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LTC1543 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 LTC1544, LTC1344A Operates from Single 5V Supply
The LTC(R)1543 is a 3-driver/3-receiver multiprotocol transceiver that operates from a single 5V supply. The LTC1543 and LTC1544 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 may be implemented using the LTC1344A software-selectable cable termination chip or by using existing discrete designs. The LTC1543 runs from a single 5V supply using an internal charge pump that requires only five space-saving surface mounted capacitors. The part is available in a 28-lead SSOP surface mount package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
APPLICATIO S
s s s
Data Networking CSU and DSU Data Routers
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
CTS B CTS A (106)
10 8
DSR B DSR A (109)
22 6
DCD B DCD A (107)
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
1543 TA01
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U
1
LTC1543
ABSOLUTE MAXIMUM RATINGS
(Note 1)
PACKAGE/ORDER INFORMATION
TOP VIEW C1- C1+ VDD VCC D1 D2 D3 R1 R2 1 2 3 4 5 D1 6 7 8 9 R1 R2 R3 D2 D3 23 D1 B 22 D2 A 21 D2 B 20 D3/R1 A 19 D3/R1 B 18 R2 A 17 R2 B 16 R3 A 15 R3 B G PACKAGE 28-LEAD PLASTIC SSOP CHARGE PUMP 28 C2
+
Supply Voltage ....................................................... 6.5V 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 (VCC + 0.3V) Logic Pins .............................. - 0.3V to (VCC + 0.3V) VEE ........................................................ - 10V to 0.3V VDD ....................................................... - 0.3V to 10V Short-Circuit Duration Transmitter Output ..................................... Indefinite Receiver Output .......................................... Indefinite VEE .................................................................. 30 sec Operating Temperature Range LTC1543C .............................................. 0C to 70C LTC1543I ........................................... - 40C to 85C Storage Temperature Range ................ - 65C to 150C Lead Temperature (Soldering, 10 sec)................. 300C
ORDER PART NUMBER LTC1543CG LTC1543IG
27 C2 - 26 VEE 25 GND 24 D1 A
R3 10 M0 11 M1 12 M2 13 DCE/DTE 14
TJMAX = 150C, JA = 65C/ W
Consult factory for Military grade parts.
ELECTRICAL CHARACTERISTICS
SYMBOL Supplies ICC VCC Supply Current (DCE Mode, All Digital Pins = GND or VCC) PARAMETER
VCC = 5V (Notes 2, 3)
MIN TYP 13 100 20 126 20 40 120 230 600 140
q q
CONDITIONS RS530, RS530-A, X.21 Modes, No Load RS530, RS530-A, X.21 Modes, Full Load V.35 Mode, No Load V.35 Mode, Full Load V.28 Mode, No Load V.28 Mode, Full Load No-Cable Mode RS530, RS530-A, X.21 Modes, Full Load V.35 Mode, Full Load V.28 Mode, Full Load Any Mode, No Load V.28 Mode, with Load V.28 Mode, with Load, IDD = 10mA V.28, V.35 Modes, No Load V.28 Mode, Full Load V.35 Mode, Full Load RS530, RS530-A, X.21 Modes, Full Load No-Cable Mode or Power-Up to Turn On
q q
MAX
UNITS mA mA mA mA mA mA A mW mW mW V V V V V V V kHz ms V
q q q q
130 170 75 500
PD
Internal Power Dissipation (DCE Mode)
V+
Positive Charge Pump Output Voltage
8.0 8.0
9.4 8.7 6.5 - 9.6 - 8.5 - 6.7 - 5.7 150 2
V-
Negative Charge Pump Output Voltage
q q q
- 8.0 - 5.5 - 4.5
fOSC tr VIH VIL
Charge Pump Oscillator Frequency Supply Rise Time Logic Input High Voltage Logic Input Low Voltage
Logic Inputs and Outputs 2 0.8 V
2
U
W
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U
WW
W
LTC1543
ELECTRICAL CHARACTERISTICS
SYMBOL IIN PARAMETER Logic Input Current
VCC = 5V (Notes 2, 3)
MIN
q q q q q q q
