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Global Mixed-mode Technology Inc.
G218B
Ultra160 Multi-mode LVD/SE SCSI Terminator
Features
Auto-selectable multi-mode Single-Ended or LVD Termination Meets SCSI-1, SCSI-2, SCSI-3 SPI Ultra (Fast-20), Ultra 2(SPI-2 LVD), Ultra160 (SPI-3 LVD) standards. Supports active negation 3pF channel capacitance Thermal protection Hot-Swap compatible 5% tolerance on SE and LVD termination resistance 28 and 36 pin SSOP package 28 Pin SSOP: Pin Compatible with DS2119 36 Pin SSOP: Pin Compatible with DS2118, LX5241 and UCC5630
General Description
The G218B Multi-mode LVD/SE SCSI terminator provides a smooth transition into the next generation of the SCSI Parallel Interface (SPI-3). It automatically senses the bus, via DIFFSENS, and switches the termination to either single-ended (SE) or low voltage differential (LVD) SCSI, dependent on which type of devices are connected to the bus. If the G218B detects a HVD SCSI device, it switches to a high impedance state. For a 16-bit Wide SCSI bus to be operational, three G218B terminators are needed. The Multi-mode terminator contains all functions required to terminate and auto detect and switch modes for SCSI Parallel Interface (SPI) bus architectures. For the SE termination, one regulator and nine precision 110ohm resistors are used. For the LVD termination, the G218B integrates 18 regulated supplies with nine precision resistor strings.
Applications
Server and workstation High-end PC Industrial PC Disk Array (RAID) SCSI cable
Pin Configuration
G218B G218B
VREF R1+ R1R2+ R2NC/HS GND R3+ R3R4+ R4R5+ R5DISCNCT GND 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 TPWR TPWR R9R9+ R8R8+ NC/HS GND R7R7+ R6R6+ DIFFB DIFFSENSE M/S VREF NC NC R1+ R1R2+ R2HS/GND HS/GND 1 2 3 4 5 6 7 8 9 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 TPWR HVD LVD SE R9R9+ R8R8+ HS/GND HS/GND HS/GND R7R7+ R6R6+ DIFFB DIFFSENSE M/S
HS/GND 10 R3+ 11 R3R4+ R4R5+ R5DISCNCT 12 13 14 15 16 17
SSOP-28/TSSOP-28
GND 18
SSOP-36
Ver 1.4 Apr 07, 2005
TEL: 886-3-5788833 http://www.gmt.com.tw
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Global Mixed-mode Technology Inc.
Ordering Information
ORDER NUMBER
G218BT-S4 G218BR-S4 G218BT-S5 G218BR-S5 G218BT-D3 G218BR-D3
G218B
FEATURE
DISCNCT does not disable VREF DISCNCT does not disable VREF DISCNCT does not disable VREF DISCNCT does not disable VREF DISCNCT does not disable VREF DISCNCT does not disable VREF
ORDER NUMBER (Pb free)
G218BT-S4f G218BR-S4f G218BT-S5f G218BR-S5f G218BT-D3f G218BR-D3f
TEMP. RANGE
0C-70C 0C-70C 0C-70C 0C-70C 0C-70C 0C-70C
PACKAGE
SSOP-28 / Tube SSOP-28 / Tape & Reel SSOP-36 / Tube SSOP-36 / Tape & Reel TSSOP-28 / Tube TSSOP-28 / Tape & Reel
Note: DIFFSENSRefers to the SCSI bus signal. DIFFSENSERefers to the G218B pin name and internal circuitry relating to differential sensing. DIFFBRefers to the G218B pin name and internal circuitry relating to monitoring the DIFFSENS line.
