Datasheet sa647 DATASHEETS (Philips)

INTEGRATED CIRCUITS

SA647
Low-voltage digital IF receiver

Product specification 1998 Aug 10

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Philips Semiconductors Product specification

SA647Low-voltage digital IF receiver

DESCRIPTION

The SA647 is a low-voltage high performance monolithic digital
system with high-speed RSSI incorporating a mixer, oscillator with
buffered output, two limiting intermediate frequency amplifiers, fast
logarithmic received signal strength indicator (RSSI), voltage
regulator, RSSI op amp and power down pin. The SA647 is
available in TSSOP (thin shrink small outline package).

The SA647 was designed for portable digital communication
applications and will function down to 2.7V . The limiter amplifier has
differential outputs with 2MHz small signal bandwidth. The RSSI
output has access to the feedback pin. This enables the designer to
level adjust the outputs or add filtering.

FEA TURES

•V

= 2.7 to 5.5V

CC

•Low power receiver (5.3mA @ 3V)

•Power down mode (I

= 110µA)

CC

•Fast RSSI rise and fall times

•Extended RSSI range with temperature compensation

•RSSI op amp

•2MHz limiter small signal bandwidth

•Filter matching (1.5kΩ)

•Differential limiter output

•Oscillator buffer

•TSSOP-20 package

APPLICA TIONS

•NADC (North American Digital Cellular)

•Digital receiver systems

•Cellular radio

PIN CONFIGURATION

1

RF

IN+

2

RF

IN–

3

OSC E

4

OSC B

OSC

BUF

LIM OUT (-)

5

OUT

6

V

CC

7

RSSI

8

RSSI FB

9

P

D

10

Figure 1. Pin Configuration

20

MIX

19

IF AMP

18

IF AMP

17

IF AMP

16

IF AMP

15

GND

14

LIM

13

LIM

12

LIM

11

LIM OUT (+)

OUT

DECOUP
IN

DECOUP

OUT

IN

DECOUP

DECOUP

SR01456

ORDERING INFORMATION

DESCRIPTION TEMPERATURE RANGE ORDER CODE DWG #

20-Pin Plastic Thin Shrink Small Outline Package (Surface-mount) –40 to +85°C SA647DH SOT360–1

20 19 18 17 16 15 14 13 12 11

GND

IF
AMP

MIXER

OSCILLATOR

FAST RSSI

+–

EB

123 45678 910

V

CC

Figure 2. Block Diagram

+–

LIMITER

POWER

DOWN

SR01727

1998 Aug 10 853–2037 19849

2

Philips Semiconductors Product specification

SA647Low-voltage digital IF receiver

PIN DESCRIPTION

PIN NO. SYMBOL FUNCTION

1 RF

IN

2 RF BYPASS RF bypass
3 OSC
4 OSC
5 OSC
6 V

E
B

OUT Oscillator buffer output

BUF

CC

7 RSSI RSSI output
8 RSSI FB RSSI Feedback

9 P
10 LIM
11 LIM
12 LIM
13 LIM
14 LIM

D

OUT(–)
OUT(+)
DECOUP
DECOUP
IN

15 GND Ground
16 IF AMP
17 IF AMP
18 IF AMP
19 IF AMP
20 MIX

OUT
DECOUP
IN
DECOUP

OUT

RF input

Oscillator emitter
Oscillator base (input)

Supply voltage

Power Down
Limiter output (neg)
Limiter output (pos)
Limiter decoupling
Limiter decoupling
Limiter input

IF amplifier output
IF amplifier decoupling
IF amplifier input
IF amplifier decoupling
Mixer output

1998 Aug 10

3

Philips Semiconductors Product specification

SYMBOL

PARAMETER

TEST CONDITIONS

UNITS

A

V

SA647Low-voltage digital IF receiver

ABSOLUTE MAXIMUM RATINGS

SYMBOL PARAMETER RATING UNITS

V

CC

V

IN

T

STG

T

A

NOTE: Thermal impedance (θJA) = 135°C/W

DC ELECTRICAL CHARACTERISTICS

VCC = +3.0V , TA = 25°C; unless otherwise stated.