CONDITIONS D1, D2, D3 M0, M1, M2, DCE = GND (LTC1543C) M0, M1, M2, DCE = GND (LTC1543I) M0, M1, M2, DCE = VCC IO = - 4mA IO = 4mA 0V VO VCC M0 = M1 = M2 = VCC, 0V VO VCC RL = 1.95k (Figure 1) RL = 50 (Figure 1) RL = 50 (Figure 1) RL = 50 (Figure 1) RL = 50 (Figure 1) RL = 50 (Figure 1) VOUT = GND - 0.25V VO 0.25V, Power Off or No-Cable Mode or Driver Disabled (Figures 2, 6) (LTC1543C) (Figures 2, 6) (LTC1543I) (Figures 2, 6) (LTC1543C) (Figures 2, 6) (LTC1543I) (Figures 2, 6) (LTC1543C) (Figures 2, 6) (LTC1543I) (Figures 2, 6) (LTC1543C) (Figures 2, 6) (LTC1543I) (Figures 2, 6) - 7V VCM 7V - 7V VCM 7V - 10V VA,B 10V - 10V VA,B 10V (Figures 2, 7) (Figures 2, 7) (LTC1543C) (Figures 2, 7) (LTC1543I) (Figures 2, 7) (LTC1543C) (Figures 2, 7) (LTC1543I) (Figures 2, 7) (LTC1543C) (Figures 2, 7) (LTC1543I) Open Circuit With Load, - 4V VCM 4V (Figure 3) VA, B = 0V VA, B = 0V - 0.25V VA, B 0.25V
q q q q q q q q q q q q q q q q q q q q q q q q
TYP - 50 - 50 4.5 0.3
MAX 10 - 30 - 30 10 0.8 50
UNITS A A A A V V mA A
- 100 - 120 3 - 50
VOH VOL IOSR IOZR V.11 Driver VODO VODL VOD VOC VOC ISS IOZ t r, t f t PLH t PHL t t SKEW VTH VTH IIN RIN t r, t f t PLH t PHL t V.35 Driver VOD IOH IOL IOZ
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, tPLH - tPHL 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, tPLH - tPHL
1 5 0.5VODO 2 0.67VODO 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 10.00 0.66 - 9.0 13 100 0.2 40 0.66 100 25 35 65 75 65 75 12 17
V V V V V V mA A ns ns ns ns ns ns ns ns ns V mV mA k ns ns ns ns ns ns ns V V mA mA A
V.11 Receiver
Differential Output Voltage Transmitter Output High Current Transmitter Output Low Current Transmitter Output Leakage Current
q q q q q
0.44 - 13 9.0
0.55 - 11 11 1
3
LTC1543
ELECTRICAL CHARACTERISTICS
SYMBOL t r , tf t PLH t PHL t t SKEW VTH VTH IIN RIN t r, t f tPLH tPHL t V.28 Driver VO ISS IOZ SR t PLH t PHL VTHL VTLH VTH RIN t r , tf tPLH tPHL 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 Hysteresis Receiver Input Impedance Rise or Fall Time Input to Output Input to Output - 15V VA 15V (Figures 5, 9) (Figures 5, 9) (Figures 5, 9)
q q
VCC = 5V (Notes 2, 3)
MIN
q q q q q q
PARAMETER Rise or Fall Time Input to Output Input to Output Input to Output Difference, tPLH - tPHL Output to Output Skew Differential Receiver Input Threshold Voltage Receiver Input Hysteresis Receiver Input Current (A, B) Receiver Input Impedance Rise or Fall Time Input to Output Input to Output Input to Output Difference, tPLH - tPHL
CONDITIONS (Figures 3, 6) (Figures 3, 6) (LTC1543C) (Figures 3, 6) (LTC1543I) (Figures 3, 6) (LTC1543C) (Figures 3, 6) (LTC1543I) (Figures 3, 6) (LTC1543C) (Figures 3, 6) (LTC1543I) (Figures 3, 6) - 2V (VA + VB)/2 2V (Figure 3) - 2V (VA + VB)/2 2V (Figure 3) - 10V VA,B 10V - 10V VA,B 10V (Figures 3, 7) (Figures 3, 7) (LTC1543C) (Figures 3, 7) (LTC1543I) (Figures 3, 7) (LTC1543C) (Figures 3, 7) (LTC1543I) (Figures 3, 7) (LTC1543C) (Figures 3, 7) (LTC1543I) Open Circuit RL = 3k (Figure 4) VOUT = GND - 0.25V VO 0.25V, Power Off or No-Cable Mode or Driver Disabled RL = 3k, CL = 2500pF (Figures 4, 8) RL = 3k, CL = 2500pF (Figures 4, 8) RL = 3k, CL = 2500pF (Figures 4, 8)
q q q q q q q q q q
TYP 5 35 35 35 35 4 4 4
MAX 65 75 65 75 16 21
UNITS ns ns ns ns ns ns ns ns
20 20 20 20 0 0
V.35 Receiver - 0.2 15 15 30 15 50 50 50 50 0 0 4 4 80 90 80 90 16 21 10 150 1 4 1.5 1.5 1.2 2 0 3 1.2 0.05 5 15 60 160 100 250 0.3 7 100 30 2.5 3 0.8 0.2 40 0.66 V mV mA k ns ns ns ns ns ns ns V V mA A V/s s s V V V k ns ns ns
q q q q q q q
5
8.5
V.28 Receiver
q q q q
The q denotes specifications which apply over the full operating temperature range. 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 VCC = 5V, C1 = C2 = CVCC = 1F, CVDD = CVEE = 3.3F tantalum capacitors and TA = 25C.
