Philips TDA4857PS Datasheet

INTEGRATED CIRCUITS

DATA SH EET

TDA4857PS

C-bus autosync deflection

controller for PC monitors

Product speciﬁcation File under Integrated Circuits, IC02

2000 Jan 31

Philips Semiconductors Product speciﬁcation

I2C-bus autosync deﬂection controller for PC monitors

FEATURES Concept features

• Full horizontal plus vertical autosync capability

• Extended horizontal frequency range from

15 to 130 kHz

• Comprehensive set of I2C-bus driven geometry adjustments and functions, including standby mode

• Very good vertical linearity

• Moire cancellation

• Start-up and switch-off sequence for safe operation of

all power components

• X-ray protection

• Flexible switched mode B+ supply function block for

feedback and feed forward converter

• Internally stabilized voltage reference

• Drive signal for focus amplifier with vertical parabola

waveforms

• DC controllable inputs for Extremely High Tension (EHT) compensation

• SDIP32 package.

Synchronization

• Output for I2C-bus controllable vertical sawtooth and

• Vertical picture size independent of frequency

• Differential current outputs for DC coupling to vertical

• 50 to 160 Hz vertical autosync range.

East-West (EW) section

• I2C-bus controllable output for horizontal pincushion,

• Optional tracking of EW drive waveform with line

Focus section

• I2C-bus controllable output for vertical parabola

• Verticalparabolaisindependentoffrequencyandtracks

TDA4857PS

parabola (for pin unbalance and parallelogram)

booster

horizontal size, corner and trapezium correction

frequency selectable by I2C-bus.

with vertical adjustments.

• Can handle all sync signals (horizontal, vertical, composite and sync-on-video)

• Output for video clamping (leading/trailing edge selectable by I2C-bus), vertical blanking and protection blanking

• Output for fast unlock status of horizontal synchronization and blanking on grid 1 of picture tube.

Horizontal section

• I2C-bus controllable wide range linear picture position, pin unbalance and parallelogram correction via horizontal phase

• Frequency-lockedloopforsmoothcatchingofhorizontal frequency

• Simple frequency preset of f resistors

• Low jitter

• Soft start for horizontal and B+ control drive signals.

Vertical section

• I2C-bus controllable vertical picture size, picture position, linearity (S-correction) and linearity balance

min

and f

by external

max

GENERAL DESCRIPTION

The TDA4857PS is a high performance and efficient solution for autosync monitors. All functions are controllable by the I2C-bus.

The TDA4857PS provides synchronization processing, horizontal and vertical synchronization with full autosync capability and very short settling times after mode changes. External power components are given a great deal of protection. The IC generates the drive waveforms for DC-coupled vertical boosters such as the TDA486x and TDA835x.

The TDA4857PS provides extended functions e.g. as a flexible B+ control, an extensive set of geometry control facilities and an output for vertical focus signals.

Together with the I2C-bus driven Philips TDA488x video processor family, a very advanced system solution is offered.

2000 Jan 31 2

Philips Semiconductors Product speciﬁcation

I2C-bus autosync deﬂection controller for

TDA4857PS

PC monitors

QUICK REFERENCE DATA

SYMBOL PARAMETER MIN. TYP. MAX. UNIT

CC(stb)

VSIZE vertical size 60 − 100 % VGA VGA overscan for vertical size − 16.8 − % VPOS vertical position −±11.5 − % VLIN vertical linearity (S-correction) −2 −−46 % VLINBAL vertical linearity balance −±2.5 − % V

HSIZE

HPIN

HEHT

HTRAP

HCOR

HPOS horizontal position −±13 − % HPARAL horizontal parallelogram −±1−% HPINBAL EW pin unbalance −±1−% T

amb

supply voltage 9.2 − 16 V supply current − 70 − mA supply current during standby mode − 9 − mA

horizontal size voltage 0.13 − 3.6 V horizontal pincushion voltage (EW parabola) 0.04 − 1.42 V horizontal size modulation voltage 0.02 − 0.69 V horizontal trapezium correction voltage −±0.33 − V horizontal corner correction voltage −0.64 − +0.08 V

ambient temperature −20 − +70 °C

ORDERING INFORMATION

TYPE

NUMBER

NAME DESCRIPTION VERSION

PACKAGE

TDA4857PS SDIP32 plastic shrink dual in-line package; 32 leads (400 mil) SOT232-1

2000 Jan 31 3

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BLOCK DIAGRAM

Philips Semiconductors Product speciﬁcation

PC monitors

C-bus autosync deﬂection controller for

clamping

blanking

HUNLOCK

9.2 to 16 V

(TTL level)

SDA SCL

(TTL level)

VSYNC

CLBL

PGND

SGND

HSYNC

VIDEO CLAMPING

VERTICAL BLANK

HUNLOCK

OUTPUT

19 18

RECEIVER

H/C SYNC INPUT

VERTICAL

SYNC INPUT

AND POLARITY

CORRECTION

AND

I2C-BUS

SUPPLY

AND

REFERENCE

AND POLARITY

CORRECTION

VERTICAL

SYNC

INTEGRATOR

HORIZONTAL

VERTICAL POSITION

VERTICAL SIZE, VOVSCN

PROTECTION

AND SOFT START

I2C-BUS REGISTERS

COINCIDENCE DETECTOR

FREQUENCY DETECTOR

PLL1 AND POSITION

100

kΩ (1%)

(5%)

