tb62732fug TOSHIBA Semiconductor CORPORATION, tb62732fug Datasheet - Page 5

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

Basic Operation
pulse.
with energy.
reached, the inductance is turned off.
The basic TB62732FUG circuit uses a step-up DC/DC converter, and features peak control of the current
The inductance is turned on and off with the fixed frequency f
When the inductance is turned on, the inductor current IL increases from IL = 0; and when IL = ILpeak is
At this point, the Schottky diode is turned on and IL = Ic2 flows so that the coil may retain IL = ILpeak.
After that, Ic2 is decreased, and IL = 0 is reached.
This operation is repeated; and as soon as Ic2 has fully charged C2, I
The details of the basic pulse used for the current control are shown in Figure 2.
0 (mA)
min
IL = ILpeak
SHDN
Figure 2 Switching Waveform of Inductance
Waveform of recommend
Recommended inductor
1.1 MHz
inductance 1
IL, ILpeak
V
waveform 1
CC
Figure 1 Application Circuit
T = 1/f
S
Maximum duty 85%
R
OSC
Q
, f
10 µH
OSC
GND
5
= 1.1 MHz (typ.)
Amp
Recommended inductor
waveform (max.)
OSC
A
(1.1 MHz (typ.)), and the inductor is charged
o
flows to the LED.
K
Z
D
Ic2
TB62732FUG
2006-06-14
I
o=
I
f LED