TZA1025T View Datasheet(PDF) - Philips Electronics

Part Name

Description

Manufacturer

TZA1025T

Data amplifier and laser supply circuit for CD audio and video optical systems (ADALASLC)

Philips Electronics 

Philips Semiconductors

Data amplifier and laser supply circuit for CD

audio and video optical systems (ADALASLC)

Product specification

TZA1025

FEATURES

• Supports a wide range of voltage output mechanisms

• RF amplifier designed for audio and video applications

with 1 × data rate

• Programmable RF gain for CD-Audio/Video (CD-A/V)

and CD-Read/Write (CD-R/W) discs

• Equalizer for optimal performance

• Fully Automatic Laser Power Control (ALPC) including

stabilization plus a separate laser supply voltage for

power efficiency

• Adjustable current range of ALPC output

• Automatic N- or P-substrate monitor diode selection

• Adjustable laser bandwidth and laser switch-on current

slope using external capacitor

• Protection circuit to prevent laser damage due to laser

supply voltage dip

• Optimized interconnection between data amplifier and

Philips’ digital signal processor CD10LC (SAA7325)

• Wide supply voltage range

• Power-down switch to reduce power consumption

during standby

• Low power consumption.

GENERAL DESCRIPTION

The TZA1025 is a data amplifier and laser supply circuit for

voltage output mechanisms found in a wide range of audio

and video CD systems. The device contains an RF

amplifier and an automatic laser power control circuit.

The preamplifier forms an interface for voltage output CD

mechanisms to the Philips’ digital signal processor

CD10LC (SAA7325).

The RF bandwidth allows this device to be used in CD-A/V

applications with a data rate of n = 1 times speed. The RF

gain can be adapted for CD-A/V discs or CD-R/W discs by

means of the gain select signal.

The equalizer ensures an optimal performance.

The TZA1025 can be adapted to a wide range of voltage

output mechanisms by means of external resistors.

The ALPC circuit will maintain control over the laser diode

current. With an on-chip reference voltage generator, a

constant and stabilized output power is ensured

independent of ageing. The ALPC can accommodate

N- or P-substrate monitor diodes.

A separate supply voltage connection for the laser allows

the internal power dissipation to be reduced by connecting

a low voltage supply. The laser output current range can

be optimized to fit the requirements of the laser diode by

means of one external resistor. When a DC-to-DC

converter is used, in combination with the control loop of

the ALPC, the adjustable output current range provides

the possibility to compensate for the extra gain a DC-to-DC

converter introduces in the control loop.

ORDERING INFORMATION

TYPE

NUMBER

TZA1025T

NAME

SO14

PACKAGE

DESCRIPTION

plastic small outline package; 14 leads; body width 3.9 mm

VERSION

SOT108-1

1998 Oct 30

2

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