HIT HA12181FP Datasheet

HA12181FP

AM Radio Noise Reduction System

ADE-207-171A (Z)

2nd. Edition June 1997

Functions

•Buffer amp. for audio

•Linear approximate circuit for noise reduction

•IF Amp., detector, audio amp. and AGC circuit for noise detection

•Gate pulse generator

Features

•High noise cancelling capacity: 46 dB typ.

•Less gain loss: GV = –0.5 dB typ.

•Low total harmonic destortion and high signal-to noise ratio: THD = 0.06% typ., S/N = 75 dB typ.

•Operation supply voltage range: 7.0 V to 10 V (8.2 V typ.)

•Less external parts count

page1997,RevJun2,..

R500

+ C502

C503

C504

R505

DiagramBlock

HA12181FP

100 k

0.01

0.22

47 k

R502

IF AGC

1 3.3

14

Det.

15

AF AGC

22 k

12

of 2

IF

OR

Pulse

21

AGC

Det.(1)

IF Input

Gate pulse

IF

AF

AF

Noise

2nd IFT

C501

16

Amp. LPF

Det.

HPF1

LPF

Amp.

AGC

AGC

Pulse

Gen.

Det.(2)

ANT

1st IFT

1000 p

Stabi.

Pulse

HPF

VCC

4

(1)

Volt.

Det.

R506

(2)

13

(8.2 V)

+

Gate pulse (1)

12 k

7

Gate pulse (2)

AF Input

C506

SW2

Hight-pass Amp.

SW4

RF

MIX

IF

Det.

+

3

Phase

Buffer

100

(waveform

C513

SW1

Circuit

compensation)

Amp.

OSC

1

Level Diff.

Stabilized

SW3

SW5

AM-IC

Stabilized

Det.

Current Circuit

Voltage

Circuit

(waveform

Circuit

compensation)

2

5

6

8

10

9

AF Output

11

Gate Time

C500

Capacitor

Capacitor

Capacitor

C509

Constant

for Pahse

for Hold

for By-pass

0.033

+

R503

C507

0.033

C512

C511

C510

C508

180 k

R504

2200 p

0.068

0.033

0.033

Capacitor

1

4.7 k

for waveform

compensation

Unit

R : Ω

C : F

HA12181FP

Table of Pin Description and External Parts

							Influence of External
					External parts		parts
							Larger	Smaller
			DC				than	than
No.			voltage			recom-	recom-	recom-
of			(V) (No			mended	mended	mended
pin	Name	Function input)		Equivalent circuit	No.	value	value	value
1	IF AGC Time		2.7		R500	100 K	Longer	Longer
		constant			C502	3.3 µ	time to	distortion
		for IF					stabilize	of recover.
		AGC.					AGC.
					C502
				1	3.3
					+
				R500
				100k
2	Bias1	Bypass	3.2		C500	0.033 µ	—	Increased
		for		2				noise.
		voltage
		Stabi.		C500
				0.033
3	AF	Input of	3.3		C513	1 µ	—	—
	input	AF.		20k
				3
				+
				C513
				AF IN
4	Bias2	Decide	1.3		R506	12 K	Cut off	Cut off
		the		4			frequency	frequency
		current of					of L·P·F	of L·P·F
		filter					and H·P·Fand H·P·F
		network.					shifted	shifted
							lower.	higher.
5	Phase	Phase	3.3		C512	0.068 µ	Must be used on the
		circuit					recommended value.
				5
				C512
				0.068

Rev.2, Jun. 1997, page 3 of 21

HA12181FP

Table of Pin Description and External Parts (cont)

Influence of External

External parts

parts

Larger

Smaller

DC

than

than

No.

voltage

recom-

recom-

recom-

of

(V) (No

mended

mended

mended

pin

Name

Function input)

Equivalent circuit

No.

value

value

value

6

Hold

Hold of

3.3

C511

0.033 µ

Must be used on the

level

recommended value.

differ-

ence.

