View CY28352_929940.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

CY28352
Differential Clock Buffer/Driver DDR400- and DDR333-Compliant
Features
* Supports 333 MHz and 400-MHz DDR SDRAM * 60- 200 MHz operating frequency * Phase-locked loop (PLL) clock distribution for double data rate synchronous DRAM applications * Distributes one clock input to six differential outputs * External feedback pin FBIN is used to synchronize output to clock input * Conforms to DDRI specification * Spread AwareTM for electromagnetic interference (EMI) reduction * 28-pin SSOP package
Description
This PLL clock buffer is designed for 2.5-VDD and 2.5-AVDD operation and differential output levels. This device is a zero delay buffer that distributes a clock input CLKIN to six differential pairs of clock outputs (CLKT[0:5], CLKC[0:5]) and one feedback clock output FBOUT. The clock outputs are controlled by the input clock CLKIN and the feedback clock FBIN. The two-line serial bus can set each output clock pair (CLKT[0:5], CLKC[0:5]) to the Hi-Z state. When AVDD is grounded, the PLL is turned off and bypassed for test purposes. The PLL in this device uses the input clock CLKIN and the feedback clock FBIN to provide high-performance, low-skew, low-jitter output differential clocks.
Block Diagram
Pin Configuration
10
SCLK SDATA
Serial Interface Logic
CLKT2 CLKC2 CLKT3 CLKC3
CLKIN NC AVDD AGND VDD CLKT2 CLKC2
CY28352
CLKT0 CLKC0 CLKT1 CLKC1
CLKC0 CLKT0 VDD CLKT1 CLKC1 GND SCLK
CLKIN PLL FBIN
CLKT4 CLKC4 CLKT5 CLKC5
1 2 3 4 5 6 7 8 9 10 11 12 13 14
28 27 26 25 24 23 22 21 20 19 18 17 16 15
GND CLKC5 CLKT5 CLKC4 CLKT4 VDD SDATA NC FBIN FBOUT NC CLKT3 CLKC3 GND
AVDD
FBOUT
28 pin SSOP
Rev 1.0, November 21, 2006
2200 Laurelwood Road, Santa Clara, CA 95054 Tel:(408) 855-0555 Fax:(408) 855-0550
Page 1 of 7
www.SpectraLinear.com
CY28352
Pin Description[1]
Pin Number Pin Name 8 CLKIN 20 FBIN I/O I I O O O I I/O Pin Description Complementary Clock Input. Feedback Clock Input. Connect to FBOUT for accessing the PLL. Clock Outputs Clock Outputs Feedback Clock Output. Connect to FBIN for normal operation. A bypass delay capacitor at this output will control Input Reference/Output Clocks phase relationships. 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. 2.5V Power Supply for Logic 2.5V Power Supply for PLL Ground Analog Ground for PLL Not Connected Output Electrical Characteristics Input Input Differential Outputs
2,4,13,17,24, CLKT(0:5) 26 1,5,14,16,25, CLKC(0:5) 27 19 7 22 3,12,23 10 6,15,28 11 9, 18, 21 FBOUT SCLK SDATA VDD AVDD GND AGND NC
Data Input for the two line serial bus Data Input and Output for the two line serial bus 2.5V Nominal 2.5V Nominal
Zero Delay Buffer
When used as a zero delay buffer the CY28352 will likely be in a nested clock tree application. For these applications the CY28352 offers a clock input as a PLL reference. The CY28352 can then lock onto the reference and translate with near zero delay to low-skew outputs. For normal operation, the external feedback input, FBIN, is connected to the feedback output, FBOUT. By connecting the feedback output to the feedback input 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. When VDDA is strapped LOW, the PLL is turned off and bypassed for test purposes.
Power Management
The individual output enable/disable control of the CY28352 allows the user to implement unique power management schemes into the design. Outputs are three-stated when disabled through the two-line interface as individual bits are set low in Byte0 and Byte1 registers. The feedback output FBOUT cannot be disabled via two line serial bus. The enabling and disabling of individual outputs is done in such a manner as to eliminate the possibility of partial "runt" clocks.