Functional Description
The G218B is used in multi-mode active termination applications, where single ended (SE) and low voltage differential (LVD) devices might coexist. The LVD termination section consists of 18 source/sink amplifiers (VTOP, VBOT), biasing circuitry and nine precision resistor strings (RTOP, RMID, RBOT). The SE termination section consists of a 2.85V source/sink regulator with 9 precision 110ohm resistor. The DIFFSENSE section consists of a 1.3V, 5mA driver and a sensing circuit (Figure 1) DIFFSENS is used to identify which types of SCSI devices are present on the bus. If the voltage on DIFFSENS is between 0-0.5V the bus is single-ended; if it is between 0.7-1.9V the bus is LVD; and if it is greater than 2.4V, the bus is HVD. The G218B DIFFB pin monitors the DIFFSENS line to determine the proper operating mode of the device; this mode is indicated by the SE/LVD/HVD outputs. HVD Isolation Mode The G218B identifies that there is an HVD (high voltage differential) device on the SCSI bus and isolates the termination pins from the bus. When DISCNCT is pulled high, the termination pins are isolated from the SCSI bus, and the bus mode indicators (SE/LVD/HVD) as well as VREF remains active. During thermal shutdown, the termination pins are isolated from the SCSI bus and VREF becomes high impedance. The DIFFSENSE driver is shut down during either of these two events. To ensure proper operation, the TPWR pin should be connected to the SCSI bus TERMPWR line. As with all analog circuitry, the TERMPWR lines should be bypassed locally. A 2.2F capacitor and a 0.01F high frequency capacitor is recommended between TPWR
and ground and placed as close as possible to the G218B. The G218B should be placed as close as possible to the SCSI connector to minimize signal and power trace length, thereby resulting in less input capacitance and reflections which can degrade the bus signals. The DIFFSENSE pin can drive the SCSI DIFFSENS line (when M/S is pulled high) to determine the SCSI bus operating mode. The G218B switches to the termination mode that is appropriate for the bus based on the value of the DIFFSENS voltage. These modes are: LVD mode LVD termination is provided by a precision resistor string with two amplifiers. This configuration yields a 105 differential and 150 common mode impedance. A fail safe bias of 112mV is maintained when no drivers are connected to the SCSI bus. SE mode When the external driver for a given signal line turns off, the active terminator will pull that signal line to 2.85 volts (quiescent state). When used with an active negation driver, the power amp can sink 22mA per line while keeping the voltage reference in regulation. The terminating resistors maintain their 110 value. To maintain the specified regulation, a 4.7F capacitor is required between the VREF pin and ground of each G218B. A high frequency cap (0.1F ceramic recommended) can also be placed on the VREF pin in applications that use fast rise/fall time drivers. A typical SCSI bus configuration is shown in Figure2. An internal pull down resistor assures that the G218B will be terminating the bus if the DISCNCT pin is left floating.
Ver 1.4 Apr 07, 2005
TEL: 886-3-5788833 http://www.gmt.com.tw
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Global Mixed-mode Technology Inc.
Block Diagram
(Figure 1)
G218B
( 36pin SSOP only ) M/S DIFFSENSE SE LVD HVD DISCNCT
THERMAL SHUTDOWN CIRCUITRY
DIFFSENSE CIRCUITRY VREF VREF 110 Ohms
CONTROL LOGIC
DIFFB
R1-
R9110 Ohms
REFERENCE GENERATION
+ _
VTOP1
X9 RTOP1 R1-
RTOP9
R1R9R9-
RMID1 R1+
RMID9 R1+ R9+ R9+
RBOT1 + _
RBOT9
VBOT1
X9 SE GND DRIV ER
Ver 1.4 Apr 07, 2005
TEL: 886-3-5788833 http://www.gmt.com.tw
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Global Mixed-mode Technology Inc.
SCSI Bus Configuration (Figure 2)
G218B
TERMPWR 2.2F TPWR M/S DISCNCT
CONTROL LINES (9) TPWR M/S DISCNCT
TERMPWR 2.2F
G218B
G218B
DIFFSENSE VREF DIFFB 20K 4.7F 0.1F
DIFFSENS
DIFFSENSE DIFFB VREF 20K 0.1F 4.7F
2.2F
TPWR M/S DISCNCT
DATA LINES (9)
TPWR M/S DISCNCT
2.2F
G218B
G218B
VREF
DIFFB
DIFFB
VREF
4.7F 2.2F TPWR M/S DISCNCT DATA LINES (9)
4.7F TPWR M/S DISCNCT 2.2F
G218B
G218B
VREF
DIFFB
DIFFB
VREF
4.7F
4.7F
Ver 1.4 Apr 07, 2005
TEL: 886-3-5788833 http://www.gmt.com.tw
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Global Mixed-mode Technology Inc.
