Datasheet SA636D, SA636DK Datasheet (Philips)

Philips Semiconductors

SA636

Low voltage high performance mixer FM
IF system with high-speed RSSI

Product specification
Replaces data of 1994 Jun 16

1997 Nov 07

RF COMMUNICATIONS PRODUCTS

IC17 Data Handbook

Philips Semiconductors Product specification

SA636

Low voltage high performance mixer FM IF
system with high-speed RSSI

2

1997 Nov 07 853-1757 18664

DESCRIPTION

The SA636 is a low-voltage high performance monolithic FM IF
system with high-speed RSSI incorporating a mixer/oscillator, two
limiting intermediate frequency amplifiers, quadrature detector,
logarithmic received signal strength indicator (RSSI), voltage
regulator, wideband data output and fast RSSI op amps. The
SA636 is available in 20-lead SSOP (shrink small outline package).

The SA636 was designed for high bandwidth portable
communication applications and will function down to 2.7V . The RF
section is similar to the famous SA605. The data output has a
minimum bandwidth of 600kHz. This is designed to demodulate
wideband data. The RSSI output is amplified. The RSSI output has
access to the feedback pin. This enables the designer to adjust the
level of the outputs or add filtering.

SA636 incorporates a power down mode which powers down the
device when Pin 8 is low. Power down logic levels are CMOS and
TTL compatible with high input impedance.

APPLICA TIONS

•DECT (Digital European Cordless Telephone)

•Digital cordless telephones

•Digital cellular telephones

•Portable high performance communications receivers

•Single conversion VHF/UHF receivers

•FSK and ASK data receivers

•Wireless LANs

FEATURES

•Wideband data output (600kHz min.)

•Fast RSSI rise and fall times

•Low power consumption: 6.5mA typ at 3V

•Mixer input to >500MHz

•Mixer conversion power gain of 11dB at 240MHz

•Mixer noise figure of 12dB at 240MHz

PIN CONFIGURATION

RF

IN

RF BYPASS

RSSI

OUT

MIXER OUT

IF AMP IN

IF AMP OUT

GND

LIMITER IN

LIMITER OUT

DK Package

POWER DOWN CONTROL

DATA OUT

QUADRATURE IN

IF AMP DECOUPLING

IF AMP DECOUPLING

LIMITER DECOUPLING

LIMITER DECOUPLING

V

CC

RSSI FEEDBACK

XTAL OSC (EMITTER)

XTAL OSC (BASE)

1
2
3
4
5
6
7
8
9

10

20
19
18
17
16
15
14
13
12
11

SR00491

Figure 1. Pin Configuration

•XTAL oscillator effective to 150MHz (L.C. oscillator to 1GHz local

oscillator can be injected)

•92dB of IF Amp/Limiter gain

•25MHz limiter small signal bandwidth

•Temperature compensated logarithmic Received Signal Strength

Indicator (RSSI) with a dynamic range in excess of 90dB

•RSSI output internal op amp

•Internal op amps with rail-to-rail outputs

•Low external component count; suitable for crystal/ceramic/LC

filters

•Excellent sensitivity: 0.54µV into 50Ω matching network for 12dB

SINAD (Signal to Noise and Distortion ratio) for 1kHz tone with RF
at 240MHz and IF at 10.7MHz

•ESD hardened

•10.7MHz filter matching (330Ω)

•Power down mode (I

CC

= 200µA)

ORDERING INFORMATION

DESCRIPTION TEMPERATURE RANGE ORDER CODE DWG #

20-Pin Plastic Shrink Small Outline Package (Surface-mount) -40 to +85°C SA636DK

SOT266-1

Philips Semiconductors Product specification

SA636

Low voltage high performance mixer FM IF system
with high-speed RSSI

1997 Nov 07

3

BLOCK DIAGRAM

20 19 18 17 16 15 14 13 12 11

10987654321

FAST

IF
AMP

EB

OSCILLATOR

LIMITER

MIXER

QUAD

+–

+–

RSSI

GND

PWR
DWN

RSSI

AUDIO

V

CC

SR00492

Figure 2. Block Diagram

ABSOLUTE MAXIMUM RATINGS

SYMBOL PARAMETER RATING UNITS

V

CC

Single supply voltage 0.3 to 7 V

V

IN

Voltage applied to any other pin –0.3 to (VCC+0.3) V

T

STG

Storage temperature range -65 to +150

°C

T

A

Operating ambient temperature range SA636 –40 to +85

°C

NOTE: θJA, Thermal impedance DK package 117°C/W

DC ELECTRICAL CHARACTERISTICS

VCC = +3V, TA = 25°C; unless otherwise stated.