6

C511

0.033

7

GND

GND

—

—

—

—

—

8

High-

High-

3.3

C510

0.033 µ

Must be used on the

Pass.

Pass

recommended value.

AMP.

(Wave-

form

Compen-

8

sation)

C510

0.033

9

AF out

Output of

3.3

C508

1 µ

Output DC cut

AF

R504

4.7 K

Output load

	9
	+
	C508	R504
	1	4.7k
10 Wave	Wave- 3.3	C509	0.033 µ Must be used on the
form	form		recommended value.
	Compen-
	sation
	10
		C509
		0.033

Rev.2, Jun. 1997, page 4 of 21

HA12181FP

Table of Pin Description and External Parts (cont)

Influence of External

External parts

parts

Larger

Smaller

DC

than

than

No.

voltage

recom-

recom-

recom-

of

(V) (No

mended

mended

mended

pin

Name

Function input)

Equivalent circuit

No.

value

value

value

11

Gate

Gate

R503

180 K

Gate

Gate

pulse

4.5V

C507

2200 P

pulse

pulse

genera-

width

width

tion

0

become

become

wider.

narrow.

11

C507

R503

2200p

180k

12

Vth

Determi-

1.1

R502

22 K

Higher

Lower

nation of

noise

noise

noise

12

detection

detection

detection

sensitivity. sensitivity.

sensitivit

R502

y

22k

13

VCC

VCC

8.2

—

—

—

—

—

14

IF Det. IF AGC

3.3

C503

0.01 µ

—

—

detector

14

13

C503

0.01

15

AF

Time

0

R505

47 K

Longer

Miss-

AGC

constant

C504

0.22 µ

time to

operaton

for AF

stabilize

in noise

AGC

15

AGC.

detector.

C504

R505

0.22

47k

Rev.2, Jun. 1997, page 5 of 21

HA12181FP

Table of Pin Description and External Parts (cont)

Influence of External

External parts

parts

Larger

Smaller

DC

than

than

No.

voltage

recom-

recom-

recom-

of

(V) (No

mended

mended

mended

pin

Name

Function input) Equivalent circuit

No.

value

value

value

16

IF in

IF input 1.3

IF Input

Coupling

—

Instability

30k

16

C501

1000p

IF IN

Absolute Maximum Ratings (Ta = 25°C)

Item	Symbol	Rating	Unit
Supply voltage	VCC	16	V
Power dissipation	Pd	400*1	mW
Operating temperature	Topr	–40 to +85	°C
Storage temperature	Tstg	–55 to +125	°C
Note: 1. Value at Ta = 85°C

Rev.2, Jun. 1997, page 6 of 21

HA12181FP

Electrical Characteristics (Tentative) (VCC = 8.2 V, Ta = 25°C, Pin 3 input: Vin = 100 mVrms, f = 1 KHz, Pin 16 input: Vin = 74 dBµ, fc = 450 KHz, fm = 1 KHz, m = 30%)

Item	Symbol	Min	Typ	Max	Unit			Test conditions
Supply current	ICC	—	11.0	—	mA	No input signal, IC only
Output voltage	Vout	70	95	120	mVrms			Pin 3 input only
Total harmonic distortion	THD1	—	0.06	0.3	%
Signal-to-noise ratio	S/N (1)	60	75	—	dB		Pin 3 input Vin = 100 mVrms
								(Reference), Rg = 10 KΩ
Strong input total harmonic	THD2	—	1.0	2.5	%		Pin 3 input Vin = 500 mVrms
distortion
Recovered output voltage	VO (AF)	50	78	120	mVrms			Pin 16 input only
Recovered output signal-to-	S/N (2)	35	45	—	dB
noise-ratio
Noise suppression ratio	NSR	35	46	—	dB		Input the waveform below.
								Pin 3 input Vin = 100 mVrms
								(Reference) no input sine wave

100mV

10 s

Pin 16 Input

2ms

Figure 1 Input Waveform at Measurement of Noise Suppression Ratio

Rev.2, Jun. 1997, page 7 of 21