tb7102f TOSHIBA Semiconductor CORPORATION, tb7102f Datasheet - Page 6

• Manufacturer Part Number: tb7102f
• Description: Buck Dc-dc Converter Ic
• Manufacturer: TOSHIBA Semiconductor CORPORATION

Application Circuit Example
Application Notes
Component values (@V
These values are presented only as a guide.
Component values (@V
These values are presented only as a guide.
Component values need to be adjusted, depending on the TB7102F’s input/output conditions and the board layout.
Inductor Selection
*: Generally, ΔI
appropriate inductor, taking the V
The inductance required for inductor L can be calculated as follows:
When V
C
C
R
R
L:
C
C
R
R
L:
current of the TB7102F is 1 A, ΔI
greater than the peak output current of 1.15 A. If the inductor current rating is exceeded, the inductor becomes
saturated, leading to an unstable DC-DC converter operation.
IN
OUT
FB1
FB2
IN
OUT
FB1
FB2
L
:
:
: Output voltage setting resistor = 7.5 kΩ
: Output voltage setting resistor = 2.4 kΩ
: Output voltage setting resistance = 1.2 kΩ
: Output voltage setting resistance = 2.4 kΩ
=
: Output filter capacitor = 10 μF
: Output filter capacitor = 22 μF
IN
Input filter capacitor = 10 μF
(ceramic capacitor: GRM21BB30J106K from Murata Manufacturing Co., Ltd.)
(ceramic capacitor: GRM21BB30J106K from Murata Manufacturing Co., Ltd.)
Inductor = 3.3 μH (NP04SB3R3N from Taiyo Yuden Co., Ltd.)
Input filter capacitor = 10 μF
(ceramic capacitor: GRM21BB30J106K from Murata Manufacturing Co., Ltd.)
(ceramic capacitor: GRM31CB30J226K from Murata Manufacturing Co., Ltd.)
Inductor = 3.3 μH (NP04SB3R3N from Taiyo Yuden Co., Ltd.)
V
GND
IN
V
f
osc
= 5 V and V
IN
−
L
Δ ⋅
V
should be set to approximately 30% of the maximum output current. Since the maximum output
OUT
I
L
IN
IN
⋅
V
OUT
V
= 5 V, V
= 5 V, V
OUT
IN
Figure 1 TB7102F Application Circuit Example
= 3.3 V, the required inductance can be calculated as follows. Be sure to select an
········· (1)
OUT
OUT
IN
L
should be 0.3 A or so. Therefore, the inductor should have a current rating
range into account.
= 3.3 V, Ta = 25°C)
= 1.2 V, Ta = 25°C)
TB7102F
EN
SGND
V
V
f
ΔI
osc
IN
OUT
L
:
:
:
:
6
V
PGND
Input voltage (V)
Output voltage (V)
Oscillation frequency = 1 MHz (typ.)
Inductor ripple current (A)
IN
V
L
X
FB
L
V
GND
OUT
2008-04-03
TB7102F