Recommended Operating Conditions
PARAMETER
Termpower Voltage Logic 0 Logic 1 Operating Temperature
G218B
MAX
5.5 5.5 +0.8 Vtpwr+0.3 70
SYMBOL
Vtpwr (SE) Vtpwr (LVD) Vil Vih Tamb
MIN
4.0 2.9 -0.3 2.0 0
TYP
5 5 -------
UNITS
V V V C
Electrical Characteristics
Unless otherwise specified, these specifications apply over the operating ambient temperature range of 0CTA70C. PARAMETER
LVD Terminator Section Differential Mode Termination Resistance Common Mode Termination Resistance Differential Mode Bias Common Mode Bias Single Ended Terminator Section Output Capacitance SE Termination Resistance SE Voltage Reference SE output Current Regulator Section Line Regulation Load Regulation Current Limit Sink Current DC Section Termpower Current Input Leakage High Input Leakage Low Output Current High Output Current Low DIFFSENS Section DIFFSENS SE Operating Range DIFFSENS LVD Operating Range DIFFSENS HVD Operating Range DIFFSENSE Driver Output Voltage DIFFSENSE Driver Source Current DIFFSENSE Driver Sink Current Rdm Rcm Vdm Vcm Cout Rse Vref Iose LIREG LOREG ILIM ISINK SE mode (No Load) LVD mode (No Load) -1.0 1.0 Vout = 2.4 volts;SE/LVD/HVD Pins only Vout=0.4 volts;SE/LVD/HVD Pins only -1.0 4.0 -0.3 0.7 2.4 1.2 5 20 0.5 1.9 Vtpwr+0.3 1.4 15 200 100 110 100 1.125 105 150 112 1.25 110 190 125 1.375 3 115.5 2.93 25.4 2.5 3.5 Ohms Ohms mV V pF Ohms Volts mA % % mA mA
SYMBOL
Condition
MIN
TYP
MAX
UNITS
All lines Open
Note Vline = 0-3.0 volts Vline = 0.2 volts
104.5 2.79
110 2.85
1.0 1.3 350 200 4 20
Itpmr Iih Iil Ioh Iol Vseor Vlvdor Vhvdor Vdso Idsh Idsl
mA A A mA mA V V V V mA A
M/S=1; Ids = 0-5mA M/S = 1; Vdso=0V M/S=1; Vdso=2.75V
Note: Guaranteed by Design.
Ver 1.4 Apr 07, 2005
TEL: 886-3-5788833 http://www.gmt.com.tw
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Global Mixed-mode Technology Inc.
Typical Operating Characteristics
Common Mode Bias Vcm - Vtpwr 1.375 1.325 T=80C Vcm(V) 1.375 1.325 1.275 1.225 1.175 1.125 2.5 3.5 4.5 Vtpwr 5.5 -20 0 Vtpwr=2.8V Vtpwr=5.8V Common Mode Bias Vcm Temperature
G218B
Vcm(V)
1.275 1.225 1.175 1.125 T=-10C
20 40 60 80 Temperature()
100
Differential Mode Bias Vdm - Vtpwr 0.125 0.12 T=-10C Vdm(V) Vdm(V) 0.115 0.11 T=80C 0.105 0.1 2.5 3.5 4.5 Vtpwr 5.5 0.105 0.1 -20 0.115 0.11 0.125 0.12
Differential Mode Bias Vdm Temperature @Vtpwr=5V
0
20 40 60 Temperature(C)
80
100
Common Mode Termination Resistance Rcm - Vtpwr@Temperature=24C 190 180 170 Rcm(Ohm) Rcm(Ohm) 2.5 3.5 4.5 Vtpwr 5.5 160 150 140 130 120 110
Common Mode Termination Resistance Rcm - Temperature@Vtpwr=5V
190 180 170 160 150 140 130 120 110 -20 0 20 40 60 80 Temperature(C) 100
Differential Mode Termination Resistance Rdm - Vtpwr 110 108 Rdm(Ohm) Rdm(Ohm) 106 104 102 100 2.5 T=-10C 3.5 4.5 Vtpwr 5.5
Differential Mode Termination Resistance Rdm - Temperature 110 108 106 104 102 100 -20 0 Vtpwr=5.8V 20 40 60 Temperature(C) 80 100 Vtpwr=2.8V
T=80C
Ver 1.4 Apr 07, 2005
TEL: 886-3-5788833 http://www.gmt.com.tw
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Global Mixed-mode Technology Inc.
