U6239B

TELEFUNKEN Semiconductors

Rev. A3, 28-May-97

3 (15)

Functional Description

3-wire bus depending on the received data format. In

SDA, SCL and address select inputs or in 3-wire bus

mode as date, clock and enable inputs, respectively. The

data include the scaling factor SF and port output

functions available (ADC, bidirectional ports, etc.)

Oscillator frequency calculation :

SPF

Locked frequency of voltage controlled oscillator

SPF : Scaling factor of programmable divider (15 bit in

SRF : Scaling factor of reference divider

(

B25/B50/B140/B250/B256/B512/B1024

B25/B50/B100/B140/B250

B280/B500 in 3-wire bus mode)

3.2/ 4 MHz crystal or external reference

frequency (max. 8 MHz)

The input amplifier together with a divide-by-16

prescaler provides excellent sensitivity (see “Typical

prescaler input sensitivity”). The input impedance is

shown in the diagram “Typical input impedance”. When

a new divider ratio is entered according to the requested

control voltage of the VCO together with the tuning

amplifier until the output signals of the programmable

divider and the reference divider are in frequency locked

and phase locked. The reference frequency may be pro-

vided by an external source, capacitively coupled into

Pin 2, or by using an on-board crystal with an 18 pF ca-

pacitor in series. The crystal operates in the series

resonance mode. The reference divider division ratio

is selectable to

B25/ B50/ B140/ B250/ B256/ B512/

B140/ B250/ B280/ B500 in the 3-wire bus mode.

bits, in 3-wire bus mode via two bits and a voltage at the

reference divider select input Pin 3. In addition, there are

port outputs available for band switching and other

purposes.

Application

A typical application is shown on page 14. All input/

output interface circuits are shown on the pages 12 and

13. Some special features which are related to test- and

alignment procedures for tuner production are explained

together with the bus mode descriptions.

Absolute Maximum Ratings

All voltages are referred to GND (Pin 15)

Parameters

Symbol

Conditions

Min.

Max.

Unit

Supply voltage

Pin 12

Vs

–0.3

6

V

RF input voltage

Pins 13, 14

RFi

–0.3

Vs + 0.3

V

Port output current

Pins 6-11

P0, P3-7

Open collector

–1

15

mA

Total port output current

Pins 6-11

P0, P3-7

Open collector

–1

50

mA

Port input/ output voltage

Pins 6-10

P3-7

In off state

–0.3

14

V

Port output voltage

Pins 6-11

P0, P3-7

In on state

–0.3

6

V

Bus input/ output voltage

Pins 4 and 5

VSDA,

VSCL

–0.3

6

V

SDA output current

Pin 4

ISDA

Open collector

–1

5

mA

Address select/ Enable input

Pin 10

Port output voltage

AS/

ENABLE/

P3

Port in off

state

–0.3

14

V

Charge pump output voltage

Pin 1

PD

–0.3

Vs + 0.3

V

Active filter output voltage

Pin 16

VD

–0.3

Vs + 0.3

V

Crystal oscillator voltage

Pin 2

Q1

–0.3

Vs + 0.3

V

Reference divider select input/

Pin 3

Address mode select input

RDS/

AMS

–0.3

V

Junction temperature

–40

125

°C

Storage temperature

–40

125

°C