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CY29973
3.3V 125-MHz Multi-Output Zero Delay Buffer
Features
* Output Frequency up to 125 MHz * 12 Clock Outputs: Frequency Configurable * 350-ps max. Output to Output Skew * Configurable Output Disable * Two Reference Clock Inputs for Dynamic Toggling * Oscillator or PECL Reference Input * Spread Spectrum Compatible * Glitch-free Output Clocks Transitioning * 3.3V Power Supply * Pin Compatible with MPC973 * Industrial Temp. Rang: -40C to +85C * 52-Pin TQFP Package Table 1. Frequency Table[1] VC0_SEL 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 FB_SEL2 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 FB_SEL1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 FB_SEL0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 FVC0 8x 12x 16x 20x 16x 24x 32x 40x 4x 6x 8x 10x 8x 12x 16x 20x
Block Diagram
PECL_CLK PECL_CLK# VCO_SEL PLL_EN REF_SEL DQ TCLK0 TCLK1 TCLK_SEL FB_IN DQ Sync Frz 0 1 Phase Detector LPF VCO 0 1 Sync Frz QA0 QA1 QA2 QA3 QB0 QB1 FB_SEL2 QB2 QB3
Pin Configuration
52 51 50 49 48 47 46 45 44 43 42 41 40 VSS MR#/OE SCLK SDATA FB_SEL2 PLL_EN REF_SEL TCLK_SEL TCLK0 TCLK1 PECL_CLK PECL_CLK# VDD 1 2 3 4 5 6 7 8 9 10 11 12 13 39 38 37 36 35 34 33 32 31 30 29 28 27 VSS QB0 VDDC QB1 VSS QB2 VDDC QB3 FB_IN VSS FB_OUT VDDC FB_SEL0
SELB1 SELB0 SELA1 SELA0 QA3 VDDC QA2 VSS QA1 VDDC QA0 VSS VCO_SEL
CY29973
MR#/OE Power-On Reset SELA(0,1) SELB(0,1) SELC(0,1) FB_SEL(0,1) SCLK SDATA INV_CLK 2 2 2 2 /4, /6, /8, /10 Sync Pulse Data Generator /2 0 1 /4, /6, /8, /12 /4, /6, /8, /10 /2, /4, /6, /8
DQ
Sync Frz
QC0 QC1
DQ
Sync Frz Sync Frz Sync Frz
QC2 QC3
14 15 16 17 18 19 20 21 22 23 24 25 26 FB_SEL1 SYNC VSS QC0 VDDC QC1 SELC0 SELC1 QC2 VDDC QC3 VSS INV_CLK
DQ
FB_OUT
DQ
SYNC
Output Disable Circuitry
12
Note: 1. x = the reference input frequency, 200 MHz < FVCO < 480 MHz.
Cypress Semiconductor Corporation Document #: 38-07291 Rev. *B
*
3901 North First Street
*
San Jose, CA 95134 * 408-943-2600 Revised January 19, 2004
CY29973
Pin Description[2]
Pin 11 12 9 10 Name PECL_CLK PECL_CLK# TCLK0 TCLK1 VDDC VDDC VDDC VDDC PWR I/O I I I I O O O O Type PU PD PU PU PECL Clock Input. PECL Clock Input. External Reference/Test Clock Input. External Reference/Test Clock Input. Clock Outputs. See Table 2 on page 3 for frequency selections. Clock Outputs. See Table 2 on page 3 for frequency selections. Clock Outputs. See Table 2 on page 3 for frequency selections. Feedback Clock Output. Connect to FB_IN for normal operation. The divider ratio for this output is set by FB_SEL(0:2). See Table 1 on page 1. A bypass delay capacitor at this output will control Input Reference/ Output Banks phase relationships. Synchronous Pulse Output. This output is used for system synchronization. The rising edge of the output pulse is in sync with both the rising edges of QA (0:3) and QC(0:3) output clocks regardless of the divider ratios selected. PU PU PU PU PU PU PU PU PU PU Frequency Select Inputs. These inputs select the divider ratio at QA(0:3) outputs. See Table 2 on page 3. Frequency Select Inputs. These inputs select the divider ratio at QB(0:3) outputs. See Table 2 on page 3. Frequency Select Inputs. These inputs select the divider ratio at QC(0:3) outputs. See Table 2 on page 3. Feedback Select Inputs. These inputs select the divide ratio at FB_OUT output. See Table 1 on page 1. VCO Divider Select Input. When set LOW, the VCO output is divided by 2. When set HIGH, the divider is bypassed. See Table 1 on page 1. Feedback Clock Input. Connect to FB_OUT for accessing the PLL. PLL Enable Input. When asserted HIGH, PLL is enabled. When LOW, PLL is bypassed. Reference Select Input. When HIGH, the PECL inputs are selected. When LOW, TCLK[0:1] are selected. TCLK Select Input. When LOW, TCLK0 is selected. When HIGH TCLK1 is selected. Master Reset/Output Enable Input. When asserted LOW, resets all of the internal flip-flops and also disables all of the outputs. When pulled HIGH, releases the internal flip-flops from reset and enables all of the outputs. Inverted Clock Input. When set HIGH, QC(2,3) outputs are inverted. When set LOW, the inverter is bypassed. Serial Clock Input. Clocks data at SDATA into the internal register. Serial Data Input. Input data is clocked to the internal register to enable/disable individual outputs. This provides flexibility in power management. 3.3V Power Supply for Output Clock Buffers. 3.3V Supply for PLL. Common Ground. Description