LIMITS

SYMBOL PARAMETER TEST CONDITIONS SA636 UNITS

MIN TYP MAX

V

CC

Power supply voltage range 2.7 3.0 5.5 V

I

CC

DC current drain Pin 8 = HIGH 5.5 6.5 7.5 mA

p

Pin 8 LOW –10 10

Input current

Pin 8 HIGH –10 10

µ

A

p

Pin 8 LOW 0 0.3V

CC

Input level

Pin 8 HIGH 0.7V

CC

V

CC

V

I

CC

Standby Pin 8 = LOW 0.2 0.5 mA

t

ON

Power up time RSSI valid (10% to 90%) 10 µs

t

OFF

Power down time RSSI invalid (90% to 10%) 5 µs

Philips Semiconductors Product specification

SA636

Low voltage high performance mixer FM IF system
with high-speed RSSI

1997 Nov 07

4

AC ELECTRICAL CHARACTERISTICS

TA = 25°C; VCC = +3V , unless otherwise stated. RF frequency = 240.05MHz + 14.5dBV RF input step-up; IF frequency = 10.7MHz; RF level =

-45dBm; FM modulation = 1kHz with ±125kHz peak deviation. Audio output with C-message weighted filter and de-emphasis capacitor. Test
circuit Figure 1. The parameters listed below are tested using automatic test equipment to assure consistent electrical characteristics. The
limits do not represent the ultimate performance limits of the device. Use of an optimized RF layout will improve many of the listed parameters.

LIMITS

SYMBOL PARAMETER TEST CONDITIONS SA636 UNITS

MIN TYP MAX

Mixer/Osc section (ext LO = 160mV

RMS

)

f

IN

Input signal frequency 500 MHz

f

OSC

External oscillator (buffer) 500 MHz
Noise figure at 240MHz 12 dB
Third-order input intercept point Matched f1=240.05; f2=240.35MHz -16 dBm
Conversion power gain Matched 14.5dBV step-up 8 11 14 dB
RF input resistance Single-ended input 700 Ω
RF input capacitance 3.5 pF
Mixer output resistance (Pin 20) 330 Ω

IF section

IF amp gain 330Ω load 38 dB
Limiter gain 330Ω load 54 dB
Input limiting -3dB Test at Pin 18 –105 dBm
AM rejection 80% AM 1kHz 50 dB
Data level R

LOAD

= 100kΩ 120 130 mV

RMS

3dB data bandwidth 600 700 kHz
SINAD sensitivity RF level = -111dBm 16 dB

THD Total harmonic distortion -43 -38 dB

S/N Signal-to-noise ratio No modulation for noise 60 dB

IF level = -118dBm 0.2 0.5 V

IF RSSI output with buffer IF level = -68dBm 0.3 0.6 1.0 V

IF level = -10dBm 0.9 1.3 1.8 V
IF RSSI output rise time IF frequency = 10.7MHz
(10kHz pulse, no 10.7MHz filter) RF level = -56dBm 1.2 µs
(no RSSI bypass capacitor) RF level = -28dBm 1.1 µs
IF RSSI output fall time IF frequency = 10.7MHz
(10kHz pulse, no 10.7MHz filter) RF level = -56dBm 2.0 µs
(no RSSI bypass capacitor) RF level = -28dBm 7.3 µs
RSSI range 90 dB
RSSI accuracy +1.5 dB
IF input impedance 330 Ω
IF output impedance 330 Ω
Limiter input impedance 330 Ω
Limiter output impedance 300 Ω
Limiter output level with no load 130 mV

RMS

RF/IF section (int LO)