Function Table
Inputs VDDA GND GND 2.5V 2.5V 2.5V CLKIN L H L H <20 MHz CLKT(0:5)[2] L H L H Hi-Z Outputs CLKC(0:5)[2] H L H L Hi-Z FBOUT L H L H Hi-Z PLL BYPASSED/OFF BYPASSED/OFF On On Off
Notes: 1. A bypass capacitor (0.1F) should be placed as close as possible to each positive power pin (< 0.2"). If these bypass capacitors are not close to the pins, their high-frequency filtering characteristic will be cancelled by the lead inductance of the traces. 2. Each output pair can be three-stated via the two-line serial interface.
Rev 1.0, November 21, 2006
Page 2 of 7
CY28352
Serial Control Registers
Following the acknowledge of the Address Byte, two additional bytes must be sent: * Command Code byte * Byte Count byte. Byte0: Output Register1 (1 = Enable, 0 = Disable) Bit 7 6 5 4 3 2 1 0 @Pup 1 1 1 1 1 1 1 1 Pin# 2, 1 4, 5 - - 13, 14 26, 27 - 24, 25 CLKT0, CLKC0 CLKT1, CLKC1 Reserved Reserved CLKT2, CLKC2 CLKT5, CLKC5 Reserved CLKT4, CLKC4 Description
Byte1: Output Register 2 (1 = Enable, 0 = Disable) Bit 7 6 5 4 3 2 1 0 Byte2: Test Register 3 Bit 7 6 5 4 3 2 1 0 @Pup 1 1 0 0 0 0 0 0 Pin# - - - - - - - - Reserved Reserved Reserved Reserved Reserved Reserved Reserved Description 0 = PLL leakage test, 1 = disable test @Pup 1 1 0 0 0 0 0 0 Pin# - 17, 16 - - - - - - Reserved CLKT3, CLKC3 Reserved Reserved Reserved Reserved Reserved Reserved Description
Rev 1.0, November 21, 2006
Page 3 of 7
CY28352
Maximum Ratings[3]
Input Voltage Relative to VSS:...............................VSS - 0.3V Input Voltage Relative to VDDQ or AVDD:............ VDD + 0.3V Storage Temperature: ................................ -65C to + 150C Operating Temperature:.................................... 0C to +70C Maximum Power Supply: ................................................ 3.5V 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 VDDA = VDDQ = 2.5V 5%, TA = 0C to +70C[4]
Parameter VIL VIH VIL VIH IIN IOL IOH VOL VOH VOUT VOC IOZ IDDQ IDSTAT IDD Cin Description Input Low Voltage Input High Voltage Input Voltage Low Input Voltage High Input Current Output Low Current Condition SDATA, SCLK SDATA, SCLK CLKIN, FBIN CLKIN, FBIN VIN = 0V or VIN = VDDQ, CLKIN, FBIN VDDQ = 2.375V, VOUT = 1.2V Min. 2.2 0.4 2.1 -10 26 -18 35 -32 0.6 VDDQ - 0.4 (VDDQ/2) + 0.2 10 300 1 9 4 12 6 10 Typ. Max. 1.0 Unit V V V V A mA mA V V V V A mA mA mA pF
Output High Current VDDQ = 2.375V, VOUT = 1V Output Low Voltage VDDQ = 2.375V, IOL = 12 mA Output High Voltage VDDQ = 2.375V, IOH = -12 mA 1.7 Output Voltage Swing[5] 1.1 Output Crossing Voltage[6] (VDDQ/2) - 0.2 High-Impedance Output -10 VO = GND or VO = VDDQ Current All VDDQ and VDDI, Dynamic Supply Current[7] FO = 170 MHz Static Supply Current PLL Supply Current VDDA only Input Pin Capacitance
[7, 9]
VDDQ/2
235
AC Parameters VDD = VDDQ = 2.5V 5%, TA = 0C to +70C
Parameter fCLK tDC tlock Tr / Tf tpZL, tpZH tpLZ, tpHZ tCCJ tjit(h-per) Description Operating Clock Frequency Input Clock Duty Cycle Maximum PLL lock Time Output Clocks Slew Rate Output Enable Time[10] (all outputs) Output Disable Time[10] (all outputs) Cycle-to-Cycle Jitter[12] Half-period jitter[12]
Condition
Min. 60 40 1
Typ.
