1996 Mar 11

21

Philips Semiconductors

Preliminary specification

TDA8745

AC CHARACTERISTICS

All voltages referenced to ground (pins 6, 10, 14 and 32); in accordance with the block diagram (see Fig.1);

SFE 10.7MJA (narrow), SFE 10.52MJA (narrow) and SFE 10.7MS3 (wide) ceramic filters; unless otherwise specified.

SYMBOL

PARAMETER

CONDITIONS

MIN.

TYP.

MAX.

UNIT

Band-pass filter, mixer and buffer

input resistance

10

12.5

15

k

Ω

baseband input voltage (RMS value)

note 1

−−

200

mV

1 dB compression point (RMS value)

−

180

−

mV

filter transfer at 200 kHz

with respect to 7.3 MHz

−−−60

dB

filter transfer at 2 MHz

with respect to 7.3 MHz

−−28

−20

dB

filter transfer at 5.3 MHz

with respect to 7.3 MHz

−2

+2+4dB

filter transfer at 7.3 MHz and

mixer amplification

15

17

19

dB

filter transfer at 7.3 MHz and

mixer conversion gain

note 3

10

12

14

dB

mixer output current (peak)

5

7

−

mA

mixer output resistance

f = 10.7 MHz; note 4

−

12

30

Ω

Charge pump, buffer amplifier and VCO

t

repetition time of charge pump pulses

−

50

−µs

VCO sensitivity

note 5

−−9

−

MHz/V

VCO frequency

−

35.4

−

MHz

Crystal oscillator (4 MHz)

crystal oscillator frequency

−

4

−

MHz

resonance resistance of crystal

−−

60

Ω

parallel capacitance of crystal

−

4.5

10

pF

input current from external 4 MHz

source (peak)

note 6

50

−−µA

IF inputs (pins 9, 11, 13, 15, 7 and 8) and limiters

input sensitivity (RMS value)

S/N(A) = 40 dB;

de-emphasis = 75

µs

−

0.3

1

mV

S/N(A) = 40 dB;

∆f

de-emphasis = 50

µs

−

0.8

2

mV

input signal

THD

≤ 0.5%

−−

200

mV