LTC2845CUHF#TR Linear Technology, LTC2845CUHF#TR Datasheet - Page 12

• Manufacturer Part Number: LTC2845CUHF#TR
• Description: IC TXRX 3.3V MULTIPROTOCOL 38QFN
• Manufacturer: Linear Technology
• Type: Transceiverr

Specifications of LTC2845CUHF#TR

• Number Of Drivers/receivers: 5/5
• Protocol: Multiprotocol
• Voltage - Supply: 3.3V
• Mounting Type: Surface Mount
• Package / Case: 38-QFN
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

–3.25mA
APPLICATIONS
LTC2845
The V.10 receiver configuration in the LTC2845 is shown
in Figure 13. In V.10 mode switch S3 inside the LTC2845
is turned off. The noninverting input is disconnected
inside the LTC2845 receiver and connected to ground.The
cable termination is then the 30k input impedance to
ground of the LTC2845 V.10 receiver.
12
GENERATOR
–10V
Figure 12. V.10 Receiver Input Impedance
Figure 13. V.10 Receiver Configuration
B
C
A
Figure 11. Typical V.10 Interface
'
'
'
C
A
INTERCONNECTING
U
GND
R8
6k
BALANCED
–3V
S3
CABLE
20k
20k
R5
R4
INFORMATION
U
I
Z
R6
10k
R7
10k
C
A
TERMINATION
'
3V
'
W
CABLE
RECEIVER
LTC2845
LOAD
2845 F13
U
RECEIVER
10V
2845 F12
2845 F11
V
3.25mA
Z
V.11 (RS422) 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
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 imped-
ance curve shown in Figure 12.
In V.11 mode, all switches are off except S1 of the
LTC2846’s receivers which connects a 103 differential
termination impedance to the cable as shown in Fig-
ure 15
termination other than its V.11 receivers’ 30k input imped-
ance is necessary.
1
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.
Actually, there is no switch S1 in receivers R2 and R3. However, for simplicity, all termination
GENERATOR
1
. The LTC2845 only handles control signals, so no
B
C
A
'
'
'
'
, inputs A
Figure 15. V.11 Receiver Configuration
R1
51.5
R2
51.5
S1
Figure 14. Typical V.11 Interface
A
B
C
S2
INTERCONNECTING
'
124
connected to A, B
R3
BALANCED
CABLE
GND
R8
6k
S3
20k
20k
R5
R4
A
B
C
TERMINATION
'
'
'
CABLE
'
R6
10k
R7
10k
connected to B. The
100
MIN
RECEIVER
LOAD
LTC2846
RECEIVER
2845 F15
sn2845 2845fs
2845 F14