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Zero Delay Buffers (ZDB)

Zero-delay buffers (ZDB) provide a synchronous copy (no propagation delay) of the input clock at the outputs, usually without frequency translation. IDT’s ZDBs are PLL-based devices that regenerate the input clock signal with fanout to drive multiple loads offering various signal levels, including LVPECL, LVDS, HCSL, CML, HSTL, SSTL or LVCMOS. ZDBs are ideal for applications requiring synchronized clocking for FPGAs, CPUs, logic and synchronous memory.

Most zero-delay buffers allow the delay through the device to be adjusted through an external feedback path. This allows precise control of the timing of the clock signals to the loads. Simple frequency translation is possible with a ZDB when a single divider is used for all outputs, including feedback output, to maintain clock synchronization.

Hint: If more than one unique output frequency is required (eg. 100MHz and 125Mhz), make use of the “Output Banks” parametric selector. Each bank corresponds to a unique output frequency.

►  Download the IDT Clock Distribution Overview (PDF)

Industry-leading Zero-delay Buffer Solutions

IDT's zero-delay buffer (ZDB) IC families are available with a wide range of options and features. Differential outputs such as LVPECL, LVDS, HCSL, CML, HSTL, SSTL, as well as selectable outputs, are supported for output frequencies up to 3.2 GHz and single-ended LVCMOS outputs for frequencies up to 350 MHz. In addition, IDT's PLL portfolio has devices supporting supply voltages from 1.2 V up to 3.3 V and that are available in the commercial and industrial temperature ranges.

Using an IDT PLL product has many benefits. Reducing the number of quartz crystals on a board improves reliability because crystals are highly susceptible to shock and vibration. Using a clock signal generator also reduces a customer's board cost and space, bill of materials (BOM) and inventory levels by replacing multiple crystals and oscillators with one device. They are ideal for use in a large variety of systems, from personal computers to consumer electronics or industrial systems, as well as high-performance networking and communications systems.

Selecting a Zero-delay Buffer (ZDB)

There are many important factors when choosing a ZDB for a particular application. The following parameters will give users a basic starting point to narrow down the potential solutions:

  • # of outputs: choose a ZDB with enough outputs to simplify your clock tree. Fewer components simplifies the design and procurement process for faster time to market, and can even improve reliability for better production yields. IDT offers some of the industry’s most integrated solutions for highly-complex systems, along with right-sized solutions for those that fall in between.
  • output type: this is the signalling type of the output that is required of the zero-delay buffer. IDT offers LVPECL, LVDS, HCSL, CML, HSTL, SSTL or LVCMOS.
  • input / output frequency range: the valid range of input and output frequencies. IDT offers zero-delay buffers to address the frequency needs of all popular applications.
  • core voltage: the supply voltage used to power the ZDB. This is typically defined by the power rails available in the system, and often has implications on voltage levels of the output. IDT’s zero-delay buffers are offered in voltages from 3.3 V down to 1.5V.
Video: Zero-delay Buffer Overview Video

