Datasheet SA2421 Datasheet (Philips)

INTEGRATED CIRCUITS

SA2421

2.45 GHz low voltage RF transceiver

Product specification
Supersedes data of 2000 Feb 11

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2000 Mar 13

Philips Semiconductors Product specification

SA24212.45 GHz low voltage RF transceiver

DESCRIPTION

The SA2421 transceiver is a combined low–noise amplifier, receive
mixer, transmit mixer and LO buffer IC designed using a 20 GHz f

T

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.

FEA TURES

•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

GND

1

LNA IN

2

GND

3
4

GND

GND

LOP

Tx/Rx

LOM

5
6
7
8

9
10
11
12

Rx IF OUT
Rx IF OUT

Tx IF IN
Tx IF IN

Figure 1. Pin configuration

APPLICATIONS

•IEEE 802.11 (WLAN)

•2.45 GHz ISM band

DH Package

V

24

LNA OUT

23

GND

22

ATTEN SW

21

GND

20
19

Rx IN
GND

18

Tx OUT

17

GND

16

GND

15

V

14

CHIP EN

13

SR01756

CC

LO

CC

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

V

24 23 22 21 20

GND GND

LNA

OUT GND

CC

LNA

LNA

IN

GND

ATTEN

SW

ATTENUATOR

43215

GND

Figure 2. SA2421 block diagram

GND

Rx IF
OUT

Rx IN GND

19 18 17 16 15

RX

RX TX

Rx IF
OUT

Tx OUT GND

PRE-DRIVER

BPF

761098

Tx IFINTx IF

IN

LO

BUFFER

X1

V

CC

LO

14 13

Tx/RxGND LOP

CHIP

EN

1211

LOM

SR01757

2000 Mar 13 853-2189 23308

2

Philips Semiconductors Product specification

SYMBOL

PARAMETER

TEST CONDITIONS

UNITS

I

Input bias current

SA24212.45 GHz low voltage RF transceiver

ABSOLUTE MAXIMUM RATINGS

SYMBOL PARAMETER RATING UNITS

V

CC

V

IN

P

D

T

JMAX

P

MAX

T

STG

NOTES:

1. Transients exceeding these conditions may damage the product.

2. Maximum dissipation is determined by the operating ambient temperature and the thermal resistance, and absolute maximum ratings may
impact product reliability θJA: 24-Pin TSSOP = 117°C/W

3. IC is protected for ESD voltages up to 2000 V, human body model.

RECOMMENDED OPERATING CONDITIONS

SYMBOL PARAMETER RATING UNITS

V

CC

T

amb

Supply voltage –0.3 to +6 V
Voltage applied to any pin –0.3 to (VCC + 0.3) V
Power dissipation, T

24-Pin Plastic TSSOP

= 25°C (still air)

amb

555 mW
Maximum operating junction temperature 150 °C
Maximum power (RF/IF/LO pins) +20 dBm
Storage temperature range –65 to +150 °C

Supply voltage 2.7 to 5.5 V
Operating ambient temperature range –40 to +85 °C

DC ELECTRICAL CHARACTERISTICS

VCC = +3V, T

I

CCTX

I

CCRX

I

CC OFF

V

LNA-IN

V

LO GHz

V

TX IF

V

TX IFB

BIAS

= 25°C; unless otherwise stated.

amb

Total supply current, Transmit Tx/Rx = Hi 22 34 42 mA
Total supply current, Receive

Power down mode

LNA input voltage Receive mode 0.855 V
LO buffer DC input voltage Tx/Rx = Lo –0.1 V
Tx Mixer input voltage Tx/Rx = Hi 1.7 V
Tx Mixer input voltage Tx/Rx = Hi 1.7 V

p

LIMITS

MIN TYP MAX

Tx/Rx mode = Lo,

LNA = Hi gain

14 20 26 mA

Tx/Rx = GND

Atten SW = V

Enable = GND

CC

10 µA

CC

Logic 1 6 µA
Logic 0 0 µA

V

2000 Mar 13

3

Philips Semiconductors Product specification

SYMBOL

PARAMETER

TEST CONDITIONS

UNITS

SA24212.45 GHz low voltage RF transceiver

AC ELECTRICAL CHARACTERISTICS

VCC = +3 V, T

f

RF

f

IF

LNA High gain mode (In = Pin 2; Out = 23)

S

21

S

12

S

11

S

22

ISO Isolation: LOX to LNA

P

-1dB

IP3 Amplifier input third order intercept

NF Amplifier noise figure (50Ω) LNA gain = Hi 3.1 3.2 3.3 dB

LNA High Overload Mode (low gain mode)

