S-8351B46MA-J5FT2G Seiko Instruments, S-8351B46MA-J5FT2G Datasheet - Page 19
S-8351B46MA-J5FT2G
Manufacturer Part Number
S-8351B46MA-J5FT2G
Description
IC REG SW 100KHZ 4.6V SOT23-3
Manufacturer
Seiko Instruments
Type
Step-Up (Boost)r
Datasheet
1.S-8351A22MC-J2HT2G.pdf
(51 pages)
Specifications of S-8351B46MA-J5FT2G
Internal Switch(s)
Yes
Synchronous Rectifier
No
Number Of Outputs
1
Voltage - Output
4.6V
Frequency - Switching
100kHz
Voltage - Input
0.9 ~ 10 V
Operating Temperature
-40°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
SOT-23-3
Power - Output
150mW
Output Voltage
4.6 V
Input Voltage
10 V
Maximum Operating Temperature
+ 85 C
Mounting Style
SMD/SMT
Minimum Operating Temperature
- 40 C
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Current - Output
-
Lead Free Status / Rohs Status
Lead free / RoHS Compliant
Rev.3.0
Therefore to reduce the ripple voltage, it is important that the capacitor connected to the output pin has a large
capacity and a small R
Integration of the equation (6) is as follows :
During t
V
lowest level after M1 is turned ON (t
diode to C
(ripple voltage (V
Next, the ripple voltage is determined as follows.
I
When M1 is turned OFF (t
When substituting equation (10) for equation (9) :
Electric charge
When substituting equation (12) for equation (9) :
A rise in voltage (V
When taking into consideration I
When substituting equation (11) for equation (15) :
OUT
STEP-UP, BUILT-IN / EXTERNAL FET PFM CONTROL SWITCHING REGULATOR / SWITCHING REGULATOR CONTROLLER
OUT
∴
I
I
⎛
⎜
⎜
⎝
t
Δ
Δ
V
V
V
L
vs. t
OUT
_00
, the energy of the capacitor (C
1
V
Q
Q
P
P
P
t
=
=
−
−
−
1
OUT
1
1
P
P
P
I
t
ON
=
PK
=
=
1
OFF
=
=
=
=
I (
(time) from when M1 is turned OFF (after t
I
I
, the energy is stored in L and is not transmitted to V
L
PK
+
∫
PK
PK
−
I (
, and the voltage of C
Δ
Δ
C
C
L
1 t
0
V
−
PK
⎛
⎜
⎝
Q
Q
−
I
−
L
L
D
−
L
V
⎛
⎜
⎜
⎝
1
1
dt
I 2
⎛
⎜
⎝
I
−
I
OUT
−
1
2
OUT
OUT
I
Δ
=
PK
=
V
PK
I
P
V
(
OUT
=
Q
OUT
I
−
PK
C
C
IN
P
P
1
1
+
)
1
I
⎞
• ⎟ ⎟
⎠
L
PK
L
) ) when the current flowing through into V
−
•
⎞
⎟
⎟
⎠
L
)
which is charged in C
P
V
−
•
2
•
+
⎛
⎜
⎜
⎝
) due to
=
t
D
I
ESR
•
⎛
⎜
⎝
OFF
OUT
⎛
⎜
⎝
L
V
•
V
I
−
t
∫
I
OUT
PK
I
PK
D
OFF
t
OFF
PK
C
OFF
1 t
0
.
V
−
)
dt
L
IN
+
•
+
), I
2
2
V
+
I
t
I
⎞
• ⎟
⎠
OUT
+
IN
−
1
OUT
L
V
L
Δ
=
⎛
⎜
⎝
D
⎞
• ⎟
⎠
V
= 0 (when the energy of the inductor is completely transmitted). Based on equation (7) :
t
OUT
Q
I
PK
I
OUT
L
−
⎞
• ⎟
⎠
PK
⎞
• ⎟
⎠
t
1
rises rapidly. V
1
V
+
:
to be consumed during t
1 t
IN
+
t
2
L
ON
2
1
+
I
) is consumed. As a result, the pin voltage of C
OUT
I
+
⎞
⎟
⎟
⎠
OUT
L
V
). When M1 is turned OFF, the energy stored in L is transmitted through the
⎛
⎜
⎝
D
I
PK
⎞
• ⎟
⎠
L
−
•
Seiko Instruments Inc.
during t
t
+
R
V
1
2
IN
I
ESR
OUT
•
∫
⎞
• ⎟
⎠
0
1 t
1
OUT
tdt
ON
R
:
ESR
) to when V
is a time function, and therefore indicates the maximum value
=
I
PK
−
I
1
OUT
•
and the Equivalent Series Resistance (R
OUT
C
t
1
L
•
−
OUT
t
and load current (I
OUT
1
V
OUT
. When receiving the output current (I
reaches the maximum level :
+
L
V
D
−
V
IN
•
OUT
1
2
t
1
) match.
L
2
S-8351/8352 Series
is reduced, and goes to the
ESR
) of C
OUT
L
) from
(10)
(11)
(12)
(13)
(14)
(15)
(16)
:
(7)
(8)
(9)
19