G218B
SE Termination Resistance Rse - Vtpwr @T=24C;Vline=0V 115 114 113 112 111 110 109 108 107 106 105 3.5 4.5 Vtpwr 5.5
SE Termination Resistance Rse - Vtpwr @Vline=0V 115 114 113 Vtpwr=3.8V 112 111 110 109 108 107 Vtpwr=5.8V 106 105 -20 0 20 40 60 80 100 Temperature(C)
Rse(Ohm)
SE Termination Resistance Rse - Vtpwr @Vtpwr=5V;T=24C 115 114 113 112 111 110 109 108 107 106 105 0 1 2 3 Vline
Rse(Ohm)
Vref - Ivref@Vtpwr=5V;T=24C 2.93 2.91 2.89 Vref 2.87 2.85 2.83 2.81 2.79 -250 -150 -50 50 150 Ivref(mA) 250 350
Rse(Ohm)
Vref - Temperature@Ivref=0mA 2.93 2.91 2.89 Vref Vref 2.87 2.85 2.83 2.81 2.79 -20 0 20 40 60 Temperature(C) 80 100 Vtpwr=3.8V Vtpwr=5.8V 2.93 2.91 2.89 2.87
Vref - Vtpwr@T=24C
Ivref=-200mA 2.85 2.83 2.81 2.79 3.5 4.5 Vtpwr 5.5 6.5 Ivref=350mA
Ver 1.4 Apr 07, 2005
TEL: 886-3-5788833 http://www.gmt.com.tw
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Global Mixed-mode Technology Inc.
Pin Description
PIN
1 VREF*
G218B
(for 28pin SSOP/TSSOP) DESCRIPTION
SYMBOL
Reference Voltage. 2.85-volt reference; must be connected to a 4.7F capacitor. Signal Termination. (X=1,2,3,.....9) 2-5,7-12, Rx+: Ground line for single-ended or positive line for differential applications for the SCSI bus. Rx+, Rx18-21, 23-26 Rx-: Signal line/active line for single-ended or negative line in differential applications for the SCSI bus. 6,22 NC/ HS GND No Connect/ HS GND. Should be grounded for heat sinking purpose. 13 DISCNCT Disconnect. When pulled high, the G218B isolates its bus pins (Rx+, Rx-) from the SCSI bus. Ground. Terminator ground pin. Connected to ground. 14 GND Master/slave. Used to select which terminator is the controlling device. M/S pin high enables the 15 M/S DIFFSENSE driver. 16 DIFFSENSE Output to drive the SCSI bus DIFFSENS line. 17 27,28 DIFFB TPWR DIFFB pin should be connected to a 0.1F capacitor to GND and 20k resistor to SCSI/Bus DIFFSENS line. An input pin to detect the type of device (differential or single-ended) on the SCSI bus. Terminator Power. Connect to the SCSI TERMPWR line and de-couple with a 2.2F capacitor.
*The VREF keeps the level at 2.85 volt, despite the DISCNCT pin is asserted or not; even the termination mode is changed.
(36pin SSOP) PIN
1 2,3 4-7,11-16, 22-25, 29-32 8, 9,10,26, 27,28 17 18 19 20 21 33 34 35 36
SYMBOL
VREF* NC Rx+ Rx-
DESCRIPTION
Reference Voltage. 2.85-volt reference; must be connected to a 4.7F capacitor. No Connect. Do not connect these pins.
Signal Termination. (X=1,2,3,.....9) Rx+: Ground line for single-ended or positive line for differential applications for the SCSI bus. Rx-: Signal line/active line for single-ended or negative line in differential applications for the SCSI bus. Heat Sink Ground. Connect to large area PC board traces to increase power dissipation capabilHS/GND ity. DISCNCT Disconnect. When pulled high, the G218 isolates its bus pins (Rx+, Rx-) from the SCSI bus. Ground. Terminator ground pin. Connected to ground. GND Master/slave. Used to select which terminator is the controlling device. M/S pin high enables the M/S DIFFSENSE driver. DIFFSENSE Output to drive the SCSI bus DIFFSENS line. DIFFB pin should be connected to a 0.1F capacitor to GND and 20k resistor to SCSI/Bus DIFFB DIFFSENS line. An input pin to detect the type of device (differential or single-ended) on the SCSI bus. Single ended mode indicator. It is HIGH when terminator is operating in SE mode. SE Low Voltage Differential mode indicator. It is HIGH when terminator is operating in LVD mode. LVD High Voltage Differential mode indicator. It is HIGH when terminator is operating in HVD mode HVD Terminator Power. Connect to SCSI bus TERMPWR line and decouple with 2.2F capacitor. TPWR
*The VREF keeps the level at 2.85 volt, despite the DISCNCT pin is asserted or not; even the termination mode is changed.
