BD3883FS ROHM Co. Ltd., BD3883FS Datasheet - Page 14

• Manufacturer Part Number: BD3883FS
• Description: Audio Sound Controller For Home Audio
• Manufacturer: ROHM Co. Ltd.

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Cautions on use
1.
2.
3.
4.
5.
6.
7.
8.
9.
10. Function switching
11. Power-ON Reset (BD3883FS)
12. Step switching noise (BD3883FS)
Numbers and data in entries are representative design values and are not guaranteed values of the items.
Although ROHM is confident that the example application circuit reflects the best possible recommendations, be sure to
verify circuit characteristics for your particular application. Modification of constants for other externally connected
circuits may cause variations in both static and transient characteristics for external components as well as this Rohm IC.
Allow for sufficient margins when determining circuit constants.
Absolute maximum ratings
GND potential
Thermal design
Short circuit between terminals and erroneous mounting
Operation in strong electromagnetic field
2-wire serial control
E Input external resistance (BD3883FS)
Use of the IC in excess of absolute maximum ratings, such as the applied voltage or operating temperature range
(Topr), may result in IC damage. Assumptions should not be made regarding the state of the IC (short mode or open
mode) when such damage is suffered. A physical safety measure, such as a fuse, should be implemented when
using the IC at times where the absolute maximum ratings may be exceeded.
Ensure a minimum GND pin potential in all operating conditions. Make sure that no pins are at a voltage below the
GND at any time, regardless of whether it is a transient signal or not.
Perform thermal design, in which there are adequate margins, by taking into account the permissible dissipation (Pd)
in actual states of use.
Pay attention to the assembly direction of the ICs. Wrong mounting direction or shorts between terminals, GND, or other
components on the circuits, can damage the IC.
Using the ICs in a strong electromagnetic field can cause operation malfunction.
Because SC and SI terminals are designed for inputting high-frequency digital signals, wiring and layout
patterns should be routed as not to cause interference with the analog-signal-related lines.
To avoid a sudden noise into E Input, external resistance (4.7kΩ) should be connected as close as possible to
the IC terminal.
Action to absorb shock sounds is taken when switching between the Volume, Treble, Middle and Bass
functions.
A built-in circuit for performing initialization inside the IC at Power-ON is provided. Specifically, the initial states
are set as described in the table below. In the case of the setting design, however, to be on the safe side, it is
recommended that data shall be sent to all the addresses as initial data at power-ON and, until this sending
operation is completed, MUTE shall be applied. To avoid malfunctions, serial data signals must be set to the
Low state at power-ON/OFF.
For Surround and Rear Volume, an external capacitor C is attached to the CAP pin to control the switching step
noise. In the application circuit, a constant value, as an example, is shown by the CAP pin.
The time constant for charge/discharge of the capacitor C (varying between VBE to 5VBE (2.65V)) controls the slow
switching operation.
The switching time constant T is calculated as the follows:
VBE has temperature characteristics and may affect the value of the time constant T.
T=2.55×10
5
×C
Input Selector
Rear Volume
Input Gain
RECOUT
Surround
Function
Volume
Middle
Treble
Bass
14/16
Initial State
MUTE
−∞dB
0 dB
0 dB
0 dB
0 dB
OFF
OFF
0dB