bh3874aks2 ROHM Co. Ltd., bh3874aks2 Datasheet - Page 7

• Manufacturer Part Number: bh3874aks2
• Description: Multi-function Sound Processor Built-in 5-band Equalizer
• Manufacturer: ROHM Co. Ltd.

●Cautions on use
●Thermal derating characteristic
1.
2.
3.
4.
5.
6.
7.
8.
9.
10. Schmidt circuit
11. Power ON/OFF
12. Spectrum analyzer minimum light level
13. Spectrum analyzer control
14. Serial data input at power ON
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
Serial control
Ground line
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.
The IC ground must be connected at one point to the ground line on the set. Common impedance on the ground
line may generate noise when switching the functions.
This IC is provided with the Schmidt circuit to provide protection for the logic signal inputs of the DATA (34pin) and
CLK (35pin) terminals. Noise control measures against the logic signal lines are enhanced.
It is recommended to activate a mute function on the set to eliminate a pop noise at power ON/OFF.
Output offset voltages may shift due to ambient environment (temperature, stress, etc.). Therefore, when setting the
spectrum analyzer minimum light level, an appropriate margin of 30% or more (for the spectrum analyzer output
offset voltage: VOS), should be provided.
The spectrum analyzers should be controlled in parallel. Controlling them in serial generates noise on the signal
outputs. If it is necessary to control in serial, noise measures should be taken into consideration.
In order to determine the initial state of the IC, serial data should be sent at least two times at power ON.
1400
1200
1000
800
600
400
200
0
0
25
50
Fig.19
Ta [ ℃ ]
75
Fig.19
7/8
100
125
BH3874AKS2
ROHM standard board packaging time value
Board size: 70×70×1.6mm
Material: Glass epoxy board