LTC2844IG#TRPBF [Linear]
LTC2844 - 3.3V Software-Selectable Multiprotocol Transceiver; Package: SSOP; Pins: 28; Temperature Range: -40°C to 85°C;
| 型号： | LTC2844IG#TRPBF |
| 厂家： | 
Linear |
| 描述： | LTC2844 - 3.3V Software-Selectable Multiprotocol Transceiver; Package: SSOP; Pins: 28; Temperature Range: -40°C to 85°C 驱动 光电二极管 接口集成电路 驱动器 |
| 文件： | 总20页 (文件大小：268K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
LTC2844
3.3V Software-Selectable
Multiprotocol Transceiver
U
FEATURES
DESCRIPTIO
The LTC®2844 is a 4-driver/4-receiver multiprotocol trans-
ceiver. 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.
■
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
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.
■
Complete DTE or DCE Port with LTC2846
■
28-Lead SSOP Surface Mount Package
U
, LTC and LT are registered trademarks of Linear Technology Corporation.
APPLICATIO S
■
Data Networking
■
CSU and DSU
■
Data Routers
U
TYPICAL APPLICATIO
DTE or DCE Multiprotocol Serial Interface with DB-25 Connector
LL
CTS
R3
DSR
R2
DCD
DTR
RTS
TXC
SCTE
TXD
RXD
RXC
LTC2846
LTC2844
D3
D4
D2
D1
D3
D2
T
D1
T
R4
R1
R3
T
R2
T
R1
T
18
13
5
22
6
10
8
23 20 19
4
1
7
16
3
9
17
12 15 11 24 14
2
DB-25 CONNECTOR
2844 TA01
sn2844 2844fs
1
LTC2844
W W U W
U W
U
ABSOLUTE AXI U RATI GS
(Note 1)
PACKAGE/ORDER I FOR ATIO
Supply Voltage
TOP VIEW
ORDER PART
NUMBER
VCC ....................................................... –0.3V to 6.5V
VIN ..................................................................... –0.3V to 6.5V
VEE ...................................................................... –10V to 0.3V
VDD ..................................................................... –0.3V to 10V
Input Voltage
V
1
2
3
4
5
6
7
8
9
28 V
EE
CC
V
27 GND
DD
D1
D2
D3
R1
R2
R3
D4
26 D1 A
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
LTC2844CG
LTC2844IG
D1
D2
D3
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
R1
R2
R3
R4 10
M0 11
D4
R4
M1 12
M2 13
Transmitter Output ...................................... Indefinite
Receiver Output........................................... Indefinite
VEE................................................................... 30 sec
Operating Temperature Range
DCE/DTE 14
15 V
IN
G PACKAGE
28-LEAD PLASTIC SSOP
TJMAX = 125°C, θJA = 90°C/ W, θJC = 35°C/ W
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
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating tempera-
ture 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
Supplies
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
I
I
V
Supply Current (DCE Mode,
CC
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
2.7
95
1
1
600
mA
mA
mA
mA
µA
CC
All Digital Pins = GND or V )
●
●
●
●
120
2
2
IN
1200
V
Supply Current (DCE Mode Unless
RS530, RS530-A, X.21 Modes, No Load
1.6
14
25
1
7.5
10
mA
mA
mA
mA
mA
µA
EE
EE
Otherwise Noted, All Digital Pins = GND or V ) RS530, X.21 Modes, Full Load (DTE Mode)
IN
RS530-A, Full Load (DTE Mode)
V.28 Mode, No Load
V.28 Mode, Full Load
No-Cable Mode
I
I
V
Supply Current (DCE Mode,
DD
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
DD
All Digital Pins = GND or V )
IN
V
Supply Current (DCE Mode,
IN
All Modes Except No-Cable Mode
490
µA
VIN
All Digital Pins = GND or V )
IN
sn2844 2844fs
2
LTC2844
ELECTRICAL CHARACTERISTICS
(Notes 2, 3)
