
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APPLICATIONS INFORMATION
Overview
A complete DCE-to-DTE interface operating in EIA530
mode is shown in Figure 9. The LTC2846 of each port is
used to generate the clock and data signals. The LTC2844
is used to generate the control signals along with LL (local
loop-back). Cable termination is used only for the clock
and data signals. The control signals do not need any
external resistors.
The LTC2846/LTC2844 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.
SERIAL
CONTROLLER
DTE
DCE
LTC2846
LTC2846
SERIAL
CONTROLLER
TXD
D1
TXD
103Ω
R3
TXD
SCTE
D2
SCTE
103Ω
R2
SCTE
R1
D3
TXC
R1
103Ω
TXC
D3
TXC
RXC
R2
103Ω
RXC
D2
RXC
RXD
R3
103Ω
RXD
D1
RXD
LTC2844
LTC2844
RTS
D1
RTS
R3
RTS
DTR
D2
DTR
R2
DTR
D3
R1
DCD
R1
DCD
D3
DCD
DSR
R2
DSR
D2
DSR
CTS
R3
CTS
D1
CTS
LL
LL
D4
R4
R4
LL
D4
2844 F09
Figure 9. Complete Multiprotocol Interface in EIA530 Mode
sn2844 2844fs
10
LTC2844
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APPLICATIONS INFORMATION
Mode Selection
The interface protocol is selected using the mode select
pins M0, M1 and M2 (see the Mode Selection table).
For example, if the port is configured as a V.35 interface,
the mode selection pins should be M2 = 1, M1 = 0, M0 = 0.
For the control signals, the drivers and receivers will
operate in V.28 (RS232) electrical mode. For the clock and
data signals, the drivers and receivers will operate in V.35
electrical mode. The DCE/DTE pin will configure the port
for DCE mode when high, and DTE when low.
The interface protocol may be selected simply by plugging the appropriate interface cable into the connector.
The mode pins are routed to the connector and are left
unconnected (1) or wired to ground (0) in the cable as
shown in Figure 10.
The internal pull-up current sources will ensure a binary 1
when a pin is left unconnected and that the LTC2846/
LTC2844 enter the no-cable mode when the cable is
removed. In the no-cable mode the LTC2846/LTC2844
supply current drops to less than 900µA and all driver
outputs are forced into a high impedance state.
The mode selection may also be accomplished by using
jumpers to connect the mode pins to ground or VIN.
CONNECTOR
(DATA)
M0
LTC2846
M1
M2
DCE/DTE
15
16
18
19
NC
NC
CABLE
LTC2844
DCE/DTE
M2
M1
M0
14
13
12
11
2844 F10
(DATA)
Figure 10. Single Port DCE V.35 Mode Selection in the Cable
sn2844 2844fs
11
LTC2844
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APPLICATIONS INFORMATION
Cable Termination
Traditional implementations have included switching
resistors with expensive relays, or required the user to
change termination modules every time the interface
standard has changed. Custom cables have been used
with the termination in the cable head or separate terminations are built on the board and a custom cable routes the
signals to the appropriate termination. Switching the
termination with FETs is difficult because the FETs must
remain off even though the signal voltage is beyond the
supply voltage for the FET drivers or the power is off.
The V.10 receiver configuration in the LTC2844 is shown
in Figure 13. In V.10 mode switch S3 inside the LTC2844
is turned off.The noninverting input is disconnected inside
the LTC2844 receiver and connected to ground. The cable
termination is then the 30k input impedance to ground of
the LTC2844 V.10 receiver.
IZ
Using the LTC2846/LTC2844 solves the cable termination
switching problem. Via software control, appropriate termination for the V.10 (RS423), V.11 (RS422), V.28 (RS232)
and V.35 electrical protocols is chosen.
3.25mA
–3V
–10V
VZ
3V
10V
V.10 (RS423) Interface
A typical V.10 unbalanced interface is shown in Figure 11.
