TDA6502 datasheet(30/44 Pages) PHILIPS

30 / 44 page

2000 Mar 16

Philips Semiconductors

Preliminary speciﬁcation

5 V mixers/oscillators and synthesizers for

cable TV and VCR 2-band tuners

TDA6502; TDA6502A;

TDA6503; TDA6503A

Table 19 Transistors

13.3

Tuning ampliﬁer

The tuning amplifier is capable of driving the varicap

voltage without an external transistor. The tuning voltage

output must be connected to an external load of 27 k

Ω

which is connected to the tuning voltage supply rail.

The loop filter design depends on the oscillator

characteristics and the selected reference frequency.

13.4

Crystal oscillator

The crystal oscillator uses a 4 MHz crystal connected in

series with an 18 pF capacitor thereby operating in the

series resonance mode. Connecting the crystal to the

ground is preferred, but it can also be connected to the

supply voltage.

13.5

Examples of I2C-bus data format sequences for

TDA6502 and TDA6503

Tables 20 to 24 show the various write sequences where:

S = START bit

A = acknowledge bit

P = STOP bit.

Conditions:

fxtal = 4 MHz

N = 1600

fosc = 100 MHz

fstep = 62.5 kHz

Port register VHFL is ‘on’ to switch-on band VHF low

Port register FMST is ‘on’ to switch-on an FM sound trap

ICP = 280 µA.

COMPONENT

VALUE

TR1

BC847B

TR2

BC847B

13.5.1

WRITE SEQUENCES TO REGISTER C2

Table 20 Complete sequence with ﬁrst the divider bytes (ﬁrst data bit = 0)

Table 21 Complete sequence with ﬁrst the control and band-switch bytes (ﬁrst data bit = 1)

Table 22 Sequence with divider bytes only (ﬁrst data bit = 0)

Table 23 Sequence with control and band-switch bytes only (ﬁrst data bit = 1)

Table 24 Sequence with control byte only (ﬁrst data bit = 1)

START

ADDRESS

BYTE

ACK

DIVIDER

BYTE 1

ACK

DIVIDER

BYTE 2

ACK

CONTROL

BYTE

ACK

BAND-

SWITCH

BYTE

ACK

STOP

START

ADDRESS

BYTE

ACK

CONTROL

BYTE

ACK

BAND-

SWITCH

BYTE

ACK

DIVIDER

BYTE 1

ACK

DIVIDER

BYTE 2

ACK

STOP

06A40A

START

ADDRESS BYTE

ACK

DIVIDER BYTE 1

ACK

DIVIDER BYTE 2

ACK

STOP

06A40A

START

ADDRESS BYTE

ACK

CONTROL BYTE

ACK

BAND-SWITCH BYTE

ACK

STOP

A09A

START

ADDRESS BYTE

ACK

CONTROL BYTE

ACK

STOP

SC2

TDA6502 Datasheet(PDF) 30 Page - NXP Semiconductors

TDA6502 Datasheet(HTML) 30 Page - NXP Semiconductors

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44

Datasheet Download

Link URL