PHILIPS SA636

RF COMMUNICATIONS PRODUCTS
SA636
Low voltage high performance mixer FM
IF system with high-speed RSSI
Product specification
Replaces data of 1994 Jun 16
IC17 Data Handbook
Philips Semiconductors
1997 Nov 07
Philips Semiconductors
Product specification
Low voltage high performance mixer FM IF
system with high-speed RSSI
DESCRIPTION
SA636
PIN CONFIGURATION
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).
DK 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.
RFIN
1
20
MIXER OUT
RF BYPASS
2
19
IF AMP DECOUPLING
(EMITTER)
3
18
IF AMP IN
(BASE)
4
17
IF AMP DECOUPLING
VCC
5
16
IF AMP OUT
RSSI FEEDBACK
6
15
GND
RSSIOUT
7
14
LIMITER IN
POWER DOWN CONTROL
8
13
LIMITER DECOUPLING
DATA OUT
9
12
LIMITER DECOUPLING
QUADRATURE IN
10
11
LIMITER OUT
XTAL OSC
XTAL OSC
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
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
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
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 (ICC = 200µA)
ORDERING INFORMATION
DESCRIPTION
TEMPERATURE RANGE
20-Pin Plastic Shrink Small Outline Package (Surface-mount)
1997 Nov 07
-40 to +85°C
2
ORDER CODE
DWG #
SA636DK
SOT266-1
853-1757 18664
Philips Semiconductors
Product specification
Low voltage high performance mixer FM IF system
with high-speed RSSI
SA636
BLOCK DIAGRAM
20
19
18
17
16
15
14
13
12
11
GND
IF
AMP
LIMITER
MIXER
– +
VCC
1
2
E
B
3
4
QUAD
FAST
RSSI
OSCILLATOR
PWR
DWN
– +
AUDIO
RSSI
5
6
7
8
9
10
SR00492
Figure 2. Block Diagram
ABSOLUTE MAXIMUM RATINGS
SYMBOL
PARAMETER
VCC
Single supply voltage
VIN
Voltage applied to any other pin
TSTG
TA
RATING
UNITS
0.3 to 7
V
–0.3 to (VCC+0.3)
V
-65 to +150
°C
–40 to +85
°C
Storage temperature range
Operating ambient temperature range SA636
NOTE: θJA, Thermal impedance
DK package
117°C/W
DC ELECTRICAL CHARACTERISTICS
VCC = +3V, TA = 25°C; unless otherwise stated.
LIMITS
SYMBOL
PARAMETER
VCC
Power supply voltage range
ICC
DC current drain
Input current
Input level
ICC
Standby
tON
Power up time
tOFF
Power down time
1997 Nov 07
TEST CONDITIONS
SA636
UNITS
MIN
TYP
MAX
2.7
3.0
5.5
V
Pin 8 = HIGH
5.5
6.5
7.5
mA
Pin 8 LOW
–10
10
Pin 8 HIGH
–10
10
Pin 8 LOW
0
0.3VCC
Pin 8 HIGH
0.7VCC
VCC
V
Pin 8 = LOW
0.2
RSSI valid (10% to 90%)
10
µs
RSSI invalid (90% to 10%)
5
µs
3
0.5
µA
mA
Philips Semiconductors
Product specification
Low voltage high performance mixer FM IF system
with high-speed RSSI
SA636
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
MIN
TYP
UNITS
MAX
Mixer/Osc section (ext LO = 160mVRMS)
fIN
fOSC
Input signal frequency
500
MHz
External oscillator (buffer)
500
MHz
Noise figure at 240MHz
12
dB
-16
dBm
Third-order input intercept point
Conversion power gain
Matched f1=240.05; f2=240.35MHz
Matched 14.5dBV step-up
8
11
14
dB
700
Ω
3.5
pF
(Pin 20)
330
Ω
IF amp gain
330Ω load
38
dB
Limiter gain
330Ω load
54
dB
Test at Pin 18
–105
dBm
RF input resistance
Single-ended input
RF input capacitance
Mixer output resistance
IF section
Input limiting -3dB
AM rejection
Data level
80% AM 1kHz
RLOAD = 100kΩ
3dB data bandwidth
SINAD sensitivity
THD