A V.10 single-ended generator output A with ground C is
connected to a differential receiver with inputs A' connected to A, and input C' connected to the signal return
ground C. Usually, no cable termination is required for
V.10 interfaces, but the receiver inputs must be compliant
with the impedance curve shown in Figure 12.
2844 F12
–3.25mA
Figure 12. V.10 Receiver Input Impedance
A'
BALANCED
INTERCONNECTING
CABLE
GENERATOR
A
R8
6k
LOAD
CABLE
TERMINATION
LTC2844
R6
10k
S3
RECEIVER
RECEIVER
A'
R4
20k
B'
C
R5
20k
C'
Figure 11. Typical V.10 Interface
2844 F11
C'
GND
R7
10k
2844 F13
Figure 13. V.10 Receiver Configuration
sn2844 2844fs
12
LTC2844
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APPLICATIONS INFORMATION
V.11 (RS422) Interface
V.28 (RS232) Interface
A typical V.11 balanced interface is shown in Figure 14. A
V.11 differential generator with outputs A and B with
ground C is connected to a differential receiver with
ground C', inputs A' connected to A, B' connected to B. The
V.11 interface has a differential termination at the receiver
end that has a minimum value of 100Ω. The termination
resistor is optional in the V.11 specification, but for the
high speed clock and data lines, the termination is required
to prevent reflections from corrupting the data. The
receiver inputs must also be compliant with the impedance curve shown in Figure 12.
A typical V.28 unbalanced interface is shown in Figure 16.
A V.28 single-ended generator output A with ground C is
connected to a single-ended receiver with input A' connected to A, ground C' connected via the signal return
ground C.
In V.11 mode, all switches are off except S1 of the
LTC2846’s receivers which connects a 103Ω differential
termination impedance to the cable as shown in Figure
151. The LTC2844 only handles control signals, so no
termination other than its V.11 receivers’ 30k input impedance is necessary.
In V.28 mode all switches are off except S3 inside the
LTC2846/LTC2844 which connects a 6k (R8) impedance
to ground in parallel with 20k (R5) plus 10k (R6) for a
combined impedance of 5k as shown in Figure 17. The
noninverting input is disconnected inside the LTC2846/
LTC2844 receiver and connected to a TTL level reference
voltage for a 1.4V receiver trip point.
A'
BALANCED
INTERCONNECTING
CABLE
GENERATOR
LOAD
CABLE
TERMINATION
LTC2846
R1
51.5Ω
R6
10k
RECEIVER
S1
S2
A'
A
B
B'
C
C'
R8
6k
R5
20k
100Ω
MIN
B'
R3
124Ω
R2
51.5Ω
R7
10k
R4
20k
C'
2844 F14
GND
2844 F15
Figure 15. V.11 Receiver Configuration
Figure 14. Typical V.11 Interface
A'
BALANCED
INTERCONNECTING
CABLE
GENERATOR
A
LTC2844
R8
6k
LOAD
CABLE
TERMINATION
R5
20k
R6
10k
S3
RECEIVER
RECEIVER
A'
R4
20k
B'
C
RECEIVER
S3
C'
2844 F16
C'
Figure 16. Typical V.28 Interface
GND
R7
10k
2844 F17
Figure 17. V.28 Receiver Configuration
1Actually,
there is no switch S1 in receivers R2 and R3. However, for simplicity, all termination
networks on the LTC2846 can be treated identically if it is assumed that an S1 switch exists and is
always closed on the R2 and R3 receivers.
sn2844 2844fs
13
LTC2844
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APPLICATIONS INFORMATION
V.35 Interface
No-Cable Mode
A typical V.35 balanced interface is shown in Figure 18. A
V.35 differential generator with outputs A and B with
ground C is connected to a differential receiver with
ground C', inputs A' connected to A, B' connected to B. The
V.35 interface requires a T or delta network termination at
the receiver end and the generator end. The receiver
differential impedance measured at the connector must be
100Ω␣ ±10Ω, and the impedance between shorted terminals (A' and B') and ground C' must be 150Ω ±15Ω.
