tza1032 NXP Semiconductors, tza1032 Datasheet - Page 4

• Manufacturer Part Number: tza1032
• Description: Laser Driver And Controller Circuit
• Manufacturer: NXP Semiconductors

Philips Semiconductors
The TZA1032 fulfils three main functions:
3
2002 May 06
TYPE NUMBER
TZA1032UK
Drives the laser with a sequence of programmable write
strategy pulses with high timing accuracy and high peak
current levels
Encodes the input modulated data to a sequence of
write strategy pulses. This encoding is flexible with
respect to input modulation code (EFM, EFMplus,
17 pp, etc.). Any RLC with run lengths in the range from
1 to 15 is possible. The write strategy is programmable
with high flexibility for CD-R/RW, DVD-R/RW, DVR or
other optical recording systems using comparable write
strategies. For this purpose the TZA1032 includes two
Random Access Memories (RAMs) which can be
loaded (non real-time) via an I
microcontroller
Controls the exact light power levels coming from the
laser and controls the exact power absorbed by the disc
during recording. This is not trivial since the laser
characteristics (both threshold and gain) are strongly
temperature dependent. A first control loop controls the
laser power levels based on the signal from a forward
sense diode (FS control). This will make the laser
virtually temperature and aging independent. The loop is
fully self-contained, only an external forward sense
diode must be connected. A second control loop
controls the laser power based on an alpha signal,
generated by additional electronics based on signals
from the diode during writing. It is primarily intended to
compensate for writing performance variations due to
Laser driver and controller circuit
ORDERING INFORMATION
NAME
bare die with solder bumps
2
C-bus from a PC or
4
DESCRIPTION
When required, non-real time control is possible via an
interrupt feedback signal at pin IRQ.
The TZA1032 can supply the analog, digital and driver part
separately to obtain maximum performance.
The TZA1032 features three independent power supplies.
These are the analog and digital power supplies and a
local power supply for the laser driver function. The
supplies can be delivered separately to obtain maximum
output performance of the TZA1032 in environments with
large and highly dynamic current flows. The driver supply
has no accompanying ground because the laser driver
block only sources current to the laser. Ensure that all
power supply pins are connected to the appropriate
voltage rails.
For evaluation purposes only (by special request) the
TZA1032 can be delivered in a LQFP64 package.
PACKAGE
imperfections in the optical path and/or disc (e.g. finger
prints). The alpha signal is a measure of the power
absorption of the disc material during the writing process
or in general of the writing quality on the disc. For this
second loop, a method of stepping the set point under
external control is provided. The TZA1032 contains a
programmable counter that can be clocked via the
external OPC-strobe (pin OPC). This function is
typically used during OPC in order to calibrate the
optimum laser writing power.
Preliminary specification
TZA1032
VERSION