System RSSI output RF level = -10dBm 1.4 V
System SINAD RF level = -106dBm 12 dB

Philips Semiconductors Product specification

SA636

Low voltage high performance mixer FM IF system
with high-speed RSSI

1997 Nov 07

5

PERFORMANCE CHARACTERISTICS

0.50

0.45

0.40

0.35

0.30

0.25

0.20

0.15

0.10

0.05

0.00

POWER DOWN SUPPLY CURRENT (mA)

–50 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 90

TEMPERATURE (°C)

100

Power Down Supply Current vs Temperature and Supply Voltage

VCC = 5V

V

CC

= 3V

V

CC

= 2.7V

9.0

8.5

8.0

7.5

7.0

6.5

6.0

5.5

5.0

SUPPLY CURRENT (mA)

–50 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 90

TEMPERATURE (°C)

Supply Current vs Temperature and Supply Voltage

Mixer Power Gain vs Temperature and Supply Voltage

20

0

–20

–40

–60

–80

–100

–120

AUDIO (dB)

–50–40 –30 –20 –10 0 10 20 30 40 50 60 70 80 90

TEMPERATURE (°C)

12dB SINAD and Relative Audio, THD, Noise

and AM Rejection for VCC = 3V vs Temperature

RF = 240MHz, Level = –68dBm, Deviation = 125kHz

VCC = 3V

V

CC

= 2.7V

V

CC

= 5V

AUDIO

AM REJECTION

DISTORTION

NOISE

12dB SINAD

MIXER GAIN

(dB)

Temperature (°C)

–40 0 25 70 85

20
19
18
17
16
15
14
13
12
11
10

9
8
7
6
5

5.5V

2.7V

3.0V

RF level = -45 dBm

Mixer IIP3 at 240MHz vs Temperature and Supply Voltage

Temperature (°C)

–40 0 25 70 85

MIXER IIP3 (deB)

–5

–7

–9

–11

–13

–15

–17

–19

–21

–23

–25

5.5V

2.7V

3.0V

RF level = -45 dBm

Temperature (°C)

–40 0257085

300

AUDIO REFERENCE (mVrms)

5.5V

2.7V

3.0V

250

200

150

100

50

0

Audio Reference Level vs Temperature and Supply Voltage

SR00493

Figure 3. Performance Characteristics

Philips Semiconductors Product specification

SA636

Low voltage high performance mixer FM IF system
with high-speed RSSI

1997 Nov 07

6

PERFORMANCE CHARACTERISTICS (continued)

10

0

–10

–20

–30

–40

–50

–60

–70

–80

–90

2

1.8

1.6

1.4

1.3

1.0

0.8

0.6

0.4

0.2

0

RSSI (V)

RELATIVE TO AUDIO OUTPUT (dB)

RF INPUT LEVEL (dBm)

Receiver RF Performance — T = 25°C,

Audio Level = 129mV

RMS

10

0

–10

–20

–30

–40

–50

–60

–70

–80

–90

2.0

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0.0

RSSI (V)

RELATIVE TO AUDIO OUTPUT (dB)

RF INPUT LEVEL (dBm)

AUDIO

AM REJECTION

THD+N

NOISE

RSSI

Receiver RF Performance — T = –40°C,

Audio Level = 118mV

RMS

0
–10
–20
–30
–40
–50
–60
–70
–80
–90

–100
–110

–65

–60

–55

–50

–45

–40

–35

–30

–25

–20

–15

–10

RF INPUT POWER (dBm)

IF OUTPUT POWER (dBm)

Mixer Third Order Intercept and Compression

RF INPUT LEVEL (dBm)

RSSI (V)

RSSI vs RF Input Level and Temperature

–40°C

25°C

85°C

10

0

–10

–20

–30

–40

–50

–60

–70

–80

–90

–110

–100

–90

–80

–70

–60

–50

–40

–30

–20

–10

0

2

1.8

1.6

1.4

1.2

1

0.8

0.6

0.4

0.2

0

RSSI (V)

RELATIVE TO AUDIO OUTPUT (dB)

