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Details, datasheet, quote on part number:P1707A-08TR
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Datasheet text preview:
Production February 2003
®
P1707A
Notebook LCD Panel EMI Reduction IC
Features
· · · · · · · · FCC approved method of EMI attenuation Generates a low EMI spread spectrum of the input clock frequency Optimized for frequency range from 60 to 175 MHz operation Internal loop filter minimizes external components and board space Four selectable spread ranges Low inherent cycle-to-cycle jitter 3.3 V operating voltage CMOS/TTL compatible inputs and outputs · Ultra low power CMOS design: 14.85 mA @ 3.3 V, 140 MHz 16.69 mA @ 3.3 V, 162 MHz
17.78 mA @ 3.3 V, 175 MHz
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Supports notebook VGA and other LCD timing controller applications Pinout compatible to ICS MK1707 and Cypress CY25561 / CY25560 SSON/SBM pin for spread spectrum on/off and standby mode controls Available in 8-pin SOIC and TSSOP
Product Description
The P1707A is a versatile spread spectrum frequency modulator designed specifically for a wide range of clock frequencies. The P1707A reduces electromagnetic interference (EMI) at the clock source, allowing system wide reduction of EMI of down stream clock and data dependent signals. The P1707A allows significant system cost savings by reducing the number of circuit board layers and shielding that are traditionally required to pass EMI regulations. The P1707A modulates the output of a single PLL in order to "spread" the bandwidth of a synthesized clock, thereby decreasing the peak amplitudes of its harmonics. This results in significantly lower system EMI compared to the typical narrow band signal produced by oscillators and most clock generators. Lowering EMI by increasing a signal's bandwidth is called spread spectrum clock generation. The P1707A uses the most efficient and optimized modulation profile approved by the FCC and is implemented by using a proprietary all-digital method.
Applications
The P1707A is targeted toward notebook LCD displays, other displays using an LVDS interface, PC peripheral devices, and embedded systems.
Pin Diagram
CLKIN VDD VSS ModOUT
1 2 3 4
8 7 6 5
NC SR0 SR1 SSON/SBM
Alliance Semiconductor
2575 Augustine Drive · Santa Clara, CA 95054 · Tel: 408.855.4900 · Fax: 408.855.4999 · www.alsc.com
Notice: The information in this document is subject to change without notice.
P1707A
®
Block Diagram
VDD SR0 SR1 SSON
M o d u la t io n C L K IN F re q u e n c y D iv id e r Feedback D iv id e r
PLL
P hase D e te c to r
Loop F ilt e r
VCO
O u tp u t D iv id e r
M odO UT
P 1 7 0 7 A B lo c k D ia g r a m VSS
Standby Mode Selection
CLKIN Disabled Disabled Enabled Enabled SSON/SBM 0 1 0 1 Spread Spectrum N/ A N/ A O FF ON ModOut Disabled Disabled Reference Normal PLL Dis abled Free running Disabled Normal Mode Standby Free running Buffer out Normal
Spread Range Selection
SR1 0 0 1 1 SR 0 0 1 0 1 Spreading Range ± 1.50% ± 2.50% ± 0.50% ± 1.00% Modulation rate (Fin/80)*34.72 KHz (Fin/80)*34.72 KHz (Fin/80)*34.72 KHz (Fin/80)*34.72 KHz
February 2003
Notebook LCD Panel EMI Reduction IC
Notice: The information in this document is subject to change without notice.
2 of 7
P1707A
®
Pin Description
Pin # 1 Na m e CLKIN Type I Description Connect to externally generated clock signal. To put the part into standby mode, disable the input clock signal to this pin and pull SSON/SBM (pin 5) low (see Standby Mode Selection). Connect to +3.3 V Ground connection. Connects to system ground. Spread spectrum clock output. Spread spectrum on/off and standby mode control (see Standby Mode Selection). This pin has an internal pullup resistor. Digital logic input used to select the spreading range (see Spread Range Selection). This pin has an internal pull-up resistor. Digital logic input used to select the spreading range (see Spread Range Selection). This pin has an internal pull-up resistor. No connect
2 3 4 5
VDD VSS ModOUT SSON/SBM
P P O I
6
S R1
I
7
S R0
I
8
NC
NC
Schematic for Notebook VGA Application
60 MHz to 175 MHz pixel clock input from VGA chip
0.1 uF FB VDD
1 CLKIN 2 VDD 3 VSS 4 ModOUT
NC SR 0 SR 1 SSON
8 7 6 5
Pin 8 can be tied either high or low, or it can be left unconnected. Tie SR0 and SR1 high/low according to spread range desired. External resistors are not needed to pull these pins high. Pin 5 SSON should be left unconnected to turn on spread spectrum. Pull this pin low to turn spread spectrum OFF and enable stand-by mode.
P1707A
Note: To set the P1707A into standby mode, disable the input clock (CLKIN, pin1) and pull SSON (pin 5) low (see Standby Mode Selection).
February 2003
Notebook LCD Panel EMI Reduction IC
Notice: The information in this document is subject to change without notice.
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