Philips sa627 DATASHEETS

RF COMMUNICATIONS PRODUCTS

SA627

High performance low power FM IF system with high-speed RSSI

Product specification Replaces data of November 3, 1992

RF Communications Handbook

Philips Semiconductors

1997 Nov 07

Philips Semiconductors Product specification

High performance low power mixer FM IF system with high-speed RSSI

DESCRIPTION

The SA627 has faster RSSI rise and fall times. The SA627 is a high performance monolithic low-power FM IF system incorporating a mixer/oscillator, two limiting intermediate frequency amplifiers, quadrature detector, muting, logarithmic received signal strength indicator (RSSI) with fast rise and fall time, voltage regulator and frequency check/limiter out (–). The SA627 also has an extra limiter output. This signal is buffered from the output of the limiter and provides a negative (–) limiter output. This can be used to provide a frequency check function. The SA627 is available in 20-lead SOL (surface-mounted miniature package) and 20-lead SSOP (shrink small outline package).

FEA TURES

•Fast RSSI rise and fall times

•Low power consumption: 5.8mA typical at 6V

•Mixer input to >500MHz

•Mixer conversion power gain of 13dB at 45MHz

•Mixer noise figure of 4.6dB at 45MHz

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

oscillator can be injected)

•102dB 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

•Audio output - mutable

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

filters

•Excellent sensitivity: 0.22µV into 50Ω matching network for 12dB

SINAD (Signal to Noise and Distortion ratio) for 1kHz tone, 8kHz deviation with RF at 45MHz and IF at 455kHz

•SA627 meets cellular radio specifications

•ESD hardened

PIN CONFIGURATION

MUTED AUDIO OUT

QUADRATURE IN

FREQ CHECK/ LIM OUT (–)

APPLICATIONS

•Digital cellular base stations

•High performance communications receivers

•Single conversion VHF/UHF receivers

•SCA receivers

•RF level meter

•Spectrum analyzer

•Instrumentation

•FSK and ASK data receivers

•Log amps

•Wideband low current amplification

•Digital cordless telephones

D and DK Packages

RF BYPASS 2

XTAL OSC

XTAL OSC 4

MUTE

RSSI

OUT

Figure 1. Pin Configuration

SA627

20 MIXER OUT 19

IF AMP DECOUPLING

18 IF AMP IN

IF AMP DECOUPLING

16 IF AMP OUT 15 GND 14 LIMITER IN

LIMITER DECOUPLING

11 LIMITER OUT (+)

SR00481

ORDERING INFORMATION

DESCRIPTION TEMPERATURE RANGE ORDER CODE DWG #

20-Pin Plastic Small Outline Large (SOL) package (Surface-mount) -40 to +85°C SA627D SOT163-1 20-Pin Plastic Shrink Small Outline Package (SSOP) (Surface-mount) -40 to +85°C SA627DK SOT266-1

1997 Nov 07 853-1649 18664

Philips Semiconductors Product specification

High performance low power mixer FM IF system with high-speed RSSI

BLOCK DIAGRAM

19 18 17 16 15 14

IF AMP

MIXER

OSCILLATOR

700

LIMITER

Figure 2. Block Diagram

RSSI

13 12 11

QUAD

DETECTOR

MUTE

SWITCH

10987654321

SA627

SR00482

ABSOLUTE MAXIMUM RATINGS

SYMBOL PARAMETER RATING UNITS

STG

Single supply voltage 9 V Storage temperature range -65 to +150

Operating ambient temperature range SA627 -40 to +85 Thermal impedance D package 90

DK package 117

°C/W °C/W

°C °C

DC ELECTRICAL CHARACTERISTICS

VCC = +6V, TA = 25°C; unless otherwise stated.

LIMITS

SYMBOL PARAMETER TEST CONDITIONS SA627 UNITS

MIN TYP MAX

Power supply voltage range 4.5 8.0 V DC current drain 4.55 5.8 6.75 mA Mute switch input threshold

(ON)

(OFF) 1.0 V

1.7 V

1997 Nov 07

Philips Semiconductors Product specification

High performance low power mixer FM IF system with high-speed RSSI

AC ELECTRICAL CHARACTERISTICS

TA = 25°C; VCC = +6V, unless otherwise stated. RF frequency = 45MHz + 14.5dBV RF input step-up; IF frequency = 455kHz; R17 = 5.1k; RF level = -45dBm; FM modulation = 1kHz with ±8kHz peak deviation. Audio output with C-message weighted filter and de-emphasis capacitor. Test circuit Figure 3. The parameters listed below are tested using automatic test equipment to assure consistent electrical characterristics. 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 SA627 UNITS

