ak4370 AKM Semiconductor, Inc., ak4370 Datasheet - Page 16

• Manufacturer Part Number: ak4370
• Description: 24-bit 2ch Dac With Hp-amp & Output Mixer
• Manufacturer: AKM Semiconductor, Inc.

ASAHI KASEI
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The AK4370 supports both master and slave modes to interface with external devices. (See Table 1).
The M/S bit selects either master or slave mode. M/S bit = “1” selects master mode and “0” selects slave mode. When the
AK4370 is power-down mode (PDN pin = “L”) and exits reset state, the AK4370 is slave mode. After exiting reset state,
the AK4370 goes to master mode by changing M/S bit = “1”.
When the AK4370 is used by master mode, LRCK and BICK pins are a floating state until M/S bit becomes “1”. LRCK
and BICK pins of the AK4370 should be pulled-down or pulled-up by the resistor (about 100kΩ) externally to avoid the
floating state.
The frequency of master clock inputted to the MCKI pin can be selected FS3-0 bits. (Refer to Table 2)
If the sampling frequency is changed during normal operation of the DAC (PMDAC bit = “1”), the change should occur
after the input is muted by SMUTE bit = “1”, or the input is set to “0” data.
LRCK and BICK are output from the AK4370 in master mode (Figure 11). The clock input to the MCKI pin should
always be present whenever the DAC is in normal operation (PMDAC bit = “1”). If these clocks are not provided, the
AK4370 may draw excessive current and will not operate properly because it utilizes these clocks for internal dynamic
refresh of registers. If the external clocks are not present, the DAC should be placed in power-down mode (PMDAC bit =
“0”).
MS0595-E-00
M/S bit
System Clock
1
0
Master Mode
Slave Mode
Mode
Selected by FS3-0 bits
Selected by FS3-0 bits
AK4370
MCKI pin
Table 1. Clock Mode Setting (x: Don’t care)
MCKI
BICK
LRCK
SDATA
OPERATION OVERVIEW
Figure 11. Master Mode
256fs, 384fs, 512fs,
768fs or 1024fs
32fs, 64fs
(Selected by BF bit)
1fs
- 16 -
(32fs ∼ 64fs)
BICK pin
Output
Input
MCLK
BCLK
LRCK
SDTO
DSP or μP
LRCK pin
Output
Input
(1fs)
(1fs)
Figure 11
Figure 12
Figure
[AK4370]
default
2007/03