Resistor values are typically 120 to 240 ohms for 3.3V operation and 82 to 120 ohms for 2.5V
operation.
Figure 7 - Pull Up Pull Down Termination
Resistor values are typically for 3.3V operation
For 2.5V operation, the resistor to ground is 62 ohms and the resistor to supply is 240 ohms
There are numerous application notes on terminating and interfacing PECL logic and the two most common methods are a single resistor to ground, Figure 6,
and a pull-up/pull-down scheme as shown in Figure 7. An AC coupling capacitor is optional, depending on the application and the input logic requirements of
the next stage.
One of the most important considerations is terminating the Output and Complementary Outputs equally. An unused output should not be left un-
terminated, and if one of the two outputs is left open it will result in excessive jitter on both. PC board layout must take this and 50 ohm impedance matching
into account. Load matching and power supply noise are the main contributors to jitter related problems.
LVDS Application Diagrams
+3.3V
OE or NC
10nF
1nF
1
6
Receiver
100
3
4
+3.3V
OE or NC
10nF
1nF
1
6
10nF
100
3
4
Receiver
OE or NC
2
5
OE or NC
2
5
10nF
Figure 8 - LVDS to LVDS, internal 100Ω
Some LVDS structures have an internal 100 ohm resistor on the
input and do not need additional components.
Figure 9 - LVDS to LVDS, External 100Ω and AC block ing caps
One of the most important considerations is terminating the Output and Complementary Outputs equally. An unused output should not be left un-
terminated, and if one of the two outputs is left open it will result in excessive jitter on both. PC board layout must take this and 50 ohm impedance matching
into account. Load matching and power supply noise are the main contributors to jitter related problems.
随着阅读器与标签价格的降低和全球市场的扩大，射频标识 RFID(以下简称RFID)的应用与日俱增。标签既可由阅读器供电(无源标签)，也可以由标签的板上电源供电(半有源标签和有源标签)。由于亚微型无源 CMOS 标签的成本降低，库存和其他应用迅速增加。一些评估表明，随着无源标签的价格持续下降，几乎每一个售出产品的内部都将有一个 RFID 标签。由于无源 RFID 标签的重要性及其独特的工程实现...[详细]
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