44, 46, 48, 50 QA(3:0) 32, 34, 36, 38 QB(3:0) 16, 18, 21, 23 QC(3:0) 29 FB_OUT
25
SYNC
VDDC
O
42, 43 40, 41 19, 20 5, 26, 27 52 31 6 7 8 2
SELA(1,0) SELB(1,0) SELC(1,0) FB_SEL(2:0) VCO_SEL FB_IN PLL_EN REF_SEL TCLK_SEL MR#/OE
I I I I I I I I I I
14 3 4
INV_CLK SCLK SDATA
I I I
PU PU PU
17, 22, 28, 33,37, 45, 49 13
VDDC VDD
1, 15, 24, 30, VSS 35, 39, 47, 51
Note: 2. A bypass capacitor (0.1F) should be placed as close as possible to each positive power (<0.2"). If these bypass capacitors are not close to the pins their high frequency filtering characteristics will be cancelled by the lead inductance of the traces.
Document #: 38-07291 Rev. *B
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CY29973
Description
The CY29973 has an integrated PLL that provides low-skew and low-jitter clock outputs for high-performance microprocessors. Three independent banks of four outputs as well as an independent PLL feedback output, FB_OUT, provide exceptional flexibility for possible output configurations. The PLL is ensured stable operation given that the VCO is configured to run between 200 MHz to 480 MHz. This allows a wide range of output frequencies up to125 MHz. The phase detector compares the input reference clock to the external feedback input. For normal operation, the external feedback input, FB_IN, is connected to the feedback output, FB_OUT. The internal VCO is running at multiples of the input reference clock set by FB_SEL(0:2) and VCO_SEL select inputs, refer to Table 1. The VCO frequency is then divided down to provide the required output frequencies. These dividers are set by SELA(0,1), SELB(0,1), SELC(0,1) select inputs, see Table 2 below. For situations were the VCO needs to run at relatively low frequencies and hence might not be stable, assert VCO_SEL LOW to divide the VCO frequency by 2. This will maintain the desired output relationships, but will provide an enhanced PLL lock range. The CY29973 is also capable of providing inverted output clocks. When INV_CLK is asserted high, QC2 and QC3 output clocks are inverted. These clocks could be used as feedback outputs to the CY29973 or a second PLL device to generate early or late clocks for a specific design. This inversion does not affect the output to output skew.
Zero Delay Buffer
When used as a zero delay buffer the CY29973 will likely be in a nested clock tree application. For these applications the CY29973 offers a low voltage PECL clock input as a PLL reference. This allows the user to use LVPECL as the primary clock distribution device to take advantage of its far superior skew performance. The CY29973 then can lock onto the LVPECL reference and translate with near zero delay to low skew outputs. By using one of the outputs as a feedback to the PLL the propagation delay through the device is eliminated. The PLL works to align the output edge with the input reference edge thus producing a near zero delay. The reference frequency affects the static phase offset of the PLL and thus the relative delay between the inputs and outputs. Because the static phase offset is a function of the reference clock the Tpd of the CY29973 is a function of the configuration used.
Glitch-Free Output Frequency Transitions
Customarily when output buffers have their internal counter's changed "on the fly' their output clock periods will: 1. Contain short or OruntO clock periods. These are clock cycles in which the cycle(s) are shorter in period than either the old or new frequency that is being transitioned to. 2. Contain stretched clock periods. These are clock cycles in which the cycle(s) are longer in period than either the old or new frequency that is being transitioned to. This device specifically includes logic to guarantee that runt and stretched clock pulses do not occur if the device logic levels of any or all of the following pins changed "on the fly" while it is operating: SELA, SELB, SELC, and VCO_SEL.