The ● denotes specifications which apply over the full operating tempera-
ture 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
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
P
Internal Power Dissipation (DCE Mode,
RS530, RS530-A, X.21 Modes, Full Load
V.28 Mode, Full Load
210
54
mW
mW
D
All Digital Pins = GND or V )
IN
Logic Inputs and Outputs
V
V
Logic Input High Voltage
Logic Input Low Voltage
Logic Input Current
●
●
2
V
V
IH
IL
0.8
I
D1, D2, D3, D4
M0, M1, M2, DCE = GND
M0, M1, M2, DCE = V
●
●
●
±10
–120
±10
µA
µA
µA
IN
–30
–75
IN
V
V
Output High Voltage
I = –3mA
●
●
●
2.7
3
V
V
OH
OL
O
Output Low Voltage
I = 1.6mA
O
0.2
0.4
I
I
Output Short-Circuit Current
Three-State Output Current
0V ≤ V ≤ V
IN
±50
mA
OSR
OZR
O
M0 = M1 = M2 = V , V = 0V
M0 = M1 = M2 = V , V = V
●
●
–30
–85
–160
±10
µA
µA
IN
O
IN
O
IN
V.11 Driver
V
V
Open Circuit Differential Output Voltage
Loaded Differential Output Voltage
R = 1.95k (Figure 1)
●
±5
V
ODO
ODL
L
R = 50Ω (Figure 1)
L
0.5V
±2
0.67V
ODO
V
V
ODO
●
●
∆V
Change in Magnitude of Differential
Output Voltage
R = 50Ω (Figure 1)
L
0.2
V
OD
V
Common Mode Output Voltage
R = 50Ω (Figure 1)
●
●
3
V
V
OC
L
∆V
Change in Magnitude of Common Mode
Output Voltage
R = 50Ω (Figure 1)
L
0.2
OC
I
I
Short-Circuit Current
V
= GND
OUT
±150
±100
mA
SS
OZ
Output Leakage Current
–0.25V ≤ V ≤ 0.25V, Power Off or
No-Cable Mode or Driver Disabled
●
±1
µA
O
t , t
Rise or Fall Time
Input to Output
Input to Output
LTC2844C (Figures 2, 5)
LTC2844I (Figures 2, 5)
●
●
2
2
15
15
25
35
ns
ns
r
f
PLH
PHL
t
t
LTC2844C (Figures 2, 5)
LTC28441 (Figures 2, 5)
●
●
20
20
40
40
65
75
ns
ns
LTC2844C (Figures 2, 5)
LTC2844I (Figures 2, 5)
●
●
20
20
40
40
65
75
ns
ns
∆t
Input to Output Difference,
Output to Output Skew
t
– t
PHL
LTC2844C (Figures 2, 5)
LTC2844I (Figures 2, 5)
●
●
0
0
3
3
12
17
ns
ns
PLH
t
(Figures 2, 5)
3
ns
SKEW
V.11 Receiver
V
Input Threshold Voltage
Input Hysteresis
–7V ≤ V ≤ 7V
●
●
●
●
–0.2
15
0.2
40
V
mV
mA
kΩ
ns
TH
CM
∆V
–7V ≤ V ≤ 7V
15
TH
CM
I
Input Current (A, B)
Input Impedance
Rise or Fall Time
Input to Output
–10V ≤ V ≤ 10V
±0.66
IN
A,B
R
–10V ≤ V ≤ 10V
30
15
IN
A,B
t , t
r
(Figures 2, 6)
f
t
LTC2844C C = 50pF (Figures 2, 6)
●
●
50
50
80
90
ns
ns
PLH
L
LTC2844I C = 50pF (Figures 2, 6)
L
sn2844 2844fs
3
LTC2844
ELECTRICAL CHARACTERISTICS
(Notes 2, 3)
The ● denotes specifications which apply over the full operating tempera-
ture 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
SYMBOL
PARAMETER
CONDITIONS
LTC2844C C = 50pF (Figures 2, 6)
MIN
TYP
MAX
UNITS
t
Input to Output
●
●
50
50
80
90
ns
ns
PHL
L
LTC2844I C = 50pF (Figures 2, 6)
L
∆t
Input to Output Difference,
t
– t
PHL
LTC2844C C = 50pF (Figures 2, 6)
●
●
0
0
4
4
16
21
ns
ns
PLH
L
LTC2844I C = 50pF (Figures 2, 6)
L
V.10 Driver
V
V
Output Voltage
Output Voltage
Open Circuit, R = 3.9k
●
●
±4
±3.6
0.9V
±6
V
V
O
T
L
R = 450Ω (Figure 3)
L
R = 450Ω (Figure 3)
L
O
I
I
Short-Circuit Current
V = GND
±150
±100
mA
SS
OZ
O
Output Leakage Current
–0.25V ≤ V ≤ 0.25V, Power Off or
No-Cable Mode or Driver Disabled
●
±0.1
µA
O
t , t
Rise or Fall Time
Input to Output
Input to Output
R = 450Ω, C = 100pF (Figures 3, 7)
2
1
1
µs
µs
µs
r
f
PLH
PHL
L
L
t
t
R = 450Ω, C = 100pF (Figures 3, 7)
L L
R = 450Ω, C = 100pF (Figures 3, 7)
L
L
V.10 Receiver
V
Receiver Input Threshold Voltage
Receiver Input Hysteresis
Receiver Input Current
