Philips SA1921 Datasheet

INTEGRATED CIRCUITS

SA1921

Satellite and cellular dual-band RF
front-end

Product specification
Supersedes data of 1998 Sep 11
IC17 Data Handbook




1999 Mar 02

Philips Semiconductors Product specification

SA1921Satellite and cellular dual-band RF front-end

DESCRIPTION

The SA1921 is an integrated dual-band RF front-end that operates
at both cellular (AMPS, DAMPS, and GSM) and satellite
(1515–1600 MHz) frequencies, and is designed in a 13 GHz f

T

BiCMOS process—QUBiC1. The low-band is a combined low-noise
amplifier (LNA) and mixer. The LNA has a 1.7 dB noise figure at 943
MHz with 18.3 dB of gain and an IIP3 of –5 dBm. The wide-dynamic
range mixer has a 11 dB noise figure at 943 MHz with 7.2 dB of gain
and an IIP3 of +5 dBm.

The high-band contains a receiver front-end, and a high frequency
transmit mixer intended for closed loop transmitters. One advantage
of the high-band architecture is an image-rejection mixer with over
30 dB of image rejection; thus, eliminating external filter cost while
saving board space. The system noise figure is 3.9 dB at 1550 MHz
with a power gain of 22.2 dB and an IIP3 of –11.5 dB.

PIN CONFIGURATION

Tx B

GND

Tx A

HI/LO

SYN ON
HIGH BAND IF A
HIGH BAND IF B

LOW BAND IF A

LOW BAND IF B

GND
HIGH BAND LO A
HIGH BAND LO B

LOW BAND LO A

LOW BAND LO A

Rx ON

N/C

13
14
15
16

17

18
19
20
21
22

23
24

FEATURES

•Low current consumption

•Outstanding low- and high-band noise figure

•Excellent gain stability versus temperature and supply

•Image reject high-band mixer with over 30 dB of rejection

•Increased low-band LNA gain compression during analog

transmission

•LO input and output buffers

•On chip logic for network selection and power down

•Very small outline package

APPLICATIONS

•800 to 1000 MHz analog and digital receivers

•1515 to 1600 MHz digital receivers

•Portable radios

•Digital mobile communications equipment

GND

CC

GND

V

789101112

MIX IN

GND

Tx IF B

Tx IF A

N/C

123456

N/C

48
47

GND

46

GND
LOW BAND LNA OUT

45

GND

44

LOW BAND LNA IN

43

HIGH BAND LNA IN

42

GND

41

V

40

CC

GND

39

STRONG SIGNAL

38

N/C

37

25 26 27 28 29 30 31

CC

V

Tx ON

CC

V

GND

HIGH BAND IMAGE SET I

32 33 34 35 36

GND

LOW BAND LO INPUT

HIGH BAND LO INPUT

HIGH BAND IMAGE SET Q

GND

GND

N/C

SR01732

Figure 1. Pin Configuration

ORDERING INFORMATION

TYPE NUMBER

NAME DESCRIPTION VERSION

SA1921 LQFP48 Plastic low profile quad flat package; 48 leads; body 7x7x1.4 mm SOT313-2

1999 Mar 02 853–2121 20917

PACKAGE

2

Philips Semiconductors Product specification

SA1921Satellite and cellular dual-band RF front-end

PIN DESCRIPTIONS

PIN
NO.