V

CC

I

CC

τ

on

τ

off

Supply voltage -0.3 to +6.0 V
Voltage applied to any other pin -0.3 to (VCC + 0.3) V

Storage temperature range -65 to +150
Operating ambient temperature range -40 to +85

°C
°C

LIMITS

MIN TYP MAX

Power supply voltage range 2.7 5.5 V
DC current drain 4 5.3 7 mA
Standby Pin 9 = LOW 0.11 mA
Input current Pin 9 = LOW -10 10

Pin 9 = HIGH -10 10

Input level Pin 9 = LOW 0 0.3V

Pin 9 = HIGH 0.7 V

CC

V
Power–up time RSSI valid (10% to 90%) 10
Power–down time RSSI valid (90% to 10%) 5

CC

CC

µ

sec
sec

1998 Aug 10

4

Philips Semiconductors Product specification

SYMBOL

PARAMETER

TEST CONDITIONS

UNITS

SA647Low-voltage digital IF receiver

AC ELECTRICAL CHARACTERISTICS

VCC = +3.0V , Mixer input freq = 110.52MHz, LO input freq = 109.92MHz, TA = 25°C; unless otherwise stated.

LIMITS

MIN TYP MAX

Mixer/Osc section

f

IN

f

OSC

NF Noise figure at 110.52MHz Matched input and output 50Ω 4.5 dB
IIP3 Third-order input intercept point Matched input and output to 50Ω -29.5 dBm
G

CP

R

C

R

OUT

I

SOL

IF section

IF

BW

Input signal frequency 200 MHz
Crystal oscillator frequency 200 MHz

Conversion power gain Matched input and output to 50Ω 17 20 23 dB
Mixer input resistance at 110.52 MHz 670 Ω

IN

Mixer input capacitance at 110.52 MHz 3.0 pF

IN

Mixer output resistance at 600 kHz 1.5 kΩ
Mixer RF to LO isolation 32 dB
Buffered LO output level, DC coupled 10kII3.9pF load 110 230 320 mV
External input level f = 110.52 MHz at Pin 4 250 mV

IF amp power gain

Matched input and output 50W

30 36 dB
Limiter power gain 51 60 dB
IF amp bandwidth 2 MHz
RSSI output Input power level = -113dBm, Pin 1 0.30 V

Input power level = -68dBm, Pin 1 1.00 V

Input power level = -29dBm, Pin 1 1.55 V
RSSI range 85 dB
RSSI accuracy ±1.5 dB
RSSI ripple 30 mV
RSSI speed – (Rise Time)

Input @ Pin 1 No filter

RSSI speed – (Fall time)

Input @ Pin 1

No filter 25 µs

5 µs

IF input impedance 1.5 kΩ
IF output impedance 1.5 kΩ
Limiter input impedance 1.5 kΩ
Limiter output impedance (Pin 10, Pin 11) 230 Ω

Limiter output (each pin)

Output load is 1.5K in parallel with 30

pF to GND each pin

240 350 420 mV

Limiter output DC level 1.27 V
Differential output matching ±5 mV
Limiter output offset 0.09 V

P–P
P–P

P–P

P–P

1998 Aug 10

5

Philips Semiconductors Product specification

SA647Low-voltage digital IF receiver

CIRCUIT DESCRIPTION
Mixer

The mixer has a single–ended input. The input impedance is 670Ω
in parallel with a 3.0pF cap at 110.52MHz RF. The mixer output can
drive a 1500Ω ceramic filter without any matching required.

Oscillator and Buffer

The on-board oscillator supplies the signal for the mixer
down-conversion. The internally biased transistor can be configured
as a Colpitts or Butler overtone crystal oscillator. The transistor’s
bias current can be increased if desired by adding a shunt resistor
from Pin 3 to ground. The oscillator’s buffered output (Pin 5) can be
used as a feedback signal to lock the oscillator to an appropriate
reference.

IF Amplifier and IF Limiter

The IF strip provides more than 96dB of power gain for the down
converted signal. Its bandwidth is 2MHz. The input and output
impedance of the IF amplifier and the input impedance of the IF
limiter are set to 1500Ω. A second filter is connected between the IF
amplifier and the limiter for improved channel selectivity and
reduced instability . The overall gain can be reduced if desired by
adding an external attenuator after the IF amplifier The differential
limiter outputs (Pins 10 and 11) are available for demodulator
circuits.

