DS2127 MAXIM | Alldatasheet

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Technical content

Features

♦ Fully Compliant with Ultra2, Ultra3, Ultra160, and Ultra320 SCSI Standards ♦ Provides LVD/SE Termination for 14 Signal Pairs ♦ Auto-Selection of LVD or SE Termination ♦ 5% Tolerance on SE and LVD Termination Resistance ♦ Low 3pF Power-Down Capacitance ♦ Built-In Mode-Change Filter/Delay ♦ On-Board Thermal-Shutdown Circuitry ♦ SCSI Bus Hot-Plug Compatible ♦ Fully Supports Actively Negated SE SCSI Signals DS2127 Ultra3 LVD/SE SCSI 14-Line Terminator R13N R13P R12N R12P R11N R11P R10N R10P R9N R9P R8N R8P R2P R2N R3P R3N R4P R4N R5P R5N R6P R6N R7P R7N LQFP GND SE LVD HS_GND HS_GND HS_GND HS_GND HS_GND HS_GND DIFF_CAP DIFFSENS ISO R1N R1P V REF HS_GND HS_GND HS_GND HS_GND HS_GND HS_GND TPWR R14N R14P DS2127 TOP VIEW Pin Configuration

Ordering Information

Rev 1; 3/04 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. PART TEMP RANGE PIN- PACKAGE TOP MARK DS2127 0°C to +70 °C 48 LQFP DS2127

Ultra3 LVD/SE SCSI 14-Line Terminator ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(TPWR = VTPWR(MIN) to VTPWR(MAX), TA = 0°C to +70°C, unless otherwise noted.) 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 specificatio ns is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. J-STD-020A Specification PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS LVD 2.7 3.3 5.5TPWR Operating Supply Range (Note 1) VTPWR SE 4 5.0 5.5 V TPWR SUPPLY CURRENT ITPWR_LVD LVD SCSI mode 32 ITPWR_SE SE SCSI mode 10 mATPWR Supply Current (All Lines Open) ITPWR_ISO ISO mode (terminators disabled) 750 µA LVD TERMINATION (Applies to each line pair, 1 to 14 in LVD mode) Differential-Mode Termination Resistance RDM 100 110 Ω Common-Mode Termination Resistance RCM RP and RN shorted together (VCM(MAX) = 2V, VCM(MIN) = 0.5V) 110 165 Ω Differential-Mode Bias V DM All lines open 100 125 mV Common-Mode Bias V CM RP and RN shorted together (Note 1) 1.15 1.25 1.35 V SE TERMINATION (Applies to single-ended terminators, 1 to 14 in SE mode) Single-Ended Mode Termination Resistance RSE RSE = (VLX - 0.2) / ILX, where VLX = voltage at terminator pin with pin unloaded and ILX = current for each terminator pin with the pin forced to 0.2V 104.5 110 115.5 Ω Signal level at 0.2V, all lines low -21 -24 -25.4Termination Current I SE Signal level at 0.5V -18 -22.4 mA SE Voltage Reference V REF 2.7 2.85 3.0 V Pin Leakage With ISO high 400 nA Single-Ended GND Resistance R GND Measured at RP pins, I = 10mA 20 60 Ω TERMINATOR PIN CAPACITANCE Terminator Pin Capacitance C IN With ISO high (Note 2) 3 pF VREF REGULATOR 1.25V Regulator Output Voltage VREF_LVD 0.5V ≤ VCM ≤ 2.0V, VCM applied to all RP and RN lines simultaneously 1.15 1.25 1.35 V 1.25V Regulator Short-Circuit Source Current ISOURCE VREF = 0V -375 -700 -1000 mA 1.25V Regulator Short-Circuit Sink Current ISINK VREF = 3.3V 170 300 700 mA

Ultra3 LVD/SE SCSI 14-Line Terminator Note 1: All voltages are referenced to ground. Note 2: Guaranteed by design and not production tested. Note 3: Room temperature only. ELECTRICAL CHARACTERISTICS (continued) (TPWR = VTPWR(MIN) to VTPWR(MAX), TA = 0°C to +70°C, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS VREF REGULATOR 1.25V Regulator Line Regulation VREF unloaded; vary TPWR from 2.7V to 5.5V 1.0 2.5 % 2.85V Regulator 2.7 2.85 3.0 V 2.85V Regulator Short-Circuit Source Current VREF = 0V -375 -700 -1000 mA 2.85V Regulator Short-Circuit Sink Current VREF = 3.3V 170 300 700 mA 2.85V Regulator Line Regulation VREF unloaded; vary TPWR from 2.7V to 5.5V 1.0 2.5 % DIFFSENS OUTPUT DIFFSENS Driver Output Voltage VDSO -5mA ≤ IDIFFSENS ≤ 50µA 1.2 1.4 V DIFFSENS Driver Source Current IDSH VDIFFSENS = 0V -15 -5 mA DIFFSENS Driver Sink Current IDSL VDIFFSENS = 2.75V 100 200 µA ILEAK, LOW With ISO high, |VDIFFSENS| = 0.3V -3 +1 DIFFSENS Leakage (Note 3) ILEAK, HIGH With ISO high, |VDIFFSENS - VTPWR| = 0.3V 1 3 µA THERMAL SHUTDOWN Thermal-Shutdown Threshold For increasing temperature 130 °C Thermal-Shutdown Hysteresis 10 °C MODE CHANGE DELAY/FILTER Mode Change Delay t DELAY 0.66 1.25 2.00 ms LOGICAL SIGNALS (ISO) Input Low Voltage V IL -0.3 +0.8 V Input High Voltage V IH 2.0 TPWR + 0.3 V Input Current I IL VCC = 3.3V -30 -10 µA STATUS BITS (LVD, SE) Source Current I OH VCC = 3.3V, VLOAD = 2.4V -4 -6 mA Sink Current I OL VCC = 3.3V, VLOAD = 0.4V 2 5 mA DIFF_CAP Input Current IL V IL = -0.3V -1 +1 µA DIFF_CAP SE Operating Range VSEOR -0.3 +0.5 V DIFF_CAP LVD Operating Range VLVDOR 0.7 1.9 V DIFF_CAP HVD Operating Range VHVDOR 2.4 VTPWR + 0.3 V

SCSI bus. R_ _ P pins are the ground line for SE operation and the positive lines in differential mode. R_ _ N pins are the signal lines in SE operation and the negative lines in differential mode.

10 V REF

use fast rise/fall-time drivers.

25 GND Signal Ground

26 SE SE Mode Indicator. A high state indicates SE mode detected on SCSI bus. 27 LVD LVD Mode Indicator. A high state indicates LVD mode detected on SCSI. device (differential or single-ended) on the SCSI bus. 35 DIFFSENS DIFFSENSE. Output to drive the SCSI bus DIFFSENS line.

36 ISO

Figure 1. Block Diagram

mode node is connected to a 1.25V voltage regulator. are connected to the SCSI bus. ed to 2.85V through a 110Ω resistor. from the SCSI bus and the resistor pins are left floating. pin is in a high-impedance state. previous mode change has been detected. for the typical operating circuit. the SCSI bus segment is in LVD or SE mode. Figure 2. Typical Operating Circuit

Ultra3 LVD/SE SCSI 14-Line Terminator Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circu it patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 6 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circu it patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 6 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

Package Information

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.)