Rev 1; 2/06 LVD SCSI 27-Line Regulator The DS2129 is a triple-output voltage regulator for 27-line, low-voltage-differential (LVD) SCSI termination for SPI-2 and SPI-3 applications using LVD termination networks. The device provides reference voltages and bias currents for LVD-termination resistor pi (π) networks. With a pi network (475Ω, 121Ω, 475Ω), the DS2129 meets the common-mode bias, differential bias, and termination-impedance requirements of SPI-2 (Ultra2) and SPI-3 (Ultra3). The device also provides a 1.3V output for DIFFSENSE signaling, and includes protection features such as thermal shutdown and active current limiting. Features ♦ Fully Compliant with SPI-2 and SPI-3 ♦ 2.7V to 5.25V Operation ♦ Differential Fail-Safe Bias Ordering Information Applications SCSI Array Backplane PART* SCSI Cables VOLTAGE (V) DS2129S Block Diagram PTAT REF125 THERMAL SHUTDOWN TOP MARK** DS2129 DS2129S+ 5 16 SO DS2129 DS2129S/T&R 5 16 SO DS2129 DS2129S+T&R 5 16 SO DS2129 +Denotes lead-free package. *All devices rated for the commercial (0°C to +70°C) temperature range. **A “+” anywhere on the topmark denotes a lead-free package. TERMPWR BANDGAP (1.25V) 5 PINPACKAGE 16 SO TS DS2129 REFERENCES TS REF175 1.75V Pin Configuration REG1 TOP VIEW REF130 N.C. 1 16 N.C. TERMPWR 2 15 N.C. TS 0.75V REG2 REG2 3 GND 4 REF075 TS 1.3V DIFFSENSE 14 HS_GND DS2129 12 HS_GND REG1 6 11 HS_GND DIFFSENSE 7 10 N.C. N.C. 8 GND 13 HS_GND HS_GND 5 9 N.C. SO (150 mils) ______________________________________________ Maxim Integrated Products 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. 1 DS2129 General Description DS2129 LVD SCSI 27-Line Regulator ABSOLUTE MAXIMUM RATINGS TERMPWR, DIFFSENSE, REG1, REG2 ....................-0.3V, +6.0V REG1, REG2 Continuous Output Current.......................±200mA Continuous Power Dissipation (TA = +70°C) 16-Pin SO (derate 13mW/°C above +70°C)........................1W Operating Temperature Range...............................0°C to +70°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +150°C Soldering Temperature .......................................See IPC/JEDEC J-STD-020A Specification 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. ELECTRICAL CHARACTERISTICS (TERMPWR = 3.3V, TA = 0°C to +70°C, unless otherwise noted.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 40 mA 5.25 V 0.8 V -200 mA TERMPWR TERMPWR Supply Current ITERM TERMPWR Voltage VTERM No load 2.7 VREF REGULATOR 0.75V Regulator Output Voltage, REG2 V075 0.75V Regulator Source Current, REG2 ISRC_075 VOUT = 0.25V 0.75V Regulator Sink Current, REG2 ISINK_075 VOUT = 1.25V +200 mA 0.75V Regulator Source Current Limit ISRCL_075 VOUT = 0V -700 mA 0.75V Regulator Sink Current Limit ISINKL_075 VOUT = 3.3V IOUT = ±125mA 0.7 0.75 +700 mA 1.8 V -200 mA 1.75V Regulator Output Voltage, REG1 V175 1.75V Regulator Source Current, REG1 ISRC_175 VOUT = 1.25V 1.75V Regulator Sink Current, REG1 ISINK_175 VOUT = 2.25V +200 mA 1.75V Regulator Source Current Limit ISRCL_175 VREF = 0V -700 mA 1.75V Regulator Sink Current Limit ISINKL_175 VREF = 3.3V IOUT = ±125mA 1.7 1.75 +700 mA 1.4 V DIFFSENSE OUTPUT DIFFSENSE Driver Output Voltage VDSO -5mA ≤ IDIFFSENSE ≤ 50µA 1.2 DIFFSENSE Driver Source Current IDSH VDIFFSENSE = 0V -5 -15 mA DIFFSENSE Driver Sink Current IDSL VDIFFSENSE = 2.4V 100 200 µA 2 _____________________________________________________________________ 1.3 LVD SCSI 27-Line Regulator (TERMPWR = 3.3V, TA = 0°C to +70°C, unless otherwise noted.