Technical Note

9/10

www.rohm.com

2010.06 - Rev.A

© 2010 ROHM Co., Ltd. All rights reserved.

BH7884EFV

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Operation Notes

1. Numbers and data in entries are representative design values and are not guaranteed values of the items.

2. 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.

3. Absolute maximum ratings

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.

4. GND potential

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.

5. Thermal design

Perform thermal design, in which there are adequate margins, by taking into account the permissible dissipation (Pd) in

actual states of use.

6. Short circuit between terminals and erroneous mounting

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.

7. Operation in strong electromagnetic field

Using the ICs in a strong electromagnetic field can cause operation malfunction.

8. Pop noise when switching power ON/OFF

To prevent pop noise when switching VCC ON/OFF or switching SUSPEND ON/OFF, use SUSPEND (11PIN=L), HP

MUTE (10PIN=L), and SUSPEND (2PIN=L) for noise control, as shown below.

(VCC OFF→ON)

(VCC ON→OFF)

VCC

SPND

HPMT

SPMT

VCC

SPND

HPMT

SPMT

1) OFF

L

L

L

1) OFF

H

H

H

2) ON

L

L

L

2) ON

H

H

L

3) ON

H

L

L

3) ON

H

L

L

4) ON

H

H

L

4) ON

L

L

L

5) ON

H

H

H

5) ON

L

L

L

9. Power supply bypass capacitor

Place the bypass capacitor close to the VCC ~ GND pins.

10. Mode switching

Do not apply a voltage that exceeds VCC or a voltage that is less than GND, at a control pin.

11. Power package

Ensure heat dissipation by connecting the heatsink to the back of the IC and to the GND board. Ensure that the GND area

is large.

12. HPOUT

Connect resistance (100 Ω is recommended) to the output for SPAMP input level adjustment and to prevent HPAMP

oscillation.

13. Capacitive load

Do not connect a capacitive load to SPAMP or HPAMP output as it may cause oscillation.

14. Startup time at low temperature and reduced power

Use the following methods to eliminate longer start up time at low temperatures (less than about -10℃) and reduced

power (less than about 3.0 V):

1) Start in SPMUTE state and then cancel SPMUTE.

2) Add to transistor and resistance, as shown in the application circuit diagram.