AN7243

AN7243S PANASONIC

Document overview

• Manufacturer or author: Provided By digicamel.com
• PDF pages: 7

Technical content

The AN7243S is an FM front-end IC designed for DTS except RF amp. of car radio. It is built-in local oscillation frequency buffer output and PIN diode (ADX) driver for antenna damping. n Features

• High sensitivity · High S/N ratio
• Good IM characteristics at strong input
• Timing for AGC input level is variable.
• Built-in pre-IF-Amp. having negative (positive) temper- ature characteristics to RF amp. AN7243S FM Front-end Circuit for Car Radio Unit : mm 1.240.4–0.25 1.27 0.1–0.1 0.3 1.5–0.2 0.65 0.15 6.5–0.3 4.2–0.3 10.1–0.3 14-Lead SOP Package (SOP014-P-0225) 14 13 12 11 10 9 8 1 2 3 4 5 6 7 ADX Driver Mix. GND Buffer BufferOSC AGC & Det. V CC IF-Amp. n Block Diagram

ICs for FM/AM T unerAN7243S n Absolute M axim um R atings (Ta=25˚C ) V C C IC C PD Topr Tstg Supply V oltage Supply C urrent Pow er D issipation O perating A m bient Tem perature Storage Tem perature V m A m W Param eter Sym bol R ating U nit 9.6 380 –40 ~ + 80 –55 ~ + 125 n R ecom m ended O perating R ange (Ta=25˚C ) Param eter Sym bol R ange O perating Supply V oltage R ange V C C 6.5V ~ 9.6V V in =17dB µ no conversion H ow ever, S= output at 400H z 30% conversion fO SC =108.7M H z M easured by Pin4, N o signal N o m odulation, V in = 53dB µ Input level at V A G C = 3V V in = 72dB µ V in = 58dB µ A t S1O N , difference betw een input level at V A G C = 3V and A G C m axim um sensitivity V in = 72dB µ V in = 63dB µ Param eter Sym bol C ondition m in. typ. m ax. U nit n Electrical C haracteristics (V C C = 8V , fin = 98M H z, 400H z 30% M odulation, S1 : O pen, Ta= 25˚C ) S/N R atio Local O scillation O utput Level IF O utput Level A G C M axim um Sensitivity A G C Level (L) A G C Level (H ) A G C Sensitivity V ariable R ange A D X D rive C urrent A D X Leak C urrent N O U T V O SC V O U T SA G C V A G C (L) V A G C (H ) IX (m ax.) IX (leak) 160 250 0.02 6.6 330 0.5 dB m V m V dB µ V V dB m A µA Itot – VC C V C C (V ) Itot (m A ) 60 2 4 12108 IF – Am p. Input/O utput C haracteristics 120 100 IF IN (M H z) IF O U T (dB µ) 40 60 80 100 120 AG C Start Point Variable Axis A N 7243SIF IN IF O U T0.01µF 0.01µF 330Ω V in (dB µ) IA G C (V ) 0 10 60 70 80 90 100 110 6.6V A G C A dj. R = 0 A G C A dj. R = ∞ n Characteristics Curve

ICs for FM/AM T uner AN7243S AG C Freq. C haracteristics 120 110 100 Input Frequency fin (M H z) A G C Start Point (dB µ) 88 92 96 100 104 108 IAD X – VAD X I A D X (m A ) V A D X (V ) 0 5 10 15 20 25 30 35 AG C Adj. R – AG C O N Level A G C A dj R (Ω ) A G C O N LEV EL (dB µ) 0 10 100 1000 ∞ VAG C (H ) Supply Voltage C haracteristics V C C (V ) V A G C (H ) (V ) 4 6 8 10 12 14 IF Am p. Saturation Level 400 300 200 100 V C C (V ) Saturation Level (m V rm s) 42 6 8 10 12 14 V C C =8V Total G ain =0dB at Ta =25˚C Total G ain Tem perature C haracteristics T (˚C ) D Total G (dB ) –40–60 –20 0 20 40 60 80 100 M ixer + IF Am p. AG C O N Level Tem perature C haracteristics 100 T (˚C ) V in (dB µ) –40–60 –20 0 20 40 60 80 100 A G C O N LEV EL R A dj = ∞ A G C O N LEV EL R A dj = 0Ω AG C O N Level VC C D ependence V C C (V ) V in (dB µ) 2 4 6 8 10 12 14 16 A G C O N LEV EL R A dj = ∞ A G C O N LEV EL R A dj = 0Ω O SC O U T – fO SC 130 120 110 100 fO SC (M H z) O SC O U T (dB µ) 50 60 70 80 90 100 110 120 130 V C C =8V Input 115dB µV from SG to Pin2 Pin3 O PEN C =3pF C =10pF A N 7243S SG C 0.01µF O SC O U T A N 7243S 50Ω +75Ω 103 A G C A dj. R fO SC =108.7M H z

