TDA8777HL/24/C1 View Datasheet(PDF) - Philips Electronics

Part Name

Description

Manufacturer

TDA8777HL/24/C1

Triple 10-bit video DAC, up to 330 MHz sample frequency

Philips Electronics 

Philips Semiconductors

TDA8777

Triple 10-bit video DAC, up to 330 MHz sample frequency

An external reference resistor must be connected between pin RSET and analog ground.

This resistor sets the reference current which determines the analog output level, and is

specified to be 560 Ω. This value allows a 1 V (p-p) output (video plus sync) into a 37.5 Ω

load, such as a double-terminated 75 Ω coaxial cable.

8.2 Blanking and sync pulse insertion

The video signal (see Figure 3) is comprised of the following three parts:

• The video information: defined by the 10 bits used to drive the DAC; nominal signal

amplitude = 700 mV (p-p)

• The sync pulse: a horizontal synchronization (hsync) pulse indicates the end of a

video line and the start of the next video line; sync nominal amplitude = 300 mV; sync

is added to the video signal output via the SYNC input (active LOW)

• The blanking period: allows interface-free detection of both sync and video, blanking

is allocated either side of the sync pulse; the blank level is equal to the video black

level; blanking is added to the video signal output via the BLANK input (active LOW).

The values of SYNC and BLANK are latched on the rising edge of the clock signal. When

no sync and no blank are applied, the DAC can be used continuously. This is the so-called

generic mode.

Because the signal delay in the DAC is 1.5 times the clock period, the sync and blank are

also delayed by 1.5 times the clock period.

0.7 V

blanking period

sync pulse

video information

0.3 V

Fig 3. Video signal sync pulse and blanking period

mle291

9. Limiting values

Table 4. Limiting values

In accordance with the Absolute Maximum Rating System (IEC 60134).

Symbol Parameter

Conditions

Min

VDDA

Vn

Tstg

Tamb

Tj

analog supply voltage

voltage on digital input pins

storage temperature

ambient temperature

junction temperature

referred to VSSA1

referred to VSSA2

−0.5

−0.5

−55

0

−40

Max Unit

+6.5 V

+5.5 V

+150 °C

70

°C

+125 °C

TDA8777_4

Product data sheet

Rev. 04 — 11 April 2006

© Koninklijke Philips Electronics N.V. 2006. All rights reserved.

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