
Philips Semiconductors
Product specification
SA2421
2.45 GHz low voltage RF transceiver
2
2000 Mar 13
853-2189 23308
DESCRIPTION
The SA2421 transceiver is a combined low–noise amplifier, receive
mixer, transmit mixer and LO buffer IC designed using a 20 GHz fT
BiCMOS process, QUBiC2, for high–performance low–power
communication systems for 2.4–2.5 GHz applications. The LNA has
a 3.2 dB noise figure at 2.45 GHz with 14.3 dB gain and an IP3
intercept of –3 dBm at the input. The wide–dynamic–range receive
mixer has a 11.2 dB noise figure and an input IP3 of +2.5 dBm at
2.45 GHz. The nominal current drawn from a single 3 V supply is
34 mA in transmit mode and 20 mA in receive mode. The SA2421
differs from the SA2420 by removal of the LO doubler and LO
switch. The LNA reverse isolation is improved, and a separate pin is
allocated for the transmit output.
FEATURES
Low current consumption: 34 mA nominal transmit mode and
20 mA nominal receive mode
High system power gain: 24 dB (LNA + Mixer) at 2.45 GHz
Excellent gain stability versus temperature and supply voltage
Separate Rx IN and Tx OUT pins
Wide IF range: 50–500 MHz
–10dBm typical LO input power
Improved LNA reverse isolation S12
TSSOP24 package
PIN CONFIGURATION
1
2
3
4
5
6
7
8
9
10
11
12
13
14
24
23
22
21
20
19
18
17
16
15
DH Package
ATTEN SW
Tx OUT
GND
Rx IN
GND
LNA OUT
VCC
GND
Rx IF OUT
GND
LOP
LNA IN
GND
Rx IF OUT
Tx IF IN
Tx/Rx
LOM
VCC LO
CHIP EN
SR01756
Figure 1.
Pin configuration
APPLICATIONS
IEEE 802.11 (WLAN)
2.45 GHz ISM band
ORDERING INFORMATION
DESCRIPTION
TEMPERATURE RANGE
ORDER CODE
DWG #
24-Pin Plastic Thin Shrink Small Outline Package (Surface-mount, TSSOP)
–40
°C to +85°C
SA2421DH
SOT355-1
BLOCK DIAGRAM
4
3
2
15
24
23
22
21
20
7
610
9
8
19
18
17
16
15
Tx/Rx
GND
LOP
GND
VCC
Rx IN
GND
ATTEN
SW
CHIP
EN
GND
LNA
OUT
GND
LNA
GND
12
11
14
13
LOM
LO
Tx OUT
GND
VCC
LNA
IN
Rx IF
OUT
Rx IF
OUT
Tx IF
IN
Tx IF
IN
RX
TX
LO
BUFFER
BPF
PRE-DRIVER
ATTENUATOR
SR01757
X1
Figure 2.
SA2421 block diagram