HI2555, CXD2555
Master Mode/Slave Mode
Crystal Oscillator Frequency Selection
(f = 32kHz to 48kHz)
S
(Related Pins) MS, LRCK, BCK
(Related Pins) XTLI, XTLO, XSLO, XSL1, XSL2, UNCLK,
XCLK
When using the XCS2555Q in multiple units or in a pair with
DA converters such as the CXD2558M, one of these
CXD2555Qs should be in the master mode to serve as the
source of clocks LRCK and BCK. The other CXD2555Qs are
used in the slave mode, with their clocks LRCK and BCK
supplied by the master CXD2555Q.
By setting a combination of XSLO and XSL1, with XSL2
fixed Low, the frequency of the external crystal oscillator
connected to XTLI and XTLO can be selected. In this case,
XCLK outputs a clock whose frequency is always 256 times
f , and UCLK outputs a clock that is half the crystal oscillator
S
TABLE 3.
frequency.
MS
H
MODE
LRCK AND BCK I/O
When supplying the master clock fro some other external
source, not a crystal oscillator, use XTLI for this clock input
and leave XTLO open.
Master Mode
Slave Mode
Output
Input
L
TABLE 4.
CRYSTAL OSCILLATOR FREQUENCY
256f
XSL2
XSL1
XSL0
XCLK
256f
UCLK
128f
L
L
L
L
L
L
L
H
L
S
S
S
512f
256f
256f
S
S
S
H
H
768f
256f
384f
S
S
S
H
1024f
256f
512f
S
S
S
INPUT
INPUT
OUTPUT
OUTPUT
LRCK
LRCK
CXD2555Q
(SLAVE MODE)
MS
L
H
MS
(MASTER MODE)
BCK
CXD2555Q
BCK
INPUT
INPUT
LRCK
BCK
CXD2558M
FIGURE 37. CONNECTION EXAMPLE
Crystal Oscillator Frequency Selection
(f = 8kHz to 24kHz)
S
512f
256f
S
S
TO EXTERNAL IC,
SUCH AS DSP
UCLK
CXD2555Q
L
XSL2
XSL1
XSL0
(Related Pins) XTLI, XTLO, XSLO, XSL1, XSL2, UNCLK,
XCLK
H
H
TO CXD2555Q IN
SLAVE MODE
With XSL2 fixed High, the device can be operated with low-
XCLK
XTL0
f
frequencies which may be 1/2 or 1/4 the normal f
S
S
XTL1
frequency. In this case, the frequency of the crystal oscillator
can be selected by setting a combination of XSL0 and XSL1
accordingly.
1024f
S
FIGURE 38. CONNECTION EXAMPLE
Example: When input level = 1.4V (4V
AD Converter Input Level
)
P-P
RMS
Given the constants shown in the Test Circuit on page 7, the
R
= 4200 • 1.4 - 1200 = 4680
AD converter input level V (operational amplifier input IN)
IN
IN
→ 4700 [Ω]
is such that 4V
(1.4V
) is equivalent to the full-scale
RMS
P-P
output. Also, the large-amplitude inputs are possible by
varying the AD converter input resistance value (R ). Use
IN
the equation shown below to calculate this resistance value.
The AD converter generates full-scale outputs for inputs
equal to or greater than the values thus obtained.
R
= 420 • V [RMS] - 1200 [Ω]
IN
IN
4-308
INTERSIL [ Intersil ]