1 N/C No Connection
2 Tx IF A Transmit IF A
3 Tx IF B Transmit IF B
4 GND Ground
5 MIX IN Low Band Mixer Input
6 GND Ground
7 V
8 GND Ground

9 Tx A Transmit Signal A
10 Tx B Transmit Signal B
11 GND Ground
12 N/C No Connection
13 HI/LO High Band/Low Band Control
14 SYN ON LO Buffer Power Control
15 HIGH BAND IF A High Band IF A
16 HIGH BAND IF B High Band IF B
17 LOW BAND IF A Low Band IF A
18 LOW BAND IF B Low Band IF B
19 GND Ground
20 HIGH BAND LO A High Band LO Output
21 HIGH BAND LO B High Band LO Output
22 LOW BAND LO A Low Band LO Output
23 LOW BAND LO B Low Band LO Output
24 Rx ON LNA/Mixer Power Control
25 V
26 Tx ON Tx Mixer/Driver Power
27 V
28 HIGH BAND IMAGE SET I High Band Image Set I
29 GND Ground
30 HIGH BAND LO INPUT High Band LO Connection
31 LOW BAND LO INPUT Low Band LO Connection
32 GND Ground
33 HIGH BAND IMAGE SET Q High Band Image Set Q
34 GND Ground
35 GND Ground
36 N/C No Connection
37 N/C No Connection
38 STRONG SIGNAL Strong Signal Detection
39 GND Ground
40 V
41 GND Ground
42 HIGH BAND LNA IN High Band LNA Input
43 LOW BAND LNA IN Low Band LNA Input
44 GND Ground
45 LOW BAND LNA OUT Low Band LNA Output
46 GND Ground
47 GND Ground
48 N/C No Connection

PIN NAME DESCRIPTION

CC

CC

CC

CC

V

CC

V

CC

V

CC

V

CC

1999 Mar 02

3

Philips Semiconductors Product specification

SA1921Satellite and cellular dual-band RF front-end

HI/LO

SYN ON

HIGH BAND IF A

HIGH BAND IF B

LOW BAND IF A

LOW BAND IF B

GND

HIGH BAND LO A

HIGH BAND LO B

LOW BAND LO A

LOW BAND LO B

5 pF

5 pF

N/C

GND

Tx B

Tx A

REJECT

IMAGE

MIXER

GND

CC

V

GND

MIX IN

GND

Tx IF B

N/C

Tx IF A

N/C

GND

GND

LNA OUT

GND

LOW BAND LNA IN

HIGH BAND LNA IN

GND

V

CC

GND

STRONG SIGNAL

Rx ON

N/C

Tx ON

CC

V

GND

HIGH BAND IMAGE SET I

HIGH BAND LO INPUT

GND

LOW BAND LO INPUT

GND

HIGH BAND IMAGE SET Q

GND

N/C

SR01733

CC

V

Figure 2. Block Diagram

1999 Mar 02

4

Philips Semiconductors Product specification

SA1921Satellite and cellular dual-band RF front-end

T able 1. POWER DOWN CONTROL

LO BUFFER LNA MIXER

Control State
(Hi/Lo, Syn On, Rx On, Tx On, Strong Signal)

x000x Sleep Off Off Off Off Off Off Off Off
01000 Low-Band LO Buf fer on Off On Off Off Off Off Off Off
01100 Low-Band Receive Normal Off On Off On Off On Off Off
01101 Low-Band receive Strong Signal Off On Off Off Off On Off Off
01110 Low-Band Transmit (Analog only) Off On Off On

01010 N/A Off On Off Off Off Off Off On
11000 High-Band LO Buffer On On Off Off Off Off Off Off Off
11100 High-Band Receive Normal On Off On Off On Off Off Off
11101 High-Band Receive Strong Signal On Off Of f Off On Off Off Of f
11010 N/A On Off Off Off Off Off On Of f

NOTE:

1. “0” is low logic state; “1” is high logic state.

High
Band

Low

Band

High

Band

Low

Band

High Bias

High

Band

Off On Off On

Low

Band

TX MIXER

DRIVER

High

Band

Low

Band

1999 Mar 02

5

Philips Semiconductors Product specification

SA1921Satellite and cellular dual-band RF front-end

OPERATION

The low-band contains both an LNA and mixer that is designed to
operate in the 800 to 1000 MHz frequency range. The high-band
contains an LNA and image-rejection mixer that is designed to
operate in the 1515 to 1600 MHz frequency range with over 30 dB of
rejection over an intermediate frequency (IF) range from 150 to
185 MHz.