The no-cable mode (M0 = M1 = M2 = 1) is intended for the
case when the cable is disconnected from the connector.
The bias circuitry, drivers and receivers are turned off, the
driver outputs are forced into a high impedance state, and
the supply current drops to less than 600µA.
In V.35 mode, both switches S1 and S2 inside the LTC2846
are on, connecting the T network impedance as shown in
Figure 19. The 30k input impedance of the receiver is
placed in parallel with the T network termination, but does
not affect the overall input impedance significantly.
The generator differential impedance must be 50Ω to
150Ω and the impedance between shorted terminals (A
and B) and ground C must be 150Ω ±15Ω. For the
generator termination, switches S1 and S2 are both on as
shown in Figure 20.
BALANCED
INTERCONNECTING
CABLE
GENERATOR
LTC2846 Supplies
The LTC2846 uses an internal capacitive charge pump to
generate VDD and VEE as shown in Figure 21. A voltage
doubler generates about 8V on VDD and a voltage inverter
generates about – 7.5V for VEE. Three 1µF surface mounted
tantalum or ceramic capacitors are required for C1, C2 and
C3. The VEE capacitor C4 should be a minimum of 3.3µF.
All capacitors are 16V and should be placed as close as
possible to the LTC2846 to reduce EMI.
The LTC2846 has an internal boost switching regulator
which generates a 5V output from the 3.3V supply as
shown in Figure 22. The 5V VCC supplies its internal charge
pump and transceivers as well as its companion chip.
A'
LTC2846
LOAD
CABLE
TERMINATION
R1
51.5Ω
R6
10k
A'
A
S1
S2
50Ω
125Ω
50Ω
125Ω
50Ω
50Ω
B
B'
C
C'
R8
6k
RECEIVER
R5
20k
R3
124Ω
R2
51.5Ω
B'
RECEIVER
S3
R7
10k
R4
20k
GND
C'
2844 F19
2844 F18
Figure 19. V.35 Receiver Configuration
Figure 18. Typical V.35 Interface
A
7
LTC2846
C3
1µF
51.5Ω
C1
1µF 5
S1
V.35 DRIVER
124Ω
6
S2
51.5Ω
8
5V
B
VDD
C2 +
33
C1+
C2 –
32
C2
1µF
LTC2846
C1–
VCC
VEE
GND
31
30
+
C4
3.3µF
C5
10µF
C
2844 F21
2844 F20
Figure 20. V.35 Driver
Figure 21. Charge Pump
sn2844 2844fs
14
LTC2844
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APPLICATIONS INFORMATION
L1
5.6µH
VIN
3.3V
D1
3
C6
10µF
SHDN
VIN
VCC
5V
480mA
36
SW
BOOST
SWITCHING
REGULATOR
35
4
SHDN
FB
GND
2, 34
R1
13k
C5
10µF
R2
4.3k
C1,C2: TAIYO YUDEN X5R JMK316BJ106ML
D1: ON SEMICONDUCTOR MBR0520
L1: SUMIDA CR43-5R6
2844 F22
Figure 22. Boost Switching Regulator
Receiver Fail-Safe
All LTC2846/LTC2844 receivers feature fail-safe operation in all modes. If the receiver inputs are left floating or
shorted together by a termination resistor, the receiver
output will always be forced to a logic high.
DTE vs DCE Operation
The DCE/DTE pin acts as an enable for Driver 3/Receiver␣ 1
in the LTC2846, and Driver 3/Receiver 1 and Receiver 4/
Driver 4 in the LTC2844.
The LTC2846/LTC2844 can be configured for either DTE
or DCE operation in one of two ways: a dedicated DTE or
DCE port with a connector of appropriate gender or a port
with one connector that can be configured for DTE or DCE
operation by rerouting the signals to the LTC2846/LTC2844
using a dedicated DTE cable or dedicated DCE cable.