RSSI

The received signal strength indicator provides a linear voltage
indication of the received signal strength in dB for a typical range of
85dB. The response time to a change in input signal is less than a
few microseconds and the delay is kept to a minimum because of
the use of a minimum phase shift circuit. Because of the speed of
the RSSI circuit, the RSSI rise and fall time will be dominated by the
bandwidth of the external bandpass filter that is placed between the
mixer and the IF. Since the RSSI function requires the signal to
propagate through the whole IF strip, and the rise and fall time of the
filters are inversely proportional to their bandwidth, there is a
trade-off between channel selectivity and RSSI response.
Therefore, it is recommended that all channel selection filters be
placed before the IF strip, just after the mixer. This will make the
delay of the RSSI independent of the mixer input signal amplitude.
Also, a 6dB insertion loss between the IF and limiter sections (Pins
16 and 14) will give optimum flatness of RSSI versus mixer input
signal.

The RSSI curve is temperature compensated and in addition is
designed for improved consistency from unit to unit.

DC Power Supply

The IC is designed for operation between 2.7 and 5.5V. A power
supply dependent biasing scheme is used in the mixers to benefit
from the large headroom available at higher V

CC

s.

1998 Aug 10

6

Philips Semiconductors Product specification

SA647Low-voltage digital IF receiver

PERFORMANCE CHARACTERISTICS

VCC = +3.0V , Mixer input freq = 110.52MHz, LO input freq = 109.92MHz, TA = 25°C; unless otherwise stated.

7.00

6.50

6.00

5.50

5.00

4.50

Current (mA)

4.00

3.50

3.00
–40 0 25 70 85

24.0

23.0

22.0

21.0

20.0

19.0

Gain (dB)

18.0

17.0

16.0

15.0

5.5

5.0

4.5

Noise Figure (dB)

4.0

3.5

550
500
450
400
350
300
250

LO Output (mVp–p)

200
150
100

Supply Current vs Temperature and Supply Voltage

5.5V

3.8V

3.0V

2.7V

Temperature (°C)

Mixer Gain vs Temperature and Supply Voltage

5.5V

3.0V

2.7V

–40 0 25 70 85

Mixer Noise Figure vs Temperature and Supply Voltage

2.7V

–40 0 25 70 85

0

1 2.2 3 3.9 4.7 5.6

Temperature (°C)

5.5V

3.0V

Temperature (°C)

LO Buffer Output with Load Variation

5.1KW

10KW

Capacitor Load (pF)

Mixer 3rd Order Intercept and Compression vs Input Power

0
–10
–20

Fund. Product

–30
–40
–50
–60
–70

Output Power (dBm)

–80
–90

–100

–75 –70 –65 –60 –55 –50 –45 –40 –35 –30 –25

Mixer 3rd Order Input Intercept Point vs Temperature

–25
–26
–27
–28
–29

IP3 (dBm)

–30
–31

–32
–33

–40 0 25 70 85

Mixer 1dB Input Compression vs Temperature and Supply Voltage

–36

–37

–38

–39

–40

Compression (dBm)

–41

–42

–40 0 25 70 85

310
290
270
250
230
210
190

LO Buffer Output (mVp–p)

170
150

LO Buffer Output vs Temperature and Supply Voltage

5.5V

3.0V

2.7V

–40 0 25 70 85

Input Power (dBm)

and Supply Voltage

2.7V

3.0V

5.5V

Temperature (°C)

3.0V

5.5V

Temperature (°C)

Temperature (°C)

3rd Order Product

2.7V

Load = 10KW 3.9pF

SR01554

1998 Aug 10

Figure 3.

