Motorola MC13027P, MC13027DW, MC13022DW, MC13022P Datasheet

		Order this document from Analog Marketing
		MC13027
Product	Preview	MC13122
AMAX	Stereo	Chipset

The MC13027 and MC13122 have been specifically designed for AM									AMAX STEREO
radio which can meet the EIA/NAB AMAX requirements. They are
essentially the same as the MC13022A and MC13025 with the addition of										IC CHIPSET
noise blanking circuitry. The noise blanker consists of a wide band amplifier
with an RF switch for blanking ahead the IF amplifier and a stereo audio
blanker with adjustable delay and blanking times.
• Operating Voltage Range of 6.0 V to 10 V										MC13027
• RF Blanker with Built±In Wide Band AGC Amplifier
• Audio Noise Blanker with Audio Track and Hold
• Mixer Third Order Intercept of 8.0 dBm (115 dBμV)											20
• Wide Band AGC Detector for RF Amplifier								20			1
								1
• Local Oscillator VCO Divide±by±4 for Better Phase Noise
									P SUFFIX		DW SUFFIX
• Buffered Local Oscillator Output at the Fundamental Frequency
								PLASTIC PACKAGE			PLASTIC PACKAGE
• Fast Stereo Decoder Lock									CASE 738		CASE 751D
											(SO±20L)
• Soft Stereo Blend
• Signal Quality Detector to Control Variable Q±Notch Filters for Adaptive										MC13122
Audio Bandwidth and Whistle Reduction
• Signal Quality Detector for AM Stereo
• Very Low Distortion Envelope and Synchronous Detectors
• Variable Bandwidth IF											P SUFFIX
		ORDERING INFORMATION						28			PLASTIC PACKAGE
											CASE 710
			Operating						1
	Device	Temperature Range					Package
MC13027DW							SO±20L				DW SUFFIX
MC13027P							Plastic DIP				PLASTIC PACKAGE
		TA = ±40		°		°			28		CASE 751F
MC13122DW					to +85 C		SO±28L				(SO±28L)
										1
MC13122P							Plastic DIP
						Functional Block Diagram
	To Synthesizer	Oscillator	RF Input
		Buffer
Osc	Voltage						450 kHz IF
	Controlled	4			Mixer	IF Amplifier					Left Audio
Tank									L
	Oscillator						IF Amplifier
								Decoder		Track & Hold	Post Detector
						RF	AGC				Filter
AGC	Wide Band	AGC							R
											Right Audio
Input	AGC	Output				Blanking	Fast	Q	450 kHz	Blend cosθ
			Pulse Length			Shunt	AGC
										Fast Lock
			Timer			Switch	Control	Pilot
	AM	Pulse								Control
								Detector
	Detector	Detector
											Stereo Indicator Lamp

Fast/

Audio

RF

Automatic

Slow

Blanking

Input

Gain Controlled

Pulse Delay

Pulse Length

Timer

Timer

I

Yes/No

RF Amplifier

Signal Quality

Signal Level

Detector

Stop±Sense

MC13027

MC13122

RF AGC Meter Drive

This device contains 428 active transistors.

This device contains 670 active transistors.

This document contains information on a product under development. Motorola reserves the

Motorola, Inc. 1996

Issue 1

right to change or discontinue this product without notice.

MC13027 MC13122

MC13027

MAXIMUM RATINGS

Rating	Symbol	Value	Unit
Power Supply Input Voltage	VCC	12	Vdc
Ambient Operating Temperature	TA	±40 to +85	°C
Storage Temperature Range	Tstg	±60 to +150	°C
Operating Junction Temperature	TJ	150	°C

NOTE: ESD data available upon request.

MC13027

ELECTRICAL CHARACTERISTICS (TA = 25°C, 8.0 VCC Test Circuit as shown in Figure 1.)

