Document
U U
LTC2845
3.3V Software-Selectable Multiprotocol Transceiver
FEATURES
s Software-Selectable Transceiver Supports: RS232, RS449, EIA530, EIA530-A, V.35, V.36, X.21
s Operates from Single 3.3V Supply with LTC2846 or a Single 5V Supply with 3.3V Logic with LTC2847
s TUV Rheinland of North America Inc. Certified NET1, NET2 and TBR2 Compliant, Report No.: TBR2/050101/02
s Complete DTE or DCE Port with LTC2846 or LTC2847 s Available in a 36-Lead Narrow (0.209") SSOP and
38-Lead (7mm x 5mm) QFN package
U APPLICATIO S
s Data Networking s CSU and DSU s Data Routers
DESCRIPTIO
The LTC®2845 is a 5-driver/5-receiver multiprotocol transceiver. The LTC2845 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 LTC2845 operates from a 3.3V supply and supplies provided by the LTC2846. This part is available in a 36-lead SSOP and 38-lead (7mm x 5mm) QFN package. The LTC2845 andLTC2847inQFNpackagesofferthesmallestmultiprotocol serial port available.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
DTE or DCE Multiprotocol Serial Interface with DB-25 Connector
RL TM RI LL CTS DSR
DCD DTR RTS
RXD RXC
TXC SCTE TXD
LTC2845
D5 D4
R5 R4
R3 R2 R1
D3 D2 D1
LTC2846
D3 D2 D1 R3 R2 R1
TT
TTT
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) DTR B DCD A (109) DCD B
DSR A (107) DSR B CTS A (106) CTS B LL A (141) RI A (125)
TM A (142) RL A (140)
21 25 * 18 13 5 22 6
10 8 23 20 19 4 1 7 16 3 9 17 DB-25 CONNECTOR
12 15 11 24 14 2
*OPTIONAL
2845 TA01
sn2845 2845fs
1
U WU U WW W
LTC2845
ABSOLUTE MAXIMUM RATINGS (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
LTC2845C ............................................... 0°C to 70°C LTC2845I ........................................... – 40°C to 85°C Storage Temperature Range ................ – 65°C to 150°C Lead Temperature (Soldering, 10 sec)................. 300°C
PACKAGE/ORDER INFORMATION
TOP VIEW
VCC 1 VDD 2 D1 3 D2 4 D3 5 R1 6 R2 7 R3 8 D4 9 R4 10 M0 11 M1 12 M2 13 DCE/DTE 14 D4ENB 15 R4EN 16 R5 17 D5 18
D1 D2 D3
R1 R2 R3 D4 R4
R5 D5
36 VEE 35 GND 34 D1 A 33 D1 B 32 D2 A 31 D2 B 30 D3/R1 A 29 D3/R1 B 28 R2 A 27 R2 B 26 R3 A 25 R3 B 24 D4 A 23 R4 A 22 R5 A 21 D5 A 20 VIN 19 VCC
G PACKAGE 36-LEAD PLASTIC SSOP
TJMAX = 125°C, θJA = 90°C/ W, θJC = 35°C/ W
ORDER PART NUMBER
LTC2845CG LTC2845IG
Consult LTC Marketing for parts specified with wider operating temperature ranges.
TOP VIEW
D1 VDD VCC VEE VEE GND D1 A
D2 1 D3 2 R1 3 R2 4 R3 5 D4 6 R4 7 M0 8 M1 9 M2 10 NC 11 DCE/DTE 12
38 37 36 35 34 33 32 39
13 14 15 16 17 18 19
31 D1 B 30 D2 A 29 D2 B 28 D3/R1 A 27 D3/R1 B 26 R2 A 25 R2 B 24 R3 A 23 R3 B 22 D4 A 21 R4 A 20 R5 A
D4ENB R4EN R5 D5 VCC VIN D5 A
UHF PACKAGE 38-LEAD (7mm × 5mm) PLASTIC QFN
TJMAX = 125°C, θJA = 34°C/ W EXPOSED PAD IS VEE (PIN 39) MUST BE SOLDERED TO PCB
ORDER PART NUMBER
LTC2845CUHF LTC2845IUHF
UHF PART MARKING
2845 2845I
ELECTRICAL CHARACTERISTICS The q 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 ICC
PARAMETER
VCC Supply Current (DCE Mode, All Digital Pins = GND or VIN)
CONDITIONS
MIN
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
q q q q
TYP MAX UNITS
2.7 110 150 13 13 700 1400
mA mA mA mA µA
sn2845 2845fs
2
LTC2845
ELECTRICAL CHARACTERISTICS The q 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 IEE
PARAMETER
VEE Supply Current (DCE Mode, All Digital Pins = GND or VIN)
IDD VDD Supply Current (DCE Mode, All Digital Pins = GN.