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) LTC2846 3.3V Software-Selectable Multiprotocol Transceiver with Termination FEATURES DESCRIPTIO n Software-Selectable Transceiver Supports: The LTC 2846 is a 3-driver/3-receiver multiprotocol trans- RS232, RS449, EIA530, EIA530-A, V.35, V.36, X.21 ceiver with on-chip cable termination. When combined with n Operates from Single 3.3V Supply the LTC2844 or LTC2845, this chip set forms a complete n TUV Rheinland of North America Inc. Certified NET1, software-selectable DTE or DCE interface port that supports NET2 and TBR2 Compliant, Report No.: the RS232, RS449, EIA530, EIA530-A, V.35, V.36 and X.21 TBR2/050101/02, TBR2/051501/02 protocols. All necessary cable termination is provided inside n 1.2MHz Boost Switching Regulator for 3.3V to 5V the LTC2846. The LTC2846 has a boost regulator that takes Conversion in a 3.3V input and switches at 1.2MHz, allowing the use of n On-Chip Cable Termination tiny, low cost capacitors and inductors 2mm or less in height. n Complete DTE or DCE Port with LTC2844 or LTC2845 The 5V output drives an internal charge pump that requires n Small Footprint only five space-saving surface mounted capacitors. The n Available in 36-Lead SSOP (0.209 Wide) Package LTC2846 is available in a 36-lead SSOP surface mount U package. APPLICATIO S , LTC and LT are registered trademarks of Linear Technology Corporation. n Data Networking n CSU and DSU n Data Routers TYPICAL APPLICATIO Complete DTE or DCE Multiprotocol Serial Interface with DB-25 Connector LL CTS DSR DCD DTR RTS RXD RXC TXC SCTE TXD LTC2846 LTC2844 D4 D3 D2 D1 D3 D2 D1 R4 R3 R2 R1 R3 R2 R1 T T T T T 18 13 5 226210 83 20 19 4 1 7 16 3 9 17 12 15 11 24 14 2 DB-25 CONNECTOR 2846 TA01 sn2846 2846fs 1 U ULTC2846 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) V Voltage.............................................. 0.3V to 6.5V ORDER PART CC TOP VIEW NUMBER V Voltage .............................................. 0.3V to 6.5V IN NC 1 36 SW Input Voltage LTC2846CG BOOST PGND 2 35 FB Transmitters ........................... 0.3V to (V + 0.3V) CC SWITCHING LTC2846IG V 3 34 SGND REGULATOR Receivers............................................... 18V to 18V IN + SHDN 4 33 C2 Logic Pins .............................. 0.3V to (V + 0.3V) CC C1 5 32 C2 Output Voltage + Transmitters ................. (V 0.3V) to (V + 0.3V) C1 6 31 V EE EE DD CHARGE PUMP Receivers................................. 0.3V to (V + 0.3V) V 7 30 GND IN DD V ........................................................ 10V to 0.3V V 8 29 D1 A EE CC V ....................................................... 0.3V to 10V D1 9 28 D1 B DD D1 T Short-Circuit Duration D2 10 27 D2 A Transmitter Output ..................................... Indefinite D2 D3 11 T 26 D2 B Receiver Output .......................................... Indefinite R1 12 25 D3/R1 A D3 T V .................................................................. 30 sec EE R2 13 24 D3/R1 B SW Voltage ............................................... 0.4V to 36V R3 14 23 R2 A R1 T FB Voltage ............................................... 0.3V to 2.5V M0 15 22 R2 B Current into FB Pin .............................................. 1mA R2 M1 16 21 R3 A T SHDN Voltage ........................................... 0.3V to 10V V 17 20 R3 B IN R3 Operating Temperature Range M2 18 19 DCE/DTE LTC2846C ............................................... 0 C to 70 C G PACKAGE LTC2846I........................................... 40 C to 85 C 36-LEAD PLASTIC SSOP Storage Temperature Range ................ 65 C to 150 C T = 125 C, q = 90 C/W, q = 35 C/W JMAX JA JC Lead Temperature (Soldering, 10 sec)................. 300 C *q SOLDERED TO A CIRCUIT BOARD IS TYPICALLY 60 C/W JA Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The l denotes specifications which apply over the full operating temperature range, otherwise specifications are at T = 25 C. V = 5V, V = 3.3V, V = V , unless otherwise noted. (Notes 2, 3) A CC IN SHDN IN SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Supplies I V Supply Current (DCE Mode, RS530, RS530-A, X.21 Modes, No Load 14 mA CC CC All Digital Pins = GND or V ) RS530, RS530-A, X.21 Modes, Full Load l 100 130 mA IN V.35 Mode l 126 170 mA V.28 Mode, No Load 20 mA V.28 Mode, Full Load l 35 75 mA No-Cable Mode l 300 900 m A P Internal Power Dissipation (DCE Mode) RS530, RS530-A, X.21 Modes, Full Load 550 mW D V.35 Mode, Full Load 775 mW V.28 Mode, Full Load 200 mW + V Positive Charge Pump Output Voltage V.11 or V.28 Mode, No Load l 8 9.3 V V.35 Mode l 7 8.0 V V.28 Mode, with Load l 8 8.7 V V.28 Mode, with Load, I = 10mA 6.5 V DD sn2846 2846fs 2 U WWW