Receiver Input Impedance
Rise or Fall Time
●
●
●
●
–0.25
15
0.25
50
V
mV
mA
kΩ
ns
TH
∆V
25
TH
I
–10V ≤ V ≤ 10V
±0.66
IN
A
R
–10V ≤ V ≤ 10V
30
15
IN
A
t , t
C = 50pF (Figures 4, 8)
L
r
f
PLH
PHL
t
t
Input to Output
C = 50pF (Figures 4, 8)
L
55
ns
Input to Output
C = 50pF (Figures 4, 8)
L
109
60
ns
∆t
Input to Output Difference,
t
– t
PHL
C = 50pF (Figures 4, 8)
L
ns
PLH
V.28 Driver
V
Output Voltage
Open Circuit
R = 3k (Figure 3)
L
●
●
±10
V
V
O
±5
±8.5
±1
I
I
Short-Circuit Current
V = GND
O
●
●
±150
±100
mA
SS
OZ
Output Leakage Current
–0.25V ≤ V ≤ 0.25V, Power Off or
µA
O
No-Cable Mode or Driver Disabled
SR
Slew Rate
R = 3k, C = 2500pF (Figures 3, 7)
●
●
●
4
30
2.5
2.5
V/µs
µs
L
L
t
t
Input to Output
Input to Output
R = 3k, C = 2500pF (Figures 3, 7)
1.3
1.3
PLH
PHL
L
L
R = 3k, C = 2500pF (Figures 3, 7)
µs
L
L
V.28 Receiver
V
V
Input Low Threshold Voltage
●
●
●
●
0.8
V
V
THL
TLH
Input High Threshold Voltage
Receiver Input Hysterisis
Receiver Input Impedance
Rise or Fall Time
2
3
∆V
0.1
5
0.3
7
V
TH
R
–15V ≤ V ≤ 15V
kΩ
ns
ns
ns
IN
A
t , t
C = 50pF (Figures 4, 8)
L
15
60
150
r
f
PLH
PHL
t
t
Input to Output
C = 50pF (Figures 4, 8)
L
●
●
100
500
Input to Output
C = 50pF (Figures 4, 8)
L
sn2844 2844fs
4
LTC2844
ELECTRICAL CHARACTERISTICS
Note 1: Absolute Maximum Ratings are those values beyond which the life
Note 3: All typicals are given for V = 5V, V = 3.3V, V = 8V, V = –7V
CC IN DD EE
of a device may be impaired.
for V.28, –5.5V for V.10, V.11 and T = 25°C.
A
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.
U W
TYPICAL PERFOR A CE CHARACTERISTICS
RS530-A in DTE Mode
V.28 in DCE Mode
(Three V.28 Drivers with Full
Load) IDD vs Data Rate
RS530, X.21 in DCE Mode
(Three V.11 Drivers with Full
Load) ICC vs Data Rate
(Two V.10 Drivers with Full Load)
IEE vs Data Rate
26
24
22
20
18
16
14
125
120
115
110
105
100
95
10
9
T
= 25°C
T = 25°C
A
T
= 25°C
A
A
8
7
6
5
90
4
10
100
1000
10000
10
20
30 40 50 60 70 80 100
10
20
30 40 50 60 70 80 100
DATA RATE (kBd)
DATA RATE (kBd)
DATA RATE (kBd)
2844 G02
2844 G03
2844 G01
RS530-A in DTE Mode
(Two V.10 Drivers with Full Load)
IEE vs Temperature
V.28 in DCE Mode
(Three V.28 Drivers with Full
Load) IDD vs Temperature
RS530, X.21 in DCE Mode
(Three V.11 Drivers with Full
Load) ICC vs Temperature
105
100
95
23.5
25.4
25.3
25.2
25.1
25.0
24.9
24.8
24.7
24.6
24.5
8.20
8.15
8.10
8.05
8.00
7.95
7.90
7.85
7.80
90
85
80
–40 –20
0
20
40
60
80
100
–40 –20
0
20
40
60
80 100
–40 –20
0
20
40
60
80 100
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
2844 G04
2844 G05
2844 G06
sn2844 2844fs
5
LTC2844
U
U
U
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.
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.
V
DD (Pin 2): Positive Supply Voltage for V.28. Connect to
VDD Pin 7 on LTC2846 or 8V supply. Connect a 1µF
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.
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.
D3/R1 B (Pin 21): Receiver 1 Noninverting Input and
Driver 3 Noninverting Output.
R1 (Pin 6): CMOS Level Receiver 1 Output. Receiver
outputs have a weak pull up to VIN when high impedance.
D3/R1 A (Pin 22): Receiver 1 Inverting Input and Driver 3
Inverting 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.
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.
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.