7

Philips Semiconductors Product specification

SA647Low-voltage digital IF receiver

3.4

3.2

3.0

2.8

2.6

Bandwidth (MHz)

2.4

2.2

2.0
–40 0 25 70 85

Limiter Output Offset vs Temperature and Supply Voltage

0.14

0.13

0.12

0.11

0.10

0.09

0.08

Offset (Volt)

0.07

0.06

0.05

0.04
–400 257085

65.0

64.5

64.0

63.5

63.0

Gain (dB)

62.5

62.0

61.5

61.0

60.5

60.0
–40°C

IF Bandwidth vs. Temperature

Temperature (°C)

5.5V

3.0V

2.7V

Temperature (°C)

Limiter Gain vs Temperature and Supply Voltage

5.5V

3.0V

2.7V

25 70 85

Temperature (°C)

38.5

38.0

37.5

37.0

36.5

Gain (dB)

36.0

35.5

35.0

2.8

2.6

2.4

2.2

2.0

Bandwidth (MHz)

1.8

1.6
–40 0 25 70 85

450

400

350

300

Output (mVp–p)

250

200

IF Gain vs Temperature and Supply Voltage

5.5V

3.0V

2.7V

–40 0 25 70 85

Limiter Bandwidth vs Temperature

Limiter Output vs Temperature and Supply Voltage

2.7V

–400 257085

Temperature (°C)

Temperature (°C)

5.5V

3.0V

Temperature (°C)

RSSI (Volt)

1998 Aug 10

1.6

1.4

1.2

1.0

0.8

0.6
85°C

0.4

0.2

0.0

–118 –108 –98 –88 –78 –68 –58 –48 –38 –28

RSSI vs Temperature

25°C

–40°C

RF Input (dBm)

Figure 4.

8

1.80

1.60

1.40

1.20

1.00

0.80

RSSI (Volt)

0.60

0.40

0.20

0.00
–118 –108 –98 –88 –78 –68 –58 –48 –38 –28

RSSI vs Supply Voltage

5.5V

3.0V

2.7V

RF Input (dBm)

SR01555

Philips Semiconductors Product specification

SA647Low-voltage digital IF receiver

GENERAL TEST CIRCUIT DESCRIPTION

IF OR LIMITER INPUT

FLT

2

MIXER OUT

C28

R21

R29

R28

R30

R22

R23

4

R27

3

5

1

R25

C27

R24

R26

C26

C25

R18

C24

R19

C22

R20

C23

R17

C21

R16

C19

C20

L3

R15

C18

R13

R14

C17

LIMITER OUT (+)

C14

C16

R11

C15

20 19 18 17 16 15 14

MX OUT

RF IN

C2

R1

RF INPUT

MIXER

C1

+–

L1

C3

R3

R2

IF DEC

IF IN

IF
AMP

IF DEC

IF OUT

OSCILLATOR

OSC
BUFF

OSC E

RF BYPASS

C9

R4

OSC B

C10

C4

R5

L2

C5

C6

LO INPUT

FAST RSSI

C7

R6

C8

LO
BUFFER
OUTPUT

GND

V

VCC

C11

CC

13 12 11

LIM IN

LIMITER

+–

RSSI OUT

R9

R7

C12

RSSI
OUT

LIM DEC

RSSI FB

R8

LIM DEC

POWER DOWN

PWD

10987654321

LIM OUT+

LIM OUT –

C13

C14

LIMITER
OUT (–)

R10

Automatic Test Circuit Component List

C1 0.01mF C11 100nF C21 0.01mF R1 249W R13 50W R24 8.66W L1 120nH
C2 12pF C12 100nF C22 0.1mF R2 60.4W R14 13.7W R25 130W L2 120nH
C3 39pF C13 30pF C23 100nF R3 60.4W R15ą1.5KW R26 182W L3 56mH
C4 0.01mF C14 0.1mF C24 0.1mF R4 10KW R16 1.5KW R27 182W FLT 600kHz
C5 15pF C15 30pF C25 0.1mF R5 10KW R17 1KW R28 10KW
C6 39pF C16 100nF C26 100nF R6 10KW R18 13.7KW R29 10KW
C7 3.9pF C17 100nF C27 0.1mF R7 10KW R19 50KW R30 3.92KW
C8 0.1mF C18 0.1mF C28 0.1mF R8 10KW R20 1.69KW
C9 100nF C19 270pF R9 10KW R21 2.43KW

C10 100nF C20 1500pF R10 1.5KW R22 50W

R11 1.5KW R23 130W
R12 1.69KW

Figure 5.

