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CY29972
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 crystal reference input Spread-spectrum-compatible Glitch-free output clocks transitioning 3.3V power supply Pin-compatible with MPC972 Industrial temperature range: -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
Note: 1. x = the reference input frequency, 200 MHz < FVCO < 480 MHz.
Block Diagram
XIN XOUT 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 XIN XOUT 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
VCO_SEL
SELA0
SELA1
SELB0
SELB1
VDDC
VDDC
QA0
QA1
QA2
QA3
VSS
CY29972
VSS
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 DQ /2 0 1 DQ DQ /4, /6, /8, /12 /4, /6, /8, /10 /2, /4, /6, /8 DQ
Sync Frz
QC0 QC1
14 15 16 17 18 19 20 21 22 23 24 25 26
Sync Frz Sync Frz Sync Frz
QC2
INV_CLK
VSS
QC3
VDDC
QC2
SELC1
SELC0
QC1
VDDC
QC0
VSS
SYNC
FB_SEL1
QC3 FB_OUT
SYNC
Output Disable Circuitry
12
Cypress Semiconductor Corporation Document #: 38-07290 Rev. *A
*
3901 North First Street
*
San Jose
*
CA 95134
* 408-943-2600 December 22, 2002
CY29972
Pin Description[2]
Pin 11 12 9 10 44, 46, 48, 50 32, 34, 36, 38 16, 18, 21, 23 29 Name XIN XOUT TCLK0 TCLK1 QA(3:0) QB(3:0) QC(3:0) FB_OUT VDDC VDDC VDDC VDDC PWR I/O I O I I O O O O PU PU Type Description Oscillator Input. Connect to a crystal. Oscillator Output. Connect to a crystal. External Reference/Test Clock Input. External Reference/Test Clock Input. Clock Outputs. See Table 2 for frequency selections. Clock Outputs. See Table 2 for frequency selections. Clock Outputs. See Table 2 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. 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. Frequency Select Inputs. These inputs select the divider ratio at QB(0:3) outputs. See Table 2. Frequency Select Inputs. These inputs select the divider ratio at QC(0:3) outputs. See Table 2. Feedback Select Inputs. These inputs select the divide ratio at FB_OUT output. See Table 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. Feedback Clock Input. Connect to FB_OUT for accessing the PLL. PLL Enable Input. When asserted high, PLL is enabled. And when low, PLL is bypassed. Reference Select Input. When high, the crystal oscillator is selected. And when low, TCLK (0,1) is the reference clock. TCLK Select Input. When LOW, TCLK0 is selected and 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 power supply for PLL. Common ground.
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 1, 15, 24, 30, 35, 39, 47, 51
VDDC VDD VSS
Note: 2. A bypass capacitor (0.1 mF) 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.
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CY29972
Description
The CY29972 has an integrated PLL that provides low skew and low jitter clock outputs for high-performance microprocessors. Three independent banks of four outputs and 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 and 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 Table 2. 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 inputs (refer to Frequency Table). The VCO frequency is then divided to provide the required output frequencies. These dividers are set by SELA(0,1), SELB(0,1), SELC(0,1) select inputs (see Table 3 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 CY29972 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 CY29972 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.
Glitch-Free Output Frequency Transitions
Customarily, when output buffers have their internal counters changed "on the fly," their output clock periods will: 1. contain short or "runt" clock periods. These are clock cycles in which the cycle(s) are shorter in period than either the old or new frequencies to which the cycles are being transitioned. 2. contain stretched clock periods. These are clock cycles in which the cycle(s) are longer in period than either the old or new frequencies to which the cycles are being transitioned. 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.
SYNC Output
In situations where output frequency relationships are not integer multiples of each other, the SYNC output provides a signal for system synchronization. The CY29972 monitors the relationship between the QA and 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 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 QA and QC outputs, even though under some relationships the lower frequency clock could be used as a synchro-
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CY29972
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. Timing Diagram
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CY29972
Power Management
The individual output enable/freeze control of the CY29972 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 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.
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. Table 3. Suggested Oscillator Crystal Parameters Symbol TC TS TA CL RESR Characteristic Frequency Tolerance Frequency Temperature Stability Aging Load Capacitance Effective Series Resistance (ESR) 20 40 Min Typ Max 100 100 5 - 80 Units PPM PPM PPM/Yr pF Ohms Note 3 (TA -10 to +60C)[3] (first 3 years @ 25C)[3] The crystal's rated load.[3] Note 44 Conditions
Notes: 3. For best performance and accurate frequencies from this device, It is recommended but not mandatory that the chosen crystal meet or exceed these specifications. 4. Larger values may cause this device to exhibit oscillator start-up problems.