23 22 21 31

VERTICAL

OSCILLATOR

AND AGC

EHT compensation

via vertical size

150

EHT COMPENSATION

EHT compensation

via horizontal size

VSMODVAGCVCAPVREF HSMOD

HORIZONTAL SIZE

AND

VERTICAL SIZE

TDA4857PS

PROTECTION

HORIZONTAL OSCILLATOR

PLL2, PARALLELOGRAM,

PIN UNBALANCE AND

HORIZONTAL PINCUSHION HORIZONTAL CORNER HORIZONTAL TRAPEZIUM HORIZONTAL SIZE

X-RAY

SOFT START

EWDRV 11

EW-OUTPUT

7 V

1.2 V

VERTICAL OUTPUT

VERTICAL LINEARITY VERTICAL LINEARITY

BALANCE

OUTPUT

ASYMMETRIC

EW-CORRECTION

VERTICAL

FOCUS

B+

CONTROL

HORIZONTAL

OUTPUT

STAGE

ASCOR

32 FOCUS

BDRV

BSENS

BOP

BIN

HDRV

VOUT2

VOUT1

X-RAY

B+ CONTROL APPLICATION

(2)

(video)

3.3 kΩ

100 nF

8.2 nF

HBUF

HREF

(1%)

28 29

(1)

(1) For the calculation of fH range see Section “Calculation of line frequency range”. (2) See Figs 21 and 22.

Fig.1 Block diagram and application circuit.

10 nF

(2%)

30 1

HPLL2HCAPHREFHBUFHPLL1

8.2 nF

HFLB

XSEL XRAY

MHB658

TDA4857PS

Philips Semiconductors Product speciﬁcation

I2C-bus autosync deﬂection controller for PC monitors

PINNING

SYMBOL PIN DESCRIPTION

HFLB 1 horizontal ﬂyback input XRAY 2 X-ray protection input BOP 3 B+ control OTA output BSENS 4 B+ control comparator input BIN 5 B+ control OTA input BDRV 6 B+ control driver output PGND 7 power ground HDRV 8 horizontal driver output XSEL 9 select input for X-ray reset V

EWDRV 11 EW waveform output VOUT2 12 vertical output 2 (ascending sawtooth) VOUT1 13 vertical output 1 (descending sawtooth) VSYNC 14 vertical synchronization input HSYNC 15 horizontal/composite synchronization input CLBL 16 video clamping pulse/vertical blanking output HUNLOCK 17 horizontal synchronization unlock/protection/vertical blanking output SCL 18 I SDA 19 I ASCOR 20 output for asymmetric EW corrections VSMOD 21 input for EHT compensation (via vertical size) VAGC 22 external capacitor for vertical amplitude control VREF 23 external resistor for vertical oscillator VCAP 24 external capacitor for vertical oscillator SGND 25 signal ground HPLL1 26 external ﬁlter for PLL1 HBUF 27 buffered f/v voltage output HREF 28 reference current for horizontal oscillator HCAP 29 external capacitor for horizontal oscillator HPLL2 30 external ﬁlter for PLL2/soft start HSMOD 31 input for EHT compensation (via horizontal size) FOCUS 32 output for vertical focus

10 supply voltage

C-bus clock input

C-bus data input/output

TDA4857PS

2000 Jan 31 5

Philips Semiconductors Product speciﬁcation

I2C-bus autosync deﬂection controller for PC monitors

handbook, halfpage

HFLB

XRAY

BOP

BSENS

EWDRV

VOUT2 VOUT1 VSYNC

HSYNC

BIN

BDRV PGND HDRV

XSEL

CLBL

4 5 6 7 8

TDA4857PS

9 10 11 12 13 14 15 16

MHB656

Fig.2 Pin configuration.

FOCUS

HSMOD

HPLL2

HCAP

HREF

HBUF

HPLL1

SGND

VCAP

VREF

VAGC

VSMOD

ASCOR

SDA

SCL

HUNLOCK

TDA4857PS

Vertical sync integrator

Normalized composite sync signals from HSYNC are integrated on an internal capacitor in order to extract vertical sync pulses. The integration time is dependent on the horizontal oscillator reference current at HREF (pin 28). The integrator output directly triggers the vertical oscillator.

Vertical sync slicer and polarity correction

Vertical sync signals (TTL) applied to VSYNC (pin 14) are sliced at 1.4 V. The output signal of the sync slicer is integrated on an internalcapacitor to detect and normalize the sync polarity. The output signals of vertical sync integrator and sync normalizer are disjuncted before they are fed to the vertical oscillator.

Video clamping/vertical blanking generator

The video clamping/vertical blanking signal at CLBL (pin 16) is a two-level sandcastle pulse which is especially suitableforvideoICs such as the TDA488x family, but also for direct applications in video output stages.

The upper level is the video clamping pulse, which is triggeredbythehorizontalsyncpulse.Either the leading or trailing edge can be selected by setting control bit CLAMP via the I2C-bus. The width of the video clamping pulse is determined by an internal single-shot multivibrator.

FUNCTIONAL DESCRIPTION Horizontal sync separator and polarity correction

HSYNC (pin 15) is the input for horizontal synchronization signals, which can be DC-coupled TTL signals (horizontal or composite sync) and AC-coupled negative-going video sync signals. Video syncs are clamped to 1.28 V and sliced at 1.4 V. This results in a fixed absolute slicing level of 120 mV related to top sync.

For DC-coupled TTL signals the input clamping current is limited. The slicing level for TTL signals is 1.4 V.

The separated sync signal (either video or TTL) is integrated on an internalcapacitor to detect and normalize the sync polarity.

Normalized horizontal sync pulses are used as input signals for the vertical sync integrator, the PLL1 phase detector and the frequency-locked loop.

The lower level of the sandcastle pulse is the vertical blanking pulse, which is derived directly from the internal oscillator waveform. It is started by the vertical sync and stopped with the start of the vertical scan. This results in optimum vertical blanking. Two different vertical blanking times are accessible, by control bit VBLK, via the I2C-bus.