Table 2. Divider Table VCO_SEL 0 0 0 0 1 1 1 1 SELA1 0 0 1 1 0 0 1 1 SELA0 0 1 0 1 0 1 0 1 QA VCO/8 VCO/12 VCO/16 VCO/24 VCO/4 VCO/6 VCO/8 VCO/12 SELB1 0 0 1 1 0 0 1 1 SELB0 0 1 0 1 0 1 0 1 QB VCO/8 VCO/12 VCO/16 VCO/20 VCO/4 VCO/6 VCO/8 VCO/10 SELC1 0 0 1 1 0 0 1 1 SELC0 0 1 0 1 0 1 0 1 QC VCO/4 VCO/8 VCO/12 VCO/16 VCO/2 VCO/4 VCO/6 VCO/8
SYNC Output
In situations were output frequency relationships are not integer multiples of each other the SYNC output provides a signal for system synchronization. The CY29973 monitors the relationship between the QA and the QC output clocks. It provides a low going pulse, one period in duration, one period prior to the coincident rising edges of the QA and QC outputs.
The duration and the placement of the pulse depend on the higher of the QA and QC output frequencies. The following timing diagram illustrates various waveforms for the SYNC output. Note that the SYNC output is defined for all possible combinations of the QA and QC outputs even though under some relationships the lower frequency clock could be used as a synchronizing signal.
Document #: 38-07291 Rev. *B
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CY29973
VCO 1:1 Mode QA QC SYNC 2:1 Mode QA QC SYNC 3:1 Mode QC QA SYNC 3:2 Mode QA QC SYNC 4:1 Mode QC QA SYNC 4:3 Mode QA QC SYNC 6:1 Mode QA QC SYNC
Figure 1.
Power Management
The individual output enable/freeze control of the CY29973 allows the user to implement unique power management schemes into the design. The outputs are stopped in the logic `0' state when the freeze control bits are activated. The serial input register contains one programmable freeze enable bit for 12 of the 14 output clocks. The QC0 and FB_OUT outputs can not be frozen with the serial port, this avoids any potential lock up situation should an error occur in the loading of the serial data. An output is frozen when a logic `0' is programmed and Document #: 38-07291 Rev. *B
enabled when a logic `1' is written. The enabling and freezing of individual outputs is done in such a manner as to eliminate the possibility of partial "runt" clocks. The serial input register is programmed through the SDATA input by writing a logic `0' start bit followed by 12 NRZ freeze enable bits. The period of each SDATA bit equals the period of the free running SCLK signal. The SDATA is sampled on the rising edge of SCLK.
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CY29973
Start Bit D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 D10 D11
D0-D3 are the control bits for QA0-QA3, respectively D4-D7 are the control bits for QB0-QB3, respectively D8-D10 are the control bits for QC1-QC3, respectively D11 is the control bit for SYNC
Figure 2.
Document #: 38-07291 Rev. *B
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CY29973
Absolute Maximum Conditions [3]
Maximum Input Voltage Relative to VSS: ............ VSS - 0.3V Maximum Input Voltage Relative to VDD: ............. VDD + 0.3V Storage Temperature: ................................ -65C to + 150C Operating Temperature: ................................ -40C to +85C Maximum ESD protection ............................................... 2 kV Maximum Power Supply: ................................................5.5V Maximum Input Current: ................................................ 20 mA This device contains circuitry to protect the inputs against damage due to high static voltages or electric field; however, precautions should be taken to avoid application of any voltage higher than the maximum rated voltages to this circuit. For proper operation, Vin and Vout should be constrained to the range: VSS < (Vin or Vout) < VDD Unused inputs must always be tied to an appropriate logic voltage level (either VSS or VDD).
