CXA2542AQ
Commands
The input data to operate this IC is configured as 8-bit/12-bit data; however, below, this input data is
represented by 2-digit hexadecimal numerals in the form $XX, where X is a hexadecimal numeral between 0
and F/$XXX for 12-bit.
Commands for the CXA2542AQ can be broadly divided into four groups ranging in value from $0X, $1X, $2X,
$3XX.
1. $0X (FZC at SENS1 pin (Pin 23), H (Hi-Z) at SENS2 pin (Pin 24))
These commands are related to the focus servo control.
The bit configuration is as shown below.
D7
0
D6
0
D5
0
D4
0
D3
D2
—
D1
D0
FS4
FS2
FS1
Four focus related switches exist: FS1, FS2, FS4 and DFCT.
$00 When FS1 = 0, Pin 7 is charged to (22µA – 11µA) × 50kΩ = 0.55V.
If, in addition, FS2 = 0, this voltage is no longer transferred, and the output at Pin 5 becomes 0V.
$02 From the state described above, the only FS2 becomes 1. When this occurs, a negative signal is output
to Pin 5. This voltage level is obtained by equation 1 below.
resistance between Pins 5 and 6
(22µA – 11µA) × 50kΩ ×
.... Equation 1
50kΩ
The SRCH DOWN speed can be increased by the charge up circuit.
$03 From the state described above, FS1 becomes 1, and a current source of +22µA is split off.
Then, a CR charge/discharge circuit is formed, and the voltage at Pin 7 decreases with the time as
shown in Fig. 1 below.
0V
Fig. 1. Voltage at Pin 7 when FS1 goes from 0 → 1
This time constant is obtained with the 50kΩ resistance and an external capacitor.
By alternating the commands between $02 and $03, the focus search voltage can be constructed. (Fig. 2)
0V
$
00 02
03
02
03
02
00
Fig. 2. Constructing the search voltage by alternating between $02 and $03. (Voltage at Pin 5)
– 29 –
SONY [ SONY CORPORATION ]