Blanking will be activated continuously if one of the following conditions is true:

Soft start of horizontal and B+ drive [voltage at HPLL2 (pin 30) pulled down externally or by the I2C-bus]

PLL1 is unlocked while frequency-locked loop is in search mode or if horizontal sync pulses are absent

No horizontal flyback pulses at HFLB (pin 1) X-ray protection is activated Supply voltage at VCC (pin 10) is low (see Fig.23).

Horizontal unlock blanking can be switched off, by control bit BLKDIS, via the I2C-bus while vertical blanking and protection blanking is maintained.

2000 Jan 31 6

Philips Semiconductors Product speciﬁcation

I2C-bus autosync deﬂection controller for PC monitors

Frequency-locked loop

The frequency-locked loop can lock the horizontal oscillatorover a wide frequencyrange. This is achievedby a combined search and PLL operation. The frequency range is preset by two external resistors and the

recommended maximum ratio is

---------f

This can, for instance, be a range from 15.625 to 90 kHz with all tolerances included.

Without a horizontal sync signal the oscillator will be free-running at f

. Any change of sync conditions is

min

detected by the internal coincidence detector. A deviation of more than 4% between horizontal sync and oscillator frequency will switch the horizontal section into search mode.This means that PLL1control currents are switched off immediately.

The internal frequency detector then starts tuning the oscillator. Very small DC currents at HPLL1 (pin 26) are usedtoperformthis tuning with a well defined change rate. When coincidence between horizontal sync and oscillator frequency is detected, thesearch mode is first replaced by a soft-lock mode which lasts for the first part of the next vertical period. The soft-lock mode is then replaced by a normal PLL operation. This operation ensures smooth tuning and avoids fast changes of horizontal frequency during catching.

In this concept it is not allowed to load HPLL1. The frequency dependent voltage at this pin is fed internally to HBUF (pin 27) via a sample-and-hold and buffer stage. The sample-and-hold stage removes all disturbances caused by horizontal sync or composite vertical sync from the buffered voltage. An external resistorconnected between pins HBUF andHREF defines the frequency range.

Out-of-lock indication (pin HUNLOCK)

Pin HUNLOCK is floating during search mode if no sync pulses are applied, or if a protection condition is true. All this can be detected by the microcontroller if a pull-up resistor is connected to its own supply voltage.

For an additional fast vertical blanking at grid 1 of the picture tube a 1 V signal referenced to ground is available at this output. The continuous protection blanking (see Section“Videoclamping/verticalblankinggenerator”) is also available at this pin. Horizontal unlock blanking can be switched off, by control bit BLKDIS via the I2C-bus, while vertical blanking is maintained.

max

min

6.5

------- 1

TDA4857PS

Horizontal oscillator

The horizontal oscillator is of the relaxation type and requires a capacitor of 10 nF to be connected at HCAP (pin 29).For optimum jitter performance the valueof10 nF must not be changed.

The minimum oscillator frequency is determined by a resistor connected between pin HREF and ground. A resistor connected between pins HREF and HBUF defines the frequency range.

The reference current at pin HREF also defines the integration time constant of the vertical sync integration.

Calculation of line frequency range

The oscillator frequencies f calculated. This is achieved by adding the spread of the relevant components to the highest and lowest sync frequencies f

sync(min)

by the currents in R

and f

HREF

The following example is a 31.45 to 90 kHz application:

Table 1 Calculation of total spread

spread of for f

IC ±3% ±5% C

HCAP

, R

HREF

HBUF

Total ±7% ±9%

Thus the typical frequency range of the oscillator in this example is:

maxfsync max()

min

sync min()

-----------------------

1.09

1.07× 96.3 kHz==

28.9 kHz==

The TV mode is centred around f ±10%. Activation of the TV mode is only allowed between

15.625 and 35 kHz. The resistors R

HREF

and R

the following formulae:

HREF

HBUFpar

78 kHz k××Ω

----------------------------------------------------------------f

0.0012 f

min

78 kHz k××Ω

-------------------------------------------------------------------f

0.0012 f

max

min

sync(max)

and R

and f

HBUF

max

must first be

max

. The oscillator is driven

±2% ±2% ±2% ±2%

with a control range of

min

HBUFpar

×+ kHz[]

min

can be calculated using

2.61 kΩ==

×+ kHz[]

max

726 Ω==

for f

min

2000 Jan 31 7

Philips Semiconductors Product speciﬁcation

I2C-bus autosync deﬂection controller for PC monitors

The resistor R and R

in parallel. The formulae for R

HBUF

into account the voltage swing across this resistor

HBUF

HREFRHBUFpar

---------------------------------------------R

HREFRHBUFpar

PLL1 phase detector

The phase detector is a standard type using switched current sources, which are independent of the horizontal frequency. It compares the middle of the horizontal sync with a fixed point on the oscillator sawtooth voltage. The PLL1 loop filter is connected to HPLL1 (pin 26).

See also Section “Horizontal position adjustment and corrections”.

Horizontal position adjustment and corrections

A linear adjustment of the relative phase between the horizontal sync and the oscillator sawtooth (in PLL1 loop) is achieved via register HPOS.Once adjusted, the relative phase remains constant over the whole frequency range.

Correctionof pin unbalance and parallelogramis achieved by modulating the phase between the oscillator sawtooth and horizontal flyback (in loop PLL2) via registers HPARAL and HPINBAL. If those asymmetric EW corrections are performed in the deflection stage, both registers can be disconnected from the horizontal phase via control bit ACD. This does not change the output at pin ASCOR.

Horizontal moire cancellation

To achieve a cancellation of horizontal moire (also known as ‘video moire’), the horizontal frequency is divided-by-two to achieve a modulation of the horizontal phase via PLL2. The amplitude is controlled by register HMOIRE. To avoid a visible structure on screen the polaritychanges with half of the verticalfrequency.Control bit MOD disables the moire cancellation function.

is calculated as the value of R

HBUFpar

–

0.8×= 805 Ω=

HBUF

HREF

also takes

TDA4857PS

For the TDA4857PS external modulation of the PLL2 phase is not allowed, because this would disturb the start advance of the horizontal focus parabola.

