VSC838UG VITESSE [Vitesse Semiconductor Corporation], VSC838UG Datasheet - Page 9

• Manufacturer Part Number: VSC838UG
• Description: 3.2Gb/s 36x37 Crosspoint Switch
• Manufacturer: VITESSE [Vitesse Semiconductor Corporation]

G52351-0, Rev 3.0
02/12/01
Preliminary Data Sheet
VSC838
I/O Equivalent Circuits
Input Termination
complement inputs. Termination resistors are isolated from each other on-chip. The termination will self-bias to
+2.0V (nominal) for AC-coupled applications. The ITC pin enables direct interconnection of multiple VSC838
devices. With ITC tied to V
terminations to act as loads for an open-drain or open-collector differential output.
Table 7: Allowed Input Termination Schemes
Table 8.
Table 8: Additional Current and Power
Parameter
Type
PAD
P
I
The high-speed inputs of the VSC838 are internally terminated by a 100
Some allowed termination schemes result in additional I
1
2
3
4
5
CC-C
CC-C
Description
AC-coupled input
DC-coupled from open-drain CML
DC-coupled from back-terminated 2.5V CML
DC-coupled from back-terminated 2.5V CML
DC-coupled from back-terminated 3.3V LV-PECL
Additional ICC current when receiving DC-
Coupled CML (ITC = HIGH)
Additional power dissipated on-chip for
DC terminating CML at inputs
H/S Input Equivalent Circuit
50
© VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012
Description
Tel: (800) VITESSE • FAX: [phone] • Email: [e-mail]
CC
, the center point of the 100
VITESSE
50
SEMICONDUCTOR CORPORATION
ITC
VCC
Internet: www.vitesse.com
PAD
Min
PAD
Tie ITC LOW, 100 differential input termination,
input self-biased
Tie ITC HIGH, terminations acts as 50 load to V
Tie ITC HIGH, terminations acts as 50 load to V
Tie ITC LOW, 100 differential termination
(preferred over Type 3)
Tie ITC LOW, 100 differential termination
termination impedance is tied to V
Typ
CC
current and power dissipation on-chip. See
H/S Output Equivalent Circuit
Max
0.180
180
50
Units
Comments
mA
W
impedance between true and
36x37 Crosspoint Switch
50
TERM_CTRL
Conditions
DRIVE_CTRL
CC
, causing the
PAD
CC
CC
3.2Gb/s
Page 9