ICs for FM/AM T unerAN7243S O SC Buff O U T VC C D ependence 120 110 100 V C C (V ) V in (dB µ) 2 4 6 8 10 12 14 16 Input/O utput C haracteristics Exam ple –10 –20 –30 –40 –50 –60 –70 V in (dB µ) V o (dB µ) –10 100806040200 V C C = 8V fin= 98M H z fm = 1kH z, 30% M od. 400H z H PF 30kH z LPF O N IF : A N 7257S Lim iting Sensitivity, U sable Sensitivity VC C D ependence V C C (V ) V in (dB µ) 2 4 6 8 10 12 14 16 IF : A N 7257S U sable Sensitivity Lim iting Sensitivity 110 100 SU D 1 (dB µ) fin (M H z) V in (dB µ) 88 92 96 100 104 108 SD = 45dB µ SD = 35dB µ IM C haracteristics (1) Lim iting Sensitivity, U sable Sensitivity, Tem perature C haracteristics T (˚C ) V in (dB µ) –60 –40 –20 0 20 40 60 80 100 IM C haracteristics (2) SU D 1, SU D 2 (dB µ) 0 60 70 80 90 100 110 120 130 130 120 110 100 SD (dB µ) fD =98M H z, C W fU D 1=98M H z–ΔfU D 1kH z, 30% M od. fU D 2=98M H z–2ΔfU D , C W 400H zH PF, 30kH z LPF O N IFT– C F M atching R Set SU D 1 and SU D 2 up w ith the sam e level, M easure SD level (R eferred to M ix. In) w hich can obtain S/N (30dB ). 470Ω 330Ω To C FTo IFT Sp M ixer SU D 1 SU D 2 A N 7243S 1F : 7256S To 1F 50Ω → 75Ω ΔfU D = + 400H z, + 800H z ΔfU D = – 400H z, + 800H z 0.01µF 50Ω fD = 98M H z, C W fU D 1= 98M H z + ΔfU D 1kH z, 30% M od. fU D 2= 98M H z + 2ΔfU D , C W 100dB µ M easure SU D 1 level (R eferred to M ix. In) w hich can obtain S/N = 30dB IF is A N 7257S Sp M ixer SU D 1 SU D 2 A N 7243S 0.01µF ΔfU D (M H z) –5 –4 –3 –2 –1 0 1 2 3 4 5 Lim iting Sensitivity U sable Sensitivity U sable Sensitivity Lim iting Sensitivity (0.2061V ) O SC B uff O U T Lim iting Sensitivity, U sable Sensitivity, Frequency C haracteristics

ICs for FM/AM T uner AN7243S A N 7243S IF O U T A G C A dj. 1µF O SC O U T 0.01µF 39pF 39pF 5pF 20kΩ V C 3 V C 2 100kΩ 1000pF 510Ω 2kΩ 470pF22Ω 2.2µF 3SK 181 470pF 100kΩ 47kΩ 100kΩ 470pF 47kΩ 18pF V C 1 680Ω 18pF 1000pF 100pF Pin D iode A N T. 4pF IFT 470Ω330Ω 0.01µF V C C (8V ) 100kΩ V V C N ote) V C 1 ~ V C 3 TO K O K V 1340A –3 A bove application circuit and circuit constant indicate only an exam ple. It is not assure the design as m ass production set. IFT : 7E7137A (M A TSU SH ITA ) n Application Circuit

ICs for FM/AM T unerAN7243S n Pin D escriptions Equivalent C ircuitD escriptionPin N o. Pin N am e

1 O scillation Em itter O scillation transistor's em itter pin

Typ. W aveform

2 O scillation B ase O scillation transistor's base pin

3 V C C M ain circuit V C C

4 O SC O utput

5 A G C O utput

6 A G C -A m p. G ain A djustm ent 7 IF A m p. O utput IF signal (10.7M H z) output pin Zout ≅ 330Ω 8 IF A m p. B y-pass IF am p. by-pass control 9 IF A m p. Input IF signal (10.7M H z) input pin C onvert R F signal to IF signal and output. O utput oscillation signal to m icrocom puter through buffer. O utput A G C signal according to M ix. output dim ensions. A djust A G C -A m p. gain by external resistance. (R efer to P.275 A G C circuit.) M ix. O utput V C C 330Ω ≅70µA 10 11 108.7M H z 108.7M H z D C 108.7M H z 6.6V D C 0.8V D C 3.2V 10.7M H z 10.7M H z 10.7M H z 10.7M H z ≅ 0V N ote) Typical w aveform frequency is the value w hen tuning receiving frequency to 98.0M H z.

ICs for FM/AM T uner AN7243S n Pin D escriptions (C ont.) Equivalent C ircuitD escriptionPin N o. Pin N am e Typ. W aveform 13 M ix.O utput Input signal from R F A m p.

12 PIN D iode

D rive PIN diode for input attenuate of R F-A m p. D eterm ine drive current by Pin12 external resistance.

14 G N D M ain circuit G N D

7.2V .0V R F V C C 2.2kΩ 2.2kΩ N ote) Typical w aveform frequency is the value w hen tuning receiving frequency 98.0 M H z. n Supplem entary Explanation

• AG C A G C used at the A N 7243S uses m ixer output (IFT prim ary side) signal and controls A G C output. R F A m p. M ixer A G C A m p. A G C D et. IFT IF – A m p. R A dj. (SA G C variable) V5, V12 –VIN (R F) V C C = 8V V IN (R F) (dB µ) A G C V oltage (V ) SA G C V ariable V 5 V 12