4
LTC1543
PIN FUNCTIONS
C1 - (Pin 1): Capacitor C1 Negative Terminal. Connect a 1F capacitor between C1+ and C1-. C1 + (Pin 2): Capacitor C1 Positive Terminal. Connect a 1F capacitor between C1 + and C1 -. VDD (Pin 3): Generated Positive Supply Voltage for V.28. Connect a 1F capacitor to ground. VCC (Pin 4): Positive Supply Voltage Input. 4.75V VCC 5.25V. Bypass with a 1F capacitor to ground. D1 (Pin 5): TTL Level Driver 1 Input. D2 (Pin 6): TTL Level Driver 2 Input. D3 (Pin 7): TTL Level Driver 3 Input. R1 (Pin 8): CMOS Level Receiver 1 Output. R2 (Pin 9): CMOS Level Receiver 2 Output. R3 (Pin 10): CMOS Level Receiver 3 Output. M0 (Pin 11): TTL Level Mode Select Input 0 with Pull-Up to VCC. M1 (Pin 12): TTL Level Mode Select Input 1 with Pull-Up to VCC. M2 (Pin 13): TTL Level Mode Select Input 2 with Pull-Up to VCC. DCE/DTE (Pin 14): TTL Level Mode Select Input with PullUp to VCC. R3 B (Pin 15): Receiver 3 Noninverting Input with Pull-Up to VCC. R3 A (Pin 16): Receiver 3 Inverting Input. R2 B (Pin 17): Receiver 2 Noninverting Input. R2 A (Pin 18): Receiver 2 Inverting Input. D3/R1 B (Pin 19): Receiver 1 Noninverting Input and Driver 3 Noninverting Output. D3/R1 A (Pin 20): Receiver 1 Inverting Input and Driver 3 Inverting Output. D2 B (Pin 21): Driver 2 Noninverting Output. D2 A (Pin 22): Driver 2 Inverting Output. D1 B (Pin 23): Driver 1 Noninverting Output. D1 A (Pin 24): Driver 1 Inverting Output. GND (Pin 25): Ground. VEE (Pin 26): Negative Supply Voltage. Connect a 3.3F capacitor to GND. C2 - (Pin 27): Capacitor C2 Negative Terminal. Connect a 1F capacitor between C2 + and C2 -. C2 + (Pin 28): Capacitor C2 Positive Terminal. Connect a 1F capacitor between C2 + and C2 - .
TEST CIRCUITS
A RL 50 VOD RL 50 B VOC
CL 100pF CL 100pF
Figure 1. V.11 Driver Test Circuit
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B A
RL 100
B A
R
15pF
1543 F01
1543 F02
Figure 2. V.11 Driver/Receiver AC Test Circuit
5
LTC1543
TEST CIRCUITS
50 D B VOD A 50 50 A 15pF
1543 F03
125
VCM
50 125 B R
Figure 3. V.35 Driver/Receiver Test Circuit
D A
D A A R 15pF
1543 F04
CL
RL
1543 F04
Figure 4. V.10/V.28 Driver Test Circuit
Figure 5. V.10/V.28 Receiver Test Circuit
ODE SELECTIO
LTC1543 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 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1
6
U
M1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 M0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 DCE/DTE 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 D1 V.11 V.11 V.11 V.11 V.35 V.11 V.28 Z V.11 V.11 V.11 V.11 V.35 V.11 V.28 Z D2 V.11 V.11 V.11 V.11 V.35 V.11 V.28 Z V.11 V.11 V.11 V.11 V.35 V.11 V.28 Z D3 Z Z Z Z Z Z Z Z V.11 V.11 V.11 V.11 V.35 V.11 V.28 Z R1 V.11 V.11 V.11 V.11 V.35 V.11 V.28 Z Z Z Z Z Z Z Z Z R2 V.11 V.11 V.11 V.11 V.35 V.11 V.28 Z V.11 V.11 V.11 V.11 V.35 V.11 V.28 Z R3 V.11 V.11 V.11 V.11 V.35 V.11 V.28 Z V.11 V.11 V.11 V.11 V.35 V.11 V.28 Z
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LTC1543
SWITCHI G TI E WAVEFOR S
5V D 0V VO B-A -VO A VO B t SKEW t SKEW
1543 F06
1.5V t PLH 50% tr 90% 10%
f = 1MHz : t r 10ns : t f 10ns
1/2 VO
Figure 6. V.11, V.35 Driver Propagation Delays
VOD2 B-A -VOD2 VOH R VOL
0V t PLH 1.5V
f = 1MHz : t r 10ns : t f 10ns
Figure 7. V.11, V.35 Receiver Propagation Delays
3V D 0V VO A -VO tf 1.5V t PHL 3V 0V -3V -3V tr 0V 1.5V t PLH 3V
1543 F08
Figure 8. V.10, V.28 Driver Propagation Delays
VIH A VIL VOH R VOL 1.3V t PHL 1.7V t PLH 2.4V 0.8V
1543 F09
Figure 9. V.10, V.28 Receiver Propagation Delays
W
W
U
1.5V t PHL
VDIFF = V(A) - V(B)
90% tf
50%
10%
INPUT
0V t PHL
OUTPUT
1.5V
1543 F07
7
LTC1543
