Datasheet

8/20

BD6586MUV

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TSZ22111

･15･001

TSZ02201-0G3G0C400190-1-2

10.Dec.2012 Rev.001

4.7

μF

VDET

SW

LED 4

4.7

μH

6LED x 4Parallel

GND

Each 20mA

2.2

μF

EN1

GND

24k

Ω

PGND

Battery

PWM

LED2

LED 3

Power

ON /OFF

SW

EN2

TEST

ISET

VBAT

SW

LED 1

TESTO

TRSW

GND

PGND

6V to 25V

Other Power Supply

2.7V to 5.5V

●The Separations of the IC Power Supply and Coil Power Supply

This IC can work in separating the power source in both IC power supply and coil power supply. With this application, it can

obtain that decrease of IC power consumption, and the applied voltage exceeds IC rating 5.5V.

That application is shown in below Figure 9. The higher voltage source is applied to the power source of coil that is

connected from an adapter etc. Next, the IC power supply is connected with a different coil power supply.

When the coil power supply is applied, it is no any problem even though IC power supply is the state of 0V. Although IC

power supply is set to 0V, pull-down resistance is arranged for the power off which cuts off the leak route from coil power

supply in IC inside, the leak route is cut off. And, there is no power on-off sequence of coil power supply and IC power

supply.

Figure 9. Each battery and coil power supply

●The Coil Selection

The DC/DC is designed by more than 4.7µH. When L value sets to a lower value, it is possibility that the specific

sub-harmonic oscillation of current mode DC / DC will be happened.

Please do not let L value to 3.3µH or below.

And, L value increases, the phase margin of DC / DC becomes to zero. Please enlarge the output capacitor value when you

increase L value.

Example)

4.7µH

=

output capacitor

2.2µF/50V

1pcs

6.8µH

=

output capacitor

2.2µF/50V

2pcs

10µH

=

output capacitor

2.2µF/50V

3pcs

This value is just examples, please made sure the final judgment is under an enough evaluation.

●The Adjustment of the Switching Wave Form

A switching wave form between the coil and the switch terminal can be adjusted by connecting a capacitor to TRSW.

Switching noise can be restrained though efficiency is made to decrease by connecting a capacitor.

Decide capacity value after the enough evaluation when you adjust switching noise.

TRSW

PGND

SW

TRSW

PGND

SW

Figure 10. The adjustment of the switching wave form