PACDT Datasheet, PDF (1/2 Pages) California Micro Devices Corp – P/Active 1% Tolerance Dual Thevenin Termination Network

CALIFORNIA MICRO DEVICES
PACDT
P/Active 1% Tolerance Dual Thévenin Termination Network
Features
• Minimal ground bounce, crosstalk
• Stable 1% absolute tolerance elements
• 16 terminating lines per QSOP package
• Saves board space and reduces assembly cost
Applications
• HSTL termination
• Thévenin termination
• ECL, TTL termination
Product Description
High speed logic devices like HSTL (High Speed
Transceiver Logic) demand unique, high speed bus
terminations. The dual Thévenin termination network
provides 16 terminating channels per package, and
optimizes signal integrity by reducing reflections and
ringing. The terminations are available in a range of
standard values and are ideal for use in HSTL busses.
As seen in the schematic, R1 is typically tied to V_CC and
serves as a pull-up resistor, while R2 functions as a pull-
down resistor and is tied to ground (or the most negative
supply voltage). In addition, the equivalent Thévenin
resistance (R1 in parallel with R2) should match the
impedance of the trace. Ground-bounce and crosstalk
are virtually eliminated using a proprietary lead-frame
which includes four direct ground connections to the die
substrate, as well as four double-bonded connections to
V_CC, for a total of 8 commons. In addition, the resistors
are trimmed to a tight absolute tolerance of 1% which
provides tight impedance-matching and results in greatly
reduced reflections. This unique proprietary design
provides optimal signal integrity.
STANDARD VALUES
Absolute Tolerance (R1 & R2) ±1%
TCR
±100ppm
Operating Temperature Range
Power Rating/Resistor
0_˚C to 70_˚C
100mW
Crosstalk (see Test Circuit)
30mV TYP
Package
24 Pin QSOP
BUS IMPEDANCE (Ω)
47
50
56
68
R1(Ω)
94
100
112
136
R2 (Ω)
94
100
112
136
CODE
001
002
003
004
SCHEMATIC CONFIGURATION
24
23
V_CC
21
22 20
17
19
18 16
15
14
13
1
2
3
46
7
5
8 10
11
9
GND
12
R Code
001
002
003
004
STANDARD PART ORDERING INFORMATION
Package
Ordering Part Number
Pin
Style
Tubes
Tape & Reel
24
QSOP
PAC001DTFQ/T
PAC001DTFQ/R
24
QSOP
PAC002DTFQ/T
PAC002DTFQ/R
24
QSOP
PAC003DTFQ/T
PAC003DTFQ/R
24
QSOP
PAC004DTFQ/T
PAC004DTFQ/R
© 2000 California Micro Devices Corp. All rights reserved.
215 Topaz Street, Milpitas, California 95035 
11/19/2000
Tel: [phone]
Fax: [phone]
Part Marking
PAC001DTFQ
PAC002DTFQ
PAC003DTFQ
PAC004DTFQ
C1611100
www.calmicro.com
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