Soft start and standby

If HPLL2 is pulled to ground by resetting the register SOFTST, the horizontal output pulses, vertical output currents and B+ control driver pulses will be inhibited. This means that HDRV (pin 8), BDRV (pin 6), VOUT1 (pin 13) and VOUT2 (pin 12) are floating in this state. If HPLL2 is pulled to ground by an external DC current, vertical output currents stay active while HDRV (pin 8) and BDRV (pin 6) are in floating state. In both cases the PLL2 and the frequency-locked loop are disabled, CLBL (pin 16) provides a continuous blanking signal and HUNLOCK (pin 17) is floating.

This option can be used for soft start, protection and power-down modes. When the HPLL2 pin is released again, an automatic soft start sequence on the horizontal drive as well as on the B+ drive output will be performed (see Figs 24 and 25).

A soft start can only be performed if the supply voltage for the IC is a minimum of 8.6 V.

The soft start timing is determined by the filter capacitor at HPLL2 (pin 30), which is charged with a constant current during soft start. If the voltage at pin 30 (HPLL2) reaches

1.1 V,thevertical output currents are enabled. At 1.7 Vthe horizontaldriverstage generates very small output pulses. The width of these pulses increases with the voltage at HPLL2 until the final duty cycle is reached. The voltage at HPLL2increasesfurtherandperformsa soft start at BDRV (pin 6)as well. The voltage at HPLL2 continuestorise until HPLL2 enters its normal operating range. The internal charge current is now disabled. Finally PLL2 and the frequency-locked loop are activated. If both functions reachnormaloperation, HUNLOCK (pin 17) switches from the floating status to normal vertical blanking, and continuous blanking at CLBL (pin 16) is removed.

PLL2 phase detector

The PLL2 phase detector is similar to the PLL1 detector and compares the line flyback pulse at HFLB (pin 1) with the oscillator sawtooth voltage. The control currents are independent of the horizontal frequency. The PLL2 detector thus compensates for the delay in the external horizontal deflection circuit by adjusting the phase of the HDRV (pin 8) output pulse.

2000 Jan 31 8

Output stage for line drive pulses [HDRV (pin 8)]

An open-collector output stage allows direct drive of an inverting driver transistor because of a low saturation voltage of 0.3 V at 20 mA. To protect the line deflection transistor, the output stage is disabled (floating) for a low supply voltage at V

(see Fig.23).

The duty cycle of line drive pulses is slightly dependent on the actual horizontal frequency. This ensures optimum drive conditions over the whole frequency range.

Philips Semiconductors Product speciﬁcation

I2C-bus autosync deﬂection controller for PC monitors

X-ray protection

TheX-rayprotectioninputXRAY(pin 2)providesavoltage detector with a precise threshold. If the input voltage at XRAY exceeds this threshold level for a certain time then control bit SOFTST is reset, which switches the IC into protection mode. In this mode several pins are forced into defined states:

HUNLOCK (pin 17) is floating The capacitor connected to HPLL2 (pin 30) is

discharged Horizontal output stage (HDRV) is floating B+ control driver stage (BDRV) is floating Vertical output stages (VOUT1 and VOUT2) are floating CLBL provides a continuous blanking signal.

There are two different methods of restarting the IC:

1. XSEL (pin 9) is open-circuit or connected to ground. The control bit SOFTST must be set to logic 1 via the I2C-bus. The IC then returns to normal operation via soft start.

2. XSEL (pin 9) is connected to VCC via an external resistor.Thesupplyvoltage of the IC must be switched off for a certain period of time before the IC can be restarted again using the standard power-on procedure.

Vertical oscillator and amplitude control

This stage is designed for fast stabilization of vertical size after changes in sync frequency conditions.

The free-running frequency f resistor R

connected to pin 24. The value of R

VCAP

connected to pin 23 and the capacitor

VREF

optimized for noise and linearity performance in the whole vertical and EW section, but also influences several internal references. Therefore the value of R be changed.

Capacitor C

should be used to select the free-running

VCAP

frequency of the vertical oscillator in accordance with the

following formula:

fr V()

To achieve a stabilized amplitude the free-running frequencyf

,withoutadjustment,shouldbe at least 10%

fr(V)

lower than the minimum trigger frequency. The contributions shown in Table 2 can be assumed.

is determined by the

fr(V)

VREF

-----------------------------------------------------------

10.8 R

× C

VREF

VCAP

is not only

must not

TDA4857PS

Table 2 Calculation of f

Contributing elements

Minimum frequency offset between f lowest trigger frequency

Spread of IC ±3% Spread of R Spread of C

VREF VCAP

Total 19%

Result for 50 to 160 Hz application:

fr V()

50 Hz

---------------

1.19

42 Hz==

The AGC of the vertical oscillator can be disabled by setting control bit AGCDIS via the I external current has to be injected into VCAP (pin 24) to obtain the correct vertical size. This special application mode can be used when the vertical sync pulses are serrated (shifted); this condition is found in some display modes, e.g. when using a 100 Hz upconverter for video signals.

Application hint: VAGC (pin 22) has a high input impedance during scan. Therefore, the pin must not be loaded externally otherwise non-linearities in the vertical output currents may occur due to the changing charge current during scan.

Adjustment of vertical size, VGA overscan and EHT compensation

The amplitude of the differential output currents at VOUT1 and VOUT2 can be adjusted via register VSIZE. Register VOVSCN can activate a +17% step in vertical size for the VGA350 mode.