Characteristic	Min	Typ	Max	Unit
Supply Voltage Range (Pin 8)	±	6.0 to 10	±	V
Wideband (WB) AGC Threshold	±	1.0	±	mVrms
IF Output DC Current	±	1.0	±	mAdc
Mixer DC Current Output	±	0.83	±	mAdc
Local Oscillator Output	±	600	±	mVpp
Wideband AGC Pull±Down Current (Pin 20)	±	1.0	±	mAdc
Power Supply Current	±	16	±	mAdc
Mixer 3rd Order Intercept Point (Pin 6)	±	8.0	±	dBm
Mixer Conversion Gain	±	2.9	±	mS
IF Amplifier Input Impedance (Pin 14)	±	2.2	±	kΩ
IF Amplifier Transconductance	±	2.8	±	mS
IF Amplifier Load Resistance (Pin 16)	±	5.7	±	kΩ
IF Amplifier Collector Current (Pin 16)	±	990	±	μA

2	MOTOROLA ANALOG IC DEVICE DATA

MC13027 MC13122

Figure 1. MC13027 Test Circuit

VCC

On

AGC

Feedback

VCC

+

VCC

C14

C10

R20

47 μF

MC13027

0.01

1

20

47 k

WB AGC

WB AGC

WB AGC Out

R10

C90

RL1

In

Out

RT1

R19

56 k

0.1

500 k

39 k

51

C5 +

R4

2

Blanker

Audio

19

RF

22 μF

47

AGC

Blank Time

R3b

WB AGC

Q4

RF Module

+

C16

10 k

Audio Blank

RF In

MMBT3904L

1

3

Audio

18

Mixer In

10 μF

Feedback

Q3

RF In

R200

RM1

Blanker In

C26

+

Blank Pulse

R18

(Note 1)

560 k

R11

Q2

1.0

μ

2.35 k

16.7

RM5

CM1

47

2

F

4

Audio Blank

17

(Note 1)

V

4.0 V Reg

R17

16.7

0.01

Q1

CC

+

Delay Time

R2b

C9

VCC

500 k

MMBFJ309L

10 k

R21

RM2

RL2

R1

Gnd

3

47 μF

5

RF Gnd

IF Out

16

R16

510

R2

C87

3.3 k

16.7

51

100 k

L2 1.0 mH

82

0.1

R1b

Pulse On

IF Out

4

10 k

Pulse In

Mixer In

6

Mixer In

RF Blank

15

C16

120

Blanker RF In

Time

VCC C103

R15

500 k

0.1

R299

5

C293

7

Murata

R12

14

Mixer 4.0 V

10 μF

4.0 Filter

IF In

51

C11

+

SFG450E

1.8 k

5

0.1

4 3 2

1

Tuning V

6

8

V

Gnd2

13

C6

CC

0.1

VCLO

7

9

VCO

RF Blank

12

RF Blank

R201

Q1b

(Note 1)

8

120

10

11

VCLO 4.0 V

LO Out

Mixer Out

100

R5b

C37

390 k

0.01

Tuning Voltage

LO Out

4.0 V Reg

NOTE: 1. General purpose NPN transistor 2N3904 or equivalent.

MOTOROLA ANALOG IC DEVICE DATA	3

MC13027 MC13122

MC13122

MAXIMUM RATINGS

Rating	Symbol	Value	Unit
Power Supply Input Voltage	VCC	12	Vdc
Stereo (Pilot) Indicator Lamp Current (Pin 21)	±	30	mAdc
Operating Ambient Temperature	TA	±40 to +85	°C
Storage Temperature Range	Tstg	±65 to +150	°C
Operating Junction Temperature	TJ(max)	150	°C
Power Dissipation Derated above 25°C	PD	1.25	Ω
		10	mW/C

NOTE: ESD data available upon request.

MC13122

ELECTRICAL CHARACTERISTICS (VCC = 8.0 V, TA = 25°C, Test Circuit of Figure 2.)

Characteristic	Min	Typ	Max	Unit
Power Supply Operating Range	6.0	8.0	10	V
Supply Current Drain (Pin 25)	10	20	25	mA
Minimum Input Signal Level, Unmodulated, for AGC Start	±	5.0	±	mV
Audio Output Level, 50% Modulation, L Only or R Only	290	400	530	mVrms
Audio Output Level, 50% Mono	140	200	265	mVrms
Output THD, 50% Modulation (Monaural Stereo)	±	0.3	0.8	%
	±	0.5	1.6
Channel Separation, L Only or R Only, 50% Modulation	22	35	±	dB
IF Input Voltage Range	±	1.0±1000	±	mV
IF Input Resistance Range	±	10 to 50	±	kΩ
IF Amplifier Transconductance	±	9.6	±	mS
IF Detector Circuit Impedance	±	8.3	±	kΩ
Input AGC Threshold	±	5.0	±	mV
Stop±Sense Output Range	±	2.2 to 4.0	±	V
Audio Output Impedance at 1.0 kHz (Pins 7 and 14)	±	300	±	Ω
Stereo Indicator Lamp Leakage	±	±	1.0	μA
Stereo Indicator Saturation Voltage @ 3.0 mA	±	±	200	mVdc
Oscillator Capture Range	±	±3.0	±	kHz