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CY29972
Maximum Ratings [5]
Maximum input voltage relative to VSS: .............. VSS - 0.3V Maximum input voltage relative to VDD: ............... VDD + 0.3V Storage temperature: .............................-65 x C to +150 x C Operating temperature:............................-40 x C to +85 x C Maximum ESD protection ................................................ 2kV 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 Parameters VDD = 2.9V to 3.6V, VDDC = 3.3V 10%, TA = -40C to +85C
Parameter VIL VIH IIL IIH VOL VOH IDDQ IDDA IDD CIN Description Input Low Voltage Input High Voltage Input Low Current[6] Input High Current Output Low Voltage[7] Output High Voltage[7] Quiescent Supply Current PLL Supply Current Dynamic Supply Current Input Pin Capacitance IOL = 20mA IOH = -20mA VDD only QA and QB @ 60 MHz, QC @ 120 MHz, CL = 30 pF QA and QB @ 25 MHz, QC @ 50 MHz, CL = 30pF - 2.4 - 10 15 225 125 4 Test Conditions Min. VSS 2.0 Typ. - - - Max. 0.8 VDD -120 10 0.5 15 20 Unit V V A A V V mA mA mA pF
Notes: 5. 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. 6. Inputs have pull-up/pull-down resistors that effect input current. 7. Driving series or parallel terminated 50 (or 50 to VDD/2) transmission lines.
AC Parameters VDD = 2.9V to 3.6V, VDDC = 3.3V 10%, TA = -40C to +85C[8]
Parameter Tr / Tf Fref Fxtal FrefDC Fvco Tlock Tr / Tf Description TCLK Input Rise/Fall Reference Input Frequency Crystal Oscillator Frequency Reference Input Duty Cycle PLL VCO Lock Range Maximum PLL Lock Time Output Clocks Rise / Fall Time
[10]
Conditions
Min Note 9
Typ
Max 3.0 Note 9 25 75 480 10 1.2 125 120 80 60
Unit ns MHz MHz % MHz ms ns
see Table 3
10 25 200
0.8V to 2.0V Q (/2) Q (/4) Q (/6) Q (/8)
0.15 -
Fout
Maximum Output Frequency
MHz
FoutDC tpZL, tpZH tpLZ, tpHZ TCCJ TSKEW Tpd
Output Duty Cycle[10] Output Enable Time Cycle to Cycle Jitter
[10]
TCYCLE/2 - 750 (all outputs) 2 2 100 250 QFB = (/8) -270 -330 130 70
TCYCLE/2 + 750 10 8 350 530 470
ps ns ns ps ps ps
Output Disable Time[10](all outputs)
[10]
(peak to peak) TCLK0 TCLK1
Any Output to Any Output Skew[10,11] Propagation Delay[11,12]
Notes: 8. Parameters are guaranteed by design and characterization. Not 100% tested in production. 9. Maximum and minimum input reference is limited by VC0 lock range. 10. Outputs loaded with 30 pF each. 11. 50W transmission line terminated into VDD/2. 12. Tpd is specified for a 50 MHz input reference. Tpd does not include jitter.
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CY29972
Ordering Information
Part Number CY29972AI Package Type 52-pin TQFP Production Flow Industrial, -40C to +85C Inches Symbol A A1
D
Package Drawing and Dimensions
Min. 0.002 0.037 -
Millimeters Max. 0.047 0.006 0.041 0.015 Min. Nom. 0.05 0.95 0.22 12.00 10.00 0.65 BSC 0.45 0.75 Max. 1.20 0.15 1.05 0.38
Nom. 0.0472 0.394
A2 D D1 b e
0.009
-
0.026 BSC 0.018 0.030
D1 10 A1 A2 A L e b
L
All product and company names are the trademarks of their respective holders.
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CY29972
Revision History
Document Title: 3.3V, 125 MHz Multi-Output Zero Delay Buffer Document Number: 38-07290 REV. ** *A ECN NO. 111101 122882 Issue Date 02/07/02 12/22/02 Orig. of Change BRK RBI New Data Sheet Added power up requirements to Maximum Ratings Description of Change
Document #: 38-07290 Rev. *A
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