Total harmonic distortion
S/N
Signal-to-noise ratio
IF RSSI output with buffer
IF RSSI output rise time
(10kHz pulse, no 10.7MHz filter)
(no RSSI bypass capacitor)
IF RSSI output fall time
50
dB
120
130
mVRMS
600
700
kHz
RF level = -111dBm
16
-43
dB
-38
dB
No modulation for noise
60
IF level = -118dBm
0.2
0.5
dB
V
IF level = -68dBm
0.3
0.6
1.0
V
IF level = -10dBm
0.9
1.3
1.8
V
IF frequency = 10.7MHz
RF level = -56dBm
1.2
µs
RF level = -28dBm
1.1
µs
µs
IF frequency = 10.7MHz
(10kHz pulse, no 10.7MHz filter)
RF level = -56dBm
2.0
(no RSSI bypass capacitor)
RF level = -28dBm
7.3
µs
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
mVRMS
RSSI range
RF/IF section (int LO)
System RSSI output
System SINAD
1997 Nov 07
RF level = -10dBm
1.4
V
RF level = -106dBm
12
dB
4
Philips Semiconductors
Product specification
Low voltage high performance mixer FM IF system
with high-speed RSSI
SA636
PERFORMANCE CHARACTERISTICS
9.0
0.50
0.45
POWER DOWN SUPPLY CURRENT (mA)
SUPPLY CURRENT (mA)
8.5
VCC = 5V
8.0
7.5
VCC = 3V
7.0
6.5
VCC = 2.7V
6.0
5.5
0.40
0.35
VCC = 5V
0.30
VCC = 3V
0.25
0.20
VCC = 2.7V
0.15
0.10
0.05
5.0
–50 –40 –30 –20 –10 0 10 20 30 40
TEMPERATURE (°C)
50
60
0.00
–50 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 90 100
TEMPERATURE (°C)
70 80 90
Supply Current vs Temperature and Supply Voltage
Power Down Supply Current vs Temperature and Supply Voltage
–5
20
RF level = -45 dBm
19
–7
18
RF level = -45 dBm
–9
17
MIXER IIP3 (deB)
MIXER GAIN
(dB)
16
15
5.5V
14
–13
13
5.5V
2.7V
–15
3.0V
12
–11
3.0V
–17
11
10
2.7V
–19
9
–21
8
7
–23
6
–25
5
–40
0
25
Temperature (°C)
70
85
–40
Mixer Power Gain vs Temperature and Supply Voltage
0
25
Temperature (°C)
70
85
Mixer IIP3 at 240MHz vs Temperature and Supply Voltage
20
300
AUDIO
0
–20
5.5V
AM REJECTION
200
AUDIO (dB)
AUDIO REFERENCE (mVrms)
250
3.0V
150
2.7V
100
–40
DISTORTION
–60
–80
50
–100
NOISE
12dB SINAD
–120
0
–40
0
25
70
–50 –40 –30 –20 –10 0 10 20 30 40 50
TEMPERATURE (°C)
85
Temperature (°C)
70 80 90
12dB SINAD and Relative Audio, THD, Noise
and AM Rejection for VCC = 3V vs Temperature
RF = 240MHz, Level = –68dBm, Deviation = 125kHz
Audio Reference Level vs Temperature and Supply Voltage
Figure 3. Performance Characteristics
1997 Nov 07
60
5
SR00493
Philips Semiconductors
Product specification
Low voltage high performance mixer FM IF system
with high-speed RSSI
SA636
PERFORMANCE CHARACTERISTICS (continued)
AUDIO
–10
–20
1.8
0
1.6
–10
1.4
AM REJECTION
1.3
RSSI
–40
RSSI (V)
–30
1.0
THD+N
–50
0.8
–60
0.6
NOISE
2.0
AUDIO
1.8
1.6
–20
1.4
AM REJECTION
–30
1.2
–40
1.0
–50
0.8
THD+N
NOISE
–60
0.6
–70
0.4
0.0
RF INPUT LEVEL (dBm)
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
–110
RSSI
0
–100
–10
–90
–20
0
–30
–90
–40
0.2
–50
–80
–60
0.2
–70
–80
–80
0.4
–90
–70
–110
RSSI (V)
0
RELATIVE TO AUDIO OUTPUT (dB)
10
2
RELATIVE TO AUDIO OUTPUT (dB)
10
RF INPUT LEVEL (dBm)
Receiver RF Performance — T = 25°C,
Audio Level = 129mVRMS
Receiver RF Performance — T = –40°C,
Audio Level = 118mVRMS
10
2
0
1.8
–10
1.6
–20
–20
IF OUTPUT POWER (dBm)
0
–10
1.4
AM REJECTION
RSSI
–30
1.2
–40
1
–50
THD+N
0.8
–60