4	MOTOROLA ANALOG IC DEVICE DATA

MC13027 MC13122

Figure 2. MC13122 Test Circuit

Envelope Det Out

I Detector Out

Q Detector Out

8.0 V

C1

C28

C27

1000

MC13122

1000

1000

C22

R10

C2

L1

1

IC2

28

220 μF

13 k

120

1.0 mH

E Det

I Det

C3

47

μ

F

2

Det In

L±R Det

27

2.2 k

3

3.0 V Reg

Q Det

26

C4

10

μ

R26

4

AGC

V

25

F

10 k

5

CC

24

450 kHz IF In

IF In

Loop Filt

100 k

R5

.01

C24

47 μF

6

SS

Blend

23

R6

C23

22 μF

7

L Out

Gnd

22

U2

1.0 k

Stereo

D1

Ch2 Out

6

8

L Filt In

Pilot Ind

21

3.6 MHz

C

A

C6

Ch2 Cont

5

9

L Filt Ctr

Osc Out

20

R20

3.9 k

51 C29

1.0

μ

4

10

19

X1

F

Ch2 In

L Mat Out

Osc In

1000

C30

3

11

18

R12

Ch1 In

R Mat Out

Pilot Det I

C18

Ch1 Cont

2

12

R Filt Ctr

Pilot I

17

22

μ

1

13

16

F

Ch1 Out

R Filt In

Pilot Q

C31

14

15

THB122

R Out

Audio Blank

1.0 μF

C16

C17

0.47 μF

10 μF

1000

1000

AF Blank

SS Out

Left

Right

C

33 k

Audio Out

Audio Out

B

R11

Blend Disable

E

MPS6515

Q3

MOTOROLA ANALOG IC DEVICE DATA	5

MC13027 MC13122

AMAX STEREO CHIPSET

What is AMAX?

In 1993, a joint proposal by the EIA (Electronic Industries Association) and the NAB (National Association of Broadcasters) was issued. It included a unified standard for pre±emphasis and distortion for broadcasters as well as a set of criteria for the certification of receivers. The purpose of this proposal was to restore quality and uniformity to the AM band and to make it possible for the consumer to receive high quality signals using the AM band. The FCC has been supportive of this initiative and has required all new broadcast licensees to meet AMAX standards. The NAB and EIA have continued to encourage receiver manufacturers by offering the AMAX certification logo to be displayed on all qualifying radios. This logo is shown below.

or

The Receiver Criteria

An AMAX receiver must have wide bandwidth: 7.5kHz for home and auto, 6.5 kHz for portables. It must have some form of bandwidth control, either manual or automatic, including at least two bandwidth provisions, such as ªnarrowº and ªwideº. It must meet NRSC receiver standards for distortion and deemphasis. It must have provisions for an external antenna. It must be capable of tuning the expanded AM band (up to 1700 kHz). And finally, home and auto receivers must have effective noise blanking. All of these requirements, except the noise blanking, have been met by Motorola's previous AM radio products, such as MC13025 Front End and the MC13022A C±QUAM stereo decoder. It is the Noise Blanker requirement which is met by the two devices on this data sheet, the MC13027 and MC13122.

Noise blanking, especially in AM auto radios, has become extremely important. The combination of higher energy

ignitions, using multiple spark coils, along with increased use of plastic in the auto body, have increased the noise energy at the radio. Also, the consumer has learned to expect higher quality audio due to advances in many other media. For the AM band to sustain interest to the consumer, a truly effective noise blanker is required.

The block diagram below shows the Motorola AMAX stereo chipset. It offers a two±pronged approach to noise blanking which is believed to be the most effective yet offered in the consumer market. The initial blanking takes place in the output of the mixer, using a shunt circuit triggered by a carefully defined wideband receiver. For most noises, some residual audible disturbance is almost always still present after this process. The disturbance becomes stretched and delayed as it passes through the rest of the selectivity in the receiver. The stretching and delay are predictable, so the MC13027 can provide a noise blanking pulse with the correct delay and stretch to the output stages of the MC13122 decoder. The MC13122 has a Track and Hold circuit which receives the blanking signal from the Front End and uses it to gently hold the audio wherever it is as the pulse arrives, and hold that value until the noise has passed. The combined effect is dramatic. A wide range of types of noise is successfully suppressed and the resulting audio seems almost clean until the noise is so intense that the blanking approaches full±time.