MIN TYP MAX

Mixer/Osc section (ext LO = 300mV)

OSC

IF section

THD Total harmonic distortion -34 -42 dB

S/N Signal-to-noise ratio No modulation for noise 73 dB

Input signal frequency 500 MHz Crystal oscillator frequency 150 MHz Noise figure at 45MHz 5.0 dB Third-order input intercept point f1 = 45.0; f2 = 45.06MHz -10 dBm Conversion power gain Matched 14.5dBV step-up 10 13 15 dB

50Ω source -1.7 dB RF input resistance Single-ended input 3.0 4.7 kΩ RF input capacitance 3.5 4.0 pF Mixer output resistance (Pin 20) 1.25 1.5 kΩ

IF amp gain 50Ω source 39.7 dB Limiter gain 50Ω source 62.5 dB Input limiting -3dB, R17 = 5.1k Test at Pin 18 -113 dBm AM rejection 80% AM 1kHz 29 34 43 dB Audio level, R10 = 100k 15nF de-emphasis 80 150 260 mV SINAD sensitivity RF level -118dB 16 dB

IF RSSI output, R9 = 100kΩ

IF RSSI output rise time RF level = -28dBm 1.2 µs (10kHz pulse, no 455kHz filter) IF frequency = 10.7MHz (no RSSI bypass capacitor) RF level = -56dBm 1.2 µs

IF RSSI output fall time RF level = -28dBm 7.6 µs (10kHz pulse, no 455kHz filter) IF frequency = 10.7MHz (no RSSI bypass capacitor) RF level = -56dBm 2.0 µs

RSSI range R9 = 100kΩ Pin 16 90 dB RSSI accuracy R9 = 100kΩ Pin 16 +1.5 dB IF input impedance 1.40 1.6 kΩ IF output impedance 0.85 1.0 kΩ Limiter input impedance 1.40 1.6 kΩ Limiter output impedance Pin 10 or 11 300 Ω

Limiter output level

IF level = -118dBm 0 160 650 mV

IF level = -68dBm 1.9 2.5 3.1 V

IF level = -18dBm 4.0 4.8 5.6 V

IF frequency = 455kHz

RF level = -56dBm 1.2 µs

RF level = -28dBm 1.1 µs

IF frequency = 455kHz

RF level = -56dBm 2.1 µs

RF level = -28dBm 7.3 µs

Pin 10 or 11 with no load

3kΩ load (min)

280 250

SA627

RMS

1997 Nov 07

Philips Semiconductors Product specification

High performance low power mixer FM IF system with high-speed RSSI

AC ELECTRICAL CHARACTERISTICS(Continued)

LIMITS

SYMBOL P ARAMETER TEST CONDITIONS SA627 UNITS

MIN TYP MAX

IF section (continued)

Muted audio output resistance 58 kΩ

RF/IF section (int LO)

System RSSI output 4.5V = VCC, RF level = -27dBm 4.3 V

NOTE:

1. The generator source impedance is 50Ω, but the SA627 input impedance at Pin 18 is 1500Ω. As a result, IF level refers to the actual signal that enters the SA627 input (Pin 8) which is about 21dB less than the ”available power” at the generator.

CIRCUIT DESCRIPTION

The SA627 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 39.7dB(v) of gain from a 50Ω source. The bandwidth of the limiter is about 28MHz with about 62.5dB(v) of gain from a 50Ω source. However, the gain/bandwidth distribution is optimized for 455kHz, 1.5kΩ source applications. The overall system is well-suited to battery operation as well as high performance and high quality products of all types.

The input stage is a Gilbert cell mixer with oscillator. Typical mixer characteristics include a noise figure of 5dB, conversion gain of 13dB, and input third-order intercept of -10dBm. 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 1.5kΩ resistor permitting direct connection to a 455kHz ceramic filter. The input resistance of the limiting IF amplifiers is also 1.5kΩ. With most 455kHz ceramic filters and many crystal filters, no impedance matching network is necessary. To achieve optimum linearity of the log signal strength indicator , there must be a 12dB(v) insertion loss between the first and second IF stages. If the IF filter or interstage

network does not cause 12dB(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 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 frequencies greater than 455kHz, special care must be given to layout, termination, and interstage loss to avoid instability.

The demodulated output of the quadrature detector is available at two pins, one continuous and one with a mute switch. Signal attenuation with the mute activated is greater than 60dB. The mute input is very high impedance and is compatible with CMOS or TTL levels.

A log signal strength 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.

NOTE: dB(v) = 20log V

OUT/VIN

SA627

° phase

1997 Nov 07

+ 11 hidden pages