A dedicated DTE port using a DB-25 male connector is
shown in Figure 23. The interface mode is selected by logic
outputs from the controller or from jumpers to either VIN
or GND on the mode select pins.
A port with one DB-25 connector, but can be configured
for either DTE or DCE operation is shown in Figure 24. The
configuration requires separate cables for proper signal
routing in DTE or DCE operation. For example, in DTE
mode, the TXD signal is routed to Pins 2 and 14 via Driver␣ 1
in the LTC2846. In DCE mode, Driver 1 now routes the RXD
signal to Pins 2 and 14.
Multiprotocol Interface with RL, LL, TM and a DB-25
Connector
If the RL, LL and TM signals are implemented, there are not
enough drivers and receivers available in the LTC2846/
LTC2844. In Figure 25, the required control signals are
handled by the LTC2845. The LTC2845 has an additional
single-ended driver/receiver pair that can handle two more
optional control signals such as TM and LL.
Cable-Selectable Multiprotocol Interface
A cable-selectable multiprotocol DTE/DCE interface is
shown in Figure 26. The select lines M0, M1 and DCE/DTE
are brought out to the connector. The mode is selected by
the cable by wiring M0 (connector Pin 18) and M1 (connector Pin 21) and DCE/DTE (connector Pin 25) to ground
(connector Pin 7) or letting them float. If M0, M1 or DCE/
DTE is floating, internal pull-up current sources will pull
the signals to VIN. The select bit M2 is floating and
therefore, internally pulled high. When the cable is pulled
out, the interface will go into the no-cable mode.
Compliance Testing
The LTC2846/LTC2844 chipset has been tested by TUV
Rheinland of North America Inc. and passed the NET1,
NET2 and TBR2 requirements. Copies of the test report are
available from LTC or TUV Rheinland of North America Inc.
The title of the report is Test Report No. TBR2/051501/02
The address of TUV Rheinland of North America Inc. is:
TUV Rheinland of North America Inc.
1775, Old Highway 8 NW, Suite 107
St. Paul, MN 55112
Tel. (651) 639-0775
Fax (651) 639-0873
sn2844 2844fs
15
LTC2844
U
TYPICAL APPLICATIO S
D1
MBR0520
L1
5.6µH
3
C6
10µF
SHDN
4
7
C3
1µF
36
BOOST
SWITCHING
REGULATOR
5
C1
1µF
VCC
5V
33
30
LTC2846
9
D1
10
SCTE
R2
4.3k
T
D2
C5
10µF
C2
1µF
31
CHARGE
PUMP
8
TXD
35
32
6
VCC
5V
R1
13k
T
+
VIN
3.3V
C4
3.3µF
29
2
28
14
27
24
26
11
25
15
24
12
23
17
