SA2421 Datasheet, PDF (6/12 Pages) NXP Semiconductors – 2.45 GHz low voltage RF transceiver

Philips Semiconductors
2.45 GHz low voltage RF transceiver
Product specification
SA2421
Table 1. Truth Table
Chip-En
ATT-SW
0
X
1
1
1
0
1
X
T_X–R_X
X
0
0
1
Mode
Sleep
Receive
Receive
Transmit
LNA Gain
N/S
+14.3 dB
–19 dB
N/S
R_X Mixer
off
on
on
off
T_X Mixer and
Predriver
off
off
off
on
FUNCTIONAL DESCRIPTION
The SA2421 is a 2.45 GHz transceiver front-end available in the
TSSOP-24 package. This integrated circuit (IC) consists of a low
noise amplifier (LNA) and up- and down-converters. There is an
enable/disable switch available to power up/down the entire chip in
1 µs, typically. This transceiver has several unique features.
The LNA has two operating modes: 1) high gain mode with a gain =
+14.3 dB; and 2) low gain mode with a gain –19 dB. The switch for
this option is internal and is controlled externally by high and low
logic to the pin. When the LNA is switched into the attenuation
mode, active matching circuitry (on-chip) is switched in (reducing the
number of off-chip components required). To reduce power
consumption when the chip is transmitting, the LNA is automatically
switched into a “sleep” mode (internally) without the use of external
circuitry.
2000 Mar 13
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