VSMOD (pin 21) can be used for a DC controlled EHT compensation of vertical size by correcting the differential output currents at VOUT1 and VOUT2. The EW waveforms, vertical focus, pin unbalance and parallelogram corrections are not affected by VSMOD.

The adjustments for vertical size and vertical position also affect the waveforms of the horizontal pincushion, vertical linearity (S-correction), vertical linearity balance, focus parabola, pin unbalance and parallelogram correction. The result of this interaction is that no re-adjustment of these parameters is necessary after an adjustment of vertical picture size or position.

total spread

fr(V)

and

fr(V)

10%

±1% ±5%

C-bus. A precise

2000 Jan 31 9

Philips Semiconductors Product speciﬁcation

I2C-bus autosync deﬂection controller for PC monitors

Adjustment of vertical position, vertical linearity and vertical linearity balance

Register VPOS provides a DC shift at the sawtooth outputs VOUT1 and VOUT2 (pins 13 and 12) and the EW drive output EWDRV (pin 11) in such a way that the whole picture moves vertically while maintaining the correct geometry.

Register VLIN is used to adjust the amount of vertical S-correction in the output signal. This function can be switched off by control bit VSC.

Register VLINBAL is used to correct the unbalance of the vertical S-correction in the output signal. This function can be switched off by control bit VLC.

Adjustment of vertical moire cancellation

To achieve a cancellation of vertical moire (also known as ‘scanmoire’)theverticalpicturepositioncanbemodulated by half the vertical frequency. The amplitude of the modulation is controlled by register VMOIRE and can be switched off via control bit MOD.

Horizontal pincushion (including horizontal size, corner correction and trapezium correction)

EWDRV(pin 11) provides a complete EW drive waveform. The components horizontal pincushion, horizontal size, corner correction and trapezium correction are controlled by the registers HPIN, HSIZE, HCOR and HTRAP. HTRAP can be set to zero by control bit VPC.

The pincushion (EW parabola) amplitude, corner and trapezium correction track with the vertical picture size (VSIZE) and also with the adjustment for vertical picture position(VPOS). The corner correctiondoes not track with the horizontal pincushion (HPIN).

Further the horizontal pincushion amplitude, corner and trapezium correction track with the horizontal picture size, which is adjusted via register HSIZE and the analog modulation input HSMOD.

If the DC component in the EWDRV output signal is increasedviaHSIZEorI trapezium component of the EWDRV output will be

reduced by a factor of

,thepincushion,cornerand

HSMOD



–

-------------------------------------------------------------------------

HSIZEVHEHT

–



14.4

HSIZE

-----------------

14.4 V

TDA4857PS

The value 14.4 V is a virtual voltage for calculation only. The output pin can not reach this value, but the gain (and DCbias)oftheexternalapplicationshouldbesuchthatthe horizontal deflection is reduced to zero when EWDRV reaches 14.4 V.

HSMOD can be used for a DC controlled EHT compensation by correcting horizontal size, horizontal pincushion, corner and trapezium. The control range at this pin tracks with the actual value of HSIZE. For an increasing DC component V signal, the DC component V

reducedbyafactor of as shown in the previous

–

-----------------

14.4 V

equation. The whole EWDRV voltage is calculated as follows:

V V

= 1.2 V + [V

EWDRV HCOR+VHTRAP

HSIZE+VHEHT

) × g(HSIZE, HSMOD)] × h(I

Where:

HEHT

f(HSIZE) 1

g(HSIZE, HSMOD) 1

()

HREF

HSMOD

------------------- 120 µA

–=

-----------------

14.4 V

-------------------------------I

HREF

0.69×=

HSIZE

–=

HREF

f70kHz=

Two different modes of operation can be chosen for the EW output waveform via control bit FHMULT:

1. Mode 1 Horizontal size is controlled via register HSIZE and

causesaDCshift at the EWDRV output. The complete waveform is also multiplied internally by a signal proportional to the line frequency [which is detected via the current at HREF (pin 28)]. This mode is to be used for driving EW diode modulator stages which require a voltage proportional to the line frequency.

2. Mode 2 The EW drive waveform does not track with the line

frequency. This mode is to be used for driving EW modulatorswhich require a voltage independent ofthe line frequency.

in the EWDRV output

HSIZE

caused by I

HEHT

HSIZE

× f(HSIZE) + (V

HSIZEVHEHT

--------------------------------------------------------------------------





14.4 V

HSMOD

HREF

–

-----------------

14.4 V

will be

HPIN

)

HSIZE

2000 Jan 31 10

Philips Semiconductors Product speciﬁcation

I2C-bus autosync deﬂection controller for PC monitors

Output stage for asymmetric correction waveforms [ASCOR (pin 20)]

This output is designed as a voltage output for superimposed waveforms of vertical parabola and sawtooth. The amplitude and polarity of both signals can be changed via registers HPARAL and HPINBAL.

Application hint: The TDA4857PS offers two possibilities to control registers HPINBAL and HPARAL.

1. Control bit ACD = 1 The two registers now control the horizontal phase by

means of internal modulation of the PLL2 horizontal phase control. The ASCOR output (pin 20) can be left unused, but it will always provide an output signal because the ASCOR output stage is not influenced by the control bit ACD.

2. Control bit ACD = 0 The internal modulation via PLL2 is disconnected.

In order to obtain the required effect on thescreen, pin ASCOR must now be fed to the DC amplifier which controls the DC shift of the horizontal deflection. This option is useful for applications which already use a DC shift transformer.

Ifthe tube does notneed HPINBAL and HPARAL,then pin ASCOR can be used for other purposes, i.e. for a simple dynamic convergence.

Dynamic focus section [FOCUS (pin 32)]

Thissectiongeneratesacompletedrivesignalfordynamic focus applications. The amplitude of the vertical parabola is independent of frequency and tracks with all vertical adjustments. The amplitude can be adjusted via register VFOCUS.FOCUS(pin 32)is designed as a voltage output for the vertical parabola.