22
9
21
3
20
16
TXD A (103)
TXD B
SCTE A (113)
SCTE B
11
D3
12
TXC
15
16
18
19
C8
1µF
RTS
DTR
R2
14
RXD
C7
1µF
R1
13
RXC
T
R3
T
T
M0
7
M1
M2
17 VIN
3.3V
DCE/DTE
1
VCC
2
VDD
3
VEE
GND
D1
4
D2
5
DSR
CTS
LL
6
R1
7
R2
8
R3
10
R4
9
M0
M1
M2
11
12
13
14
RXC A (115)
RXC B
RXD A (104)
RXD B
SG
SHIELD
DB-25 MALE
CONNECTOR
28
C9
1µF
27
TXC B
26
4
25
19
24
20
23
23
RTS A (105)
RTS B
DTR A (108)
DTR B
D3
LTC2844
DCD
1
TXC A (114)
22
8
21
10
20
6
19
22
18
5
17
13
16
18
DCD A (109)
DCD B
DSR A (107)
DSR B
CTS A (106)
CTS B
LL A (141)
D4
M0
M1
VIN
15
C10
1µF
VIN
3.3V
M2
DCE/DTE
2844 F23
Figure 23. Controller-Selectable Multiprotocol DTE Port with DB-25 Connector
sn2844 2844fs
16
LTC2844
U
TYPICAL APPLICATIO S
D1
MBR0520
L1
5.6µH
3
C6
10µF
SHDN
4
7
C3
1µF
36
BOOST
SWITCHING
REGULATOR
5
C1
1µF
VCC
5V
6
8
9
D1
10
DTE_SCTE/DCE_RXC
T
D2
R2
4.3k
33
30
LTC2846
DTE_TXD/DCE_RXD
35
T
C5
10µF
C2
1µF
32
31
CHARGE
PUMP
VCC
5V
R1
13k
+
VIN
3.3V
C4
3.3µF
29
2
28
14
27
24
26
11
25
15
24
12
23
17
22
9
21
3
20
16
DTE
DCE
TXD A
RXD A
TXD B
RXD B
SCTE A
RXC A
SCTE B
RXC B
TXC A
TXC A
TXC B
TXC B
RXC A
SCTE A
RXC B
SCTE B
RXD A
TXD A
RXD B
TXD B
11
D3
12
DTE_TXC/DCE_TXC
15
16
18
19
DTE_RTS/DCE_CTS
DTE_DTR/DCE_DSR
R2
14
DTE_RXD/DCE_TXD
C7
1µF
R1
13
DTE_RXC/DCE_SCTE
C8
1µF
T
R3
T
T
M0
7
M1
M2
DCE/DTE
1
VCC
2
VDD
3
VEE
GND
D1
4
D2
5
DTE_DSR/DCE_DTR
DTE_CTS/DCE_RTS
DTE_LL/DCE_LL
6
R1
7
R2
8
R3
10
R4
9
M0
M1
M2
DCE/DTE
11
12
13
14
SHIELD
DB-25
CONNECTOR
28
C9
1µF
27
SG
26
4
25
19
24
20
23
23
RTS A
CTS A
RTS B
CTS B
DTR A
DSR A
DTR B
DSR B
DCD A
DCD A
D3
LTC2844
DTE_DCD/DCE_DCD
1
17 VIN
3.3V
22
8
21
10
20
6
19
22
18
5
17
13
16
18
DCD B
DCD B
DSR A
DTR A
DSR B
DTR B
CTS A
RTS A
CTS B
RTS B
LL A
LL A
D4
M0
M1
VIN
15
C10
1µF
VIN
3.3V
M2
DCE/DTE
2844 F25
Figure 24. Controller-Selectable Multiprotocol DTE/DCE Port with DB-25 Connector
sn2844 2844fs
17
LTC2844
U
TYPICAL APPLICATIO S
D1
MBR0520
L1
5.6µH
36
3
C6
10µF
SHDN
4
7
C3
1µF
BOOST
SWITCHING
REGULATOR
5
C1
1µF
VCC
5V
8
LTC2846
D1
10
DTE_SCTE/DCE_RXC
T
D2
R2
4.3k
33
30
9
DTE_TXD/DCE_RXD
35
T
C5
10µF
C2
1µF
32
31
CHARGE
PUMP
6
VCC
5V
R1
13k
+
VIN
3.3V
C4
3.3µF
29
2
28
14
27
24
26
11
25
15
24
12
23
17
22
9
21
3
20
16
DTE
TXD A
DCE
RXD A
TXD B
RXD B
SCTE A
RXC A
SCTE B
RXC B
TXC A
TXC A
TXC B
TXC B
RXC A
SCTE A
RXC B
SCTE B
RXD A
TXD A
RXD B
TXD B
11
D3
12
DTE_TXC/DCE_TXC
15
16
18
19
DTE_RTS/DCE_CTS