APPLICATIONS INFORMATION
Overview The LTC1543/LTC1544 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 may be implemented using the LTC1344A software-selectable cable termination chip or by using existing discrete designs. A complete DCE-to-DTE interface operating in EIA530 mode is shown in Figure 10. The LTC1543 of each port is used to generate the clock and data signals. The LTC1544 is used to generate the control signals along with LL (Local Loopback).The LTC1344A cable termination chip is used only for the clock and data signals because they must support V.35 cable termination. The control signals do not need any external resistors. 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 11. The internal pull-up current sources will ensure a binary 1 when a pin is left unconnected and that the LTC1543/ LTC1544 and the LTC1344A enter the no-cable mode when the cable is removed. In the no-cable mode the LTC1543/LTC1544 supply current drops to less than 200A and all LTC1543/LTC1544 driver outputs and LTC1344A resistive terminations 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 VCC. Cable Termination Traditional implementations have included switching resistors with expensive relays, or requiring 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 terminations 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. Using the LTC1344A along with the LTC1543/LTC1544 solves the cable termination switching problem. Via software control, the LTC1344A provides termination for the V.10 (RS423), V.11 (RS422), V.28 (RS232) and V.35 electrical protocols. V.10 (RS423) Interface A typical V.10 unbalanced interface is shown in Figure 12. 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 13. The V.10 receiver configuration in the LTC1544 is shown in Figure 14. In V.10 mode switch S3 inside the LTC1544 is turned off.The noninverting input is disconnected inside the LTC1544 receiver and connected to ground. The cable termination is then the 30k input impedance to ground of the LTC1544 V.10 receiver.
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LTC1543
APPLICATIONS INFORMATION
DTE
SERIAL CONTROLLER TXD LTC1543 D1 LTC1344A TXD LTC1344A 103
SCTE
D2
D3
TXC
R1
RXC
R2
RXD
R3
LTC1544 RTS D1 RTS
DTR
D2
D3
DCD
R1
DSR
R2
CTS
R3
LL
D4 R4
Figure 10. Complete Multiprotocol Interface in EIA530 Mode
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DCE
LTC1543 R3 SERIAL CONTROLLER TXD
SCTE
103
R2
SCTE
R1
103
TXC
D3
TXC
103
RXC
D2
RXC
103
RXD
D1
RXD
LTC1544 R3 RTS
DTR
R2
DTR
R1
DCD
D3
DCD
DSR
D2
DSR
CTS LL
D1
CTS
R4 D4
LL
1543 F10
9
LTC1543
APPLICATIONS INFORMATION
LATCH LTC1344A DCE/ DTE M2 22 (DATA) M0 LTC1543 M1 M2 DCE/DTE 11 12 13 14 23 M1 M0 (DATA) 24 1 CONNECTOR 21
LTC1544 DCE/DTE M2 M1 M0 (DATA) 14 13 12 11
1543 F11
Figure 11: Single Port DCE V.35 Mode Selection in the Cable
GENERATOR
Figure 12. Typical V.10 Interface
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A C
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NC NC CABLE
BALANCED INTERCONNECTING CABLE
LOAD CABLE TERMINATION A' RECEIVER
C'
1543 F12
LTC1543
APPLICATIONS INFORMATION
IZ 3.25mA A' A R8 6k S3 -10V -3V VZ 3V 10V B' C' B GND R4 20k R7 10k R5 20k R6 10k RECEIVER LTC1544
-3.25mA
Figure 13. V.10 Receiver Input Impedance
V.11 (RS422) Interface A typical V.11 balanced interface is shown in Figure 15. 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 100. 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 13. In V.11 mode, all switches are off except S1 inside the LTC1344A which connects a 103 differential termination impedance to the cable as shown in Figure 16.