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS THERMAL SHUTDOWN Thermal-Shutdown Threshold (Note 2) For increasing temperature +150 °C 10 °C Thermal-Shutdown Hysteresis (Note 2) Note 1: All voltages are referenced to ground. Note 2: Guaranteed by design and not production tested. Typical Operating Circuit TERMPWR 2.7V TO 5.25V TERMPWR 4.7µF DIFFSENSE DIFFSENSE DS2129 R1N REG1 4.7µF 475Ω 1% 121Ω 1% R1P REG2 4.7µF 475Ω 1% R2N R26P R27N 475Ω 1% 121Ω 1% R27P 475Ω 1% _____________________________________________________________________ 3 DS2129 ELECTRICAL CHARACTERISTICS (continued) LVD SCSI 27-Line Regulator DS2129 Pin Description PIN NAME FUNCTION 1, 8, 9, 10, 15, 16 N.C. No Connection. Do not connect pins. 2 TERMPWR Termination Power. Connect to SCSI TERMPWR line and decouple with a 4.7µF ceramic capacitor. 3 REG2 Regulator 2, 0.75V Output. Decouple with a 4.7µF ceramic capacitor. 4 GND Signal Ground 5, 11–14 HS_GND 6 REG1 Regulator 1, 1.75V Output. Decouple with a 4.7µF ceramic capacitor. 7 DIFFSENSE DIFFSENSE Output. Drives the SCSI bus DIFFSENSE line. Chip Information TRANSISTOR COUNT: 3778 CMOS and 80 BIPOLAR PROCESS: BiCMOS SUBSTRATE CONNECTED TO GROUND Thermal Information Thermal Resistance (junction-to-ambient): θJA = +77°C/W Thermal Resistance (junction-to-case): θJC = +25°C/W Heat-Sink Ground. Internally connected to the mounting pad. Should be connected to ground. Detailed Description The DS2129 provides three regulated outputs. The REG1 provides a 1.75V output, and the REG2 provides a 0.75V output. Both regulators can sink and source 200mA of current. These regulators are current-limited to less than 700mA. The thermal-shutdown circuit disables the output buffers should the die temperature exceed +150°C. With a pi network of resistors (475Ω, 121Ω, 475Ω) connected to these two outputs, the DS2129 provides common-mode bias, differential bias, and common impedance and differential impedance, as required in a terminator specified in SPI-2 and SPI-3 standards for a SCSI system. The third regulator provides a 1.3V output for DIFFSENSE signaling. 4 _____________________________________________________________________ LVD SCSI 27-Line Regulator N E H INCHES MILLIMETERS MAX MIN 0.069 0.053 0.010 0.004 0.014 0.019 0.007 0.010 0.050 BSC 0.150 0.157 0.228 0.244 0.016 0.050 MAX MIN 1.35 1.75 0.10 0.25 0.35 0.49 0.19 0.25 1.27 BSC 3.80 4.00 5.80 6.20 0.40 SOICN .EPS DIM A A1 B C e E H L 1.27 VARIATIONS: 1 INCHES TOP VIEW DIM D D D MIN 0.189 0.337 0.386 MAX 0.197 0.344 0.394 MILLIMETERS MIN 4.80 8.55 9.80 MAX 5.00 8.75 10.00 N MS012 8 AA 14 AB 16 AC D C A B e 0∞-8∞ A1 L FRONT VIEW SIDE VIEW PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE, .150" SOIC APPROVAL DOCUMENT CONTROL NO. 21-0041 REV. B 1 1 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 5 © 2006 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc. DS2129 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).