Image rejection is achieved in the internal architecture by two RF
mixers in quadrature and two all-pass filters in the I and Q IF
channels that phase shift the IF by 45 and 135, respectively. The
two phase shifted IFs are recombined and buffered to produce the
IF output signal.

The LO section consists of an internal phase shifter to provide
quadrature LO signals to the receive mixers. The filters outputs are
buffered before being fed to the receive mixers. The transmit mixer
section consists of a low-noise amplifier, and a down-convert mixer.
In the transmit mode, an internal LO buffer is used to drive the
transmit IF down-convert mixer.

Low-Band Receive Section

The circuit contains a LNA followed by a wide-band mixer. In a
typical application circuit, the LNA output uses an external pull-up
inductor to VCC and is AC coupled. The mixer IF outputs are
differential. A typical application will load the output buffer with an
inductor across the IF outputs, a pull-up inductor to V
coupled capacitor to the matching network.

and an AC

CC

Low-Band Receive Section (Analog Transmit
Mode)

The bias current of the low-band LNA will increase during analog
transmission, which increases its gain compression point and makes
the receiver less sensitive to PA leakage power for an AMPS
application.

High-Band Receive Section

The circuit contains an LNA followed by two high dynamic range
mixers. These are Gilbert cell mixers; the internal architecture is fully
differential. The LO is shifted in phase by 45 and 135 and mixes
the amplified RF signal to create I and Q channels. The two I and Q
channels are buffered, phase shifted by 45 and 135, respectively ,
amplified and recombined internally to realize the image rejection.

The IF output is differential and of the open-collector type. A typical
application will load the output buffer with an inductor across the IF
outputs, a pull-up inductor to V
the matching network.

and an AC coupled capacitor to

CC

Control Logic Section

Pins HI/LO, SYN ON, Rx On, Tx On, Strong Signal, control the logic
functions. The HI/LO mode selects between low-band and
high-band operation. The SYN ON mode enables the LO buffers
independent of the other circuitry. When SYN ON is high, all internal
buffers in the LO path of the circuit are turned on, thus minimizing
LO pulling when the remainder of the receive or transmit chain is
powered-up.

The Rx ON mode enables the LO buffers when the device is in the
low-band receive normal, receive strong signal and transmit modes;
the Rx ON mode enables the LO buffers, also, when the device is in
the high-band receive normal, and receive strong signal modes.

The Tx ON mode enables the transmit mixer. The strong signal
mode, when disabled, allows the low- and high-band LNAs to
function normally; and when the strong signal mode is enabled, it
turns-off the low- and high-band LNAs. This is needed when the
input signal is large and needs to be attenuated.

Local Oscillator (LO) Section

The LO input directly drives the two internal all-pass networks to
provide quadrature LO to the receive mixers. A synthesizer-on (SYN
ON) mode is used to power-up all LO input buffers, thus minimizing
the pulling effect on the external VCO when entering receive or
transmit mode.

Transmit Mixer Section

The transmit mixer is used for down-conversion to the transmit IF. Its
inputs are coupled to the transmit RF which is down-converted to a
modulated transmit IF frequency , and phase-locked with the
baseband modulation.

The IF outputs are HIGH impedance (open-collector type). A typical
application will load the output buffer with an inductor across the IF
outputs, a pull-up inductor to V
matching network.

and AC coupled capacitors to the

CC

1999 Mar 02

6

Philips Semiconductors Product specification

SA1921Satellite and cellular dual-band RF front-end

ABSOLUTE MAXIMUM RATINGS

SYMBOL PARAMETERS VALUE UNIT

V

CC

P

D

P

IN

T

srg

RECOMMENDED OPERATING CONDITIONS

SYMBOL PARAMETERS RATING UNIT

V

CC

T

O

DC ELECTRICAL CHARACTERISTICS

Unless otherwise specified, all Input/Output ports are single-ended.