Parametric Search

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Outputs (#)Output TypeOutput Freq Range (MHz)Input Freq (MHz)Inputs (#)Input TypeOutput Banks (#)Core Voltage (V)Output Voltage (V)Divider Value
2308B Datasheet2308B - Block Diagram2308B
3.3V Zero Delay Clock Multip...
8CMOS, LVCMOS, TTL10 - 133.3, 10 - 13310 - 133.3, 10 - 1331LVCMOS23.33.3
527-01 Datasheet527-01 - Block Diagram527-01
Clock Slicer User Configurab...
2LVCMOS4 - 1600.6 - 2001LVCMOS23.33.3
570 Datasheet570 - Block Diagram570
Multiplier and Zero Delay Bu...
2LVCMOS10 - 17010 - 1701LVCMOS13.3, 53.3, 5
571 Datasheet571 - Block Diagram571
Low Phase Noise Zero Delay B...
2LVCMOS10 - 16010 - 1601LVCMOS23.3, 53.3, 5
574 Datasheet574 - Block Diagram574
Zero Delay, Low Skew Buffer
4LVCMOS20 - 16020 - 1601LVCMOS13.3, 53.3, 5
670-01 Datasheet670-01 Block Diagram670-01
Low Phase Noise Zero Delay B...
2LVCMOS24 - 1605 - 1601LVCMOS23.3, 53.3, 5
ics67002670-02 - Block Diagram670-02
Low Phase Noise Zero Delay B...
2LVCMOS24 - 1605 - 1601LVCMOS23.3, 53.3, 5
ics67003670-03 - Block Diagram670-03
Low Phase Noise Zero Delay B...
2LVCMOS24 - 2105 - 2101LVCMOS23.3, 53.3, 5
ics67004670-04 - Block Diagram670-04
Low Phase Noise Zero Delay B...
2LVCMOS24 - 2105 - 2101LVCMOS23.3, 53.3, 5
86004 Datasheet86004 - Block Diagram86004
15.625MHZ TO 62.5MHZ, 1:4 LV...
3LVCMOS15.625 - 62.515.625 - 62.51LVCMOS12.5, 3.32.5, 3.34, 8
86004I Final Data Sheet86004I - Block Diagram86004I
15.625MHz to 62.5MHz, 1:4 LV...
4LVCMOS15.625 - 62.515.625 - 62.51LVCMOS12.5, 3.32.5, 3.3
87002-02 Datasheet87002-02 - Block Diagram87002-02
1:2, Differential-to-LVCMOS/...
2LVCMOS15.625 - 25015.625 - 2501HCSL, HSTL, LVDS, LVPECL, SSTL12.5, 3.32.5, 3.3
87002-05 Final Data Sheet87002-05 - Block Diagram87002-05
2LVCMOS11.2783 - 24.600511.2896, 12.288, 16.384, 16.9344, 18.432, 22.5792, 24.5761LVCMOS13.33.3
87004I DATASHEET87004I - Block Diagram87004I
1:4, Differential-to-LVCMOS ...
4LVCMOS15.625 - 25015.625 - 2502HCSL, HSTL, LVDS, LVPECL, SSTL12.5, 3.32.5, 3.3
8705I Datasheet8705I - Block Diagram8705I
Zero Delay, Differential-to-...
8LVCMOS15.625 - 25015.625 - 2502HCSL, HSTL, LVCMOS, LVDS, LVPECL, SSTL12.5, 3.32.5, 3.3
8714004I Datasheet8714004I - Block Diagram8714004I
FemtoClock® Zero Delay Buff...
4HCSL98 - 16519.6 - 1652HCSL, LVDS, LVHSTL, LVPECL, M-LVDS43.33.3
8714008I Data Sheet8714008I - Block Diagram8714008I
FemtoClock® Zero Delay Buff...
8HCSL98 - 16519.6 - 1652HCSL, LVDS, LVHSTL, LVPECL, M-LVDS83.33.3
8731-01 Datasheet8731-01 - Block Diagram8731-01
Low Skew, 1-to-11 Differenti...
11LVPECL0 - 7000 - 2001HCSL, HSTL, LVDS, LVPECL, SSTL23.33.3
8732-01 Datasheet8732-01 - Block Diagram8732-01
Low Voltage, Low Skew 3.3V L...
8735-31 Data Sheet8735-31 - Block Diagram8735-31
1:5, Differential-to-3.3V LV...
5LVPECL15.625 - 35015.625 - 7002HCSL, HSTL, LVDS, LVPECL, SSTL13.33.3
8735Bi-01 Datasheet8735Bi-01 - Block Diagram8735BI-01
Low Skew, 1-to-5, Differenti...
5LVPECL31.25 - 70031.25 - 7002HCSL, HSTL, LVDS, LVPECL13.33.3
8745B-21 Datasheet8745B-21 - Block Diagram8745B-21
1:1, Differential-to-LVDS Ze...
1LVDS31.25 - 70031.25 - 7001HCSL, HSTL, LVDS, LVPECL, SSTL13.33.3
8745BI-21 Data Sheet8745BI-21 - Block Diagram8745BI-21
1:1 Differential-to-LVDS Zer...
1LVDS31.25 - 70031.25 - 7001HCSL, HSTL, LVDS, LVPECL, SSTL13.33.3
874S02I Datasheet874S02I - Block Diagram874S02I
Differential-to-LVDS Zero De...
1LVDS62.5 - 100062.5 - 10001HSTL, LVDS, LVPECL, SSTL13.33.3
87972I-147 Datasheet87972I-147 - Block Diagram87972I-147
Low Skew, 1-to-12 LVCMOS/LVT...
13LVCMOS10 - 15012 - 1503Crystal, LVCMOS43.33.3
87973I-147 Datasheet87973I-147 - Block Diagram87973I-147
Low Skew, 1-to-12 LVCMOS/LVT...
13LVCMOS10 - 1500 - 1203HCSL, HSTL, LVCMOS, LVDS, LVPECL, SSTL43.33.3
87974I Datasheet87974I - Block Diagram87974I
Low Skew, 1-to-15 LVCMOS/LVT...
14LVCMOS8.33 - 1252LVCMOS33.33.3
9ZX21200 Datasheet9ZX21200 - Block Diagram9ZX21200
12-output DB1200Z Derivative
12HCSL33 - 15033 - 1501HCSL13.30.7
9ZX21201 Datasheet9ZX21201 - Block Diagram9ZX21201
12-output DB1200Z Compliant ...
12HCSL33 - 15033 - 1501HCSL13.30.7
9ZX21501C Datasheet9ZX21501B - Block Diagram9ZX21501
15-output DB1900Z Derivative
15HCSL33 - 15033 - 1501HCSL13.30.7
9ZX21901B Datasheet9ZX21901B - Block Diagram9ZX21901B
19-output DB1900Z Compliant ...
19HCSL33 - 15033 - 1501HCSL13.30.7
9ZX21901C Datasheet9ZX21901C - Block Diagram9ZX21901C
19-output DB1900Z Compliant ...
19HCSL33 - 15033 - 1501HCSL13.30.7
9ZXL1230 Datasheet9ZXL1230 - Block Diagram9ZXL1230
12-output DB1200ZL Derivativ...
12LP-HCSL33 - 15033 - 1501HCSL13.30.7
9ZXL1530B Datasheet9ZXL1530 - Block Diagram9ZXL1530
15-output DB1900Z Derivative
15LP-HCSL33 - 15033 - 1501HCSL13.30.7
9ZXL1550 Datasheet9ZXL1550 Block Diagram9ZXL1550
15-output DB1900Z Derivative
15LP-HCSL33 - 15033 - 1501HCSL13.30.7
9ZXL1930B Datasheet9ZXL1930 Block Diagram9ZXL1930
19-output DB1900Z Low-Power ...
19LP-HCSL33 - 15033 - 1501HCSL13.30.7
9ZXL1950 Datasheet9ZXL1950 Block Diagram9ZXL1950
19-output DB1900Z Low-Power ...
19LP-HCSL33 - 15033 - 1501HCSL13.30.7