Ver 1.4 Apr 07, 2005
TEL: 886-3-5788833 http://www.gmt.com.tw
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Global Mixed-mode Technology Inc.
Package Information
0.25
G218B
C
D 28
L
E1
E
1.00 REF
1
A2 A1 b e
A
SSOP-28 Package DIMENSION IN MM TYP.
1.60 ----1.45 0.25 ----------------0.64 -------------
SYMBOL
A A1 A2 b C D E E1 e L y
MIN.
1.35 0.10 ----0.20 0.19 9.80 5.80 3.80 ----0.40 ----0
MAX.
1.75 0.25 ----0.30 0.25 10.00 6.20 4.00 ----1.27 0.10 8
MIN.
0.053 0.004 ----0.008 0.007 0.386 0.228 0.150 ----0.016 ----0
DIMENSION IN INCH TYP.
0.064 ----0.057 0.010 ----------------0.025 -------------
MAX.
0.069 0.010 ----0.012 0.010 0.394 0.244 0.157 ----0.050 0.004 8
Ver 1.4 Apr 07, 2005
TEL: 886-3-5788833 http://www.gmt.com.tw
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Global Mixed-mode Technology Inc.
G218B
C
L
E1 E
h x 45
D
A 0.004 C SEATING PLANE e b A1
SSOP-36 Package Dimension in mm TYP.
2.591 0.305 ------15.875 0.800 BASIC ---7.493 ----------
Symbol
A A1 b c D e E E1 h L
MIN.
2.413 0.203 0.300 0.127 15.748 10.033 7.391 0.381 0.508 0
MAX.
2.794 0.406 0.450 0.254 16.002 10.668 7.595 0.635 1.016 8
MIN.
0.095 0.008 0.012 0.005 0.620 0.395 0.291 0.015 0.020 0
Dimension in inch TYP.
0.102 0.012 ------0.625 0.032 BASIC ---0.295 ----------
MAX.
0.110 0.016 0.018 0.010 0.630 0.420 0.289 0.025 0.040 8
Ver 1.4 Apr 07, 2005
TEL: 886-3-5788833 http://www.gmt.com.tw
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Global Mixed-mode Technology Inc.
C
G218B
L
D 28
E1
E
1
A2 A1 e b
A
TSSOP-28 Package NOTE: 1. Package body sizes exclude mold flash protrusions or gate burrs 2. Tolerance 0.1mm unless otherwise specified 3. Coplanarity : 0.1mm 4. Controlling dimension is in millimeter. Converted inch dimensions are not necessarily accurate. 5. Follow JEDEC MO-153 SYMBOL
A A1 A2 b C D E E1 e L y
MIN.
----0.05 0.80 0.19 0.09 9.60 ----4.30 ----0.45 ----0
DIMENSION IN MM NOM.
--------1.00 --------9.70 6.40 4.40 0.65 0.60 ---------
MAX.
1.20 0.15 1.05 0.30 0.20 9.80 ----4.50 ----0.75 0.10 8
MIN.
----0.002 0.031 0.007 0.004 0.378 ----0.169 ----0.018 ----0
DIMENSION IN INCH NOM.
--------0.039 --------0.382 0.252 0.173 0.026 0.024 ---------
MAX.
0.048 0.006 0.041 0.012 0.008 0.386 ----0.177 ----0.030 0.004 8
Taping Specification
PACKAGE
SSOP-28 SSOP-36 TSSOP-28
F e e d D ire c tio n T yp ic a l S S O P , T S S O P P a c k a g e O rie n ta tio n
Q'TY/REEL
2,500 ea 1,000 ea 2,500 ea
Q'TY/TUBE
50 ea 29 ea 50 ea
GMT Inc. does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and GMT Inc. reserves the right at any time without notice to change said circuitry and specifications.
Ver 1.4 Apr 07, 2005
TEL: 886-3-5788833 http://www.gmt.com.tw
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