MAX3291/MAX3292 19-1405 Rev 1 4/99 RS-485/RS-422 Transceivers with Preemphasis for High-Speed, Long-Distance Communication General Description Features The MAX3291/MAX3292 high-speed RS-485/RS-422 Preemphasis Increases the Distance and Data transceivers feature driver preemphasis circuitry, which Rate of Reliable RS-485/RS-422 Communication extends the distance and increases the data rate of reli- Data Rate able communication by reducing intersymbol interfer- ence (ISI) caused by long cables. The MAX3291 is Optimized for 5Mbps to 10Mbps (MAX3291) programmable for data rates of 5Mbps to 10Mbps, Programmable up to 10Mbps (MAX3292) while the MAX3292 is programmable for data rates up 100nA Low-Current Shutdown Mode to 10Mbps by using a single external resistor. Allow Up to 128 Transceivers on the Bus The MAX3291/MAX3292 are full-duplex devices that operate from a single +5V supply and offer a low-cur- -7V to +12V Common-Mode Input Voltage Range rent shutdown mode that reduces supply current to Pin-Compatible with 75180, MAX489, MAX491 100nA. They feature driver output short-circuit current MAX3080, MAX3083, MAX3086, MAX1482 limiting and a fail-safe receiver input that guarantees a logic-high output if the input is open circuit. A 1/4-unit- load receiver input impedance allows up to 128 trans- Ordering Information ceivers on the bus. PART TEMP. RANGE PIN-PACKAGE MAX3291CSD 0C to +70C 14 SO MAX3291CPD 0C to +70C 14 Plastic DIP Applications MAX3291ESD -40C to +85C 14 SO Long-Distance, High-Speed RS-485/RS-422 MAX3291EPD -40C to +85C 14 Plastic DIP Communications MAX3292CSD 0C to +70C 14 SO Telecommunications MAX3292CPD 0C to +70C 14 Plastic DIP Industrial-Control Local Area Networks MAX3292ESD -40C to +85C 14 SO MAX3292EPD -40C to +85C 14 Plastic DIP Typical Operating Circuit and Functional Diagram R * R * PSET PSET 1F 1F PEE C*CPEE * PSET PSET (PSET) (PSET) 1 V 14 V CC 1 CC 14 13 13 (V)(V ) CCD CCD A 12 R = Z R = Z 9 Y O O 2 5 RO 10 DI Z B 11 4 3 DE RE 3 4 RE DE Z 10 R = Z R = Z O O 11 B 5 2 DI 12 RO Y 9 A ( ) ARE FOR MAX3292 * MAX3292 ONLY MAX3291 MAX3291 MAX3292 MAX3292 Z = THE CHARACTERISTIC O IMPEDANCE OF THE CABLE 7(6) GND 7(6) GND Pin Configuration appears at end of data sheet. Maxim Integrated Products 1 For free samples & the latest literature: RS-485/RS-422 Transceivers with Preemphasis for High-Speed, Long-Distance Communication ABSOLUTE MAXIMUM RATINGS Supply Voltage (V , V ) .................................................+6V Operating Temperature Ranges CC CCD Control Input Voltage (RE, DE, PEE, MAX329 C D......................................................0C to +70C PSET, DI) .................................................-0.3V to (V + 0.3V) MAX329 E D...................................................-40C to +85C CC Driver Output Voltage (Y, Z)................................-7.5V to +12.5V Storage Temperature Range .............................-65C to +160C Receiver Input Voltage (A, B)..............................-7.5V to +12.5V Lead Temperature (soldering, 10sec) .............................+300C Receiver Output Voltage (RO)....................-0.3V to (V + 0.3V) CC Continuous Power Dissipation (T = +70C) A 14-Pin SO (derate 8.7mW/C above +70C).................695mW 14-Pin Plastic DIP (derate 10.0mW/C above +70C) ..800mW Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. DC ELECTRICAL CHARACTERISTICS (Typical Operating Circuit, V = +5V 5%, R = 0 (MAX3292), V = V (MAX3292), T = T to T , unless otherwise CC PSET CC CCD A MIN MAX noted. Typical values are at V = +5V and T = +25C.) (Note 1) CC A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DRIVER R = 27 1.5 5.0 Differential Driver Output V Figure 1 V OD No load (Note 2) 5.25 Differential Driver Output with V R = 27 2.4 V ODP Preemphasis Differential Driver DPER Figure 1, R = 27 (Note 3) 1.65 2.0 2.35 V Preemphasis Ratio Change in Magnitude of V , OD Differential Output Voltage Figure 1, R = 27 (Note 4) 0.2 V V ODP (Normal and Preemphasis) Driver Common-Mode Output Voltage (Normal and V Figure 1, R = 27 V / 2 3 V OC CC Preemphasis) Change in Magnitude of Common-Mode Voltage V Figure 1, R = 27 (Note 5) 0.3 V OC (Normal and Preemphasis) Change in Magnitude of Common-Mode Output V Figure 1, R = 27 50 mV NP Voltage (Normal to Preemphasis) DE, DI, RE 2.4 Input High Voltage V V IH PEE 3.75 Input Low Voltage V 0.8 V IL DE, DI, RE, PEE Input Current I DE, DI, RE 2 A IN PEE Input Current (MAX3291) I -15 -30 -45 A PEE PSET Input Current (MAX3292) I V = V 70 110 A PSET PSET CC V = V = +12V 25 Y Z DE = GND, Output Leakage (Y and Z) I A O V = GND or 5.25V CC V = V = -7V -25 Y Z Driver Short-Circuit Output I -7V V +12V (Note 6) 30 250 mA OSD OUT Current 2 MAX3291/MAX3292