DTE_DTR/DCE_DSR
C8
1µF
T
R2
14
DTE_RXD/DCE_TXD
C7
1µF
R1
13
DTE_RXC/DCE_SCTE
T
T
R3
M0
7
M1
M2
1, 19
VCC
2
VDD
3
VEE
GND
D1
4
D2
5
DTE_DSR/DCE_DTR
DTE_CTS/DCE_RTS
DTE_LL/DCE_RI
DTE_RI/DCE_LL
DTE_TM/DCE_RL
DTE_RL/DCE_TM
M0
M1
M2
DCE/DTE
6
R1
7
R2
8
R3
9
D4
10
R4
17
R5
18
11
12
13
14
SHIELD
36
DB-25
CONNECTOR
C9
1µF
35
34
4
33
19
32
20
31
23
RTS A
CTS A
RTS B
CTS B
DTR A
DSR A
DTR B
DSR B
DCD A
DCD A
D3
LTC2845
DTE_DCD/DCE_DCD
1
17 VIN
3.3V
DCE/DTE
SG
D5
M0
M1
8
29
10
28
6
27
22
26
5
25
24
13
23
*
22
25
21
21
20
VIN
15
D4ENB
M2
DCE/DTE
30
R4EN
16
C10
1µF
VIN
3.3V
DCD B
DCD B
DSR A
DTR A
DSR B
DTR B
CTS A
RTS A
CTS B
18
LL
RTS B
RI
RI
LL
TM
RL
RL
TM
*OPTIONAL
2844 F26
NC
Figure 25. Controller-Selectable Multiprotocol DTE/DCE Port with RL, LL, TM and DB-25 Connector
sn2844 2844fs
18
LTC2844
U
TYPICAL APPLICATIO S
D1
MBR0520
L1
5.6µH
3
C6
10µF
SHDN
4
7
C3
1µF
36
BOOST
SWITCHING
REGULATOR
5
C1
1µF
33
30
LTC2846
9
D1
10
DTE_SCTE/DCE_RXC
R2
4.3k
T
D2
C5
10µF
C2
1µF
31
CHARGE
PUMP
8
DTE_TXD/DCE_RXD
35
32
6
VCC
5V
VCC
5V
R1
13k
T
+
VIN
3.3V
C4
3.3µF
29
2
28
14
27
24
26
11
25
15
24
12
23
17
22
9
21
3
20
16
DTE
DCE
TXD A
RXD A
TXD B
RXD B
SCTE A
RXC A
SCTE B
RXC B
TXC A
TXC A
11
D3
12
DTE_TXC/DCE_TXC
R1
13
DTE_RXC/DCE_SCTE
R2
14
DTE_RXD/DCE_TXD
15
16
NC
18
19
T
R3
T
T
M0
7
M1
M2
1
17 VIN
3.3V
DCE/DTE
TXC B
TXC B
RXC A
SCTE A
RXC B
SCTE B
RXD A
TXD A
RXD B
TXD B
SG
SHIELD
DB-25
CONNECTOR
C7
1µF
C8
1µF
1
VCC
2
VDD
VEE
GND
25
DCE/DTE
21
M1
18
M0
4
RTS A
19
RTS B
20
DTR A
23
DTR B
28
C9
1µF
27
26
3
DTE_RTS/DCE_CTS
D1
24
4
DTE_DTR/DCE_DSR
25
D2
5
23
6
R1
7
DTE_DSR/DCE_DTR
R2
8
DTE_CTS/DCE_RTS
R3
10
12
NC
13
14
22
8
21
10
20
6
19
22
18
5
13
17
R4
9
11
CTS B
DSR A
DSR B
D3
LTC2844
DTE_DCD/DCE_DCD
CTS A
16
CABLE WIRING FOR MODE SELECTION
15
MODE
V.35
RS449, V.36
RS232
D4
M0
M1
M2
DCE/DTE
VIN
C10
1µF
VIN
3.3V
PIN 18
PIN 7
NC
PIN 7
DCD A
DCD A
DCD B
DCD B
DSR A
DTR A
DSR B
DTR B
CTS A
RTS A
CTS B
RTS B
PIN 21
PIN 7
PIN 7
NC
CABLE WIRING FOR
DTE/DCE SELECTION
MODE
DTE
DCE
PIN 25
PIN 7
NC
2844 F27
Figure 26. Cable-Selectable Multiprotocol DTE/DCE Port with DB-25 Connector
sn2844 2844fs
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
19
LTC2844
U
PACKAGE DESCRIPTIO
G Package
28-Lead Plastic SSOP (5.3mm)
(Reference LTC DWG # 05-08-1640)
9.90 – 10.50*
(.390 – .413)
28 27 26 25 24 23 22 21 20 19 18 17 16 15
1.25 ±0.12
