S-8331 Seiko Instruments USA, S-8331 Datasheet - Page 15

• Manufacturer Part Number: S-8331
• Description: Step-Up Switching Regulator (DC/DC Converter ICs)
• Manufacturer: Seiko Instruments USA

Rev.5.1
V
The pin voltage at CONT rises only by the voltage corresponding to V
A change in the current (I
Integration of the above equation is as follows :
During t
from V
decreases and goes to the lowest value after t
transmitted through a diode into C
function that indicates the maximum value (ripple voltage V
through diode and load current I
equations:
I
When substituting equation (10) for equation (9):
Electric charge ΔQ
When substituting equation (12) for equation (9):
A rise in voltage (V
OUT
t
OFF
L
:
_00
V
(V
∴
I
I
⎛
⎜
⎜
⎝
t
Δ
Δ
V
dI
L
OUT
dt
1
when the time is set to t
L
when I
V
Q
Q
P
D
t
L
=
=
= (V
1
−
OUT
1
1
P
; Diode forward voltage)
OUT
I
=
=
t
PK
=
=
=
ON
OFF
=
I (
V
I
∫
I
L
OUT
PK
, the energy of the capacitor (C
+
PK
, the energy is stored in L and is not transmitted to V
PK
−
C
L
L
0
Δ
1 t
L
V
=0 (the energy of the inductor is completely transmitted). Based on equation (7)
−
⎛
⎜
⎝
OUT
I
Q
=
−
−
−
L
D
+ V
V
⎛
⎜ ⎜
⎝
dt
1
⎛
⎜
⎝
I
V
I
OUT
1
2
OUT
−
OUT
I
V
PK
OUT
STEP-UP, FOR LCD BIAS SUPPLY, 1-CHANNEL SWITCHING REGULATOR
=
(
=
V
D
I
OUT
PK
) − V
IN
I
1
C
)
PK
P-P
+
⎞
• ⎟ ⎟
⎠
•
which is charged in C
OUT
+
⎞
⎟
⎟
⎠
L
−
1
V
) due to ΔQ
+
⎛
⎜
⎜
⎝
•
L
=
V
t
I
D
OUT
L
IN
V
OFF
V
∫
D
−
t
OUT
D
•
I
0
OFF
1 t
PK
L
−
V
⎛
⎜
⎝
) which flows through a diode into V
−
dt
)
V
I
IN
•
PK
1
V
IN
+
−
t
until V
⎞
• ⎟
⎠
IN
1
L
V
+
V
=
2
⎞
• ⎟
⎠
D
OUT
I
t
OUT
OUT
1
I
−
PK
t
:
1
V
OUT
OUT
+
match. Next, the ripple voltage is found out based on the following
+
IN
⎞
• ⎟
⎠
Seiko Instruments Inc.
2
L
V
I
OUT
⎞
⎟
⎟
⎠
reaches the maximum level immediately after t
, and the pin voltage at C
t
D
1
−
OUT
•
V
IN
t
OUT
1
during t
•
) is consumed. As a result, the pin voltage at C
ON
∫
1 t
0
. When M1 is turned OFF, the energy stored in L is
tdt
1
:
=
I
PK
•
t
1
OUT
−
P-P
V
OUT
) when the current flowing into V
during t
OUT
OUT
. When output current (I
OUT
+
rises drastically. V
L
V
+V
OFF
D
−
D
:
.
V
IN
S-8330/8331 Series
•
2
1
t
1
www.DataSheet4U.com
2
ON
:
OUT
OUT
is a time
) flows
(10)
(11)
(12)
(13)
(14)
(5)
(6)
(7)
(8)
(9)
OUT
OUT
15