GENERATOR
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1543 F14
1543 F13
Figure 14. V.10 Receiver Configuration
BALANCED INTERCONNECTING CABLE
LOAD CABLE TERMINATION RECEIVER
A
A' 100 MIN
B C
B' C'
1543 F15
Figure 15. Typical V.11 Interface
A' A R1 51.5 S1 S2 R2 51.5 B' C' GND
1543 F16
LTC1344A
R8 6k S3
R5 20k R6 10k
LTC1543 LTC1544
RECEIVER
R3 124
B
R4 20k
R7 10k
Figure 16. V.11 Receiver Configuration
11
LTC1543
APPLICATIONS INFORMATION
V.28 (RS232) Interface A typical V.28 unbalanced interface is shown in Figure 17. 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.28 mode all switches are off except S3 inside the LTC1543/LTC1544 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 18. The noninverting input is disconnected inside the LTC1543/ LTC1544 receiver and connected to a TTL level reference voltage for a 1.4V receiver trip point.
BALANCED INTERCONNECTING CABLE
GENERATOR
LOAD CABLE TERMINATION RECEIVER
A
A'
50 125
C
C'
Figure 17. Typical V.28 Interface
A' A R1 51.5 S1 S2 R2 51.5 B' C' GND
1543 F18
LTC1344A
R8 6k S3
R5 20k R6 10k
LTC1543 LTC1544
A' A LTC1543 R8 6k S3 R5 20k R6 10k RECEIVER
RECEIVER
R1 51.5 S1 S2 R2 51.5 B'
R3 124
B
R4 20k
R7 10k
Figure 18. V.28 Receiver Configuration
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V.35 Interface A typical V.35 balanced interface is shown in Figure 19. 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 100 10, and the impedance between shorted terminals (A' and B') and ground C' must be 150 15. In V.35 mode, both switches S1 and S2 inside the LTC1344A are on, connecting the T network impedance as shown in Figure 20. The switch in the LTC1543 is off. The 30k input
BALANCED INTERCONNECTING CABLE
GENERATOR
LOAD CABLE TERMINATION RECEIVER
A
A' 50
125
1543 F17
50 B C B' C'
50
1543 F19
Figure 19. Typical V.35 Interface
LTC1344A
R3 124
B GND
R4 20k
R7 10k
1543 F20
C'
Figure 20. V.35 Receiver Configuration
LTC1543
APPLICATIONS INFORMATION
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 50 to 150 and the impedance between shorted terminals (A and B) and ground C must be 150 15. For the generator termination, switches S1 and S2 are both on and the top side of the center resistor is brought out to a pin so it can be bypassed with an external capacitor to reduce common mode noise as shown in Figure 21. Any mismatch in the driver rise and fall times or skew in the driver propagation delays will force current through the center termination resistor to ground, causing a high frequency common mode spike on the A and B terminals. The common mode spike can cause EMI problems that are reduced by capacitor C1 which shunts much of the common mode energy to ground rather than down the cable.
A LTC1344A
51.5 S1 ON
V.35 DRIVER 124
S2 ON
51.5 B C1 100pF C
1543 F21
5V C4 1F
4
VCC
GND
25
Figure 22. Charge Pump
+
Figure 21. V.35 Driver Using the LTC1344A
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No-Cable Mode The no-cable mode (M0 = M1 = M2 = 1) is intended for the case when the cable is disconnected from the connector. The charge pump, 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 200A. Charge Pump The LTC1543 uses an internal capacitive charge pump to generate VDD and VEE as shown in Figure 22. A voltage doubler generates about 8V on VDD and a voltage inverter generates about - 7.5V for VEE. Four 1F surface mounted tantalum or ceramic capacitors are required for C1, C2, C3 and C4. The VEE capacitor C5 should be a minimum of 3.3F. All capacitors are 16V and should be placed as close as possible to the LTC1543 to reduce EMI. Receiver Fail-Safe All LTC1543/LTC1544 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.