The amount of extra circuitry to accomplish noise blanking is relatively small. The external components for this added capability are shown in Figure 3. In the MC13027 Front end, the noise receiver/detector requires two capacitors. The presettings for blanking timing and blanking delay require three external fixed resistors. Finally the decoder requires two track and hold capacitors to store the ªaudioº voltage during the track and hold function.

Figure 3. AMAX Stereo Receiver with Noise Blanker

MC13027

MC13122

RF In

AM

Track

Left

RF

IF

AGC'd IF

Variable

Mixer

Stereo

and

Amplifier

Amplifier

Amplifier

Notch Filter

Decoder

Hold

Right

Divide

450 kHz

RF Attenuate

by 4

Filter

Audio Blank

Wideband

Pin

AGC

RF

RF Blank

Diode

VCO

Attenuator

Timer

Switch

Reset

4.0 V

Audio

Regulator

AGC'd RF

AM

Pulse

Audio

Reject

Delay

Audio Blank

Amplifier

Detector

Filter

Detector

Blank

Timer

Timer

Switch

AGC

6	MOTOROLA ANALOG IC DEVICE DATA

MC13027 MC13122

Figure 4. MC13027 Internal Block Diagram

WB AGC	Audio	Audio	Audio Blank	IF Out	RF Blank	IF In	Gnd2	RF Blank	Mixer Out
Out	Blank Time	Blank Pulse	Delay Time		Time
20	19	18	17	16	15	14	13	12	11
				IF Amp		VCC
							Mixer
	AF Time		AF Del		RF Time
		MV	MV		MV
									X1
					NB Amp
WB AGC Amp								4
					X1		Reg
1	2	3	4	5	6	7	8	9	10
WB AGC	Blanker	Feedback	4.0 V Reg	RF Gnd	Mixer In	4.0 Filter	VCC	VCO	LO Out
In	AGC				Blanker RF In

MC13027 FUNCTIONAL DESCRIPTION

The MC13027 contains the mixer, wide band AGC system, local oscillator, IF pre±amplifier and noise blanker for an AM radio receiver. It is designed to be used with the MC13122 to produce a complete AM stereo receiver. The VCO runs at 4 (Fin+FIF) and is divided internally by 4 for the mixer input and local oscillator buffered output. Dividing the VCO reduces the phase noise for AM stereo applications.

The noise blanker input is connected in parallel with the mixer input at Pin 6. The noise blanker circuitry contains a high gain amplifier with its own AGC so it remains linear throughout the mixer's linear range. It can detect noise pulses as low as 120 μV and generates three pulses when the noise threshold is exceeded. The width and timing of the blanking pulses is set by the resistors connected to Pins 15, 17 and 19. The resistor on Pin 15 sets the length of the RF blanking pulse and determines the time the transistor on

Pin 12 is ªonº. The audio blanking pulse delay is set by the resistor on Pin 17 and the width by the resistor on Pin 19. This is necessary because the IF filtering delays and stretches the noise as it arrives at the detector. The transistor on Pin 18 goes ªonº to cause noise blanking in the track and hold circuit in the MC13122 (Pin 15).

Wideband AGC is used in auto receivers to prevent overload ± it drives the base of a cascode transistor RF amplifier and also a pin diode at the antenna (See Figures 6 and 7).

A low gain IF amplifier between Pins 14 and 16 is used as a buffer amplifier between the mixer output filter and IF filter. The input resistance of the IF amplifier is designed to match a ceramic IF filter. The gain of the IF amplifier is determined by the impedance of the load on Pin 16.

MOTOROLA ANALOG IC DEVICE DATA	7

MC13027 MC13122

Figure 5. MC13122 Internal Block Diagram

I Det	L±R Det Q Det	VCC	Loop	Blend	Gnd	Pilot Ind Osc Out Osc In Pilot Det I Pilot I	Pilot Q	Audio
			Filt					Blank

28	27	26	25	24	23	22	21	20	19	18	17	16	15
I	L±R	Q
			VCC	330					VCO
							450 <90°				Pilot I	Pilot Q
									Loop		Det	Det
								8
							450 <0°		Driver	Pilot
											25.6 Hz	24.4 Hz
		Blend						Fast Lock		Level
										Det
											Clamp	Count
C±QUAM		Disable
												Control
Comparator
							32	137/144		4
	cosθ				Signal
					Quality
			L±R		Detector
	L+R
			Fast AGC	AGC	Level
										Matrix
			3.0 V	IF Amp					L	R
			1.0 V
								VGA			VGA
								±0.9			±0.9
1	2	3	4	5	6	7	8	9	10	11	12	13	14