Receiver RF Performance – T = 85°C, Audio Level = 131mV

RMS

AUDIO

AM REJECTION

THD+N

NOISE

RSSI

AUDIO

AM REJECTION

THD+N

NOISE

RSSI

–110

–100

–90

–80

–70

–60

–50

–40

–30

–20

–10

0

–110

–100

–90

–80

–70

–60

–50

–40

–30

–20

–10

0

–110

–100

–90

–80

–70

–60

–50

–40

–30

–20

–10

0

2

1.8

1.6

1.4

1.2

1

0.8

0.6

0.4

0.2

0

Temperature (°C)

–40 0 25 70

85
–5
–7
–9

–11
–13
–15
–17
–19
–21
–23
–25

MIXER IIP3 (dB)

5.5V

2.7V

3.0V

RF level = -45 dBm

Mixer IIP3 at 240MHz vs Temperature and Supply Voltage

SR00494

Figure 4. Performance Characteristics

Philips Semiconductors Product specification

SA636

Low voltage high performance mixer FM IF system
with high-speed RSSI

1997 Nov 07

7

PERFORMANCE CHARACTERISTICS (continued)

50.00

48.00

46.00

44.00

42.00

40.00

38.00

36.00

34.00

32.00

30.00

–50.00

–30.00

–10.00

10.00

30.00

50.00

70.00

90.00

POWER GAIN (dB)

TEMPERATURE (°C)

65.00

63.00

61.00

59.00

57.00

55.00

53.00

51.00

49.00

47.00

45.00

POWER GAIN (dB)

TEMPERATURE (°C)

–50.00

–30.00

–10.00

10.00

30.00

50.00

70.00

90.00

SA626 IF Amplifier Gain vs Temperature vs Supply Voltage

SA626 Limiting Amplifier Gain vs Temperature vs Supply Voltage

VCC = 3V

V

CC

= 2.7V

V

CC

= 5V

VCC = 3V

V

CC

= 2.7V

V

CC

= 5V

Data Level vs Temperature and Supply Voltage

DATA LEVEL (Vp-p)

Temperature (°C)

–40 0 25 70 85

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

5.5V

2.7V

3.0V

600kHz Data Rate,
IF = 9.85MHz,
Dev = 288kHz,
RF = -40dBm

Data Level vs Temperature and Supply Voltage

Temperature (°C)

–40 0257085

DATA LEVEL (Vp-p)

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

5.5V

2.7V

3.0V

1kHz Data Rate,
IF = 9.85MHz,
Dev = 288kHz,
RF = -40dBm

SR00495

Figure 5. Performance Characteristics

Philips Semiconductors Product specification

SA636

Low voltage high performance mixer FM IF system
with high-speed RSSI

1997 Nov 07

8

PERFORMANCE CHARACTERISTICS (continued)

Temperature (°C)

300

AUDIO REFERENCE (mVrms)

5.5V

2.7V

3.0V

–40 0 257085

250

200

150

100

50

0

Audio Reference Level vs Temperature and Supply Voltage

Temperature (°C)

0.8

DATA LEVEL (Vp-p)

5.5V

2.7V

3.0V

600kHz Data Rate,

Data Level vs Temperature and Supply Voltage

–40 0 257085

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

IF = 9.85MHz,
Dev = 288kHz,
RF = -40dBm

5.5V

2.7V

3.0V

1kHz Data Rate,
IF = 9.85MHz,
Dev = 288kHz,
RF = -40dBm

0.8

DATA LEVEL (Vp-p)

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

Temperature (°C)

Data Level vs Temperature and Supply Voltage

–40 0257085

SR00496

Figure 6. Performance Characteristics

Philips Semiconductors Product specification

SA636

Low voltage high performance mixer FM IF system
with high-speed RSSI

1997 Nov 07

9

PIN FUNCTIONS

1

0.8k

2

0.8k

4

3

18k

MIX

150µA

5

V

REF

BANDGAP

10

80k

20µA

6

+

V

CC

—

7

V

CC

+

—

8

R

R

PIN
No.

PIN

MNEMONIC

DC V EQUIVALENT CIRCUIT

PIN

No.