Input supply voltage at pins: 7, 25, 27, 40 4.75 V
Power dissipation 150 mW
Input power at all ports +20 dBm
Storage temperature range –65 to +125 °C

DC Supply voltage 3.6 to 3.9 V
Operating temperature range (pin temp) –40 to +85 °C

DC PARAMETERS

V

= +3.75 V, T

CC

SYMBOL

I
I
I
I
I
I
I
I

CC
CC
CC
CC
CC
CC
CC
CC

= +25°C unless otherwise noted

A

Current Consumption: Sleep Mode X000X 1.0 25
Low Band Receive Normal 01100 9.8 12.2 14.7 mA
Low Band Receive Strong 01101 9.0 mA
Low Band Transmit (Analog) 01111 18.0 mA
Low Band Transmit (GSM) 01010 16.5 mA
High Band Receive Normal 11100 32.0 40.0 48.0 mA
High Band Receive Strong 11101 36.0 mA
High Band Transmit (GSM) 11010 19.4 mA
Logic Low Input 0 0.5 V
Logic High Input 1.9 4.0 V

PARAMETERS CONDITION MIN. TYP. MAX. UNIT

A

1999 Mar 02

7

Philips Semiconductors Product specification

SA1921Satellite and cellular dual-band RF front-end

AC ELECTRICAL CHARACTERISTICS
Low-Band, Dual Mode of Operation

VCC = +3.75 V, FreqRF = 943 MHz, FreqLO = 1106 MHz, P

PARAMETERS

System

RF Input Frequency Range 869 943 960 MHz

IF Frequency 163 MHz

LO Frequency 1032 1106 1 123 MHz

Cascaded Power Gain; includes 3dB filter loss 21.4 22.5 23.6 dB

Power Gain Reduction (Strong Signal Mode—LNA Off) 30 36 42 dB

Cascaded Noise Figure; includes 3dB filter loss 2.6 dB

LNA

LNA Gain 17.6 18.3 19 dB

LNA IIP3 (60 kHz spacing) –6.0 –5.0 –4.0 dBm

LNA IIP3 (200 kHz spacing) –3.0 dBm

LNA Noise Figure 1.6 1.7 1.8 dB

LNA 1 dB RF Input Compression Point –21.0 dBm

Mixer

Mixer Gain 6.9 7.2 7.5 dB

Mixer IIP3 (60 kHz spacing) 4.0 5.0 6.0 dBm

Mixer Noise Figure 10.4 11.0 11.6 dB

Mixer 1 dB RF Input Compression Point –13.0 dBm

Other

Input Impedance, RF Port 50

Return Loss at LNA Inputs and Output –10 dB 1

Return Loss at Mixer Input and Outputs –10 dB 1

LO leakage at RF Port –42 dBm

LO Input Power –5 –3 –1 dBm

Turn ON/OFF Time 100

= –3 dBm, TA = +25C; unless otherwise stated.

LOin

Min

–3

TYP

+3

Max UNITS NOTES

W

msec

Low-Band LO Buffer

VCC = +3.75 V, FreqLO = 1106 MHz, P

PARAMETERS

LO Frequency 1032 1106 1 123 MHz
Differential Output Power –7 dBm
Differential Output Impedance 100
Harmonic Content –20 dBc
Input Power –5 –3 –1 dBm
Input Impedance 50
Turn On/Off T ime 10

NOTE:

1. External matching network is required.

1999 Mar 02

= –3 dBm, TA = +25C; unless otherwise stated.

LOin

Min

8

–3

TYP.

