© 2000 California Micro Devices Corp. All rights reserved.
4/00 215 Topaz Street, Milpitas, California 95035 Tel: (408) 263-3214 Fax: (408) 263-7846 www.calmicro.com 1
CALIFORNIA MICRO DEVICES PACTFSERIES
P/ACTIVE® CLOCK TERMINATION AND FILTER
Features
8 Channels in Miniature QSOP Package
Frequency Response to greater than 3 GHz
Low In-Band Insertion Loss Maintains
Signal Integrity
Low Distortion, Low Cross Talk
ESD Protected
Applications
High speed microprocessor clock termination
Product Description
High speed microprocessor systems require well controlled, precise, fast edge-rate clock signals. Clock lines behave as
transmission lines for fast-edge signals and therefore the lines may exhibit transients caused by reflections and switching
noise. The PACTF clock filter reduces reflections and slows down edges to help reduce EMI/RFI radiation.
California Micro Devices P/Active Tapped Filter is an integrated thin film resistor-capacitor network designed to filter clock
lines and suppress EMI/RFI noise in personal computers and peripherals, workstations, Local Area Network (LAN), Asynchro-
nous Transfer Mode (ATM), and Wide Area Network (WAN). The filter includes ESD protection circuitry which prevents
device destruction when subjected to ESD discharges less than 2KV. The ESD protection circuitry permits the filter to
operate on bipolar signals of up to ±6V. California Micro Devices PAC TF is housed in a surface mount package suitable
for bottom side mounting to the board. This integrated network solution minimizes space and routing problems and
improves reliability and yields.
SCHEMATIC CONFIGURATION
2021222324 19 18 17 16 15 14 13
1211
12345678910
* ESD Protection level guaranteed by design.
C0380798
Pin Assignments
SNOITACIFICEPSDRADNATS
)R(ecnareloTetulosbA %01±
)C(ecnareloTetulosbA %02±
egnaRerutarepmeTgnitarepOC°07otC°0
rotsiseR/gnitaRrewoP
Wm001
tnerruCegakaeL .xamCº52@Aµ1
)tiucriCtxeTees(klatssorC )lacipyt(%5<
pmalCDSE
pmalCevitisoP
pmalCevitageN
6>stloV
-<6stloV
*noitcetorPDSE.nimVK2
erutarepmeTegarotSC°051otC°06-
gnitaRrewoPegakcaP.xam,W00.1
©2000 California Micro Devices Corp. All rights reserved.
4/00
215 Topaz Street, Milpitas, California 95035 Tel: (408) 263-3214 Fax: (408) 263-7846 www.calmicro.com
2
CALIFORNIA MICRO DEVICES PACTFSERIES
with 0 source impedance
Filter Cross Talk Test Circuit (TA=25oC)
50 Ohm
50
V
Pulse Generator
5 volt, 10 MHz,
> 1 nS Rise /
Fall Time
V = Victim Voltage
NOITAMROFNIGNIREDROTRAPDRADNATS egakcaPrebmuNtraPgniredrO
edoCCRsniP*elytSsebuTleeR&epaTgnikraMtraP
T001/02242POSQT/QFT001/022CAPR/QFT001/022CAPQFT001/022CAP
T051/02242POSQT/QFT051/022CAPR/QFT051/022CAPQFT051/022CAP
T001/03342POSQT/QFT001/033CAPR/QFT001/033CAPQFT001/033CAP
T051/03342POSQT/QFT051/033CAPR/QFT051/033CAPQFT051/033CAP
DRADNATSSEULAV
(RΩ)(Cfp)edoCCR‡bd3@cf
22
22
01
51
T001/022
T051/022 zHM327
zHM284
33
33
01
51
T001/033
T051/033 zHM284
zHM223
© 2000 California Micro Devices Corp. All rights reserved.
4/00 215 Topaz Street, Milpitas, California 95035 Tel: (408) 263-3214 Fax: (408) 263-7846 www.calmicro.com 3
CALIFORNIA MICRO DEVICES PACTFSERIES
-2
-4
-8
-10
-12
-14
33 Ω Filter
10 MHz 100 MHz 1 GHz
S parameters are measured using a Hewlett Packard HP8753C Network Analyzer with a HP85047A S-parameter Test Set.
Filter Insertion Loss (S12, dB), Typical (TA = 25°C) Representative Sample
ATTENUATION CURVES
Application Information
The PACTF-2 is designed to minimize the EMI/RFI noise from the clock signals on PC motherboards. In order to get the best
results, the PACTF should be located as close as possible to the clock generator chips, such as Cypress CY2030 (used for
peripherals) and CY2275 (used for CPU, AGP, PCI, and SDRAM).
0
-5
-10
-15
22 Ω Filter
10 MHz 100 MHz 1 GHz
13
14
15
17
16
18
19
20
3
23
5
6
7
8
9
10
11
12
2
4
24 1
22
21
C = 10pF
C = 15pF C = 10pF
C = 15pF
