S-8353A20MC-IQFT2G Seiko Instruments, S-8353A20MC-IQFT2G Datasheet - Page 19

• Manufacturer Part Number: S-8353A20MC-IQFT2G
• Description: IC REG SW PWM 2V SOT23-5
• Manufacturer: Seiko Instruments
• Type: Step-Up (Boost)r

Specifications of S-8353A20MC-IQFT2G

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 2V
• Frequency - Switching: 50kHz
• Voltage - Input: 0.9 ~ 10 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: SOT-23-5, SC-74A, SOT-25
• Power - Output: 250mW
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Rev.3.0
STEP-UP, PWM CONTROL or PWM / PFM SWITCHABLE BUILT-IN TRANSISTOR SWITCHING REGULATOR
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) :
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
OUT
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
.
−
)
L
IN
dt
+
•
+
), 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
Q
OUT
I
PK
I
OUT
−
⎞
• ⎟
⎠
L
PK
⎞
• ⎟
⎠
1
t
rises rapidly. V
1
V
+
:
to be consumed during t
1 t
IN
+
t
2
2
1
L
ON
+
I
OUT
) is consumed. As a result, the pin voltage of C
I
+
⎞
⎟
⎟
⎠
OUT
L
V
). When M1 is turned OFF, the energy stored in L is transmitted through the
⎛
⎜
⎝
D
I
PK
⎞
• ⎟
⎠
L
−
•
during t
V
t
+
R
Seiko Instruments Inc.
1
2
IN
I
ESR
OUT
•
∫
⎞
• ⎟
⎠
1 t
0
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
t
C
1
L
•
−
OUT
t
and load current (I
OUT
V
1
OUT
. When receiving the output current (I
reaches the maximum level :
+
L
V
D
−
V
IN
•
2
OUT
1
t
1
) match.
2
L
S-8353/8354 Series
is reduced, and goes to the
ESR
) of C
OUT
L
) from
(10)
(11)
(12)
(13)
(14)
(15)
(16)
:
(7)
(8)
(9)
19