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ABE0101/02/04/06
Low EMI Spread Spectrum Multiplier Clock
FEATURES
• • • • • • • • • Spread Spectrum Clock Generator with selectable multiplier from 1x to 6x outputs. Output frequency ranges: 10MHz to 180MHz. Accepts input from crystal or reference clock. Selectable Center, Down or Asymmetric Spread Modulation. Selectable Modulation rate. TTL/CMOS compatible outputs. 3.3V Operating Voltage. Low short term jitter. Available in 8-Pin 150mil SOIC.
PIN CONFIGURATION
XIN/FIN XOUT/SD*^ SC0^ SC1^ 1 8 VDD SC2^ FOUT GND
ABE010x
2 3 4
7 6 5
XIN/FIN = 10 ~ 30 MHz
Note: ^: Internal pull-up resistor (120k Ω for SD, 30 k Ω for SC0-SC2). *: The value of SD is latched upon power-up. The internal pull-up resistor results in a default high value when no pull-down resistor is connected to this pin (recommended external pull-down resistor of 27 k Ω ).
DESCRIPTION
The ABE0101/02/04/06 are Spread Spectrum Clock Generators designed for the purpose of reducing EMI in high-speed digital systems. Any output frequency from 10 to 180MHz can be selected by programming 6 multiplier modes. The device is designed to operate from a crystal or reference clock input and provides 1x to 6x modulated clock outputs.
OUTPUT CLOCK (FOUT) SELECTION
SD
1 1 0 1 0 1 0 1 0 1 0 1 0 1
SC2
0 0 0 0 0 0 0 1 1 1 1 1 1 1
SC1
0 0 0 1 1 1 1 0 0 0 0 1 1 1
SC0
0 1 1 0 0 1 1 0 0 1 1 0 0 1
FOUT (01)
X1 X1 X1 X1 X1 X1 X1 X1 X1 X1 X1 X1 X1 X1
FOUT (02)
X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2
FOUT (04)
X4 X4 X4 X4 X4 X4 X4 X4 X4 X4 X4 X4 X4 X4
FOUT (06)
X6 X6 X6 X6 X6 X6 X6 X6 X6 X6 X6 X6 X6 X6
SST Modulation Magnitude
0.50% 1.00% 1.50% 2.00% Fin / 512 2.50% 3.00% 3.50% OFF
Freq.
C C D C A C A C A C A C A
Type
± 0.25% ± 0.5% -1.0% ± 0.75% +0.25% ~ -1.25% ± 1.0% +0.5% ~ -1.5% ± 1.25% +0.75% ~ -1.75% ± 1.5% +1.0% ~ -2.0% ± 1.75% +1.25% ~ -2.25%
Notes: C: Center Spread. A: Asymmetric Spread. D: Down Spread.
30332 Esperanza., Rancho Santa Margarita, Ca 92688 Ph: 949-546-8000 Fax: 949-546-8001 www.Abracon.com 03/21/05 Page 1
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ABE0101/02/04/06
Low EMI Spread Spectrum Multiplier Clock
BLOCK DIAGRAM
XIN/FIN XOUT
XTAL OSC
PLL SST
FOUT
SC(0:2)
Control Logic
PIN DESCRIPTIONS
Name
XIN/FIN XOUT/SD SC0 SC1 GND FOUT SC2 VDD
Number
1 2 3 4 5 6 7 8
Type
I B I I P O I P
Description
Crystal input to be connected to fundamental parallel mode crystal.(C L =18pF) or clock input. At power-up, this pin is an input pin to select modulation type. After input sampling, this pin is crystal output. Has internal pull up resistor. Digital control input to select modulation magnitude. Has internal pull-up. Digital control input to select modulation magnitude. Has internal pull-up. Ground. Modulated Clock Frequency Output. The frequency before modulation is synthesized by multiplying the input frequency by 1X, 2X, 4X, 6X depending on the part number (ABE0101, 02, 04, 06). Digital control input to select modulation magnitude. Has internal pull-up. Power Supply.
FUNCTIONAL DESCRIPTION Selectable spread spectrum and modulation magnitudes
The ABE0101/02/04/06 provides selectable spread spectrum modulation type, as well as selectable modulation magnitude. Selection is made by connecting specific pins to a logical “zero” or “one” according to the output clock selection table on page 1. In order to reduce the number of pins on the chip, the ABE0101/02/04/06 uses pin 2 (XOUT/SD) as a bi-directional pin. The pin serves as modulation type selector input (SD) upon power-up (see output clock selection table on page 1), and as XOUT crystal connection as soon as the input has been latched. Pins 3 (SC0), 4 (SC1), and 7 (SC2) are used as inputs to select the spread spectrum modulation magnitude as shown on the output clock selection table (page 1).
30332 Esperanza., Rancho Santa Margarita, Ca 92688 Ph: 949-546-8000 Fax: 949-546-8001 www.Abracon.com 03/21/05 Page 2
www.DataSheet4U.com
ABE0101/02/04/06
Low EMI Spread Spectrum Multiplier Clock
Connecting a selection pin to a logical “one”
All selection pins have an internal pull-up resistor (30k Ω for pins 3, 4, 7, and 120k Ω for pin 2). This internal pull-up resistor will pull the input value to a logical “one” (pull-up) by default, i.e. when no resistive load is connected between the pin and GND. No external pull-up resistor is therefore required for connecting a logical “one” upon power-up.
Connecting a selection pin to a logical “zero”
For an input only pin, i.e. pins 3 (SC0), 4 (SC1), and 7 (SC2), the pin simply needs to be grounded to pull the input down to a logical “zero”. Connecting the bi-directional pin (SD) to a logical “zero” will however require the use of a 27k Ω loading resistor between the pin and GND.
ELECTRICAL SPECIFICATIONS
1. Absolute Maximum Ratings PARAMETERS
Supply Voltage Input Voltage, dc Output Voltage, dc Storage Temperature Ambient Operating Temperature* Junction Temperature Lead Temperature (soldering, 10s) ESD Protection, Human Body Model
SYMBOL
V DD VI VO TS.