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.
APPLICATIONS
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
RFIN
RF BYPASS
RSSIOUT
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
VCC
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: 0.54
V into 50
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 (330
)
Power down mode (I
CC
= 200
A)
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
10
9
8
7
6
5
4
3
2
1
FAST
IF
AMP
E
B
OSCILLATOR
LIMITER
MIXER
QUAD
+
+
RSSI
GND
PWR
DWN
RSSI
AUDIO
VCC
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 (V
CC
+0.3)
V
T
STG
Storage temperature range
-65 to +150
C
T
A
Operating ambient temperature range SA636
40 to +85
C
NOTE:
JA
, Thermal impedance
DK package
117
C/W
DC ELECTRICAL CHARACTERISTICS
V
CC
= +3V, T
A
= 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
Input current
Pin 8 LOW
10
10
A
Input current
Pin 8 HIGH
10
10
A
Input level
Pin 8 LOW
0
0.3V
CC
V
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
s
t
OFF
Power down time
RSSI invalid (90% to 10%)
5
s
Philips Semiconductors
Product specification
SA636
Low voltage high performance mixer FM IF system
with high-speed RSSI
1997 Nov 07
4
AC ELECTRICAL CHARACTERISTICS
T
A
= 25
C; V
CC
= +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
RF input capacitance
3.5
pF
Mixer output resistance
(Pin 20)
330
IF section
IF amp gain
330
load
38
dB
Limiter gain
330
load
54
dB
Input limiting -3dB
Test at Pin 18
105
dBm
AM rejection
80% AM 1kHz
50
dB
Data level
R
LOAD
= 100k
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
s
(no RSSI bypass capacitor)
RF level = -28dBm
1.1
s
IF RSSI output fall time
IF frequency = 10.7MHz
(10kHz pulse, no 10.7MHz filter)
RF level = -56dBm
2.0
s
(no RSSI bypass capacitor)
RF level = -28dBm
7.3
s
RSSI range
90
dB
RSSI accuracy
+1.5
dB
IF input impedance
330
IF output impedance
330
Limiter input impedance
330
Limiter output impedance
300
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 SUPPL
Y
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
VCC = 3V
VCC = 2.7V
9.0
8.5
8.0
7.5
7.0
6.5
6.0
5.5
5.0
SUPPL
Y
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
VCC = 2.7V
VCC = 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
0
25
70
85
300
AUDIO REFERENCE (mV
rms)
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)
RELA
TIVE T
O
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)
RELA
TIVE T
O
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
1
10
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)
RELA
TIVE T
O
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
1
10
100
90
80
70
60
50
40
30
20
10
0
1
10
100
90
80
70
60
50
40
30
20
10
0
1
10
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
VCC = 2.7V
VCC = 5V
VCC = 3V
VCC = 2.7V
VCC = 5V
Data Level vs Temperature and Supply Voltage
DA
T
A
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
0
25
70
85
DA
T
A
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 (mV
rms)
5.5V
2.7V
3.0V
40
0
25
70
85
250
200
150
100
50
0
Audio Reference Level vs Temperature and Supply Voltage
Temperature (
C)
0.8
DA
T
A
LEVEL
(Vp-p)
5.5V
2.7V
3.0V
600kHz Data Rate,
Data Level vs Temperature and Supply Voltage
40
0
25
70
85
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
DA
T
A
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
0
25
70
85
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
150
A
5
VREF
BANDGAP
10
80k
20
A
6
+
VCC
--
7
VCC
+
--
8
R
R
PIN
No.
PIN
MNEMONIC
DC V
EQUIVALENT CIRCUIT
PIN
No.
PIN
MNEMONIC
DC V
EQUIVALENT CIRCUIT
9
+
--
VCC
1
RF IN
+1.07
6
RSSI
+0.20
FEEDBACK
2
RF
+1.07
7
RSSI
+0.20
OUT
BYPASS
3
XTAL
+1.57
8
POWER
+2.75
DOWN
OSC
4
XTAL
+2.32
9
DATA
+1.09
OUT
OSC
5
V
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
400
A
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
DECOUP
DECOUP
13
LIMITER
+1.23
18
IF
+1.22
AMP IN
COUPLING
14
LIMITER
+1.23
19
IF AMP
+1.22
DECOUP
IN
15
GND
0
20
MIXER
+1.03
OUT
OUT
8.8k
16
8.8k
140
13
12
330
50
A
18
19
17
330
50
A
110
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
10
9
8
7
6
5
4
3
2
1
20
19
18
17
16
15
14
13
12
11
RSSI
MIXER
QUAD
C19
C18
SW5
C13
C15
FLT1
0.1
F
6.8
F 10V
160pF select
1000pF
39pF select
0.1
F
1
F
C14
C15
C18
C19
C20
C21
L1
L2
L3
L4
L5
FLT1
0.1
F
1000pF
10.7MHz (Murata SFE10.7MA5-A)
1.272.25
H select for mixer
5.6
H 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
VCC
+
DATA
C16
0.1
F
C17
0.1
F
*NOTE: This value can be reduced when a battery is the power source.
PWR
DWN
0.1
F
100pF
15pF select for input match
0.1
F
0.1
F
15pF select for input match
47nH select for input match
0.1
F
1000pF
150nH select for input match
1pF
FLT
3
FLT
4
FLT2
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10
R11
347.8
6.42k
49.9
1k
347.8
49.9
49.9
1k
49.9
8.2k
select
6.42k
MIXER
IF/LIM OUT
IF/LIM IN
L5
C12
C11
2
1
+
IF
AMP
2
1
C14
R3
R2
R4
R5
C16
R6
2
1
2
1
C17
R8
R7
R9
C20
R10
R11
C21
L4
R1
C8
C9
C10
C6
C7
C4
C5
L3
C3
C1
*L1
*L2
RF IN
LO IN
RSSI
OUT
PWR
DWN
CTRL
DATA
OUT
VCC
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
VCC
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
VCC
L1
180nH
C1
530pF
U1
SA636
R5
1.2k
C9
82pF
L2
C10
15pF
C11
C12
10nF
100nF
1nF
1nF
15
F
2.2
H
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
Table 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
C
IN
RF input capacitance
3.6
pF
IF section
IF amp gain
330
load
38
dB
Limiter amp gain
330
load
54
dB
Data level
R
LOAD
= 3k
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
V
CC
= 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 0.1
F 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 50
source. The bandwidth of the limiter is about 28MHz
with about 54dB of gain from a 50
source. However, the
gain/bandwidth distribution is optimized for 10.7MHz, 330
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 330
resistor
permitting direct connection to a 10.7MHz ceramic filter for
narrowband applications. The input resistance of the limiting IF
amplifiers is also 330
. 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
/V
IN
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 APPLICATIONS
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 940883409
Telephone 800-234-7381
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.
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