Datasheet

SA630 All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2014. All rights reserved.
Product data sheet Rev. 3 — 23 July 2014 10 of 20
NXP Semiconductors
SA630
Single-Pole Double-Throw (SPDT) switch
The isolation and matching of the two channels over frequency is shown in Figure 9 and
Figure 10
, respectively.
The SA630 is a very versatile part and can be used in many applications. Figure 20
shows
a block diagram of a typical digital RF transceiver front-end. In this application, the SA630
replaces the duplexer, which is typically very bulky and lossy. Due to the low power
consumption of the device, it is ideally suited for handheld applications such as in CT2
cordless telephones. The SA630 can also be used to generate Amplitude Shift Keying
(ASK) or On-Off Keying (OOK) and Frequency Shift Keying (FSK) signals for digital RF
communications systems. Block diagrams for these applications are shown in Figure 21
and Figure 22
, respectively.
For applications that require a higher isolation at 1 GHz than obtained from a single
SA630, several SA630s can be cascaded as shown in Figure 23
. The cascaded
configuration has a higher loss, but greater than 35 dB of isolation at 1 GHz and greater
than 65 dB at 500 MHz can be obtained from this configuration. By modifying the enable
control, an RF multiplexer/demultiplexer or antenna selector can be constructed. The
simplicity of SA630 coupled with its ease of use and high performance lends itself to many
innovative applications.
The SA630 switch terminates the OFF channel in 50 . The 50  resistor is internal and
is in series with the external AC bypass capacitor. Matching to impedances other than
50  can be achieved by adding a resistor in series with the AC bypass capacitor (for
example, 25  additional to match to a 75  environment).
Fig 20. A typical TDMA/digital RF transceiver system front-end
Fig 21. Amplitude Shift Keying (ASK)
generator
Fig 22. Frequency Shift Keying (FSK)
generator
SA630
5200 602A IF OUT
VCO5200 modulation
aaa-014009
MICRO-
CONTROLLER
KEYPAD
AND
DISPLAY
TX/RX
SA630
aaa-014010
enable
CH1
TTL data
50 Ω
ASK output
oscillator
SA630
aaa-014011
enable
CH1
TTL data
FSK output
f
1
f
2