+3

Max UNITS NOTES

msec

W

W

1

Philips Semiconductors Product specification

50 dBm IN Referred to RF In ut Port

SA1921Satellite and cellular dual-band RF front-end

AC ELECTRICAL CHARACTERISTICS
High-Band, Single Mode of Operation

LNA and Image Reject Mixer

VCC = +3.75 V, FreqRF = 1550 MHz, FreqLO = 1713 MHz, P

PARAMETERS

RF Input Frequency Range 1515 1600 MHz
IF Frequency 150 163 185 MHz
LO Frequency 1665 1785 MHz
Power Gain 21.5 22.2 22.9 dB
Power Gain Reduction (Strong Signal Mode—LNA Off) 34 47 60 dB
Noise Figure 3.7 3.9 4.1 dB
Input Impedance, RF Port 50
Return Loss at Inputs –10 dB 1
LO leakage at RF Port –48 dBm
1 dB RF Input Compression Point –24 dBm
IP3 (3RD Order Intermodulation Product)

Referred to the RF Input Port
(2 x LO) – (2 x RF) Spur Performance

–
Measure at LO = 1688 MHz and RF = 1606 MHz

(3 x LO) – (3 x RF) Spur Performance.
–50 dBm IN Referred to RF Input Port.
Measure at LO = 1688 MHz and RF = 1634 MHz.

Image rejection, fRX+2f
Referred to the RF Input Port

LO Input Power –5 –3 –1 dBm
Turn ON/OFF Time 10

p

IF

= –3 dBm, TA = +25C; unless otherwise stated.

LOin

MIN

–3

–14 –11.5 –9 dBm

31.5 34 36.5 dB

TYP.

–62 dBc

–102 dBc

+3

MAX UNITS NOTES

W

msec

High-Band LO Buffer

VCC = +3.75 V, FreqLO = 1713 MHz, P

LO Frequency Range 1665 1785 MHz
Differential Output Power –9 dBm
Differential Output Impedance 100
Harmonic Content –20 dBc
Input Power –5 –3 –1 dBm
Input Impedance 50
Turn On/Off T ime 10

NOTE:

1. External matching network is required.

1999 Mar 02

LOin

PARAMETERS

= –3 dBm, TA = +25C; unless otherwise stated.

MIN

9

–3

TYP.

+3

MAX UNITS NOTES

W

W

msec

1

Philips Semiconductors Product specification

SA1921Satellite and cellular dual-band RF front-end

Transmit Mixer

VCC = +3.75 V, FreqRF = 1550 MHz, FreqLO = 1713 MHz, P

PARAMETERS

TX Mixer Input Frequency 824 1661 MHz
TX RF Input Impedance, Balanced 200
TX Mixer Output Frequency 70 163 200 MHz
TX IF Load Impedance 1000
Maximum TX IF Load Capacitance 2 pF
Conversion Power Gain 17 18 19 dB 1
1 dB Input Compression Point –17 dBm
IIP2 20 dBm
IIP3 –9 –7 –5 dBm
Noise Figure (double sideband) 8.5 dB
Reverse Isolation T
Isolation LOIN–T

NOTES:

1. Input and output ports matched to 50 W.

XIN

XIN

–LO

IN

= –3 dBm, TA = +25C; unless otherwise stated.

LOin

MIN

–3

40 dB
40 dB

TYP.