V
EE (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
A
V
V
1
2
28 V
EE
CC
R
R
27 GND
26 D1A
L
DD
V
OD
D1
3
4
D1
D2
V
OC
L
D1B
25
2844 F01
B
24 D2A
D2
D3
Figure 1. V.11 Driver Test Circuit
D2B
23
25 D3/R1 A
5
D3
20k
20k
10k
6k
C
L
B
A
100pF
B
A
R
R
L
S3
100Ω
C
L
100pF
C
L
10k
21 D3/R1 B
20 R2A
R1
R2
6
7
R1
2844 F02
Figure 2. V.11 Driver/Receiver AC Test Circuit
20k
6k
S3
10k
R2
10k
20k
D
A
R2B
19
R
C
L
L
18 R3A
20k
10k
6k
S3
2844 F03
R3
D4
8
9
R3
Figure 3. V.10/V.28 Driver Test Circuit
10k
20k
R3B
17
D4
16 D4/R4 A
D
A
A
R
20k
C
L
10k
6k
R4 10
R4
S3
2844 F04
Figure 4. V.10/V.28 Receiver Test Circuit
M0 11
M1 12
M2 13
MODE
SELECTION
LOGIC
DCE/DTE
V
IN
14
15
2844 BD
sn2844 2844fs
7
LTC2844
W
U
ODE SELECTIO
(Note 1) (Note 1) (Note 1)
MODE NAME
M2
M1
M0
DCE
/DTE
D1
D2
D3
D4
D1
D2
D3
D4A
A
B
A
B
A
B
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
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
X.21
V.35
RS449/V.36
V.28/RS232
No Cable
Note 1: Driver inputs are TTL level compatible.
(Note 2)
R1
(Note 2)
R2
(Note 2)
R3
(Note 2) (Note 3) (Note 3) (Note 3)
MODE NAME
M2
M1
M0
DCE
/DTE
R4A
R1
R2
R3
R4
A
B
A
B
A
B
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
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 CMOS
CMOS CMOS
CMOS CMOS
CMOS CMOS
Z
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 CMOS
CMOS CMOS
CMOS CMOS
CMOS CMOS
X.21
V.35
RS449/V.36
V.28/RS232
No Cable
Z
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 V when Z.
IN
sn2844 2844fs
8
LTC2844
U
W
W
SWITCHI G TI E WAVEFOR S
3V
f = 1MHz : t ≤ 10ns : t ≤ 10ns
r
f
1.5V
1.5V
D
0V
t
t
PHL
PLH
V
O
90%
90%
10%
V
= V(A) – V(B)
DIFF
B – A
50%
50%
10%
–V
O
1/2 V
O
t
t
f
r
A
V
O
B
t
t
2844 F05
SKEW
SKEW
Figure 5. V.11, V.35 Driver Propagation Delays
V
B – A
OD2
f = 1MHz : t ≤ 10ns : t ≤ 10ns
INPUT
r
f
0V
t
0V
–V
OD2
t
PLH
PHL
V
R
OH
OUTPUT
1.65V
1.65V
V
OL
2844 F06
Figure 6. V.11, V.35 Receiver Propagation Delays
3V
0V
D
A
1.5V
t
1.5V
PHL
3V
t
PLH
V
O
3V
2844 F07
0V
0V
–3V
–3V
–V
O
t
t
r
f
Figure 7. V.10, V.28 Driver Propagation Delays
V
IH
RECEIVER THRESHOLD
A
RECEIVER THRESHOLD
V
IL
t
PHL
t
PLH
V
OH
1.65V
1.65V
R
2844 F08
V
OL
Figure 8. V.10, V.28 Receiver Propagation Delays
sn2844 2844fs
9
LTC2844
U
W U U
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 soft-
ware-selectable DTE or DCE interface port that supports
the RS232, RS449, EIA530, EIA530-A, V.35, V.36 or X.21
protocols.
DTE
DCE
SERIAL
CONTROLLER
LTC2846
LTC2846
SERIAL
CONTROLLER
103Ω
103Ω
R3
D1
D2
D3
TXD
TXD
TXD
SCTE
R2
R1
SCTE
SCTE
D3
TXC
RXC
RXD
R1
103Ω
103Ω
103Ω
TXC
RXC
RXD
TXC
RXC
R2
R3
D2
D1
RXD
LTC2844
R3
LTC2844
D1
RTS
DTR
RTS
DTR
RTS
DTR
D2
D3
R2
R1
D3
DCD
DSR
R1
R2
R3
DCD
DSR
DCD
DSR
D2
D1
CTS
LL
CTS
LL
CTS
LL
D4
R4
R4
D4
2844 F09
Figure 9. Complete Multiprotocol Interface in EIA530 Mode
sn2844 2844fs
10
LTC2844
U
W U U
APPLICATIONS INFORMATION
Mode Selection
The interface protocol may be selected simply by plug-
ging 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 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
operateinV.28(RS232)electricalmode. Fortheclockand
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 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)
15
M0
16
LTC2846
M1
M2
18
19
NC
DCE/DTE
NC
CABLE
LTC2844
14
13
12
11
DCE/DTE
M2
M1
M0
2844 F10
(DATA)
Figure 10. Single Port DCE V.35 Mode Selection in the Cable
sn2844 2844fs
11
LTC2844
U
W U U
APPLICATIONS INFORMATION
The V.10 receiver configuration in the LTC2844 is shown
in Figure 13. In V.10 mode switch S3 inside the LTC2844
isturnedoff.Thenoninvertinginputisdisconnectedinside
the LTC2844 receiver and connected to ground. The cable
termination is then the 30k input impedance to ground of
the LTC2844 V.10 receiver.