S

21

S

12

S

11

S

22

ISO Isolation: LOX to LNA

P

-1dB

IP3 Amplifier input third order intercept

NF Amplifier noise figure (50 Ω) LNA gain = Low 18.5 dB

Rx Mixer (Rx IN = Pin 19, IF = Pins 5 and 6, LO = Pin 10 or 12, PLO = –10 dBm)

PG

C

S

11–RF

NF

M

P

-1dB

IP3 Input third order intercept f1 – f2 = 1MHz 1.8 2.2 2.6 dBm

Rx Mixer Spurious Components (PIN = P

P

RF-IF

P

LO-IF

= 25°C; LOIN = –10 dBm @ 2.1 GHz; fRF = 2.45 GHz; unless otherwise stated.

amb

LIMITS

MIN –3σ TYP +3σ MAX

RF frequency range
IF frequency range

3

3

2.4 2.45 2.5 GHz

300 350 400 MHz

Amplifier gain LNA gain = Hi 13.3 14.3 15.3 dB
Amplifier reverse isolation LNA gain = Hi –32 dB
Amplifier input match
Amplifier output match

1

1

IN

LNA gain = Hi –10 dB
LNA gain = Hi –9 dB
LNA gain = Hi –43 dB

Amplifier input 1dB gain compression LNA gain = Hi –15 dBm

f1 - f2 = 1 MHz,

LNA gain = Hi

–4.5 –3.2 –1.9 dBm

Amplifier gain LNA gain = Low –18.5 –19.4 –20.3 dB
Amplifier reverse isolation LNA gain = Low –26 dB
Amplifier input match
Amplifier output match

1

1

IN

LNA gain = Low –8 dB
LNA gain = Low –8 dB
LNA gain = Low –45 dB

Amplifier input 1dB gain compression LNA gain = Low 2 dBm

Power conversion gain into 50 Ω :
matched to 50 W using external balun
circuitry.

Input match at RF (2.45 GHz)

1

f1 – f2 = 1 MHz,

LNA gain = Low

fS = 2.45 GHz,
f

= 2.1 GHz,

LO

fIF = 350 MHz

9.5 10 10.5 dB

18 dBm

–11 dB
SSB noise figure (2.45 GHz) (50 Ω) 9.8 11.2 12.5 dB
Mixer input 1 dB gain compression –10.5 dBm

)

-1dB

CL = 2 pF per side -35 dBc
CL = 2 pF per side -32 dBc

RF feedthrough to IF
LO feedthrough to IF

4
5

2000 Mar 13

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Philips Semiconductors Product specification

SYMBOL

PARAMETER

TEST CONDITIONS

UNITS

SA24212.45 GHz low voltage RF transceiver

AC ELECTRICAL CHARACTERISTICS (continued)

LIMITS

MIN –3σ TYP +3σ MAX

Tx Mixer (Tx OUT = Pin 17, IF = Pins 7 and 8, LO = Pin 10 or 12, PLO = –10 dBm)

PG

S

NF

P

11–RF

-1dB

Power conversion gain: RL = 50 Ω

C

RS = 50 Ω
Output match at RF (2.45 GHz)

SSB noise figure (2.45 GHz) (50 Ω) 10.9 11.2 11.5 dB

M

1

Output 1dB gain compression 4.2 dBm

IP3 Output third order intercept f1 – f2 = 1 MHz 10.1 12.2 14.3 dBm

Tx Mixer Spurious Components (P

P

IF-RF

P

LO-RF

P

IMAGE-RF

IF feedthrough to RF
LO feedthrough to RF
Image feedthrough to RF

= P

OUT

4

5

6

–1dB

)

LO Buffer

P

LO IN

S

11-LO

f

LOG

Switching

t

Rx-Tx

t

Tx-Rx

t

POWER UP

t

PWR DWN

LO drive level –15 –10 –5 dBm
Mixer input match (LO = 2.1 GHz) –10 dB
LOG frequency range

2

3

Receive-to-transmit switching time 1 µs
Transmit-to-Receive switching time 1 µs
Chip enable time 1 µs
Chip disable time 1 µs

NOTES:

1. With simple external matching

2. With 50 pF coupling capacitors on all RF and IF parts

3. This part has been optimized for the stated frequency range. Operation outside this frequency range may yield performance other than
specified in this datasheet.

