Philips SA627D, SA627DK Datasheet

RF COMMUNICATIONS PRODUCTS

SA627

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

	Product specification	1997 Nov 07
	Replaces data of November 3, 1992
	RF Communications Handbook

Philips Semiconductors

Philips Semiconductors	Product specification

High performance low power mixer FM IF system

SA627

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).

FEATURES

•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

D and DK Packages

RFIN	1		20	MIXER OUT
RF BYPASS	2		19	IF AMP DECOUPLING
XTAL OSC	3		18	IF AMP IN
				IF AMP DECOUPLING
XTAL OSC	4		17
MUTEIN	5		16	IF AMP OUT
VCC	6		15	GND
RSSIOUT	7		14	LIMITER IN
MUTED AUDIO OUT	8		13	LIMITER DECOUPLING
QUADRATURE IN	9		12	LIMITER DECOUPLING
FREQ CHECK/ LIM OUT (±)	10		11	LIMITER OUT (+)

SR00481

Figure 1. Pin Configuration

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

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

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853-1649 18664

Philips Semiconductors	Product specification

High performance low power mixer FM IF system

SA627

with high-speed RSSI

BLOCK DIAGRAM

20	19	18	17	16	15	14	13	12	11
		IF AMP		700
						LIMITER
	MIXER						QUAD
							DETECTOR
		OSCILLATOR				RSSI
								MUTE
							SWITCH

1

2

3

4

5

6

7

8

9

10

SR00482

Figure 2. Block Diagram

ABSOLUTE MAXIMUM RATINGS

SYMBOL

PARAMETER

RATING

UNITS

VCC

Single supply voltage

9

V

TSTG

Storage temperature range

-65 to +150

°C

T

Operating ambient temperature range SA627

-40 to +85

°

A

C

θJA

Thermal impedance

D package

90

°C/W

DK package

117

°C/W

DC ELECTRICAL CHARACTERISTICS

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

LIMITS

SYMBOL

PARAMETER

TEST CONDITIONS

SA627

UNITS

MIN

TYP

MAX

VCC

Power supply voltage range

4.5

8.0

V

ICC

DC current drain

4.55

5.8

6.75

mA

Mute switch input threshold

1.7

V

(ON)

(OFF)

1.0

V

1997 Nov 07

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Philips Semiconductors	Product specification

High performance low power mixer FM IF system

SA627

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)
fIN	Input signal frequency			500		MHz
fOSC	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 section
	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	mVRMS
	SINAD sensitivity	RF level -118dB		16		dB
THD	Total harmonic distortion		-34	-42		dB
S/N	Signal-to-noise ratio	No modulation for noise		73		dB
	IF RSSI output, R9 = 100kΩ1	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
	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
		RF level = -28dBm		1.1		μs
		IF frequency = 455kHz
		RF level = -56dBm		2.1		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
		RF level = -28dBm		7.3		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	Pin 10 or 11 with no load		280		mVRMS
		3kΩ load (min)		250

1997 Nov 07

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Philips Semiconductors	Product specification

High performance low power mixer FM IF system

SA627

with high-speed RSSI

AC ELECTRICAL CHARACTERISTICS(Continued)

				LIMITS
SYMBOL	PARAMETER	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 ºavailable powerº 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° 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 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 VOUT/VIN

1997 Nov 07

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