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
withtheterminationinthecableheadorseparatetermina-
tions 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.
I
Z
3.25mA
Using the LTC2846/LTC2844 solves the cable termination
switching problem. Via software control, appropriate ter-
minationfortheV.10(RS423),V.11(RS422),V.28(RS232)
and V.35 electrical protocols is chosen.
–10V
–3V
V
Z
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
2844 F12
–3.25mA
connected to a differential receiver with inputs A
' con-
nected 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.
Figure 12. V.10 Receiver Input Impedance
A
'
LTC2844
R5
20k
BALANCED
R8
6k
INTERCONNECTING
CABLE
LOAD
GENERATOR
R6
10k
RECEIVER
CABLE
TERMINATION
S3
RECEIVER
A
A'
R7
10k
R4
20k
B
'
2844 F11
2844 F13
C
'
C
C'
GND
Figure 13. V.10 Receiver Configuration
Figure 11. Typical V.10 Interface
sn2844 2844fs
12
LTC2844
U
W U U
APPLICATIONS INFORMATION
V.11 (RS422) Interface
V.28 (RS232) Interface
A typical V.11 balanced interface is shown in Figure 14. A A typical V.28 unbalanced interface is shown in Figure 16.
V.11 differential generator with outputs A and B with A V.28 single-ended generator output A with ground C is
ground C is connected to a differential receiver with connected to a single-ended receiver with input A
'
con-
groundC',inputsA'connectedtoA,B'connectedtoB.The nected to A, ground C' connected via the signal return
V.11 interface has a differential termination at the receiver ground C.
end that has a minimum value of 100Ω. The termination
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
resistor is optional in the V.11 specification, but for the
highspeedclockanddatalines,theterminationisrequired
to prevent reflections from corrupting the data. The
receiver inputs must also be compliant with the imped-
ance curve shown in Figure 12.
In V.11 mode, all switches are off except S1 of the voltage for a 1.4V receiver trip point.
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
terminationotherthanitsV.11receivers’30kinputimped-
ance is necessary.
A'
LTC2846
BALANCED
INTERCONNECTING
CABLE
R5
20k
R1
R8
6k
LOAD
51.5Ω
GENERATOR
R6
10k
RECEIVER
CABLE
TERMINATION
RECEIVER
S1
S2
S3
R3
124Ω
A
A'
R7
10k
R2
51.5Ω
R4
20k
100Ω
MIN
B'
B
C
B'
C'
C'
2844 F15
2844 F14
GND
Figure 15. V.11 Receiver Configuration
Figure 14. Typical V.11 Interface
A'
LTC2844
BALANCED
INTERCONNECTING
CABLE
R5
20k
R8
6k
LOAD
GENERATOR
R6
10k
RECEIVER
CABLE
S3
TERMINATION
RECEIVER
A
A'
R7
10k
R4
20k
B'
C'
2844 F16
2844 F17
C
C'
GND
Figure 16. Typical V.28 Interface
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
U
W U U
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
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.
groundC',inputsA'connectedtoA,B'connectedtoB.The
V.35 interface requires a T or delta network termination at
the receiver end and the generator end. The receiver
differentialimpedancemeasuredattheconnectormustbe
100Ω ±10Ω, and the impedance between shorted termi-
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
generatesabout–7.5VforVEE.Three1µFsurfacemounted
tantalumorceramiccapacitorsarerequiredforC1, C2and
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.
nals (A' and B') and ground C' must be 150Ω ±15Ω.
InV.35mode,bothswitchesS1andS2insidetheLTC2846
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.
The LTC2846 has an internal boost switching regulator
which generates a 5V output from the 3.3V supply as
showninFigure22.The5VVCC suppliesitsinternalcharge
pump and transceivers as well as its companion chip.