DC Electrical Specifications VDD = 2.9V to 3.6V, VDDC = 3.3V 10%, TA = -40C to +85C
Parameter VIL VIH VPP VCMR IIL IIH VOL VOH IDDQ IDDA IDD Description Input Low Voltage Input High Voltage Peak-to-Peak Input Voltage PECL_CLK Common Mode Range PECL_CLK[4] Input Low Current[5] Voltage[6] IOL = 20 mA IOH = -20 mA VDD only QA and QB @ 60 MHz, QC @ 120 MHz, CL=30 pF QA and QB @ 25 MHz, QC @ 50 MHz, CL=30 pF Cin ZOUT Input Pin Capacitance Output Impedance Input High Current[5] Output Low Output High Voltage[6] Quiescent Supply Current PLL Supply Current Dynamic Supply Current Conditions Min. VSS 2.0 300 VDD - 2.0 - - - 2.4 - - - - - 15 Typ. - - - - - - - - 10 15 225 125 4 18 Max. 0.8 VDD 1000 VDD - 0.6 -120 120 0.5 - 15 20 - - - 22 pF Unit V V mV V A A V V mA mA mA
AC Electrical Specifications VDD = 2.9V to 3.6V, VDDC = 3.3V 10%, TA = -40C to +85C [7]
Parameter Tr/Tf Fref FrefDC Fvco Tlock Tr/Tf Fout Description TCLK Input Rise/Fall Reference Input Frequency Reference Input Duty Cycle PLL VCO Lock Range Maximum PLL lock Time Output Clocks Rise/Fall Time[9] Maximum Output Frequency 0.8V to 2.0V Q (/2) Q (/4) Q (/6) Q (/8) FoutDC Output Duty Cycle[9] Note 8 25 200 - 0.15 - - - - TCYCLE/2 - 750 Conditions Min. Typ. - - - - - - - - - - - Max. 3.0 Note 8 75 480 10 1.2 125 120 80 60 TCYCLE/2 + 750 ps Unit ns MHz % MHz ms ns MHz
Notes: 3. Multiple Supplies: The voltage on any input or I/O pin cannot exceed the power pin during power-up. Power supply sequencing is NOT required. 4. The VCMR is the difference from the most positive side of the differential input signal. Normal operation is obtained when the "High" input is within the VCMR range and the input lies within the VPP specification. 5. Inputs have pull-up/pull-down resistors that effect input current. 6. Driving series or parallel terminated 50 (or 50 to VDD/2) transmission lines. 7. Parameters are guaranteed by design and characterization. Not 100% tested in production. 8. Maximum and minimum input reference is limited by VC0 lock range. 9. Outputs loaded with 30pF each.
Document #: 38-07291 Rev. *B
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CY29973
AC Electrical Specifications VDD = 2.9V to 3.6V, VDDC = 3.3V 10%, TA = -40C to +85C (continued)[7]
Parameter tpZL, tpZH tpLZ, tpHZ TCCJ TSKEW Tpd Description Output Enable Time[9](all outputs) Output Disable Time[9](all outputs) Cycle to Cycle Jitter[9](peak to peak) Any Output to Any Output Skew[9,10] Propagation Delay[10,11] PECL_CLK TCLK0 TCLK1 QFB =(8) Conditions Min. 2 2 - - -225 -70 -130 Typ. - - 100 250 -25 130 70 Max. 10 8 - 350 175 330 270 Unit ns ns ps ps ps
Ordering Information
Part Number CY29973AI CY29973AIT Package Type 52-pin TQFP 52-pin TQFP Production Flow Industrial, -40C to +85C Industrial, -40C to +85C
Package Drawing and Dimensions
52-Lead Thin Plastic Quad Flat Pack (10 x 10 x 1.0 mm) A52B
51-85158-**
Notes: 10. 50 transmission line terminated into VDD/2. 11. Tpd is specified for a 50MHz input reference. Tpd does not include jitter.
All product and company names mentioned in this document are the trademarks of their respective holders.
Document #: 38-07291 Rev. *B
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(c) Cypress Semiconductor Corporation, 2004. The information contained herein is subject to change without notice. Cypress Semiconductor Corporation assumes no responsibility for the use of any circuitry other than circuitry embodied in a Cypress Semiconductor product. Nor does it convey or imply any license under patent or other rights. Cypress Semiconductor does not authorize its products for use as critical components in life-support systems where a malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress Semiconductor products in life-support systems application implies that the manufacturer assumes all risk of such use and in doing so indemnifies Cypress Semiconductor against all charges.
CY29973
Document History Page
Document Title: CY29973 3.3V 125-MHz Multi-Output Zero Delay Buffer Document Number: 38-07291 REV. ** *A *B ECN NO. 111102 122883 200081 Issue Date 02/07/02 12/22/02 See ECN Orig. of Change BRK RBI RGL New data sheet Added power up requirements to Maximum Ratings Added ZOUT specifications in the DC Electrical Specs Changed the Package Drawing and Dimension to CY standard Description of Change
Document #: 38-07291 Rev. *B
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