Philips SA615DK, SA615N, SA615D Datasheet

INTEGRATED CIRCUITS

SA615

High performance low power mixer FM IF system

Product specification

1997 Nov 07

Replaces data of 1992 Nov 03

IC17 Data Handbook

m n r

Philips Semiconductors	Product specification
High performance low power mixer FM IF system	SA615

DESCRIPTION

The SA615 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), and voltage regulator. The

SA615 combines the functions of Signetics' SA602 and SA604A, but features a higher mixer input intercept point, higher IF bandwidth (25MHz) and temperature compensated RSSI and limiters permitting higher performance application. The SA615 is available in

20-lead dual-in-line plastic, 20-lead SOL (surface-mounted miniature package) and 20-lead SSOP (shrink small outline package).

The SA605 and SA615 are functionally the same device types. The difference between the two devices lies in the guaranteed specifications. The SA615 has a higher ICC, lower input third order intercept point, lower conversion mixer gain, lower limiter gain, lower

AM rejection, lower SINAD, higher THD, and higher RSSI error than the SA615. Both the SA605 and SA615 devices will meet the EIA specifications for AMPS and TACS cellular radio applications.

For additional technical information please refer to application notes

AN1994, 1995 and 1996, which include example application diagrams, a complete overview of the product, and artwork for reference.

PIN CONFIGURATION

N, D and DK Packages

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

NOTE:

See back page for package dimensions

SR00341

Figure 1. Pin Configuration

FEATURES

•Low power consumption: 5.7mA 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

•Two audio outputs ± muted and unmuted

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

APPLICATIONS

•Cellular radio FM IF

•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

•Excellent sensitivity: 0.22μV into 50Ω matching network for 12dB SINAD (Signal to Noise and Distortion ratio) for 1kHz tone with RF at 45MHz and IF at 455kHz

•SA615 meets cellular radio specifications

•ESD hardened

ORDERING INFORMATION

DESCRIPTION	TEMPERATURE RANGE	ORDER CODE	DWG #
20-Pin Plastic Dual In-Line Package (DIP)	±40 to +85°C	SA615N	SOT146-1
20-Pin Plastic Small Outline Large (SOL) package	±40 to +85°C	SA615D	SOT108-1
20-Pin Plastic Shrink Small Outline Package (SSOP)	±40 to +85°C	SA615DK	SOT266-1

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853-1402 18665

Philips Semiconductors	Product specification
High performance low power mixer FM IF system	SA615

BLOCK DIAGRAM

20	19	18	17	16	15	14	13	12	11
			IF				LIMITER
			AMP
						RSSI
		OSCILLATOR
		E	B
1	2	3	4	5	6	7	8	9	10
									SR00342

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
TA	Operating ambient temperature range SA615		±40 to +85	°C
θJA	Thermal impedance	D package	90	°C/W
		N package	75
		SSOP package	117

DC ELECTRICAL CHARACTERISTICS

VCC = +6V,	TA = 25°C; unless otherwise stated.
				LIMITS
SYMBOL	PARAMETER	TEST CONDITIONS		SA615		UNITS
			MIN	TYP	MAX
VCC	Power supply voltage range		4.5		8.0	V
ICC	DC current drain			5.7	7.4	mA
	Mute switch input threshold (ON)		1.7			V
	(OFF)				1.0	V

1997 Nov 07

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Philips Semiconductors	Product specification
High performance low power mixer FM IF system	SA615

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		SA615		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 = 45.00; f2 = 45.06MHz		-12		dBm
	Conversion power gain	Matched 14.5dBV step-up	8.0	13		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	1.50		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		-109		dBm
	AM rejection	80% AM 1kHz	25	33	43	dB
	Audio level, R10 = 100k	15nF de-emphasis	60	150	260	mVRM
						S
	Unmuted audio level, R11 = 100k	150pF de-emphasis		530		mV
	SINAD sensitivity	RF level -118dB		12		dB
THD	Total harmonic distortion		-30	-42		dB
S/N	Signal-to-noise ratio	No modulation for noise		68		dB
	IF RSSI output, R9 = 100kΩ1	IF level = -118dBm	0	160	800	mV
		IF level = -68dBm	1.7	2.5	3.3	V
		IF level = -18dBm	3.6	4.8	5.8	V
	RSSI range	R9 = 100kΩ Pin 16		80		dB
	RSSI accuracy	R9 = 100kΩ Pin 16		+2		dB
	IF input impedance		1.40	1.6		kΩ
	IF output impedance		0.85	1.0		kΩ
	Limiter intput impedance		1.40	1.6		kΩ
	Unmuted audio output resistance			58		kΩ
	Muted audio output resistance			58		kΩ
RF/IF section (int LO)
	Unmuted audio level	4.5V = VCC, RF level = -27dBm		450		mVRM
						S
	System RSSI output	4.5V = VCC, RF level = -27dBm		4.3		V

NOTE:

1.The generator source impedance is 50Ω, but the SA615 input impedance at Pin 18 is 1500Ω. As a result, IF level refers to the actual signal that enters the SA615 input (Pin 8) which is about 21dB less than the ºavailable powerº at the generator.

1997 Nov 07

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Philips Semiconductors	Product specification
High performance low power mixer FM IF system	SA615

CIRCUIT DESCRIPTION

The SA615 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

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