TDA4821P

Features:

` Measuring of six horizontal and four vertical timing parameters as follows:
   Horizontal: sync width, sync period, video start, video\ end and horizontal flyback pulse start and end
   Vertical: sync width, sync period, first line of video active and last line of video active.
` Detection of H-sync and V-sync polarity
` I<sup>2</sup>C-bus interface (maximum clock frequency 400 kHz) for read-out of data and write data of the internal
    clock  multiplier using double byte (16-bit format)
` Flexible digital clock input with built-in and (via I²C-bus) adjustable clock multiplier; internal clock is 48 MHz
    (typical value)
` Horizontal measurements are expressed in number of clock pulses; precision is approximately 20 ns at 48 MHz
   and can be improved if external averaging methods are used
` Vertical measurements are expressed in number of lines
` Internal buffer keep I²C-bus registers stable between the V-sync pulses, allowing for asynchronous read-out.


Application

These products are not designed for use in life support appliances, devices, or systems where malfunction of these products can reasonably be expected to result in personal injury. Philips customers using or selling these products for
use in such applications do so at their own risk and agree to fully indemnify Philips for any damages resulting from such improper use or sale.

Pinout




Specifications

SYMBOL	PARAMETER	CONDITIONS	MIN.	MAX.	UNIT
VDD(core)	core supply voltage		-0.5	+4	V
VDD(I/O)	I/O supply voltage		-0.5	+4	V
VDD(PLL)	PLL supply voltage		-0.5	+4	V
Vi(n)	input voltage: on pins HS, VS, SCL and SDA on all other I/O pins		-0.5 -0.5	+5.5 VDD + 0.5	V V
IDD(core)	core supply current		-	30	mA
IDD(I/O)	I/O supply current	external load on pin SDA	-	30	mA
IDD(PLL))	PLL supply current		-	1	mA
Io(SDA))	output current on pin SDA	external load	-	20	mA
Ptot	total power dissipation		-	200	mW
Tstg	storage temperature		-40	+125
Tamb	ambient temperature		-20	+70
Tj	junction temperature		-20	+125
Vesd	electrostatic discharge voltage for all pins	note 1	-250	+250	V
		note 2	-4000	+4000	V

Notes
1. Machine model: equivalent to discharging a 200 pF capacitor through a 0 series resistor ('0 ' is actually
   0.75 mH + 10 ).
2. Human body model: equivalent to discharging a 100 pF capacitor through a 1500 series resistor.


Description

The TDA4821P performs the 'autosize' feature for colour monitors. The IC measures the timing of active H/V video
with respect to the H-sync and V-sync pulses and also with respect to the horizontal flyback pulse in order to allow the microcontroller to adjust the display settings automatically, in particular parameters HSIZE, VSIZE, HPOS and VPOS.

The advantages of the TDA4821P are:
   ` A more user friendly adjustment for any undefined video mode by simply pressing a button
   ` Factory alignment for a reduced number of modes
   ` Saving of EEPROM storage space for factory and user modes.

The activation of the autosizing function of the TDA4821P can be done on user command or automatically on any mode change. When autosizing is activated while the screen is only partly active or consists of sub-windows, the picture size will increase, but not more than the range limits of the monitor allow.