NOISE
0.6
RSSI (V)
RELATIVE TO AUDIO OUTPUT (dB)
AUDIO
–30
–40
–50
–60
–70
–80
–90
–70
0.4
–80
0.2
–90
0
–10
–15
–20
–25
–30
–35
–40
–45
–50
–55
–60
–65
–110
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
–110
–100
RF INPUT POWER (dBm)
Mixer Third Order Intercept and Compression
Receiver RF Performance – T = 85°C, Audio Level = 131mVRMS
85
2
–40°C
RF level = -45 dBm
–5
1.8
–7
25°C
1.6
85°C
–9
MIXER IIP3 (dB)
1.4
–11
1.2
5.5V
–13
–15
RSSI (V)
2.7V
3.0V
–17
1
0.8
0.6
–19
0.4
–21
0.2
–23
0
–10
–20
–30
–40
–50
–60
–70
RF INPUT LEVEL (dBm)
RSSI vs RF Input Level and Temperature
Mixer IIP3 at 240MHz vs Temperature and Supply Voltage
SR00494
Figure 4. Performance Characteristics
1997 Nov 07
–80
25
70
Temperature (°C)
–90
0
–110
–40
–100
0
–25
6
Philips Semiconductors
Product specification
Low voltage high performance mixer FM IF system
with high-speed RSSI
SA636
50.00
65.00
48.00
63.00
46.00
61.00
44.00
59.00
POWER GAIN (dB)
VCC = 5V
42.00
40.00
VCC = 3V
38.00
36.00
VCC = 2.7V
34.00
VCC = 5V
57.00
VCC = 3V
55.00
53.00
VCC = 2.7V
51.00
49.00
32.00
47.00
30.00
TEMPERATURE (°C)
90.00
70.00
50.00
30.00
TEMPERATURE (°C)
SA626 Limiting Amplifier Gain vs Temperature vs Supply Voltage
SA626 IF Amplifier Gain vs Temperature vs Supply Voltage
0.8
0.8
600kHz Data Rate,
IF = 9.85MHz,
Dev = 288kHz,
RF = -40dBm
0.6
0.7
0.5
5.5V
0.4
3.0V
0.3
5.5V
0.6
DATA LEVEL (Vp-p)
0.7
DATA LEVEL (Vp-p)
10.00
–10.00
–50.00
90.00
70.00
50.00
30.00
10.00
–10.00
–30.00
–50.00
45.00
–30.00
POWER GAIN (dB)
PERFORMANCE CHARACTERISTICS (continued)
2.7V
0.5
3.0V
0.4
2.7V
0.3
0.2
0.2
0.1
0.1
1kHz Data Rate,
IF = 9.85MHz,
Dev = 288kHz,
RF = -40dBm
0
0
–40
0
25
70
Temperature (°C)
–40
85
Data Level vs Temperature and Supply Voltage
0
25
70
Temperature (°C)
85
Data Level vs Temperature and Supply Voltage
SR00495
Figure 5. Performance Characteristics
1997 Nov 07
7
Philips Semiconductors
Product specification
Low voltage high performance mixer FM IF system
with high-speed RSSI
SA636
PERFORMANCE CHARACTERISTICS (continued)
300
0.8
0.7
AUDIO REFERENCE (mVrms)
250
5.5V
0.6
DATA LEVEL (Vp-p)
200
3.0V
150
600kHz Data Rate,
IF = 9.85MHz,
Dev = 288kHz,
RF = -40dBm
2.7V
100
0.5
5.5V
0.4
3.0V
0.3
2.7V
0.2
50
0.1
0
–40
0
25
70
Temperature (°C)
85
0
–40
0
Audio Reference Level vs Temperature and Supply Voltage
25
70
Temperature (°C)
85
Data Level vs Temperature and Supply Voltage
0.8
1kHz Data Rate,
IF = 9.85MHz,
Dev = 288kHz,
RF = -40dBm
0.7
5.5V
DATA LEVEL (Vp-p)
0.6
0.5
3.0V
0.4
2.7V
0.3
0.2
0.1
0
–40
0
25
70
Temperature (°C)
85
Data Level vs Temperature and Supply Voltage
SR00496
Figure 6. Performance Characteristics
1997 Nov 07
8
Philips Semiconductors
Product specification
Low voltage high performance mixer FM IF system
with high-speed RSSI
SA636
PIN FUNCTIONS
PIN
PIN
DC V
No. MNEMONIC
PIN
PIN
DC V
No. MNEMONIC
EQUIVALENT CIRCUIT
EQUIVALENT CIRCUIT
VCC
RSSI
1
RF IN
+1.07
6
0.8k
FEEDBACK
+0.20
—
6
+
0.8k
1
2
VCC
RF
2
BYPASS
RSSI
+1.07
7
OUT
+0.20
+
7
—
R
XTAL
3
OSC
POWER
18k
+1.57
8
DOWN
+2.75
8
4
R
MIX
VCC
3
XTAL
4
OSC
DATA
150µA
+2.32
9
OUT
+1.09
+
9
—
80k
5
5
VCC
VREF
10
QUAD.