E Det	Det In	3.0 V	AGC	IF In	SS	L Out	L Filt In L Filt Ctr L Mat	R Mat	R Filt	R Filt In R Out
		Reg					Out	Out	Ctr

MC13122 FUNCTIONAL DESCRIPTION

The MC13122 is designed to accept a 450 kHz C±QUAM input signal from approximately 1.0 mV to 1.0 V and produce L and R audio output signals. It has additional features: stop signal, variable bandwidth IF and audio response, stereo indicator driver and track and hold noise blanking.

The IF amplifier on Pin 5 has its own AGC system. It operates by varying the input resistance on Pin 5. With weak signals below approximate 5.0 mV, the input resistance is very high and the amplifier is at maximum gain. For this AGC to be effective, it is necessary to feed the IF input signal from a relatively high impedance. The input resistance variation also reduces the Q of the coil (T1 in the application) so the receiver bandwidth is narrow for weak signals and wide for strong signals. The value of the input resistor (R5) is selected for the desired loading of the IF coil. The impedance of the IF coil on Pin 2 determines the IF gain. Pin 2 is also the input to the C±QUAM decoder.

The IF signal drives the envelope (E), in±phase (I), quadrature (Q) and (L±R) detectors. The E detector is a quasi±synchronous true envelope detector. The others are true synchronous detectors. The E detector output provides the L+R portion of the C±QUAM signal directly to the matrix. The AGC signal of the IF amplifier drives the signal strength output at Pin 6. An external resistor on Pin 6 (sets the gain of the AGC). The Pin 6 voltage is used to control the Q of the audio notch filter, causing the audio bandwidth and depth of the 10 kHz notch to change with signal strength. It is also used as one of the inputs to the signal quality detector which generates the stop±sense and blend signal on Pins 6 and 23 respectively and tells the signal quality detector that the RF input is below the AGC threshold.

VCO

The 3.6 MHz ceramic resonator on Pins 19 and 20 is part of a phase locked loop which locks to the 450 kHz IF signal. The 3.6 MHz is divided by 8 to produce in±phase and quadrature signals for the I, Q and L±R detectors. It is also divided by 32, and 137/144 to provide signals for the pilot I and Q detectors. The pilot detector is a unique circuit which does not need filtering to detect the 25 Hz pilot.

Blend Circuit

The purpose of the blend circuit is to provide an AM stereo radio with the capability of very fast lock times, protection against stereo falsing when there is no pilot present and control of the L±R signal so as to provide as much stereo information as possible, while still sounding good in the presence of noise or interference. The circuit also provides an optional stop±sense usable by a radio with seek and/or scan. The stop±sense signal provides a ªstopº signal only when the radio is locked on station, signal strength is above minimum level, and the level of interference is less than a predetermined amount. The last feature prevents stopping on frequencies where there is is a multiplicity of strong co±channel stations. It is common for AM radios without this capability to stop on many frequencies with unlistenable stations, especially at night.

The blend circuit controls the PLL fast lock, pilot detector, IF amplifier AGC rate, decoder L±R gain, cosθ compensation and stop±sense as a function of the voltage on a signal external blend capacitor. Timing is determined by the rate of change of voltage on the blend cap. Timing is changed by varying charge and discharge current and pulled down by a current source, switch, and optionally an external switch. The current sources and switches are controlled by various measures of signal quality, signal strength, and presence or absence of pilot tone.

8	MOTOROLA ANALOG IC DEVICE DATA

MC13027 MC13122

Detectors

In AM stereo operation, the Q detector delivers pilot signal via an external low±pass filter to the pilot detector input (Pin 18). The E and I detectors drive the C±QUAM comparator. The L±R signal and the output of the envelope detector are combined in the matrix to produce the L and R signals. The C±QUAM system modifies the in±phase and quadrature components of the transmitted signal by the cosine of the phase angle of the resultant carrier, for proper stereo decoding. An uncompensated L±R would be distorted, primarily by second harmonics. Where there is noise or interference in the L±R, it has been subjectively determined that reducing the cosθ compensation at the expense of increased distortion sounds better than full decoding. The blend line operates over a small voltage range to eliminate cosine compensation.

