IMP5225 A1PROS | Alldatasheet
Document overview
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Technical content
— Dual active LOW disconnect pins N Ultra-Fast response for Fast-20 SCSI N 35MHz channel bandwidth N Sleep-mode current less than 150µA — Disconnects terminator from lows N NO external compensation capacitors N Compatible with active negation drivers N Compatible with passive and active terminations N Approved for use with SCSI 1, 2, 3 and Ultra SCSI N Hot swap compatible N Pin-for-pin compatible with LX5225, LX5205 and UC5607 Block Diagrams Enable Logic Current Biasing Circuit 24mA Current Limiting Circuit Term Power DATA OUTPUT PIN DB (0) 1 of 18 Channels DISCONNECT 1 V TERM VTERM DISCONNECT 2 0.4V 2.85V 5225_01.eps 118-Line Plug and Pla8-Line Plug and Playy SCSI TSCSI Tererminatminatoror The IMP5225 SCSI terminator is part of IMP's family of high- performance SCSI terminators, which are designed to deliver true UltraSCSI performance. The BiCMOS design offers superior perfor- mance over first generation linear passive and active techniques. IMP's new architecture employs high-speed adaptive elements for each chan- nel, thereby providing the fastest response possible — typically 35MHz, which is 100 times faster than the older linear regulator/terminator approach. Products using the older regulator/resistor architecture have bandwidths which are dominated by the reference stabilization output capacitor and are therefore limited to 500kHz (see further discussion in the Functional Description section). The IMP architecture eliminates the output compensation capacitor required in linear regulator/ resistor designs. The IMP5225 architecture tolerates marginal system designs. A key improvement offered by the IMP5225 lies in its ability to insure reliable, error-free communications even in systems which do not adhere to recommended SCSI hardware design guidelines, such as the use of improper cable lengths and impedances. Frequently, this situation is not controlled by the peripheral or host designer. The IMP5225 has two disconnect pins for SCSI Plug and Play (PnP) applications. To enter the disconnect mode, the disconnect pins must be driven LOW thereby disconnecting the IMP5225 from the SCSI bus. Quiescent current is less than 150µA when disabled. Reduced component count is inherent in the IMP5225 architecture. Traditional termination techniques require large stabilization and transient protection capacitors of up to 20 µF in value and size. The IMP5225 architecture does not require these com- ponents, allowing all the cost savings associated with inventory, board space, assembly, reliability, and compo- nent costs. The IMP5225 is a superior pin-for-pin replacement for the LX5225, LX5205, UC5607. © 2000 IMP , Inc. 408-432-9100/www.impweb.com 1 IMP5225IMP5225 DATA COMMUNICATIONS
2 408-432-9100/www.impweb.com © 2000 IMP , Inc. Pin Configuration
Ordering Information
9 HEAT SINK / GND
8 GND
7 HEAT SINK / GND
1 DISCONNECT 1
19 T13
20 HEAT SINK / GND
21 HEAT SINK / GND
22 HEAT SINK / GND
23 T14
24 T15
25 T16
26 T17
27 T18
28 DISCONNECT 2
16 T10
17 T11
18 T12
5225_02.eps IMP5225 SOWB-28 r e b m u N t r aPe g n a R e r u t a r e p m eTe g a k c a P P W D C 5 2 2 5 P MI0 ° 0 7 o t C°CB W O S c i t s a l P n i p - 8 2 T P W D C 5 2 2 5 P MI0 ° 0 7 o t C°CB W O S c i t s a l P n i p - 8 2 , l e e R d n a e p a T 3 t a . 1 0 t _ 5 2 2 5 Thermal Data Operating Junction Temperature Note: 1. Exceeding these ratings could cause damage to the device. All voltages are with respect to Ground. Currents are positive into, negative out of the specified terminal. Junction Temperature Calculation: TJ = TA + (PD x θJA). The θJA numbers are guidelines for the thermal performance of the device/pc-board system. All of the ambient airflow is assumed. IMP5IMP5 11111/51/5 111122IMP5225IMP5225
© 2000 IMP , Inc. Data Communications 3 Recommended Operating Conditions r e t e m a r aPl o b m ySn iMp yTx aMs t i n U e g a t l o V r w p m r eTV M R E T 0 .45 .5V e g a t l o V e n i L l a n g i S 00 .5V e g a t l o V t u p n I t c e n n o c s i D 0V M R E T V C 5 2 2 5 P M I–e g n a R e r u t a r e p m e T n o i t c n u J g n i t a r e p O05 21C ° . l a n o i t c n u f s i e c i v e d e h t h c i h w r e v o e g n a r e h t e t a c i d n i s n o i t i d n o c g n i t a r e p o d e d n e m m o c e R . 2 : e t o N s p e . 2 0 t _ 5 2 2 5
Electrical Characteristics
Unless otherwise specified, these specifications apply at an ambient operating temperature of T A = 25°C. TermPwr = 4.75V . Low duty cycle pulse testing techniques are used which maintains junction and case temperatures equal to the ambient temperature. r e t e m a r aPl o b m ySs n o i t i d n oCn iMp yTx aMs t i n U e g a t l o V h g i H t u p t uOV T U O 5 6 .25 8 .2V t n e r r u C y l p p u S r w P m r eTI C C l lAa t adn e p O = s e n il1 0 1 5 A m l lAa t ad= s e n ilV 2 .04 240 5 4 V 8 . 0 < s n i P T C E N N O C S ID0 50 51A µ t n e r r u C t u p t uOI T U O V T U O V 5 . 0=0 2– 2 2– 4 2– A m t u p n I t c e n n o c s iDt n e r r uCI N I V 0 = s n i P T C E N N O C S ID0 1– A µ t n e r r u C e g a k a e L t u p t uOI L O V , V 8 . 0 < s n i P T C E N N O C S I DO V 2 . 0=1 A µ h t d i w d n a B l e n n a hCW B5 3z H M l e n n a h C r e p , t n e r r u C k n i S n o i t a n i m r eTI K N I SV T U O V 4=7 A m s p e . 3 0 t _ 5 2 2 5 IMP5IMP5 11111/51/5 111122IMP5225IMP5225
4 408-432-9100/www.impweb.com © 2000 IMP , Inc.
Application Information
Cable transmission theory suggests to optimize signal speed and quality, the termination should act both as an ideal voltage refer- ence when the line is released (deasserted) and as an ideal current source when the line is active (asserted). Common active terminators which consist of linear regulators in series with resis- tors (typically 110 Ω ) are a compromise. With coventional linear terminators as the line voltage increases the amount of current decreases linearly by the equation; The IMP5225, with its unique new architecture, applies the max- imum amount of current regardless of line voltage until the termination high threshold (2.85V) is reached. Acting as a near ideal line terminator, the IMP5225 closely repro- duces the optimum case when the device is enabled. To enable the device the DISC1 and DISC2 pins are pulled HIGH. During this mode of operation, quiescent current is 10mA, and the device will respond to line demands by delivering 24mA on assertion and by imposing 2.85V on deassertion. In order to disable the device, the DISC1 and DISC2 pins must be driven LOW. In the disable mode, the device is in a sleep state with quiescent current less than 150 µA. When disabled, all outputs are in a high impedance state. Sleep mode can be used for power conservation or to remove the terminator from the SCSI chain. An additional feature of the IMP5225 is its compatibility with active negation drivers. VV R IREF LINE−() = .
1 T C E N N O C S ID2 T C E N N O C S IDs t u p t u O t n e c s e i u Q m u m i x a M
LL d e l b a s iDA µ 0 5 1 n e pOn e pOd e l b a s iDA µ 0 5 1 s p e . 4 0 t _ 5 2 2 5 Figure 3. Table 1. Power Up/ Power Down Function Table Figure 1. Receiving Waveform – 20MHz Figure 2. Driving Waveform – 20MHz
© 2000 IMP , Inc. Data Communications 5 Figure 4. Application Schematic DB (1) DB (0) DISCONNECT IMP5225 IMP5225 SCSI CABLE PERIPHERAL HOST 4.7µF 5VTERM POWER MSG RST ACK DB (1) DB (0) VTERM VTERM 4.7µF DISCONNECT 5225_04.eps IMP5IMP5 11111/51/5 111122IMP5225IMP5225
© 2000 IMP, Inc. Printed in USA Publication #: 7008 Revision: C Issue Date: 08/19/02 Type: Preliminary s e h c nIs r e t e m i l l i M n iMx aMn iMx a M * ) n i P - 8 2 ( B W O S A8 9 6 .03 1 7 .00 7 . 710 1 . 8 1 B1 9 2 .09 9 2 .00 4 .70 6 . 7 C3 9 0 .04 0 1 .05 3 .25 6 . 2 D3 1 0 .08 1 0 .03 3 .01 5 . 0 F6 1 0 .00 5 0 .00 4 .07 2 . 1 GC S B 0 5 0 .0C S B 7 2 . 1 J9 0 0 .03 1 0 .03 2 .02 3 . 0 K4 0 0 .02 1 0 .00 1 .00 3 . 0 M °0 °8 °0 °8 P4 9 3 .09 1 4 .00 0 . 015 6 . 0 1 E A 3 1 0 - O M g n i w a r D C E D E J * 3 t a . 5 0 t _ 5 2 2 5 A B P DGF 28 15 141 C K J M SEATING PLANE 28-Pin (SOWB)DWP .eps Package Dimensions SOWB (28-Pin) IMP5225IMP52251IMP5225IMP5225 IMP , Inc. Corporate Headquarters 2830 N. First Street San Jose, CA 95134-2071 Tel: 408-432-9100 Fax: 408-432-1085 e-mail: info@impinc.com http://www.impweb.com The IMP logo is a registered trademark of IMP , Inc. All other company and product names are trademarks of their respective owners.