PIN

MNEMONIC

DC V EQUIVALENT CIRCUIT

9

+

—

V

CC

1 RF IN +1.07 6

RSSI

+0.20

FEEDBACK

2

RF

+1.07 7

RSSI

+0.20

OUTBYPASS

3

XTAL

+1.57 8

POWER

+2.75

DOWNOSC

4

XTAL

+2.32 9

DATA

+1.09

OUTOSC

5V

CC

+3.00 10

QUAD.

+3.00

IN

SR00497

Figure 7. Pin Functions

Philips Semiconductors Product specification

SA636

Low voltage high performance mixer FM IF system
with high-speed RSSI

1997 Nov 07

10

PIN FUNCTIONS (continued)

11

14

20

400µA

PIN
No.

PIN

MNEMONIC

DC V EQUIVALENT CIRCUIT

PIN

No.

PIN

MNEMONIC

DC V EQUIVALENT CIRCUIT

11

LIMITER

+1.35 16

IF

+1.22

AMP OUT

12

LIMITER

+1.23 17

IF AMP

+1.22

DECOUPDECOUP

13

LIMITER

+1.23 18

IF

+1.22

AMP INCOUPLING

14

LIMITER

+1.23 19

IF AMP

+1.22

DECOUPIN

15 GND 0 20

MIXER

+1.03

OUT

OUT

8.8k

16

8.8k

140Ω

13

12

330Ω

50µA

18

19

17

330Ω

50µA

110Ω

SR00498

Figure 8. Pin Functions (cont.)

Philips Semiconductors Product specification

SA636

Low voltage high performance mixer FM IF system
with high-speed RSSI

1997 Nov 07

11

10987654321

20 19 18 17 16 15 14

13 12 11

RSSI

MIXER

QUAD

C19

C18

SW5

C13

C15

FLT1

0.1µF

6.8µF 10V

160pF select
1000pF

39pF select

0.1µF

1µF

C14

C15

C18
C19

C20
C21

L1
L2

L3
L4
L5

FLT1

0.1µF

1000pF

10.7MHz (Murata SFE10.7MA5-A)

1.27–2.25µH select for mixer

5.6µH select for input match

22nH select for input match

1000pF

C1
C2

C3
C4
C5
C6

*C7

C8

C9
C10
C11

C12
C13

Automatic Test Circuit Component List

OSCILLATOR

FLT2

10.7MHz (Murata SFE10.7MA5-A)

FLT3

Active de-emphasis

FLT4

“C” message weighted

LIMITER

V

CC

+

–

DATA

C16

0.1µF

C17

0.1µF

*NOTE: This value can be reduced when a battery is the power source.

PWR
DWN

0.1µF

100pF

1–5pF select for input match

0.1µF

0.1µF
1–5pF select for input match

47nH select for input match

0.1µF

1000pF

150nH select for input match

1pF

FLT

3

FLT

4

FLT2

R1
R2

R3
R4
R5
R6
R7
R8

R9
R10
R11

347.8Ω

6.42kΩ

49.9Ω
1kΩ

347.8Ω

49.9Ω

49.9Ω

1kΩ

49.9Ω

8.2kΩ select

6.42kΩ

MIXER

IF/LIM OUT

IF/LIM IN

L5

C12

C11

21

+

–

IF
AMP

21

C14

R3

R2

R4

R5

C16

R6

21 21

C17

R8

R7

R9

C20

R10

R11

C21

L4

R1

C8

C9

C10

C6

C7

C4

C5

L3

C3C1

*L1

*L2

RF IN LO IN

RSSI

OUT

PWR

DWN

CTRL

DATA

OUT

V

CC

output match

C2

SR00501

Figure 9. SA636 240.05MHz (RF) / 10.7MHz (IF) Test Circuit

Philips Semiconductors Product specification

SA636

Low voltage high performance mixer FM IF system
with high-speed RSSI

1997 Nov 07

12

10

9

8

7

6

5

4

3

2

1

20

19

18

17

16

15

14

13

12

11

RF IN

RF BYPASS

OSC (EMITTER)

OSC (BASE)

