DS2129 Datasheet, PDF (1/5 Pages) Dallas Semiconductor – LVD SCSI 27-Line Regulator

Rev 1; 2/06
LVD SCSI 27-Line Regulator
General Description
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) net-
works. 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 pro-
tection features such as thermal shutdown and active
current limiting.
Applications
SCSI Array Backplane
SCSI Cables
Block Diagram
TERMPWR
PTAT
BANDGAP REF125
(1.25V)
THERMAL
SHUTDOWN
REFERENCES
REF175
TS
DS2129
TS
1.75V
REG1
REF130
REF075
GND
TS
0.75V
REG2
TS
1.3V
DIFFSENSE
Features
♦ Fully Compliant with SPI-2 and SPI-3
♦ 2.7V to 5.25V Operation
♦ Differential Fail-Safe Bias
Ordering Information
PART*
DS2129S
VOLTAGE (V) ^PIN-
PACKAGE
5
16 SO
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) tempera-
ture range.
**A “+” anywhere on the topmark denotes a lead-free package.
Pin Configuration
TOP VIEW
N.C. ₁
TERMPWR 2
REG2 3
GND 4
HS_GND 5
REG1 6
DIFFSENSE 7
N.C. 8
DS2129
16 N.C.
15 N.C.
14 HS_GND
13 HS_GND
12 HS_GND
11 HS_GND
10 N.C.
9 N.C.
SO (150 mils)
______________________________________________ Maxim Integrated Products 1
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.