3 C3 1F 2 C1 1F 1
VDD C1+ LTC1543 C1-
C2 + C2 - VEE
28 27 26 C5 3.3F C2 1F
1543 F22
13
LTC1543
APPLICATIONS INFORMATION
DTE vs DCE Operation The DCE/DTE pin acts as an enable for Driver 3/Receiver 1 in the LTC1543, and Driver 3/Receiver 1 and Driver 4/ Receiver 4 in the LTC1544. The INVERT pin in the LTC1544 allows the Driver 4/Receiver 4 enable to be high or low true polarity. The LTC1543/LTC1544 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 LTC1543/LTC1544 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 VCC or GND on the mode select pins. A dedicated DCE port using a DB-25 female connector is shown in Figure 24. A port with one DB-25 connector, but can be configured for either DTE or DCE operation is shown in Figure 25. 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 LTC1543. 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 LTC1543/ LTC1544. In Figure 26, the required control signals are handled by the LTC1544 but the clock/data signals use the LTC1343. The LTC1343 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 27. 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 VCC. The select bit M2 is hard wired to VCC. When the cable is pulled out, the interface will go into the no-cable mode. Compliance Testing A European standard EN 45001 test report is available for the LTC1543/LTC1544/LTC1344A chipset. A copy of the test report is available from LTC or TUV Telecom Services Inc. (formerly Detecon Inc.) The title of the report is: Test Report No. NET2/102201/97. The address of TUV Telecom Services Inc. is: TUV Telecom Services Inc. Type Approval Division 1775 Old Highway 8, Ste 107 St. Paul, MN 55112 USA Tel. +1 (612) 639-0775 Fax. +1 (612) 639-0873
14
U
W
U
U
LTC1543
TYPICAL APPLICATIONS
VCC 5V 14 3 C3 1F 1 C1 1F 2 4 C5 1F TXD SCTE 5 LTC1543 D1 D2 CHARGE PUMP 28 27 26 25 C4 3.3F C2 1F 2 C12 1F 5467 9 10 VEE
DCE/DTE M2 M1 M0
24 23 22 21
6 7
D3 20 15 12 17 9 3 16 7 1
TXC
8
R1
19 18
RXC RXD
9
R2
17 16
10 11 12 13 14 M0 M1 M2
R3
15
DCE/DTE
C10 1F
C9 1F
VCC 1 VCC 2 VDD 3 D1
VEE GND
28 27 26 C11 1F 4 19 20 23
RTS
25 24
DTR
4
D2
23
5
D3 LTC1544 22 21 20 R2 19 18 R3 17 16 8 10 6 22 5 13 18
DCD
6 7
R1
DSR
CTS
8 10 9 11 12 13 14 M0 M1 M2
LL
R4 D4 INVERT
15
NC
DCE/DTE
M2 M1 M0
Figure 23. Controller-Selectable Multiprotocol DTE Port with DB-25 Connector
+
U
C6 C7 C8 100pF 100pF 100pF
3
8
11
12
13 LTC1344A
C13 1F
VCC
LATCH
21
16 15 18 17 19 20 22 23 24 1 2 14 24 11 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 SHIELD
DB-25 MALE CONNECTOR
RTS A (105) RTS B DTR A (108) DTR B
DCD A (109) DCD B DSR A (107) DSR B CTS A (106) CTS B LL A (141)
1543 F23
15
LTC1543
TYPICAL APPLICATIONS
VCC 5V 14 3 C3 1F 1 C1 1F C5 1F RXD RXC 5 2 4 LTC1543 D1 D2 CHARGE PUMP 28 27 26 25 C2 1F 2 C4 3.3F C12 1F 5467 9 10 VEE C13 1F VCC LATCH 21
DCE/DTE
M2
M1
16 15 18 17 19 20 22 23 24 1 VCC 3 16 17 9 RXD A (104) RXD B RXC A (115) RXC B
24 23 22 21
6
7
D3 20 15 12 24 11 2 14 7 1
M0
TXC
8
R1
19 18
SCTE TXD
9
R2
17 16