+3.00
10
IN
+3.00
BANDGAP
20µA
SR00497
Figure 7. Pin Functions
1997 Nov 07
9
Philips Semiconductors
Product specification
Low voltage high performance mixer FM IF system
with high-speed RSSI
SA636
PIN FUNCTIONS (continued)
PIN
PIN
DC V
No. MNEMONIC
EQUIVALENT CIRCUIT
PIN
PIN
DC V
No. MNEMONIC
LIMITER
11
OUT
EQUIVALENT CIRCUIT
IF
+1.35
16
11
AMP OUT
+1.22
140Ω
16
8.8k
8.8k
LIMITER
12
DECOUP
IF AMP
+1.23
17
DECOUP
+1.22
14
18
LIMITER
13
COUPLING
IF
330Ω
+1.23
18
AMP IN
330Ω
+1.22
50µA
50µA
12
17
13
19
LIMITER
14
IN
IF AMP
+1.23
19
0
20
DECOUP
+1.22
110Ω
MIXER
15
GND
OUT
20
+1.03
400µA
SR00498
Figure 8. Pin Functions (cont.)
1997 Nov 07
10
Philips Semiconductors
Product specification
Low voltage high performance mixer FM IF system
with high-speed RSSI
MIXER
IF/LIM OUT
SA636
IF/LIM IN
R9
R4
R2
C12
R3
1
1
2
19
1
C20
C17
FLT2
2
1
R10
2
C15
C13
20
R8
C14
FLT1
2
R7
R5
C11
L5
R11
R6
C16
18
17
SW5
C19
C18
16
15
14
IF
AMP
13
12
11
LIMITER
MIXER
C21
QUAD
RSSI
OSCILLATOR
– +
VCC
PWR
DWN
– +
DATA
1
2
C1
3
C3
4
5
6
7
8
9
10
C4
C6
C8
R1
*L1
C2
L3
C5
FLT
3
C7
*L2
VCC
RF IN
L4
C9
FLT
4
RSSI
OUT
PWR
DWN
CTRL
DATA
OUT
C10
LO IN
Automatic Test Circuit Component List
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10
R11
8.2kΩ select
6.42kΩ
347.8Ω
49.9Ω
1kΩ
49.9Ω
6.42kΩ
347.8Ω
49.9Ω
1kΩ
49.9Ω
C1
C2
C3
C4
C5
C6
*C7
C8
C9
C10
C11
0.1µF
1–5pF select for input match
0.1µF
0.1µF
1–5pF select for input match
100pF
6.8µF 10V
1µF
39pF select
0.1µF
0.1µF
C12 160pF select
C13 1000pF
C14 0.1µF
C15 1000pF
C16 0.1µF
C17 0.1µF
C18 1000pF
C19 1000pF
C20 0.1µF
C21 1pF
L1
L2
L3
L4
L5
FLT1
FLT2
FLT3
FLT4
*NOTE: This value can be reduced when a battery is the power source.