7.8 – 8.2
5.3 – 5.7
0.42 ±0.03
7.40 – 8.20
(.291 – .323)
0.65 BSC
1 2 3 4 5 6 7 8 9 10 11 12 13 14
RECOMMENDED SOLDER PAD LAYOUT
5.00 – 5.60**
(.197 – .221)
2.0
(.079)
0° – 8°
0.09 – 0.25
(.0035 – .010)
0.55 – 0.95
(.022 – .037)
NOTE:
1. CONTROLLING DIMENSION: MILLIMETERS
MILLIMETERS
2. DIMENSIONS ARE IN
(INCHES)
0.65
(.0256)
BSC
0.22 – 0.38
(.009 – .015)
0.05
(.002)
G28 SSOP 0802
3. DRAWING NOT TO SCALE
*DIMENSIONS DO NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED .152mm (.006") PER SIDE
**DIMENSIONS DO NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED .254mm (.010") PER SIDE
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LTC1321
Dual RS232/RS485 Transceiver
Two RS232 Driver/Receiver Pairs or Two RS485 Driver/Receiver Pairs
LTC1334
Single 5V RS232/RS485 Multiprotocol Transceiver
Two RS232 Driver/Receiver or Four RS232 Driver/Receiver Pairs
LTC1343
Software-Selectable Multiprotocol Transceiver
4-Driver/4-Receiver for Data and Clock Signals
LTC1344A
Software-Selectable Cable Terminator
Perfect for Terminating the LTC1543 (Not Needed with LTC1546)
LTC1345
Single Supply V.35 Transceiver
3-Driver/3-Receiver for Data and Clock Signals
LTC1346A
Dual Supply V.35 Transceiver
3-Driver/3-Receiver for Data and Clock Signals
LTC1543
Software-Selectable Multiprotocol Transceiver
Terminated with LTC1344A for Data and Clock Signals, Companion to
LTC1544 or LTC1545 for Control Signals
LTC1544
Software-Selectable Multiprotocol Transceiver
Companion to LTC1546 or LTC1543 for Control Signals Including LL
LTC1545
Software-Selectable Multiprotocol Transceiver
5-Driver/5-Receiver Companion to LTC1546 or LTC1543
for Control Signals Including LL, TM and RL
LTC1546
Software-Selectable Multiprotocol Transceiver
3-Driver/3-Receiver with Termination for Data and Clock Signals
LTC2845
3.3V Software-Selectable Multiprotocol Transceiver
3.3V Supply, 5-Driver/5-Receiver Companion to LTC2846 for Control
Signals Including LL, TM and RL
LTC2846
3.3V Software-Selectable Multiprotocol Transceiver
3.3V Supply, 3-Driver/3-Receiver with Termination for Data and Clock
Signals, Generates the Required 5V and ±8V Supplies for LTC2846 and
Companion Parts
sn2844 2844fs
20
Linear Technology Corporation
LT/TP 0503 1K • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
LINEAR TECHNOLOGY CORPORATION 2002
工商网监
湘ICP备2023018690号
