tb62732fug TOSHIBA Semiconductor CORPORATION, tb62732fug Datasheet - Page 7

• Manufacturer Part Number: tb62732fug
• Description: Step-up Dc/dc Converter For White Led Driver
• Manufacturer: TOSHIBA Semiconductor CORPORATION

Output-side capacitor setting
External inductance setting
To reduce the effect of ripple current, we recommend 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 for supply to the inductance
For example, the following condition is substituted for the formula:
This value does not allow for inductor variation and temperature characteristics; therefore we strongly
recommend that these factors be taken into account when selecting products.
Capacitor C 2 (µF)
OSC
O
In this case, Toshiba recommend selection of L = 5.6 (µH) when V
o
IN
: output power (power required by LED load)
f
(A): The average current value established with R_sens.
OSC
Ip
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
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
O
Typ.
Typ.
350
IN
1.1
min × I
= 18.5 mA,
F
IN
= 3.0 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
= 4.3 V).
2
= 0.47 (µF) or above.
O
(mA), LED forward voltage: V
Recommend
CC
F
Note
LED × I
= 3 V. .
F
LED
F
TB62732FUG
LED (V),
2006-06-14