20% to 80% of VOD
Max. 200 60 100 2.5
Unit MHz % s V/ns ns ns
3 3 f > 66 MHz f > 66 MHz -100 -100 100 100
ps ps
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. Unused inputs must be held HIGH or LOW to prevent them from floating. 5. For load conditions, see Figure 7. 6. The value of VOC is expected to be |VTR + VCP|/2. In case of each clock directly terminated by a 120 resistor. See Figure 7. 7. All outputs switching loaded with 16 pF in 60 environment. SeeFigure 7. 8. Parameters are guaranteed by design and characterization. Not 100% tested in production. 9. PLL is capable of meeting the specified parameters while supporting SSC synthesizers with modulation frequency between 30 kHz and 33.3 kHz, with a down spread of -0.5%. 10. Refers to transition of non-inverting output. 11. All differential input and output terminals are terminated with 120/16 pF as shown in Figure 7. 12. Period Jitter and Half-Period Jitter specifications are separate, and must be met independently of each other.
Rev 1.0, November 21, 2006
Page 4 of 7
CY28352
AC Parameters VDD = VDDQ = 2.5V 5%, TA = 0C to +70C (continued)[7, 9]
Parameter tPLH tPHL tSKEW tPHASE tPHASEJ Description LOW-to-HIGH Propagation Delay, CLKIN to CLKT[0:5] HIGH-to-LOW Propagation Delay, CLKIN to CLKT[0:5] Any Output to Any Output Skew[11] Phase Error[11] Phase Error Jitter Condition Min. 1.5 1.5 Typ. 3.5 3.5 Max. 6 6 100 150 50 Unit ns ns ps ps ps
f > 66 MHz
-150 -50
Parameter Measurement Information
CLKIN
1.25V 1.25V
FBIN
1.25V 1.25V
t()n
t()n+1
t()n =
CLKIN
1.25V
n1=N
t()n
(N is large number of samples)
Figure 1. Static Phase Offset
1.25V
FBIN
td()
t()
td()
td()
t( )
td()
Figure 2. Dynamic Phase Offset
CLKT[0:5], FBOUT CLKC[0:5] CLKT[0:5], FBOUT CLKC[0:5]
tsk(o)
Figure 3. Output Skew
Rev 1.0, November 21, 2006
Page 5 of 7
CY28352
CLKT[0:5], FBOUT CLKC[0:5]
t c(n)
CLKT[0:5], FBOUT CLKC[0:5]
1 f(o) t jit(hper) = t c(n) - 1 fo
Figure 4. Period Jitter
CLKT[0:5], FBO UT CLKC[0:5]
t (hper_n) 1 f(o)
t (hper_N+1)
t jit(hper) = t hper(n) - 1 2x fo
Figure 5. Half-period Jitter
C L K T[0:5], F B O U T C L K C [0:5]
t c(n)
t jit(c c) = t c(n ) -t c(n + 1)
t c(n)
Figure 6. Cycle-to-Cycle Jitter
T PCB C LKT
16 pF
M easurem ent Point
C LKIN 50 C LKC FBIN 50 FBO U T T PCB
110 M easurem ent Point
16 pF
Figure 7. Differential Signal Using Direct Termination Resistor
Rev 1.0, November 21, 2006
Page 6 of 7
CY28352
Ordering Information
Part Number CY28352OC CY28352OCT Lead-free CY28352OXC CY28352OXCT 28-pin SSOP 28-pin SSOP-Tape and Reel Commercial, 0 to 70C Commercial, 0 to 70C Package Type 28-pin SSOP 28-pin SSOP-Tape and Reel Product Flow Commercial, 0 to 70C Commercial, 0 to 70C
Package Drawing and Dimensions
28-lead (5.3 mm) Shrunk Small Outline Package O28
*C
While SLI has reviewed all information herein for accuracy and reliability, Spectra Linear Inc. assumes no responsibility for the use of any circuitry or for the infringement of any patents or other rights of third parties which would result from each use. This product is intended for use in normal commercial applications and is not warranted nor is it intended for use in life support, critical medical instruments, or any other application requiring extended temperature range, high reliability, or any other extraordinary environmental requirements unless pursuant to additional processing by Spectra Linear Inc., and expressed written agreement by Spectra Linear Inc. Spectra Linear Inc. reserves the right to change any circuitry or specification without notice.
Rev 1.0, November 21, 2006
Page 7 of 7

▲Up To Search▲

Price & Availability of CY28352

	To Download CY28352 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .