Termination, Single-ended alternative (b) [active terminator – FUJITSU C150-E049-02EN User Manual

Page 38

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M3099GX/GH OEM Manual

3-5

INTERFACE

Termination

All signals not defined as RESERVED, GROUND, or TERMPWR
shall be terminated at both ends of the cable. The Implementor may
choose one of the following two methods to terminate each end (see
ANSI SCSI-2 ANSI SCSI-2 5.4 Electrical description):

Single-ended alternative (a) [Passive terminator]

TERMINATOR POWER

220

330

–SIGNAL

GROUND

Figure 3.2 Alternative 1 termination for Single Ended Devices

Single-ended alternative (b) [Active terminator]

Low dropout voltage regulater
Imax

600mA

Vout = 2.85V
(See Note 1)

Vin

Vout

Vadj

R1

R2

C2

C3

+

R3

Component

Description

R1
R2

R3-R20

C1
C2
C3

121

, 1%, 0.25W

154

, 1%, 0.25W

110

, 1%

10

µ

F Alum.15V or 4.7

µ

F Tant. 15V

150

µ

F Alum.10V or 22

µ

F Tant. 10V (ESR at 120 Hz < 4)

0.1

µ

F Ceramic 25V

+

R20

NOTES
1 The voltage regulator shown is an adjustable type with Vref=1.25V.
R1 and R2 were selected to provide approximately 10mA Iquiescent.
The voltage regulator Vdropout shall be 1.25V or less at Imax.
2 Alternative values that provide lower performance at somewhat
lower cost use Vout 1%; R3

R20=100

,2%

Figure 3.3 Alternative 2 termination for Single Ended Devices

The first termination method above is the same as in SCSI-1. The
second termination method is recommended for better signal quality.

#03.pm5

98.2.22, 1:31 PM

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