B+ control function block

The B+ control function block of the TDA4857PS consists of an Operational Transconductance Amplifier (OTA), a voltagecomparator, a flip-flop and a dischargecircuit.This configuration allows easy applications for different B+ controlconcepts.Seealso Application Note AN96052:

converter Topologies for Horizontal Deflection and EHT with TDA4855/58”

“B+

TDA4857PS

GENERAL DESCRIPTION The non-inverting input of the OTA is connected internally

toa high precision referencevoltage. The inverting inputis connectedto BIN (pin 5). Aninternal clamping circuit limits the maximum positive output voltage of the OTA. The output itself is connected to BOP (pin 3) and to the inverting input of the voltage comparator. The non-inverting input of the voltage comparator can be accessed via BSENS (pin 4).

B+ drive pulses are generated by an internal flip-flop and fed to BDRV (pin 6) via an open-collector output stage. This flip-flop is set at the rising edge of the signal at HDRV (pin 8). The falling edge of the output signal at BDRV has a defined delay of t pulse (see Fig.21). When the voltage at BSENS exceeds the voltage at BOP, the voltage comparator output resets the flip-flop and, therefore, the open-collector stage at BDRV is floating again.

An internal discharge circuit allows a well defined discharge of capacitors at BSENS. BDRV is active at a LOW-level output voltage (see Figs 21 and 22), thus it requires an external inverting driver stage.

The B+ function block can be used for B+ deflection modulators in many different ways. Two popular application combinations are as follows:

• Boost converter in feedback mode (see Fig.21) In this application the OTA is used as an error amplifier

witha limited output voltagerange. The flip-flop isset on the rising edge of the signal at HDRV. A reset will be generated when the voltage at BSENS, taken from the current sense resistor, exceeds the voltage at BOP.

If no reset is generated within a line period. The rising edgeof the next HDRV pulseforces the flip-flop to reset. The flip-flop is set immediately after the voltage at BSENS has dropped below the threshold voltage V

RESTART(BSENS)

d(BDRV)

to the rising edge of the HDRV

2000 Jan 31 11

Philips Semiconductors Product speciﬁcation

I2C-bus autosync deﬂection controller for PC monitors

• Buck converter in feed forward mode (see Fig.22) This application uses an external RC combination at

BSENS to provide a pulse width which is independent from the horizontal frequency. The capacitor is charged via an external resistor and discharged by the internal discharge circuit. For normal operation the discharge circuit is activated when the flip-flop is reset by the internal voltage comparator. The capacitor will now be discharged with a constant current until the internally controlled stop level V willbe maintained until therising edge of thenext HDRV pulse sets the flip-flop again and disables the discharge circuit.

If no reset is generated within a line period, the rising edge of the next HDRV pulse automatically starts the discharge sequence and resets the flip-flop. When the voltage at BSENS reaches the threshold voltage V

RESTART(BSENS)

automatically and the flip-flop will be set immediately. This behaviour allows a definition of the maximum duty cycle of the B+ control drive pulse by the relationship of charge current to discharge current.

Supply voltage stabilizer, references, start-up procedures and protection functions

The TDA4857PS incorporates an internal supply voltage stabilizer to provide excellent stabilization for all internal references.Aninternalgap reference, especially designed for low-noise, is the reference for the internal horizontal andverticalsupplyvoltages.Allinternalreference currents and drive current for the vertical output stage are derived from this voltage via external resistors.

If either the supply voltage is below 8.3 V or no data from the I2C-bus has been received after power-up, the internal softstart and protection functions do not allowanyof those outputs [HDRV, BDRV, VOUT1, VOUT2 and HUNLOCK (see Fig.23)] to be active.

For supply voltages below 8.3 V the internal I2C-bus will not generate an acknowledge and the IC is in standby mode. This is because the internal protection circuit has generatedaresetsignalforthesoft start register SOFTST. Above 8.3 V data is accepted and all registers can be loaded. If register SOFTST has received a set from the I2C-bus,theinternalsoftstartprocedure is released, which activates all mentioned outputs.

STOP(BSENS)

, the discharge circuit will be disabled

is reached. This level

TDA4857PS

This protection mode has been implemented in order to protect the deflection stages and the picture tube during start-up, shut-down and fault conditions. This protection mode can be activated as shown in Table 3.

Table 3 Activation of protection mode

ACTIVATION RESET

Low supply voltage at pin 10

Power dip, below 8.1 V reload registers;

X-ray protection (pin 2) triggered, XSEL (pin 9) is open-circuit or connected to ground

X-ray protection (pin 2) triggered, XSEL (pin 9) connected to V external resistor

HPLL2 (pin 30) externally pulled to ground

When the protection mode is active, several pins of the TDA4857PS are forced into a defined state:

HDRV (horizontal driver output) is floating BDRV (B+ control driver output) is floating HUNLOCK (indicates, that the frequency-to-voltage

converter is out of lock) is floating (HIGH via external pull-up resistor)

CLBL provides a continuous blanking signal VOUT1 and VOUT2 (vertical outputs) are floating The capacitor at HPLL2 is discharged.

If the soft start procedure is activated via the I these actions will beperformed in a well defined sequence (see Figs 23 and 24).

via an

increase supply voltage; reload registers; soft start via I2C-bus

soft start via I reload registers;

soft start via I

switch VCC off and on again, reload registers; soft start via I2C-bus

release pin 30

C-bus

C-bus, all of

If during normal operation the supply voltage has dropped below 8.1 V, the protection mode is activated and HUNLOCK(pin 17)changesto the protection status and is floating. This can be detected by the microcontroller.