4. Measured 5dB lower than 1dB compression point, with typical output matching network.

5. Measured at 1dB compression point.

6. With typical output matching network (no image reject mixer is used).

fS = 2.45 GHz,
fLO = 2.1 GHz,

fIF = 350 MHz

22.5 23 23.5 dB

–10 dB

–50 dBc
–22 dBc
–20 dBc

1.9 2.1 2.3 GHz

2000 Mar 13

5

Philips Semiconductors Product specification

SA24212.45 GHz low voltage RF transceiver

Table 1. Truth Table

Chip-En ATT-SW TX–R

0 X X Sleep N/S off off
1 1 0 Receive +14.3 dB on off
1 0 0 Receive –19 dB on off
1 X 1 Transmit N/S off on

X

Mode LNA Gain RX Mixer

TX Mixer and

Predriver

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

6

Philips Semiconductors Product specification

SA24212.45 GHz low voltage RF transceiver

23
22
21
20
19

Current (mA)

18
17

–40_C0_C25_C70_C85_C

TEMPERATURE (°C)

2.7V 3.8V3.0V 5.5V

SR02262

Figure 3. LNA / Receive Supply Current vs Supply Voltage and

Temperature

15

14

Gain (dB)

13

12

–40_C0_C25_C70_C85_C

TEMPERATURE (°C)

2.7V 3.8V3.0V 5.5V

SR02263

4.0

3.8

3.6

3.4

Noise (dB)

3.2

3.0

2.8
–40_C0_C25_C70_C85_C

TEMPERATURE (°C)

2.7V 3.8V3.0V 5.5V

Figure 6. LNA Noise Figure vs Supply Voltage and

Temperature

11.5

10.5

Gain dB

9.5

8.5
–40_C0_C25_C70_C85_C

TEMPERATURE (°C)

2.7V 3.8V3.0V 5.5V

SR02265

SR02266

Figure 4. LNA Gain vs Supply Voltage and Temperature

–1.0
–1.5
–2.0
–2.5
–3.0
–3.5

IP3 (dBm)

–4.0
–4.5
–5.0
–5.5

–40_C0_C25_C70_C85_C

TEMPERATURE (°C)

2.7V 3.8V3.0V 5.5V

SR02264

Figure 5. LNA Input IP3 vs Supply Voltage and Temperature

Figure 7. RX Gain vs Supply Voltage and Temperature

3.0

2.5

2.0

IP3 (dBm)

1.5

1

–40_C0_C25_C70_C85_C

TEMPERATURE (°C)

2.7V 3.8V3.0V 5.5V

SR02267

Figure 8. Receive Input IP3 vs Supply Voltage and Temp

2000 Mar 13

7

Philips Semiconductors Product specification

SA24212.45 GHz low voltage RF transceiver

12.5

12.0

11.5

11.0

NF (dB)

10.5

10

–40_C0_C25_C70_C85_C

TEMPERATURE (°C)

2.7V 3.8V3.0V 5.5V

SR02268

Figure 9. Receive Noise Figure vs Supply Voltage and Temp

–9.0

–9.5
–10.0
–10.5
–11.0
–11.5

P–1dB (dBm)
–12.0

–12.5

–13

–40_C0_C25_C70_C85_C

TEMPERATURE (°C)

2.7V 3.8V3.0V 5.5V

SR02269

29
27
25
23
21

Gain (dB)

19
17
15

–40_C0_C25_C70_C85_C

TEMPERATURE (°C)

2.7V 3.8V3.0V 5.5V

SR02271

Figure 12. Transmit Gain vs Supply Voltage and Temp

20
18
16
14
12
10

8
6

Output IP3 (dBm)

4
2
0

–40_C0_C25_C70_C85_C

TEMPERATURE (°C)

2.7V 3.8V3.0V 5.5V

SR02272

Figure 10. RX 1dB Compression vs Supply Voltage and Temp

38
37
36
35
34
33

Current (mA)

32
31
30

–40_C0_C25_C70_C85_C

TEMPERATURE (°C)

2.7V 3.8V3.0V 5.5V

SR02270

Figure 11. Transmit Current vs Supply Voltage and Temp

Figure 13. Transmit Output IP3 vs Supply Voltage and Temp

13.0

12.5

12.0

11.5

11.0

10.5

10.0

NF (dB)

9.5

9.0

8.5
8

–40_C0_C25_C70_C85_C

TEMPERATURE (°C)

2.7V 3.8V3.0V 5.5V

SR02273

Figure 14. Transmit Noise Figure vs Supply Voltage and Temp

2000 Mar 13

8

Philips Semiconductors Product specification

SA24212.45 GHz low voltage RF transceiver

9
8
7
6
5
4
3

P–1dB (dBm)

2
1
0

–1

–40_C0_C25_C70_C85_C

TEMPERATURE (°C)

2.7V 3.8V3.0V 5.5V

SR02274

Figure 15. TX 1dB compression vs Supply Voltage and Temp

–10
–11
–12
–13
–14
–15

P–1dB (dBm)

–16
–17
–18

–40_C25_C85_C

TEMPERATURE (°C)

2.7V 3.8V3.0V 5.5V

SR02275

Figure 16. LNA 1dB compression vs Supply Voltage and Temp

12.0

11.5

11.0

10.5

10.0

9.5

9.0

8.5

Receive Gain (dB)