10.7MHz (Murata SFE10.7MA5-A)
10.7MHz (Murata SFE10.7MA5-A)
“C” message weighted
Active de-emphasis
SR00501
Figure 9. SA636 240.05MHz (RF) / 10.7MHz (IF) Test Circuit
1997 Nov 07
150nH select for input match
22nH select for input match
47nH select for input match
5.6µH select for input match
1.27–2.25µH select for mixer
output match
11
Philips Semiconductors
Product specification
Low voltage high performance mixer FM IF system
with high-speed RSSI
SA636
C1
5–30pF
SMA
RF IN
L4
680nH
J1
110.592MHz
+/–288kHz
L1
180nH
C20
68pF
C21
330pF
U1
1
RF IN
2
RF BYPASS
3
XTAL
OSC (EMITTER)
4
XTAL
OSC (BASE)
5
VCC
MIXER OUT
20
IF AMP
DECOUPLING 1
19
IF IN
18
C19
1nF
C18
68pF
C2
10nF
SMA
LO IN 120.392MHz
@–10dBm
C4
1nF
C3
1nF
J2
R1
51
IF AMP
DECOUPLING 2
17
IF OUT
16
C17
1nF
C16
100pF
R3
22k
6
RSSI FEEDBACK
7
RSSI OUT
GROUND
15
LIMITER IN
14
C13
100pF
R4
33k
+3V
R2
10
8
PD CTRL
LIMITER DEC1
13
9
DATA OUT
LIMITER DEC2
12
LIMITER OUT
11
VCC
GND
C5
15µF
+
C6
100nF
10
QUAD IN
C11
1nF
C12
1nF
SA636
C14
47pF
J3
RSSI
C7
470pF
C10
15pF
PWR DWN
+
R5
1.2k
C8
5-30pF
C9
82pF
L2
2.2µH
C15
330pF
L3
680nH
DATA OUT
R6
560
SR00500
Figure 10. SA636 110.592MHz (RF) / 9.8MHz (IF) DECT Application Circuit
1997 Nov 07
12
Philips Semiconductors
Product specification
Low voltage high performance mixer FM IF system
with high-speed RSSI
Table 1.
SA636
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
dB
Mixer/Osc section (ext LO = 160mVRMS)
PG
Conversion power gain
13
NF
Noise Figure at 110MHz
12
dB
IIP3
Third order input intercept
-15
dBm
RIN
RF input resistance
690
Ω
CIN
RF input capacitance
3.6
pF
dB
Matched f1 = 110.592; f2 = 110.892MHz
IF section
IF amp gain
330Ω load
38
Limiter amp gain
330Ω load
54
dB
RLOAD = 3kΩ
130
mVRMS
700
kHz
Data level
3dB data bandwidth
RF/IF section (internal LO)
System RSSI output
RF level = -10dBm
1.4
V
System S/N1
RF level = -83dBm
10
dB
NOTE:
1. 10dB S/N corresponds to BER = 10-3.
RF GENERATOR
110.592MHz
SA636 DEMO BOARD
RSSI
DATA
VCC = 3V
LO / GENERATOR
120.392MHz
DC VOLTMETER
SCOPE
SPECTRUM
ANALYZER
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.
1997 Nov 07
13
Philips Semiconductors
Product specification
Low voltage high performance mixer FM IF system
with high-speed RSSI
SA636
TOP SILK SCREEN (SSOP)
SR00503
Figure 12. SA636 Demoboard Layout (Not Actual Size)
1997 Nov 07
14
Philips Semiconductors
Product specification
Low voltage high performance mixer FM IF system
with high-speed RSSI
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.
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 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 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 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.
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
1997 Nov 07
SA636
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 VOUT/VIN
15
Philips Semiconductors
Product specification
Low voltage high performance mixer FM IF system
with high-speed RSSI
SO20: plastic small outline package; 20 leads; body width 7.5 mm
1997 Nov 07
16
SA636
SOT163-1
Philips Semiconductors
Product specification
Low voltage high performance mixer FM IF system
with high-speed RSSI
SA636
DEFINITIONS
Data Sheet Identification
Product Status
Definition
Objective Specification
Formative or in Design
This data sheet contains the design target or goal specifications for product development. Specifications
may change in any manner without notice.
Preliminary Specification
Preproduction Product
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.
Product Specification
Full Production
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.
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.
Philips Semiconductors
811 East Arques Avenue
P.O. Box 3409
Sunnyvale, California 94088–3409
Telephone 800-234-7381
1997 Nov 07
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.
17