2000 Jan 31 12

Philips Semiconductors Product speciﬁcation

I2C-bus autosync deﬂection controller for

TDA4857PS

PC monitors

LIMITING VALUES

In accordance with the Absolute Maximum Rating System (IEC 134); all voltages measured with respect to ground.

SYMBOL PARAMETER CONDITIONS MIN. MAX. UNIT

i(n)

o(n)

I/O(n)

o(HDRV)

i(HFLB)

o(CLBL)

o(BOP)

o(BDRV)

o(EWDRV)

o(FOCUS)

amb

stg

ESD

supply voltage −0.5 +16 V input voltage for pins:

BIN −0.5 +6.0 V HSYNC, VSYNC, VREF, HREF, VSMOD and HSMOD −0.5 +6.5 V SDA and SCL −0.5 +8.0 V XRAY −0.5 +8.0 V

output voltage for pins:

VOUT2, VOUT1 and HUNLOCK −0.5 +6.5 V

BDRV and HDRV −0.5 +16 V input/output voltages at pins BOP and BSENS −0.5 +6.0 V horizontal driver output current − 100 mA horizontal ﬂyback input current −10 +10 mA video clamping pulse/vertical blanking output current −−10 mA B+ control OTA output current − 1mA B+ control driver output current − 50 mA EW driver output current −−5mA focus driver output current −−5mA ambient temperature −20 +70 °C junction temperature − 150 °C storage temperature −55 +150 °C electrostatic discharge for all pins note 1 −150 +150 V

note 2 −2000 +2000 V

Notes

1. Machine model: 200 pF; 0.75 µH; 10 Ω.

2. Human body model: 100 pF; 7.5 µH; 1500 Ω.

THERMAL CHARACTERISTICS

SYMBOL PARAMETER CONDITIONS VALUE UNIT

th(j-a)

thermal resistance from junction to ambient in free air 55 K/W

QUALITY SPECIFICATION

In accordance with

“URF-4-2-59/601”

; EMC emission/immunity test in accordance with

“DIS 1000 4.6”

(IEC 801.6).

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

EMC

emission test note 1 − 1.5 − mV immunity test note 1 − 2.0 − V

Note

1. Tests are performed with application reference board. Tests with other boards will have different results.

2000 Jan 31 13

Philips Semiconductors Product speciﬁcation

I2C-bus autosync deﬂection controller for

TDA4857PS

PC monitors

CHARACTERISTICS

VCC= 12 V; T

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

Horizontal sync separator

NPUT CHARACTERISTICS FOR DC-COUPLED TTL SIGNALS: PIN HSYNC

i(HSYNC)

HSYNC(sl)

r(HSYNC)

f(HSYNC)

W(HSYNC)(min)

i(HSYNC)

INPUT CHARACTERISTICS FOR AC-COUPLED VIDEO SIGNALS (SYNC-ON-VIDEO, NEGATIVE SYNC POLARITY) V

HSYNC

HSYNC(sl)

clamp(HSYNC)

ch(HSYNC)

W(HSYNC)(min)

source(max)

i(diff)(HSYNC)

Automatic polarity correction for horizontal sync

PH()

----------- t

d(HPOL)

Vertical sync integrator

int(V)

Vertical sync slicer (DC-coupled, TTL compatible): pin VSYNC

i(VSYNC)

VSYNC(sl)

i(VSYNC)

=25°C; peripheral components in accordance with Fig.1; unless otherwise speciﬁed.

amb

sync input signal voltage 1.7 −−V slicing voltage level 1.2 1.4 1.6 V rise time of sync pulse 10 − 500 ns fall time of sync pulse 10 − 500 ns minimum width of sync pulse 0.7 −−µs input current V

sync amplitude of video input

= 0.8 V −−−200 µA

HSYNC

= 5.5 V −−10 µA

HSYNC

=50Ω−300 − mV

source

signal voltage slicing voltage level

=50Ω 90 120 150 mV

source

(measured from top sync) top sync clamping voltage level R charge current for coupling

=50Ω 1.1 1.28 1.5 V

source

HSYNC>Vclamp(HSYNC)

1.7 2.4 3.4 µA

capacitor minimum width of sync pulse 0.7 −−µs maximum source resistance duty cycle = 7% −−1500 Ω differential input resistance during sync − 80 −Ω

horizontal sync pulse width

−−25 %

related to line period

delay time for changing polarity 0.3 − 1.8 ms

integration time for generation of a vertical trigger pulse

fH= 15.625 kHz; I

= 0.52 mA

HREF

= 31.45 kHz;

= 1.052 mA

HREF

= 64 kHz;

= 2.141 mA

HREF

= 100 kHz;

= 3.345 mA

HREF

14 20 26 µs

71013µs

3.9 5.7 6.5 µs

2.5 3.8 4.5 µs

sync input signal voltage 1.7 −−V slicing voltage level 1.2 1.4 1.6 V input current 0V<V

< 5.5 V −−±10 µA

SYNC

2000 Jan 31 14

Philips Semiconductors Product speciﬁcation

I2C-bus autosync deﬂection controller for

TDA4857PS

PC monitors

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

Automatic polarity correction for vertical sync

W(VSYNC)(max)

maximumwidthof vertical sync pulse

d(VPOL)

delay time for changing polarity 0.45 − 1.8 ms

Video clamping/vertical blanking output: pin CLBL

clamp(CLBL)

width of video clamping pulse measured at V top voltage level of video

clamping pulse

clamp

STPS

clamp

temperature coefﬁcient of V

clamp(CLBL)

steepness of slopes for

RL=1MΩ; CL=20pF − 50 − ns/V

clamping pulse

d(HSYNCt-CLBL)

clamp1(max)

delay between trailing edge of horizontal sync and start of video clamping pulse

maximum duration of video clamping pulse referenced to

clamping pulse triggered on trailing edge of horizontal sync; control bit CLAMP = 0; measured at V

end of horizontal sync

d(HSYNCl-CLBL)

clamp2(max)

delay between leading edge of horizontal sync and start of video clamping pulse

maximum duration of video clamping pulse referenced to

clamping pulse triggered on leading edge of horizontal sync; control bit CLAMP = 1; measured at V

end of horizontal sync

blank(CLBL)

top voltage level of vertical

notes 1 and 2 1.7 1.9 2.1 V

blanking pulse

blank(CLBL)

blank

scan(CLBL)

width of vertical blanking pulse at pins CLBL and HUNLOCK

temperature coefﬁcient of V

blank(CLBL)

output voltage during vertical

control bit VBLK = 0 220 260 300 µs control bit VBLK = 1 305 350 395 µs

scan

sink(CLBL)