RSSI FEEDBACK

RSSI OUT

PD CTRL

DATA OUT

QUAD IN

V

CC

MIXER OUT

DECOUPLING 1

IF IN

DECOUPLING 2

GROUND

LIMITER IN

LIMITER DEC1

LIMITER DEC2

LIMITER OUT

IF OUT

SMA

LO IN

SMA

RF IN

110.592MHz

120.392MHz

C5

C6

+

R1
51

C3

1nF

C2

PWR DWN

V

CC

L1

180nH

C1

5–30pF

U1

SA636

R5

1.2k

C9

82pF

L2

C10

15pF

C11 C12

10nF

100nF

1nF 1nF

15µF

2.2µH

XTAL

XTAL

IF AMP

IF AMP

J1

+/–288kHz

J2

@–10dBm

C4

1nF

R2

10

+3V

R3

22k

R4

33k

RSSI

DATA OUT

GND

J3

C7

470pF

C8

+

5-30pF

C13

100pF

C14

47pF

C15

330pF

L3

680nH

R6

560

C16

100pF

C17
1nF

C19
1nF

L4

680nH

C21

330pF

C18

68pF

C20

68pF

SR00500

Figure 10. SA636 110.592MHz (RF) / 9.8MHz (IF) DECT Application Circuit

Philips Semiconductors Product specification

SA636

Low voltage high performance mixer FM IF system
with high-speed RSSI

1997 Nov 07

13

T able 1. DECT Application Circuit Electrical Characteristics

RF frequency = 110.592MHz; IF frequency = 9.8MHz; RF level = -45dBm; FM modulation = 100kHz with ± 288kHz peak deviation.

SYMBOL

PARAMETER TEST CONDITIONS TYPICAL UNITS

Mixer/Osc section (ext LO = 160mV

RMS

)

PG Conversion power gain 13 dB
NF Noise Figure at 110MHz 12 dB

IIP3 Third order input intercept Matched f1 = 110.592; f2 = 110.892MHz -15 dBm

R

IN

RF input resistance 690 Ω

C

IN

RF input capacitance 3.6 pF

IF section

IF amp gain 330Ω load 38 dB
Limiter amp gain 330Ω load 54 dB
Data level R

LOAD

= 3kΩ 130 mV

RMS

3dB data bandwidth 700 kHz

RF/IF section (internal LO)

System RSSI output RF level = -10dBm 1.4 V
System S/N

1

RF level = -83dBm 10 dB

NOTE:

1. 10dB S/N corresponds to BER = 10

-3

.

RF GENERATOR

SPECTRUM
ANALYZER

SCOPE

DC VOLTMETER

110.592MHz
RSSI DATA

SA636 DEMO BOARD

LO / GENERATOR

120.392MHz

VCC = 3V

SR00502

Figure 11. SA636 Application Circuit Test Set Up

NOTES:

1. RF generator: Set your RF generator at 110.592MHz, use a 100kHz modulation frequency and a ±288kHz deviation.

2. Layout: The layout is very critical in the performance of the receiver. We highly recommend our demo board layout.

3. RSSI: The smallest RSSI voltage (i.e., when no RF input is present and the input is terminated) is a measure of the quality of the layout and
design. If the lowest RSSI voltage is 500mV or higher, it means the receiver is in regenerative mode. In that case, the receiver sensitivity
will be worse than expected.

4. Supply bypass and shielding: All of the inductors, the quad tank, and their shield must be grounded. A 0.1µF bypass capacitor on the
supply pin improves sensitivity.

Philips Semiconductors Product specification

SA636

Low voltage high performance mixer FM IF system
with high-speed RSSI

1997 Nov 07

14

TOP SILK SCREEN (SSOP)

SR00503

Figure 12. SA636 Demoboard Layout (Not Actual Size)

Philips Semiconductors Product specification

SA636

Low voltage high performance mixer FM IF system
with high-speed RSSI

1997 Nov 07

15

CIRCUIT DESCRIPTION

The SA636 is an IF signal processing system suitable for second IF
or single conversion systems with input frequency as high as 1GHz.
The bandwidth of the IF amplifier is about 40MHz, with 38dB of gain
from a 50Ω source. The bandwidth of the limiter is about 28MHz
with about 54dB of gain from a 50Ω source. However, the
gain/bandwidth distribution is optimized for 10.7MHz, 330Ω source
applications. The overall system is well-suited to battery operation
as well as high performance and high quality products of all types,
such as cordless and cellular hand-held phones.

