TZA1046

The TZA1046 is a single optical pick-up IC for read/write systems and is suitable for CD and DVD applications.

The TZA1046 device contains eight RF amplifiers for the central and satellite diodes and one differential RF amplifier (RFP and RFN) which handles the sum of the four A, B, C and D central diode signals.

Programming the gain is a very versatile way to optimize interfacing between the TZA1046 and the preamplifier.The gain can be programmed for CD or DVD media with the gain switch CD/DVD. The H/L switch is a three level switch that can be used to adjust the gain for different dye and phase change media.The third level (high-impedance state)invokes the power-down mode for standby condition. Gain switch R/W is used to reduce the gain during writing.During CD-R writing with clipping, the high peak signals for the central and satellite segments are clamped internally and the output currents of the A, B, C, D, E, F, G and H segments are folded back to reduce power consumption.The output currents of TZA1046 can be folded back to almost zero,depending on the light power detected. CD-R writing can also be done without clipping for applications where averaging is used.

All outputs of TZA1046 are current outputs that can supply a maximum of 8 mA. In CD-R write clip mode, the clipping level of the output currents is between 5 mA and 8 mA.

The HTSSON16T package has a low spread on the Z tolerance. The Z tolerance is measured between the diodes (chip surface) and the bottom of the leads. The TZA1046 diodes have an offset of 54 mm the y direction with respect to the leadframe centre and a tolerance of 50mm in both x- and y-directions.

In normal operation the satellite outputs F and H are combined as one output FH and the satellite outputs E and G are combined as one output EG. In normal mode the ETST and HTST outputs are not used (high ohmic).When pulling the R/W pin above the supply or is left open the device comes into a testing mode where all four separate satellite channels are directed to the outputs.This mode is used for Optical Pick-up Unit (OPU) alignment of the TZA1046 diodes where all satellite channels must be available.