Application Circuit

TLH7509 – 4

FIGURE 3

Component

Typical Value

Comments

C1

001 mF

AC coupling for wide band AGC input

C2

001 mF

Buffer and AGC supply decoupling

C3 C4

001 mF

IF decoupling capacitors

C5

10 mF

Meter decoupling capacitor

C6

001 mF

AC coupling for IF output

C7

50 mF

Regulator decoupling capacitor affects SN floor

C8

22 mF

Level mutestop time constant

C9

5 mF

AFT decoupling affects stop time

C10

01 mF

Disables noise mutestop

C11

001 mF

AC coupling for noise mutestop threshold adjust

C12

25 mF

Supply decoupling

C13

001 mF

AGC output decoupling capacitor

R1

Tuner Dependent

Wide band AGC threshold adjust

R2 R3

Tuner Dependent

R4

Meter Dependent

Sets full-scale on meter

R5

5k1

Deviation mutestop window adjustment

R6

25k

Mutestop filter affects stop time

R7

5k

Level mutestop threshold adjustment

R8

10k Pot

Level mutestop threshold adjustment

R9

12k

Noise mutestop threshold adjustment decrease resistor for lower

SN at threshold for optimum performance over temp and gain varia-

tion set this resistor value so that the signal level mutestop threshold

R10

10k

Load for open-collector stop output

R11

50k

AGC output load resistor for open-collector output

R12

3k9

Sets Q of quadrature coil affecting THD SN and recovered audio

R13

62X

Optimises minimum THD

L1

107 MHz

Sets signal swing across quadrature coil High Q is important to mini-

TDK Electronics

mize effect variation of Q has on both minimum THD and AFT offset

TPO410-180K or equivalent

T1

107 MHz L to

resonate w82 pF

107 MHz

TOKO KAC-K2318HM or

equivalent

CF1 CF2

107 MHz ceramic resonators provide selectivity good group delay

Murata SFE107ML or equivalent

characteristics important for low THD of system

TLH7509 – 5

5