BALANCED
A
'
LTC2846
INTERCONNECTING
CABLE
GENERATOR
LOAD
R5
R1
R8
6k
20k
CABLE
TERMINATION
51.5Ω
RECEIVER
R6
RECEIVER
10k
A
'
A
S1
S2
S3
R3
124Ω
50Ω
50Ω
125Ω
125Ω
R7
10k
R2
51.5Ω
R4
20k
50Ω
50Ω
B
'
B'
B
C
2844 F19
GND
C'
C
'
2844 F18
Figure 19. V.35 Receiver Configuration
Figure 18. Typical V.35 Interface
A
7
6
5
8
33
32
31
30
LTC2846
+
–
V
C2
C2
DD
+
C2
C3
1µF
51.5Ω
1µF
C1
C1
V
C1
1µF
LTC2846
S1
V.35 DRIVER
–
124Ω
S2
V
EE
C4
3.3µF
+
51.5Ω
GND
5V
CC
C5
10µF
B
2844 F21
C
2844 F20
Figure 21. Charge Pump
Figure 20. V.35 Driver
sn2844 2844fs
14
LTC2844
U
W U U
APPLICATIONS INFORMATION
L1
mode,theTXDsignalisroutedtoPins2and14viaDriver 1
intheLTC2846.InDCEmode,Driver1nowroutestheRXD
signal to Pins 2 and 14.
D1
5.6µH
V
CC
V
IN
5V
3.3V
480mA
3
36
SW
V
R1
13k
C6
IN
BOOST
10µF
Multiprotocol Interface with RL, LL, TM and a DB-25
Connector
SWITCHING
REGULATOR
C5
10µF
35
4
SHDN
SHDN
FB
R2
4.3k
GND
2, 34
IftheRL,LLandTMsignalsareimplemented,therearenot
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-endeddriver/receiverpairthatcanhandletwomore
optional control signals such as TM and LL.
C1,C2: TAIYO YUDEN X5R JMK316BJ106ML
D1: ON SEMICONDUCTOR MBR0520
L1: SUMIDA CR43-5R6
2844 F22
Figure 22. Boost Switching Regulator
Receiver Fail-Safe
Cable-Selectable Multiprotocol Interface
All LTC2846/LTC2844 receivers feature fail-safe opera-
tion 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.
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 (con-
nector 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.
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
operationbyreroutingthesignalstotheLTC2846/LTC2844
using a dedicated DTE cable or dedicated DCE cable.
Compliance Testing
The LTC2846/LTC2844 chipset has been tested by TUV
Rheinland of North America Inc. and passed the NET1,
NET2andTBR2requirements.Copiesofthetestreportare
availablefromLTCorTUVRheinlandofNorthAmericaInc.
A dedicated DTE port using a DB-25 male connector is
showninFigure23.Theinterfacemodeisselectedbylogic
outputs from the controller or from jumpers to either VIN
or GND on the mode select pins.
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
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
sn2844 2844fs
15
LTC2844
U
TYPICAL APPLICATIO S
D1
MBR0520
L1
5.6µH
V
V
CC
5V
IN
3.3V
3
36
C6
R1
10µF
13k
BOOST
SWITCHING
REGULATOR
4
7
5
35
33
C5
10µF
SHDN
R2
4.3k
C2
C3
1µF
1µF
32
31
C1
1µF
CHARGE
PUMP
6
8
C4
V
CC
5V
+
3.3µF
30
29
LTC2846
2
TXD A (103)
9
TXD
D1
D2
D3
T
T
T
14
24
28
27
TXD B
SCTE A (113)
10
11
SCTE
11
26
SCTE B
25
15
TXC A (114)
12
13
14
TXC
RXC
RXD
R1
R2
R3
24
23
12
17
TXC B
RXC A (115)
T
T
22
21
9
3
RXC B
RXD A (104)
16
7
20
15
16
18
19
RXD B
SG
M0
M1
M2
17
1
V
IN
SHIELD
DCE/DTE
3.3V
C7
1µF
C8
1µF
DB-25 MALE
CONNECTOR
28
27
1
2
V
V
EE
GND
CC
C9
1µF
V
DD
26
4
RTS A (105)
RTS B
3
4
5
RTS
D1
D2
D3
25
24
23
19
20
23
DTR A (108)
DTR B
DTR
LTC2844