10 11 12 13 NC 14 M0 M1 M2
R3
15
DCE/DTE
C10 1F
C9 1F
VCC 1 VCC 2 VDD 3 D1 VEE GND 28 27 26 C11 1F 5 13 6 22
CTS
25 24
DSR
4
D2
23
5
D3 LTC1544 22 21 20 R2 19 18 R3 17 16 8 10 20 23 4 19 18
DCD
6 7
R1
DTR
RTS
8 10 9 11 12 13 NC 14 M0 M1 M2
LL
R4 D4 INVERT
15
NC
DCE/DTE
M2 M1 M0
Figure 24. Controller-Selectable DCE Port with DB-25 Connector
16
+
U
C6 C7 C8 100pF 100pF 100pF
3
8
11
12
13 LTC1344A
TXC A (114) TXC B SCTE A (113) SCTE B TXD A (103) TXD B SGND (102) SHIELD (101)
DB-25 FEMALE CONNECTOR
CTS A (106) CTS B DSR A (107) DSR B
DCD A (109) DCD B DTR A (108) DTR B RTS A (105) RTS B LL A (141)
1543 F24
LTC1543
TYPICAL APPLICATIONS
VCC 5V 14 3 C3 1F 1 C1 1F 2 4 C5 1F DTE_TXD/DCE_RXD DTE_SCTE/DCE_RXC 5 LTC1543 D1 D2 CHARGE PUMP 28 27 26 25 C4 3.3F C2 1F 2 C12 1F 5467 9 10 VEE DCE/DTE M2 M1 M0 C13 1F VCC LATCH 21
24 23 22 21
6 7
D3 20 19 18 R2 17 16 R3 M0 M1 1 15 15 12 17 9 3 16 7
DTE_TXC/DCE_TXC
8
S
R1
S
DTE_RXC/DCE_SCTE
9
DTE_RXD/DCE_TXD
10 11 12
13 M2 14 DCE/DTE
C10 1F
C9 1F
VCC 1 VCC 2 VDD 3 D1 VEE GND 28 27 26 C11 1F 4 19 20 23
DTE_RTS/DCE_CTS
25 24
DTE_DTR/DCE_DSR
4
D2
23
5
D3 LTC1544 22 21 20 R2 19 18 R3 17 16 8 10 6 22 5 13 18
DTE_DCD/DCE_DCD DTE_DSR/DCE_DTR
6 7
R1
DTE_CTS/DCE_RTS
8 10 9 11 12 13 14 M0 M1 M2
DTE_LL/DCE_LL
R4 D4 INVERT
15
NC
DCE/DTE
DCE/DTE M2 M1 M0
Figure 25. Controller-Selectable Multiprotocol DTE/DCE Port with DB-25 Connector
+
U
C6 C7 C8 100pF 100pF 100pF
3
8
11
12
13 LTC1344A
16 15 18 17 19 20 22 23 24 1 2 14 24 11 DTE TXD A TXD B SCTE A SCTE B DCE RXD A RXD B RXC A RXC B
TXC A TXC B RXC A RXC B RXD A RXD B SG SHIELD
TXC A TXC B SCTE A SCTE B TXD A TXD B
DB-25 CONNECTOR
RTS A RTS B DTR A DTR B
CTS A CTS B DSR A DSR B
DCD A DCD B DSR A DSR B CTS A CTS B LL A
DCD A DCD B DTR A DTR B RTS A RTS B LL A
1543 F25
17
LTC1543
TYPICAL APPLICATIONS
VCC 5V 14 1 C3 1F 2 C1 1F 4 3 8 LTC1343 5 D1 D2 39 38 DTE_TXD/DCE_RXD 6 7 37 36 DTE_SCTE/DCE_RXC D3 35 34 9 10 12 13 D4 33 32 R1 31 30 R2 29 28 R3 27 26 DCE M2 M1 M0 EC 21 19 18 17 VCC 40 GND 24 LB 23 C9 1F VCC 1 VCC 2 VDD 3 D1 28 27 26 DTE_RTS/DCE_CTS 25 24 D2 23 C11 1F CHARGE PUMP 44 43 42 41 C4 3.3F C2 1F 2 C12 1F VEE C13 1F VCC
DCE/DTE
M2
M1
C5 1F DTE_LL/DCE_TM
5467
9 10
16 15 18 17 19 20 22 23 24 1 DTE LL A TXD A TXD B SCTE A SCTE B DCE TM A RXD A RXD B RXC A RXC B
M0 18 2 14 24 11 15 12 17 9 3 16 25 7 1
DTE_TXC/DCE_TXC
DTE_RXC/DCE_SCTE
14
DTE_RXD/DCE_TXD
15
DTE_TM/DCE_LL
16 20 22 11 25 R1 100k CTRL LATCH
R4
INVERT 423SET
LB C10 1F
VEE GND
DTE_DTR/DCE_DSR
4
5
D3 LTC1544 22 21 20 R2 19 18 R3 17 16 8 10 6 22 5 13 21
DTE_DCD/DCE_DCD DTE_DSR/DCE_DTR
6 7
R1
DTE_CTS/DCE_RTS
8 10 9 11 12 13 14 M0 M1 M2
DTE_RL/DCE_RL
R4 D4 INVERT
15
NC
DCE/DTE
DCE/DTE M2 M1 M0
Figure 26. Controller-Selectable Multiprotocol DTE/DCE Port with RL, LL, TM and DB-25 Connector
18
+
U
C6 C7 C8 100pF 100pF 100pF
3
8
11
12
13 LTC1344A
LATCH
21
TXC A TXC B RXC A RXC B RXD A RXD B TM A SG SHIELD
TXC A TXC B SCTE A SCTE B TXD A TXD B LL A
DB-25 CONNECTOR
4 19 20 23
RTS A RTS B DTR A DTR B