+3

MAX UNITS NOTES

W

W

1999 Mar 02

10

Philips Semiconductors Product specification

SA1921Satellite and cellular dual-band RF front-end

AP43

R28

J1–3

L12

3.92K

C8

10 pf

DUT–48

N/C

DPS1

C38

1000 pf

C37

100 pf

4.7 nH

DUT–45

LBLOUT

R27

DUT–46

RxMxGND

332

DUT–47

GND

J29–2

AP47

R29

DUT–44

GND

R31

3.92K

DUT–41

GND

J28–3

AP16

P8

3.92K

C22

AT7

PAT–6

13

R22

51.1

L9

8.2 nH

A

B

33 pf

C30

1.5 pf

DUT–43

LBLIN

AP16

R30

J26–3

3.92K

P6

AT8

PAT–6

13

R19

51.1

L8

8.2 nH

A

B

C21

33 pf

C29

2.2 pf

DUT–42

HBLIN

DPS1

C33

0.1 uf

L5

1 uH
BA

C14

1000 pf

C17

100 pf

DUT–40

VCC

DUT–39

GND

J28–2

DP31

DUT–38

STRONG

DUT–37

N/C

DUT–36

N/C

J25–2

DP23

DUT–35

X2ON

DUT–34

GND

J26–2

AP14

DUT–33

LBBPS

R16

1

J24–4

AP36

R15

DUT–32

GND

3.92K

U1

C26

P7

6

PORT 2

3
3

AT5

1

DUT–31

LBTNK

SUM PORT

PA T–6

R21

10 pf

51.1

J22–5

J21–2

J100–4

J100–2

J100–3

J100–5

J23–4

AP39

AP11

DPS1LF

LRPS–2–11

PORT 1

4

3

R14

PA T–3

R20

10 pf

51.1

3.92K

DUT–29

GND

1

R12

DUT–28

HBBPS

AT6

1

C25

DUT–30

HBTNK

DPS1HF

DPS1LS

DPS1HS

C32

L4

1 uH
BA

C12

C16

DUT–27

VCC

0.1 uf

1000 pf

100 pf

DP19

DUT–26

TXON

C13

1000 pf

DUT–25

VCC

DO NOT ASSEMBLE
1

R1

N/C

DUT–1

AP45

J1–4

A

C23

3.92K

L2

10 pf

SA1921

TXIFA

DUT–2

150 nH

B

C24

P1

TXIFB

DUT–3

13

AT9

10 pf

R32

PAT–10

GND

DUT–4

A

C9

1

GND

DUT–6

R2

562

L1

180 nh

1

SELECT

2X

IMAGE

REJECT

MIXER

HBLOA

HBIFA

DUT–15

C3

A

5.6 pf

AT1

PA T–10

5.6 pf

L6

R10

150 nH

B

A

1

L10

R9

HBIFB

DUT–16

C27

180 nH

B

1.21K

DPS1

5.6 pf

C4

R26

1000 pf

AP46

3.92K

J11–2

LBIFA

DUT–17

C7

8.2 pf
L7

150 nH

A

A

C6

5.6 pf
1

R18

AT2

PA T–10

13

P5

B

R11

LBIFB

DUT–18

C28

L11

150 nh

B

4.32K

DPS1

1

SELECT

C11

1000 pf

R25

AP44

U2

J12–4

1

3
4

3.92K

1

R24

1

AT4

AT3

PA T–10

3

3

PORT 1

PORT 2

SUM PORT

LRPS–2–11

6

P4

GND

GND

100 pf

1000 pf

0.1 uf

DUT–8

R13

AP9

J2–4

N/C

TXA

TXB

DUT–11

DUT–12

DUT–9

DUT–10

C18

33 pf

33 pf

C19

C2

1.5 pf

R3

3.92K

R17

AT10

PA T–10

13

P2

1K

AP10

J2–5

LBMIN

VCC

DUT–5

DUT–7

C15

DPS1

C10

B

L3

1 uH

A

C31

C1

1000 pf

B

51.1
R4

AP42

J6–5

3.92K

DP33

HILO

DUT–13

DP34

J13–2

SYNON

DUT–14

C5

13

P3

J13–3

HBLOB

GND

DUT–19

DUT–20

DUT–21

C34

33 pf

1

R23

PA T–10

C20

33 pf

R8

3.92KR73.92KR53.92K

AP41

AP40

J11–5

J15–3

C36

33 pf

R6

AP38

LBLOA

DUT–22

C35

33 pf

3.92K

J20–3

LBLOB

DUT–23

AP12

J21–3

RXON

DUT–24

DP26

J16–2

SR01802

Figure 3. SA1921 Dual-Band Test Circuit

1999 Mar 02

11