8
10
6
22
21
20
19
6
7
8
DCD A (109)
DCD B
R1
R2
R3
R4
DCD
DSR
CTS
LL
DSR A (107)
22
DSR B
5
18
17
CTS A (106)
CTS B
13
10
9
16
18
LL A (141)
D4
11
12
13
14
15
V
IN
3.3V
M0
M1
M2
M0
M1
M2
V
IN
C10
1µF
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
V
V
IN
3.3V
CC
5V
3
36
C6
R1
10µF
13k
BOOST
SWITCHING
REGULATOR
4
7
5
35
33
C5
10µF
SHDN
R2
4.3k
C2
C3
1µF
1µF
32
31
C1
1µF
CHARGE
PUMP
6
8
C4
V
CC
+
3.3µF
30
29
5V
DTE
DCE
LTC2846
2
TXD A
RXD A
9
DTE_TXD/DCE_RXD
DTE_SCTE/DCE_RXC
D1
D2
D3
T
T
T
14
24
28
27
TXD B
RXD B
SCTE A RXC A
10
11
11
26
SCTE B RXC B
15
25
TXC A
TXC A
12
13
14
DTE_TXC/DCE_TXC
DTE_RXC/DCE_SCTE
DTE_RXD/DCE_TXD
R1
R2
R3
12
17
24
23
TXC B
TXC B
RXC A
SCTE A
T
T
22
21
9
3
SCTE B
TXD A
RXC B
RXD A
16
7
20
TXD B
RXD B
SG
15
16
18
19
M0
M1
M2
17
1
V
IN
3.3V
SHIELD
DCE/DTE
C7
1µF
C8
1µF
DB-25
CONNECTOR
28
27
1
2
V
V
EE
GND
CC
C9
1µF
V
DD
26
4
RTS A
CTS A
3
4
5
DTE_RTS/DCE_CTS
DTE_DTR/DCE_DSR
D1
D2
D3
25
24
23
19
20
RTS B
DTR A
DTR B
CTS B
DSR A
DSR B
23
LTC2844
8
10
6
22
21
20
19
DCD A
DCD B
DSR A
DCD A
DCD B
DTR A
6
7
8
DTE_DCD/DCE_DCD
DTE_DSR/DCE_DTR
DTE_CTS/DCE_RTS
DTE_LL/DCE_LL
R1
R2
R3
R4
22
DSR B
CTS A
CTS B
DTR B
RTS A
RTS B
5
18
17
13
10
9
16
18
LL A
LL A
D4
11
12
13
14
15
V
IN
3.3V
M0
M1
M0
M1
M2
V
IN
C10
1µF
M2
DCE/DTE
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
V
V
CC
5V
IN
3.3V
3
36
C6
R1
10µF
13k
BOOST
SWITCHING
REGULATOR
4
7
5
35
33
C5
10µF
SHDN
R2
4.3k
C2
C3
1µF
1µF
32
31
C1
1µF
CHARGE
PUMP
6
8
C4
V
+
3.3µF
CC
30
29
5V
LTC2846
DTE
TXD A
DCE
RXD A
2
9
DTE_TXD/DCE_RXD
DTE_SCTE/DCE_RXC
D1
D2
D3
T
T
T
14
24
28
27
TXD B
RXD B
SCTE A RXC A
10
11
26
11
SCTE B RXC B
15
25
TXC A
TXC B
RXC A
TXC A
TXC B
SCTE A
12
13
14
DTE_TXC/DCE_TXC
DTE_RXC/DCE_SCTE
DTE_RXD/DCE_TXD
R1
R2
R3
12
17
24
23
T
T
9
3
22
21
RXC B
RXD A
SCTE B
TXD A
20
16
7
RXD B
SG
TXD B
15
16
18
19
M0
M1
M2
1
SHIELD
17
V
IN
3.3V
DCE/DTE
C7
1µF
C8
1µF
36
35
DB-25
CONNECTOR
1, 19
2
V
V
EE
GND
CC
C9
1µF
V
DD
34
4
19
20
RTS A
CTS A
CTS B
DSR A
DSR B
3
4
5
DTE_RTS/DCE_CTS
DTE_DTR/DCE_DSR
D1
D2
D3
33
32
RTS B
DTR A
DTR B
23
31
LTC2845
8
30
29
28
27
DCD A
DCD B
DSR A
DCD A
DCD B
DTR A
6
7
R1
R2
R3
10
DTE_DCD/DCE_DCD
DTE_DSR/DCE_DTR
6
22
DSR B
CTS A
DTR B
RTS A
5
13
18
26
8
9
DTE_CTS/DCE_RTS
DTE_LL/DCE_RI
DTE_RI/DCE_LL
25
24
CTS B
LL
RTS B
RI
D4
R4
10
23
*
RI
LL
25
21
17
18
22
21
DTE_TM/DCE_RL
DTE_RL/DCE_TM
R5
TM
RL
RL
TM
D5
11
12
13
14
20
15
V
IN
M0
M1
M0
M1
M2
V
IN
3.3V
*OPTIONAL
C10
1µF
D4ENB
2844 F26
M2
16
NC
DCE/DTE
R4EN
DCE/DTE
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
L1
MBR0520
5.6µH
V
V
IN
3.3V
CC
5V
3
36
C6
R1
10µF
13k
BOOST
SWITCHING
REGULATOR
4
7
5
35
33
C5
10µF
SHDN
R2
4.3k
C2
1µF
C3
32
31
1µF
C1
1µF
CHARGE
PUMP
6
8
C4
V
+
3.3µF
CC
30
29
5V
DTE
DCE
LTC2846
2
TXD A
RXD A
9
DTE_TXD/DCE_RXD
DTE_SCTE/DCE_RXC
D1
D2
D3
T
T
T
14
24
28
27
TXD B
RXD B
RXC A
SCTE A
10
11
11
26
SCTE B
RXC B
25
15
TXC A
TXC A
12
13
14
