tb62732fu TOSHIBA Semiconductor CORPORATION, tb62732fu Datasheet - Page 7

• Manufacturer Part Number: tb62732fu
• Description: Step-up Dc/dc Converter For White Led Driver
• Manufacturer: TOSHIBA Semiconductor CORPORATION

Output-side capacitor setting
External inductance setting
The C
The minimum external inductance is calculated as follows:
The above parameters are described below:
L (µH) = ((K × P
P
V
I
f
Ip (A): Peak current value to supply to the inductance.
For example, the following condition is substituted for the formula.
It is supposed under condition.
Therefore, 6.3 µH in V
It is sufficient by the above calculation on the standard condition.
Capacitor C 2 (µF)
OSC
O
o
IN
: output power (power required by LED load)
f
(A): The average current value established with R_sens.
OSC
Ip
2
P
LED forward current: I
Schottky diode forward voltage: Vf schottky (V),
Setting resistance: R_sens (Ω)
Input voltage V
V
Setup resistance R_sens: R_sens = 2.7 (Ω),
Setup current I
L (µH) = 5.6 (µH, V
min (V): Minimum input voltage (battery voltage)
(Hz): The switching frequency of the internal MOS transistor.
is upper 0.1 (µF) above is recommended from the consideration to the I
o
F
0.01
0.47
0.1
(W) = V
LED = 16 V, schottky diode Vf: schottky = 0.3 (V),
1
0.77
Min
Min
320
F
o
) − V
LED × I
O
IN
: I
IN
: V
CC
O
Typ.
Typ.
350
IN
1.1
min × I
= 18.5 mA.
F
IN
= 3 V whose input voltage is low is chosen.
= 4.3 V) and 6.3 (µH, V
LED + Vf schottky × I
Ripple Current (mA)
F
= 3 to 4.3 V,
LED (mA) = Set current: I
O
15 to 25
) × (1/f
Max
1.43
Max
5 to 8
2 to 4
1 to 3
380
OSC
MHz
MHz
min) × 2 × (1/Ip min × Ip min) . . . formula 2
Unit
Unit
F
IN
7
LED + R_sens × I
= 3 V)
O
(mA), LED forward voltage: V
Recommend
F
Note
LED × I
F
F
peak.
LED
F
LED (V),
TB62732FU
2006-06-14