CTS A CTS B DSR A DSR B
DCD A DCD B DSR A DSR B CTS A CTS B RL A
DCD A DCD B DTR A DTR B RTS A RTS B RL A
1543 F26
LTC1543
TYPICAL APPLICATIONS
C6 C7 C8 100pF 100pF 100pF 3 VCC 5V 14 3 C3 1F 1 C1 1F C5 1F DTE_TXD/DCE_RXD DTE_SCTE/DCE_RXC 5 2 4 LTC1543 D1 D2 CHARGE PUMP 28 27 26 25 C4 3.3F C2 1F 2 C12 1F 5467 9 10 VEE C13 1F VCC LATCH 21 8 11 12 13 LTC1344A
DCE/DTE
M2
M1
16 15 18 17 19 20 22 23 24 1 VCC 2 14 24 11 DTE TXD A TXD B SCTE A SCTE B DCE RXD A RXD B RXC A RXC B
24 23 22 21
6
7 8 9
D3 20 15 12 17 9 3 16 7 1 R1 TXC A TXC B RXC A RXC B RXD A RXD B SG SHIELD DB-25 CONNECTOR TXC A TXC B SCTE A SCTE B TXD A TXD B 19 18 R2 17 16 R3 M0 M1 M2 DCE/DTE 15
DTE_TXC/DCE_TXC
DTE_RXC/DCE_SCTE
DTE_RXD/DCE_TXD
10 11 12 NC 13 14
C10 1F
C9 1F
VCC 1 VCC 2 VDD 3 D1 VEE GND 28 27 26 C11 1F
M0
25 DCE/DTE 21 M1 18 M0 4 RTS A 19 RTS B 20 DTR A 23 DTR B
DTE_RTS/DCE_CTS
25 24
DTE_DTR/DCE_DSR
4
D2
23
5
D3 LTC1544 22 21 20 R2 19 18 R3 17 16 CABLE WIRING FOR MODE SELECTION MODE V.35 RS449, V.36 RS232 15 NC PIN 18 PIN 7 NC PIN 7 PIN 21 PIN 7 PIN 7 NC CABLE WIRING FOR DTE/DCE SELECTION MODE PIN 25 DTE PIN 7 DCE NC 8 10 6 22 5 13
DTE_DCD/DCE_DCD DTE_DSR/DCE_DTR
6 7
R1
DTE_CTS/DCE_RTS
8
10 9 11 12 NC 13 14 M0 M1 M2
R4 D4
DCE/DTE INVERT
Figure 27. Cable-Selectable Multiprotocol DTE/DCE Port with DB-25 Connector
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.
+
U
CTS A CTS B DSR A DSR B
DCD A DCD B DSR A DSR B CTS A CTS B
DCD A DCD B DTR A DTR B RTS A RTS B
1543/44 F27
19
LTC1543
PACKAGE DESCRIPTION
0.205 - 0.212** (5.20 - 5.38)
0.005 - 0.009 (0.13 - 0.22)
0.022 - 0.037 (0.55 - 0.95)
*DIMENSIONS DO NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE **DIMENSIONS DO NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
RELATED PARTS
PART NUMBER
LTC1321 LTC1334 LTC1343 LTC1344A LTC1345 LTC1346A LTC1544
DESCRIPTION
Dual RS232/RS485 Transceiver Single 5V RS232/RS485 Multiprotocol Transceiver Software-Selectable Multiprotocol Transceiver Software-Selectable Cable Terminator Single Supply V.35 Transceiver Dual Supply V.35 Transceiver Software-Selectable Multiprotocol Transceiver
20
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408)432-1900 q FAX: (408) 434-0507 q www.linear-tech.com
U
Dimensions in inches (millimeters) unless otherwise noted. G Package 28-Lead Plastic SSOP (0.209)
(LTC DWG # 05-08-1640)
0.397 - 0.407* (10.07 - 10.33) 28 27 26 25 24 23 22 21 20 19 18 17 16 15
0.301 - 0.311 (7.65 - 7.90)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 0.068 - 0.078 (1.73 - 1.99)
0 - 8
0.0256 (0.65) BSC
0.010 - 0.015 (0.25 - 0.38)
0.002 - 0.008 (0.05 - 0.21)
G28 SSOP 0694
COMMENTS
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 Perfect for Terminating the LTC1543 3-Driver/3-Receiver for Data and Clock Signals 3-Driver/3-Receiver for Data and Clock Signals Companion to LTC1543 for Control Signals
1543fs, sn1543x LT/TP 0898 4K * PRINTED IN USA (c) LINEAR TECHNOLOGY CORPORATION 1998

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