The input stage is a Gilbert cell mixer with oscillator. Typical mixer
characteristics include a noise figure of 14dB, conversion gain of
11dB, and input third-order intercept of -16dBm. The oscillator will
operate in excess of 1GHz in L/C tank configurations. Hartley or
Colpitts circuits can be used up to 100MHz for xtal configurations.
Butler oscillators are recommended for xtal configurations up to
150MHz.

The output of the mixer is internally loaded with a 330Ω resistor
permitting direct connection to a 10.7MHz ceramic filter for
narrowband applications. The input resistance of the limiting IF
amplifiers is also 330Ω. With most 10.7MHz ceramic filters and
many crystal filters, no impedance matching network is necessary.
For applications requiring wideband IF filtering, such as DECT,
external LC filters are used (see Figure 10). To achieve optimum
linearity of the log signal strength indicator, there must be a 6dB(v)
insertion loss between the first and second IF stages. If the IF filter

or interstage network does not cause 6dB(v) insertion loss, a fixed
or variable resistor can be added between the first IF output (Pin 16)
and the interstage network.

The signal from the second limiting amplifier goes to a Gilbert cell
quadrature detector . One port of the Gilbert cell is internally driven
by the IF. The other output of the IF is AC-coupled to a tuned

quadrature network. This signal, which now has a 90

° phase

relationship to the internal signal, drives the other port of the
multiplier cell.

Overall, the IF section has a gain of 90dB. For operation at
intermediate frequency at 10.7MHz. Special care must be given to
layout, termination, and interstage loss to avoid instability.

The demodulated output (DATA) of the quadrature is a voltage
output. This output is designed to handle a minimum bandwidth of
600kHz. This is designed to demodulate wideband data, such as in
DECT applications.

A Receive Signal Strength Indicator (RSSI) completes the circuitry.
The output range is greater than 90dB and is temperature
compensated. This log signal strength indicator exceeds the criteria
for AMPS or TACS cellular telephone, DECT and RCR-28 cordless
telephone. This signal drives an internal op amp. The op amp is
capable of rail-to-rail output. It can be used for gain, filtering, or
2nd-order temperature compensation of the RSSI, if needed.

NOTE: dB(v) = 20log V

OUT/VIN

Philips Semiconductors Product specification

SA636

Low voltage high performance mixer FM IF system
with high-speed RSSI

1997 Nov 07

16

SO20: plastic small outline package; 20 leads; body width 7.5 mm SOT163-1

Philips Semiconductors Product specification

SA636

Low voltage high performance mixer FM IF system
with high-speed RSSI

1997 Nov 07

17

Philips Semiconductors and Philips Electronics North America Corporation reserve 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. Applications that are described herein for any of these products are for illustrative purposes
only. Philips Semiconductors makes no representation or warranty that such applications will be suitable for the specified use without further testing
or modification.

LIFE SUPPORT APPLICA TIONS
Philips Semiconductors and Philips Electronics North America Corporation Products are not designed for use in life support appliances, devices,
or systems where malfunction of a Philips Semiconductors and Philips Electronics North America Corporation Product can reasonably be expected
to result in a personal injury. Philips Semiconductors and Philips Electronics North America Corporation customers using or selling Philips
Semiconductors and Philips Electronics North America Corporation Products for use in such applications do so at their own risk and agree to fully
indemnify Philips Semiconductors and Philips Electronics North America Corporation for any damages resulting from such improper use or sale.

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.

Philips Semiconductors and Philips Electronics North America Corporation

register eligible circuits under the Semiconductor Chip Protection Act.

 Copyright Philips Electronics North America Corporation 1994

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

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

DEFINITIONS

Data Sheet Identification Product Status Definition

Objective Specification

Preliminary Specification

Product Specification

Formative or in Design

Preproduction Product

Full Production

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

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.