Pioneer AVIC-Z2/XU/UC Service Manual page 299

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1.3 Automatic adjustment functions
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This system automatically performs all circuit adjustments by combined operations of the ICs AN8703FH (FEP) and
MNZS26EDCUB (SODC). Each automatic adjustment function is explained below:
1.3.1 FE, TE and AS offset cancel
The analog signals FE, TE and AS, generated by the FEP, are A/D-converted by the A/D converter inside the SODC.
When the power is turned on, the offset cancel works to cancel the input offset of the A/D converter.
1.3.2 Data slice balance (DBAL) adjustment
The DBAL adjustment is made to adjust the data-slice level that is used when the RF signal from the FEP is
converted to a binary signal in the SODC. When the power is turned on, the test signal of the constant frequency is
output from the SODC and the jitter component of the signal is adjusted to the minimum.
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•In the same manner as the above, the PLL balance (PBAL) adjustment is made to optimize the current level balance
between the P-ch and N-ch sides of the chargeable pump.
1.3.3 FE regulating adjustment
The FE signal level measured when the focus loop is closed is A/D-converted in the SODC. Then it is adjusted so that
it becomes 190LSB at the input stage of the digital equalizer.
1.3.4 Spindle gain learning
The time is measured that is required for the spindle motor to start rotating in the stop mode and reach the
prescribed rotation. The measured time is used to adjust the SPDL gain, thereby absorbing the variation in the
motor torque.
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1.3.5 Tracking balance (TBAL) adjustment
In the focus close and tracking open mode, the lens is vibrated in the tracking direction. The tracking balance is
adjusted so that the DC offset becomes zero (the balance point) by using the Newton-Raphson's method.
1.3.6 Tracking error amplitude learning
In the focus close and tracking open mode, the lens is vibrated in the tracking direction. After A/D-converted in the
ADSC, the amplitude level of the TE signal is adjusted so that it becomes 190LSB at the input stage of the digital
equalizer.
1.3.7 Focus balance (FBAL) adjustment
In the tracking close mode, the focusing position is adjusted by minimizing the RFENV.
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1.3.8 Focus gain and tracking gain adjustments
In the tracking close mode, some disturbance signal is applied to the servo loops. The focus and tracking gains are
adjusted to the target gain cross points.
1.3.9 AS regulating adjustment
In the tracking close mode, the AS signal level is sampled the prescribed times. After A/D-converted in the ADSC,
this signal is adjusted so that it becomes 64LSB at the input stage of the digital equalizer.
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