Signal Quality Detector ± Blend Voltage Control

The signal quality detector output is dependent on signal strength, over±modulation, and whether or not the blend pin has been pulled low prior to searching. Over±modulation usually occurs when a radio is tuned one channel away from a desired strong signal, so this prevents stopping one channel away from a strong signal.

In a radio tuned to a strong, interference free C±QUAM station, the blend voltage will be approximately 3.6 V. In the presence of noise or interference, when the modulation envelope is at a minimum, it is possible for the I detector to produce a negative, or below zero carrier signal. The Signal Quality Detector produces an output each time the negative I exceeds 4%. The output of the detector sets a latch. The output of the latch turns on current source which pulls down the voltage of the blend cap at a predetermined rate. The latch is then reset by a low frequency signal from the pilot detector logic. This produces about a 200 mV change each time 4% negative I is detected. Tables 1 and 2 describe the blend behavior under various conditions.

When the blend voltage reaches 2.2 V a blend control circuit starts to reduce the amplitude of the L±R signal fed to the decoder matrix. By 1.5 V the L±R has been reduced by about 40 dB. At lower voltages it is entirely off and the decoder output is monaural. This reduction of L±R signal, or blend as it is commonly called when done in FM stereo radios, reduces undesirable interference effects as a function of the amount of interference present.

Stop±Sense

Stop±sense is enabled when the blend voltage is externally pulled below 0.45 V. An input from the AGC indicating minimum signal, or detection of 10% negative I will cause the stop±sense pin to be pulled low. With signals greater than the AGC corner and less than 10% interference the stop±sense will be a minimum of 1.0 V below the 3.0 V line. Very rapid scanning is possible because the radio can scan to the next frequency as soon as the stop±sense goes low. The maximum wait time, set by the radio, is only reached on good stations.

The decoder will not lock on an adjacent channel because it is out of the lock range of the PLL. The beat note produced in the I detector by the out of lock condition will trigger the 10% negative I detector.

Sequence For Seek Scan

•Change Station ± Pull±Down Blend

•Wait Approximately 50 ms for Synthesizer and Decoder PLL to Lock

•Observe Pin 6 Voltage

•If it is Above 2.0 V and Stays Above 2.0 V for Approximately 800 ms, Stay on the Station

•No IF Count Now Needed

•No AGC Level Detector Needed

Table 1. Normal Sequence When Changing Stations

External Pull±Down of	± Increased Current Supplied to
Blend Capacitor to Under		Loop Driver for Fast Lock
0.47 V	± Fast AGC Activated
	± Extra Current Pull±Up Activated
		on Blend Capacitor
	±	Pilot Detector Disabled
	± Loop Locks
	± Stop±Sense Activated
Blend Released	± Blend Capacitor Pulled Up to
		0.7 V ± Stops
	± Fast Lock Current Removed
	± Fast AGC Turned Off
	± Pilot Detector Enabled
Pilot Detected	±	Stereo Indicator Pin Pulled Low
	±	Blend Voltage Pulled Positive
		Rapidly
Blend Voltage Reaches	± Audio Starts Into Stereo
1.4 V	± 10% Negative I Detector
		Enabled
Blend Voltage Reaches	± Stereo Separator Reaches 20
2.2 V		to 25 dB
	± Rapid Current Pull±Up Turned
		Off
	± 4% Negative I Detector Enabled
Blend Voltage Reaches	± cosθ Enabled ± Full C±QUAM
3.0 V		Decoding
	± Blend Voltage Continues to Rise
		to 3.6 V and Stops

Table 2. Operation In Adverse Conditions

4% Negative I Detected	± Blend Pulls Down
	Approximately 200 mV for Each
	Event ± Acts Like One±Shot
	± Stops at 2.2 V ± cosθ Has Been
	Defeated, Almost Full Stereo
	Remains
10% Negative I Detected	± Blend Pulls Down 200 mV for
	Each Event
	± Stops at 1.4 V ± Stereo Has
	Blended to Mono
	± Resets Fast Pull±Up if Blend
	Has Not Been Above 2.2 V
50% Negative I Detected	± Blend Pulls Down Fast During
(Out of Lock)	Event
	± Stops at 0.47 V
	± Resets Fast Pull±Up
	± Pilot Indicator Turned Off
Minimum Signal Level	± Resets Fast Pull±Up
Detected	± Pulls Down to 0.7 V

MOTOROLA ANALOG IC DEVICE DATA	9