AND8058 Datasheet, PDF (3/4 Pages) ON Semiconductor – Two New Analog Switches Set Standards for Space Efficiency

AND8058/D
A
LVDS Signals < 250 M bits/sec
B
Xmitter
100 Ω
+
Receiver
–
Switching Between 2 LVDS Lines
1/2 NLAS4599
Figure 4. Switching Between Two LVDS Lines
Low Voltage Differential Signaling
Low Voltage Differential Signaling (LVDS) is becoming
a very popular scheme for point–to–point transfer of signals
up to 200 MHz and for distances less than 25 meters. The
LVDS signals fall under EIA–644 specifications. The LVDS
signal sits at a dc. level of about 1.25 volts and is guaranteed
to fall between 100 mV and 750 mV of differential swing.
Since the NLAS44599 provides very small insertion loss,
owing to frequency roll–off or series resistance attenuation,
it makes an ideal switch for differential pairs. The
NLAS44599 consists of two independent DPST switches;
therefore, it only takes one of this device to select between
two LVDS signals going to a single transceiver.
Figure 4 shows one–half of the mm² device used to
switch between two differential pairs. No biasing is required
since the LVDS specification calls for the signal to be at
roughly 1.25 V, well within the requirement of the
NLAS44599. The other half of the device may be used to
provide similar or entirely different switching functions.
Other differential signals such as Ethernet signals on a
Category 5 wire, ECL signals within the frequency range of
this device, and professional audio signals (600 Ω balanced)
may be switched in a similar manner.
Summary
On Semiconductor is bringing new, extremely
space–efficient analog switches to the marketplace. These
devices will be used creatively by our customers to solve
difficult problems, in small spaces. Both new products, the
NLAS4599 and the NLAS44599, represent step functions in
space efficiency and functionality over existing solutions.
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