SSTL_3, V, defined in EIA/JESD ; SSTL_2, V, defined in EIA/ JESDB used in DDR among other things. SSTL_18, V, defined in. STUB SERIES TERMINATED. LOGIC FOR VOLTS (SSTL_2). EIA/JESD SEPTEMBER ELECTRONIC INDUSTRIES ALLIANCE. JEDEC Solid State . SSTL (JESD, JESDB, JESD). • HSTL (JESD). LVTTL and LVCMOS were developed as a direct result of technology scaling. With each reduction in.
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The system designer will be able to vary impedance levels, termination resistors and supply voltage and be able to calculate the effect on system voltage margins.
Stub Series Terminated Logic
The standard defines a reference voltage VREF which is used at the receivers as well as a voltage VTT to which jesc8 resistors are connected. The tester may therefore supply signals with a 1. In some standards this ratio equals 0. With a series resistor of 25? AC test conditions may be measured ejsd8 nominal voltage conditions as long as the supplier can demonstrate by analysis, that the device will meet its timing specifications under all supported voltage conditions.
VTT is specified as being equal to 0. External resistors provide this isolation and also reduce the on-chip power dissipation of the drivers.
Making this distinction is important for the design of high gain, differential, receivers that are required. The second clause defines the minimum dc and ac input parametric requirements and ac test conditions for inputs on compliant devices. An example of ringing is illustrated in the dotted wave-form.
The relationship of the different levels is shown in figure 1. However, the drivers are connected directly onto the bus so there are no stubs present. However, in the case of VIH Max. Vx ac indicates the voltage at which differential input signals must be crossing. F or info rm ationcon tact: Units V V Notes 2. This clause hesd8 added to set the conditions under which the driver ac specifications can be tested.
Note however, that all timing specifications are still set relative to the ac input level.
EIA JEDEC STANDARD jesdb-sstl_2_百度文库
This is accomplished precisely because drivers and receivers are specified independently of each other. Clearly it is not the intention to show all possible variations in this standard. In this example a Class II type buffer jesr8 be preferred since it comes closer, in conjunction with the series resistor, to match the characteristic impedance of the transmission line. The information included in JEDEC standards and publications represents a sound approach to product specification and application, principally from the solid state device manufacturer viewpoint.
O rgan iz atio ns m ay ob tain perm issio n to rep rod uce a lim ited n um b er o f co pies thro ugh enterin jess8 in to a licen se agreem en t.
Stub Series Terminated Logic – Wikipedia
See also figure 2. While driver characteristics are derived from a 50? Jesd example of this may be address drivers on a memory board. JEDEC standards and publications are designed to serve the public interest through eliminating misunderstandings between manufacturers and purchasers, facilitating interchangeability and improvement of products, and assisting the purchaser in selecting and obtaining hesd8 minimum delay the proper product for use by those other than JEDEC members, whether the standard is to be used either domestically or internationally.
Busses may be terminated by resistors jesdd8 an external termination voltage. An example is shown in figure 7. This can be expressed by equation-1 or equation NOTE 4 AC test conditions may be measured under nominal voltage conditions as long as the supplier can demonstrate by analysis that the device will meet its timing specifications under all supported voltage conditions.
The test circuit is assumed to be similar to the circuit shown in figure 5. If the driver maintains a resistance lower than the Maximum On Resistance, more than the mV will be presented to the receiver. Almost representatives, appointed by some JEDEC member companies work together in 50 JEDEC committees to meet the needs of every segment of the industry, manufacturers and consumers alike. An example of this is shown in kesd8 6.
The Standards, Publications, jedd8 Outlines that they generate are accepted throughout the world. JEDEC jessd8 and publications are adopted without regard to whether or not their adoption may involve patents or articles, materials, or processes. The dc values are chosen such that the final logic state is unambiguously defined, that is once the receiver input has crossed this value, the receiver will change to and maintain the new logic state.
This is illustrated in figure 2. Figure 3 shows the typical dc environment that the output buffer is presented with.
The test circuit is assumed to be similar to the circuit shown in figure 4. Days after publication of this standard in Mayit was brought to the attention of the sponsor that there were errors in Table 4. Mesd8 is the leading developer of standards for the solid-state industry, they have published over documents to date.
The specifications are quite different from traditional specifications, where minimum values for VOH and maximum values for VOL are set that apply to the entire supply range.
By downloading this file the individual agrees not to charge jesx8 or resell the resulting material.
The driver specification now must guarantee that these values of VIN are obtained in the worst case conditions specified by this standard. Under these conditions VOH is 1. However a Class II buffer would dissipate more power due to its larger current drive and thus might require special cooling.
No claims to be in conformance with this standard may be made unless all requirements stated in the standard are met. In that case, the jes8d may decide to eliminate the series resistors entirely.
Class I or Note however, that all timing specifications are still set relative to the differential ac input level. Compliant devices must meet the VSwing ac specification under actual use conditions. All recipients of this errata are asked to replace page 7 with the corrected page included in this errata.