L(CLBL)

temperature coefﬁcient of V

scan(CLBL)

internal sink current 2.4 −−mA external load current −−−3.0 mA

Horizontal oscillator: pins HCAP and HREF

fr(H)

free-running frequency without PLL1 action (for testing only)

R R C

∆f

fr(H)

spread of free-running frequency (excluding spread of external components)

= 3 V 0.6 0.7 0.8 µs

CLBL

=3V

CLBL

=3V

CLBL

= 0 0.59 0.63 0.67 V

CLBL

= ∞;

HBUF

= 2.4 kΩ;

HREF

= 10 nF; note 3

HCAP

−−400 µs

4.32 4.75 5.23 V

− 4 − mV/K

− 130 − ns

−−1.0 µs

− 300 − ns

−−0.15 µs

− 2 − mV/K

−−2−mV/K

30.53 31.45 32.39 kHz

−−±3.0 %

2000 Jan 31 15

Philips Semiconductors Product speciﬁcation

I2C-bus autosync deﬂection controller for

TDA4857PS

PC monitors

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

H(max)

HREF

Unlock blanking detection: pin HUNLOCK

scan(HUNLOCK)

blank(HUNLOCK)

blank

sink

sink(int)

L(max)

PLL1 phase comparator and frequency-locked loop: pins HPLL1 and HBUF

W(HSYNC)(max)

lock(HPLL1)

ctrl(HPLL1)

HBUF

Phase adjustments and corrections via PLL1 and PLL2

HPOS horizontal position (referenced

HPINBAL horizontal pin unbalance

temperature coefﬁcient of

−100 0 +100 10−6/K

free-running frequency maximum oscillator frequency −−130 kHz voltage at input for reference

2.43 2.55 2.68 V

current

low level voltage of HUNLOCK saturation voltage in case

−−250 mV of locked PLL1; internal sink current = 1 mA

blanking level of HUNLOCK external load current = 0 0.9 1 1.1 V temperature coefﬁcient of

blank(HUNLOCK)

temperature coefﬁcient of I

sink(HUNLOCK)

internal sink current for blanking pulses;

−−0.9 − mV/K

− 0.15 − %/K

1.4 2.0 2.6 mA PLL1 locked

maximum external load current V leakage current V

HUNLOCK HUNLOCK

=1V −−−2mA = 5 V in case of

−−±5µA unlocked PLL1 and/or protection active

maximum width of horizontal

−−25 %

sync pulse (referenced to line period)

total lock-in time of PLL1 − 40 80 ms control currents notes 4 and 5

locked mode, level 1 − 15 −µA locked mode, level 2 − 145 −µA

buffered f/v voltage at HBUF (pin 27)

minimum horizontal frequency

maximum horizontal

− 2.5 − V

− 0.5 − V

frequency

to horizontal period)

correction via HPLL2 (referenced to horizontal period)

−−0.8 − %

− 0.8 − %

− 0 − %

control bit HPC = 1; note 6

2000 Jan 31 16

Philips Semiconductors Product speciﬁcation

I2C-bus autosync deﬂection controller for

TDA4857PS

PC monitors

SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNIT

HPARAL horizontal parallelogram

correction (referenced to horizontal period)

HMOIRE relative modulation of

horizontal position by 0.5f phase alternates with 0.5f

HMOIRE

off

moire cancellation off control bit MOD = 1 − 0 − %

PLL2 phase detector: pins HFLB and HPLL2

PLL2

PLL2 control (advance of horizontal drive with respect to middle of horizontal ﬂyback)

ctrl(PLL2)

PLL2

PLL2 control current − 75 −µA relative sensitivity of PLL2

phase shift related to horizontal period

PROT(PLL2)(max)

maximum voltage for PLL2 protection mode/soft start

ch(PLL2)

charge current for external

capacitor during soft start HORIZONTAL FLYBACK INPUT: PIN HFLB V

pos(HFLB)

neg(HFLB)

pos(HFLB)

neg(HFLB)

sl(HFLB)

positive clamping voltage I

negative clamping voltage I

positive clamping current −−6mA

negative clamping current −−−2mA

slicing level − 2.8 − V

Output stage for line driver pulses: pin HDRV

;

control bit MOD = 0

maximum advance; register HPINBAL = 07; register HPARAL = 07

minimum advance; register HPINBAL = 07; register HPARAL = 07

< 3.7 V − 1 −µA

HPLL2

=5mA − 5.5 − V

HFLB

= −1mA −−0.75 − V

HFLB

−−0.8 − %

− 0.8 − %

− 0 − %

− 0.05 − %

36 −−%

− 7 − %

− 28 − mV/%

− 4.4 − V

OPEN-COLLECTOR OUTPUT STAGE V

sat(HDRV)

LO(HDRV)

saturation voltage I

output leakage current V

=20mA −−0.3 V

HDRV

=60mA −−0.8 V

HDRV

2000 Jan 31 17

=16V −−10 µA

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