1998 Aug 10

9

SR01728

Philips Semiconductors Product specification

SA647Low-voltage digital IF receiver

PIN

No.

PIN

MNEMONIC

DC V EQUIVALENT CIRCUIT

1 RF IN +2.35

2

3

RF

BYPASS

OSC

E

+1.56

+2.21

RF BYPASS

4

RF IN

1

18k

PIN

No.

400

30K

26

2

6V

7

MIX

PIN

MNEMONIC

CC

RSSI

OUT

DC V EQUIVALENT CIRCUIT

V

6

REF

+3.00

BANDGAP

+0.20

+

—

V

CC

7

V

4

5

OSC

B

OSC

BUFFER

+2.78

+2.21

3

150µA

RSSI

8

FEEDBACK

POWER

9

5

150µA

DOWN

+0.20

+2.00

9

CC

—

8

+

R

R

SR01729

1998 Aug 10

Figure 6.

10

Philips Semiconductors Product specification

SA647Low-voltage digital IF receiver

PIN

No.

10

11

12

PIN

MNEMONIC

LIMITER

OUT

LIMITER

DC V EQUIVALENT CIRCUIT

PIN

No.

+1.25 16

11

8.8k

+1.28 17

PIN

MNEMONIC

IF

AMP OUT

IF AMP

DECOUPDECOUP

DC V EQUIVALENT CIRCUIT

+1.28

1.31k

6.6k

+1.28

16

14

+1.28 18

1.5k

50µA

12

13

+1.28 19

13

14

LIMITER

LIMITER

15 GND 0 20

IF

AMP INCOUPLING

IF AMP

DECOUPIN

MIXER

OUT

+1.28

+1.28

+2.03

18

1.5k

50µA

17

19

1.87k

20

1998 Aug 10

SR00509

Figure 7.

11

Philips Semiconductors Product specification

SA647Low-voltage digital IF receiver

GENERAL APPLICATIONS CIRCUIT

FLT1 FLT2

R15

2

4

5

3

1

R16

R17

R18

R19

C25

20 19 18 17 16 14

C23

R14

R13

R11

R12

C24

R10

2

4

5

3

1

R9

C22

R7 R6

R8

C21

15

GND

C20

L3

C18 C17

C19

13 12 11

C16

RF

INPUT

+–

MIXER

IF
AMP

OSCILLATOR

RSSI

LO
BUFF

RSSI BUFF

LIMITER

R5

+–

RSSI FB

108764321 5 9

C5

LO

INPUT

C8

C9

C2

L2

C6

OSC

OUT

C11

R2

R1

C10

C12

RSSI

V

CC

R3

POWER

DOWN

LIMITER

OUT(–)

C13

R4

C14

LIMITER

OUT(+)

C15

C1

C4

L1

C3

C7

1998 Aug 10

Component List

C1 5–30pF C11 0.1mF C21 10nF R1 10KW R13 240W L1 180nH
C2 5–30pF C12 6.8pF C22 0.1mFR20W (short) R14 4.5KW L2 180nH
C3 0.1mF C13 0.1mF C23 0.1mF R3 OPEN R15 180W L3 56mH
C4 0.1mF C14 30pF C24 10nF R4 5.1k R16 180W FLT1,2 600kHz
C5 0.1mF C15 30pF C25 10nF R5 5.1k R17 240W
C6 0.1mF C16 0.1mFR60W (short) R18 10KW
C7 47pF C17 0.1mF R7 1.5KW R19 10KW
C8 1nF C18 0.1mF R8 1.5KW
C9 10pF C19 10nF R9 180W

C10 3.9pF C20 1500pF R10 180W

R11 10KW
R12 0KW

NOTE:

R2 and R3 set the RSSI buffer gain. For unity gain short R2 (Pin 7 to Pin 8)
and leave R9 open.

SR01730

Figure 8.

12

Philips Semiconductors Product specification

SA647Low-voltage digital IF receiver

TSSOP20: plastic thin shrink small outline package; 20 leads; body width 4.4 mm SOT360-1

1998 Aug 10

13

Philips Semiconductors Product specification

SA647Low-voltage digital IF receiver

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 chages 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 1998

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

Date of release: 08-98

Document order number: 9397 750 04241




1998 Aug 10

14