DTE_TXC/DCE_TXC
DTE_RXC/DCE_SCTE
DTE_RXD/DCE_TXD
R1
R2
R3
12
17
24
23
TXC B
RXC A
TXC B
SCTE A
T
T
9
3
22
21
SCTE B
TXD A
RXC B
RXD A
16
7
20
RXD B
SG
15
16
18
19
TXD B
M0
M1
M2
NC
1
17
V
IN
3.3V
SHIELD
DCE/DTE
DB-25
CONNECTOR
C7
C8
1µF
25
21
18
28
27
DCE/DTE
M1
M0
1µF
1
2
V
V
EE
GND
CC
C9
1µF
V
DD
26
4
RTS A
RTS B
DTR A
DTR B
CTS A
CTS B
DSR A
DSR B
3
4
5
DTE_RTS/DCE_CTS
DTE_DTR/DCE_DSR
D1
D2
D3
25
24
23
19
20
23
LTC2844
8
10
6
22
21
20
19
6
7
8
DCD A
DCD B
DSR A
DSR B
DCD A
DCD B
DTR A
DTR B
R1
R2
R3
R4
DTE_DCD/DCE_DCD
DTE_DSR/DCE_DTR
DTE_CTS/DCE_RTS
22
5
18
17
RTS A
RTS B
CTS A
CTS B
13
CABLE WIRING FOR MODE SELECTION
10
9
16
MODE
V.35
RS449, V.36
RS232
PIN 18
PIN 7
NC
PIN 21
PIN 7
PIN 7
NC
D4
11
12
13
14
15
PIN 7
V
IN
3.3V
M0
M1
M2
V
IN
C10
1µF
CABLE WIRING FOR
DTE/DCE SELECTION
NC
MODE
DTE
DCE
PIN 25
PIN 7
NC
DCE/DTE
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 represen-
tationthattheinterconnectionofitscircuitsasdescribedhereinwillnotinfringeonexistingpatentrights.
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)
1.25 ±0.12
28 27 26 25 24 23 22 21 20 19 18
16 15
17
7.8 – 8.2
5.3 – 5.7
7.40 – 8.20
(.291 – .323)
0.42 ±0.03
0.65 BSC
5
7
8
1
2
3
4
6
9 10 11 12 13 14
RECOMMENDED SOLDER PAD LAYOUT
5.00 – 5.60**
(.197 – .221)
2.0
(.079)
0° – 8°
0.65
(.0256)
BSC
0.09 – 0.25
0.55 – 0.95
(.0035 – .010)
(.022 – .037)
0.05
0.22 – 0.38
(.009 – .015)
(.002)
NOTE:
G28 SSOP 0802
1. CONTROLLING DIMENSION: MILLIMETERS
MILLIMETERS
2. DIMENSIONS ARE IN
(INCHES)
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
Two RS232 Driver/Receiver or Four RS232 Driver/Receiver Pairs
4-Driver/4-Receiver for Data and Clock Signals
LTC1334
Single 5V RS232/RS485 Multiprotocol Transceiver
Software-Selectable Multiprotocol Transceiver
Software-Selectable Cable Terminator
Single Supply V.35 Transceiver
LTC1343
LTC1344A
LTC1345
Perfect for Terminating the LTC1543 (Not Needed with LTC1546)
3-Driver/3-Receiver for Data and Clock Signals
LTC1346A
LTC1543
Dual Supply V.35 Transceiver
3-Driver/3-Receiver for Data and Clock Signals
Software-Selectable Multiprotocol Transceiver
Terminated with LTC1344A for Data and Clock Signals, Companion to
LTC1544 or LTC1545 for Control Signals
LTC1544
LTC1545
Software-Selectable Multiprotocol Transceiver
Software-Selectable Multiprotocol Transceiver
Companion to LTC1546 or LTC1543 for Control Signals Including LL
5-Driver/5-Receiver Companion to LTC1546 or LTC1543
for Control Signals Including LL, TM and RL
LTC1546
LTC2845
Software-Selectable Multiprotocol Transceiver
3-Driver/3-Receiver with Termination for Data and Clock Signals
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
LT/TP 0503 1K • PRINTED IN USA
LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
20
●
●
LINEAR TECHNOLOGY CORPORATION 2002
(408) 432-1900 FAX: (408) 434-0507 www.linear.com
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