8.0

7.5
7

–18 –16 –14 –12 –10 –8 –5 –2

LO Input (dBm)

–40C +25C0C +70C +85C

SR02276

Figure 17. Receive Gain vs LO Input over Temp Range

26
25
24
23
22
21
20

Transmit Gain (dB)

19
18
17

–18 –16 –14 –12 –10 –8 –5 –2

LO Input (dBm)

–40C +25C0C +70C +85C

SR02277

Figure 18. Transmit Gain vs LO Input over Temp Range

2000 Mar 13

The Rx IN port is matched to 50 Ω and has an input IP3 of +2.2 dBm
(mixer only). The down-convert mixer is buffered and has open
collectors at the pins to allow for matching to common SAW filters.
The up convert mixer has an input pin to output pin gain of 23 dB.
The output of the up-converter is designed for a power level =
+4.2 dBm (P

–1dB

).

9

Philips Semiconductors Product specification

SA24212.45 GHz low voltage RF transceiver

J7

LNA OUT

J6

RxRF IN

2.45GHz

cc

V

23

LNA OUT

LNA IN
2

L7

1.2nH

GND

3

C1

1pF

22

GND

S3

21

ATTEN SW

GND
4

20

GND

Rx IF OUT
5

19

Rx IN

SA2421

Rx IF OUT

6

+

C17

10uF

cc

V

cc

V

1

2

JP1

C15

.1uF

24

cc

V

GND

U1

1

L1

3.9nH

18

GND

Tx IF IN
7

J5

2.45GHz

TxRF OUT

C14

17

Tx OUT

Tx IF IN

8

C9

100pF

L6

16

GND

GND

9

8.2pF

2.7nH

C10

15

GND

LOP

10

100pF

cc

V

14

LO
cc

V

Tx/Rx

11

C12

C13

100pF

33pF

13

CHIP EN

LOM

12

L5

2.7nH

C11

cc

V

S2

1.0pF

2000 Mar 13

L4

C6

Tx IN

33nH

10pF

350MHz

J4

C8

8.2pF

S1

C7

100pF

cc

V

J3

LO 2.1GHz

SR01758

J1

LNA IN

L2

39nH

cc

V

C16

100pF

C2

SEL

(0pF–1.0pF)

C3

10pF

Rx OUT

350MHz

L3

33nH

C5

SEL

(0pF–1.0pF)

C4

3.9pF

J2

Figure 19.

10

Philips Semiconductors Product specification

SA24212.45 GHz low voltage RF transceiver

TSSOP24: plastic thin shrink small outline package; 24 leads; body width 4.4 mm SOT355-1

2000 Mar 13

11

Philips Semiconductors Product specification

SA24212.45 GHz low voltage RF transceiver

Data sheet status

Data sheet
status

Objective
specification

Preliminary
specification

Product
specification

Product
status

Development

Qualification

Production

Definition

This data sheet contains the design target or goal specifications for product development.
Specification may change in any manner without notice.

This data sheet contains preliminary data, and supplementary data will be published at a later date.
Philips Semiconductors reserves the right to make changes at any time without notice in order to
improve design and supply the best possible product.

This data sheet contains final specifications. Philips Semiconductors reserves the right to make
changes at any time without notice in order to improve design and supply the best possible product.

[1]

[1] Please consult the most recently issued datasheet before initiating or completing a design.

Definitions

Short-form specification — The data in a short-form specification is extracted from a full data sheet with the same type number and title. For

detailed information see the relevant data sheet or data handbook.
Limiting values definition — Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 134). Stress above one

or more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or
at any other conditions above those given in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended
periods may affect device reliability.

Application information — Applications that are described herein for any of these products are for illustrative purposes only. Philips
Semiconductors make no representation or warranty that such applications will be suitable for the specified use without further testing or
modification.

Disclaimers

Life support — These products are not designed for use in life support appliances, devices or systems where malfunction of these products can

reasonably be expected to result in personal injury . Philips Semiconductors customers using or selling these products for use in such applications
do so at their own risk and agree to fully indemnify Philips Semiconductors for any damages resulting from such application.

Right to make changes — Philips Semiconductors reserves the right to make changes, without notice, in the products, including circuits, standard
cells, and/or software, described or contained herein in order to improve design and/or performance. Philips Semiconductors assumes no
responsibility or liability for the use of any of these products, conveys no license or title under any patent, copyright, or mask work right to these
products, and makes no representations or warranties that these products are free from patent, copyright, or mask work right infringement, unless
otherwise specified.

Philips Semiconductors
811 East Arques Avenue
P.O. Box 3409
Sunnyvale, California 94088–3409
Telephone [phone]

 Copyright Philips Electronics North America Corporation 2000

All rights reserved. Printed in U.S.A.

Date of release: 03-00

Document order number: 9397 750 06949

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2000 Mar 13

12