TDA9109 datasheet(16/30 Pages) STMICROELECTRONICS

16 / 30 page

OPERATING DESCRIPTION

I - GENERAL CONSIDERATIONS

I.1 - Power Supply

The typical values of the power supply voltages

VCC and VDD are 12V and 5V respectively. Opti-

mum operation is obtained for VCC between 10.8

and 13.2V and VDD between 4.5 and 5.5V.

In order to avoid erratic operation of the circuit during

the transient phase of VCC and VDD switching on, or

off, the value of VCC and VDD are monitored : if VCC

is less than 7.5V typ. or if VDD is less than 4.0V typ.,

the outputs of the circuit are inhibited.

Similarly, before VDD reaches 4V, all the I

2C register

are reset to their default value.

In order to have very good power supply rejection,

the circuit is internally supplied by several voltage

references (typ. value : 8V). Two of these voltage

references are externally accessible, one for the

vertical and one for the horizontal part. They can be

used to bias external circuitry (if ILOAD is less than

5mA). It is necessary to filter the voltage references

by external capacitors connected to ground, in order

to minimize the noise and consequently the "jitter"

on vertical and horizontal output signals.

I.2 - I

2C Control

TDA9109/S belongs to the I

2C controlled device

family. Instead of being controlled by DC voltages

on dedicated control pins, each adjustment can be

done via the I

2C Interface.

The I

2C bus is a serial bus with a clock and a data

input. The general function and the bus protocol are

specified in the Philips-bus data sheets.

The interface (Data and Clock) is a comparator with

hysteresis ; the thresholds (less then 2.2V on rising

edge, more than 0.8V on falling edge with 5V

supply) are TTL-compatible. Spikes of up to 50ns

are filtered by an integrator and the maximum clock

speed is limited to 400kHz.

The data line (SDA) can be used bidirectionally.

In read-mode the IC sends reply information

(1 byte) to the micro-processor.

The bus protocol prescribes a full-byte transmis-

sion in all cases. The first byte after the start

condition is used to transmit the IC-address

(hexa 8C for write, 8D for read).

I.3 - Write Mode

In write mode the second byte sent contains the

subaddress of the selected function to adjust (or

controls to affect) and the third byte the correspond-

ing data byte. It is possible to send more than one

data byte to the IC. If after the third byte no stop or

start condition is detected, the circuit increments

automatically by one the momentary subaddress in

the subaddress counter (auto-increment mode).

So it is possible to transmit immediately the follow-

ing data bytes without sending the IC address or

subaddress. This can be useful to reinitialize all the

controls very quickly (flash manner). This proce-

dure can be finished by a stop condition.

The circuit has 16 adjustment capabilities : 3 for the

horizontal part, 4 for the vertical, 2 for the E/W

correction, 2 for the dynamic horizontal phase con-

trol,1 for the Moiré option, 3 for the horizontal and

the vertical dynamic focus and 1 for the B+ refer-

ence adjustment.

17 bits are also dedicated to several controls

(ON/OFF, Horizontal Forced Frequency, Sync Pri-

ority, Detection Refresh and XRAY reset).

I.4 - Read Mode

During the read mode the second byte transmits

the reply information.

The reply byte contains the horizontal and vertical

lock/unlock status, the XRAY activation status and,

the horizontal and vertical polarity detection. It also

contains the sync detection status which is used by

the MCU to assign the sync priority.

A stop condition always stops all the activities of the

bus decoder and switches to high impedance both

the data and clock line (SDA and SCL).

See I

2C subaddress and control tables.

I.5 - Sync Processor

The internal sync processor allows the TDA9109/S

to accept :

- separated horizontal & vertical TTL-compatible

sync signal,

- composite horizontal & vertical TTL-compatible

sync signal.

TDA9109/S

16/30

TDA9109 датащи(PDF) 16 Page - STMicroelectronics

TDA9109 датащи(HTML) 16 Page - STMicroelectronics

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

датащи скачать

ссылки URL