BD8314NUV-E2 Rohm Semiconductor, BD8314NUV-E2 Datasheet - Page 12

• Manufacturer Part Number: BD8314NUV-E2
• Description: IC SWITCHING REG W/MOSFET SON10
• Manufacturer: Rohm Semiconductor
• Series: -r
• Type: Step-Up (Boost), PWMr

Specifications of BD8314NUV-E2

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 4 V ~ 12 V
• Current - Output: 2.5A
• Frequency - Switching: 1.2MHz
• Voltage - Input: 3 V ~ 12 V
• Operating Temperature: -25°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 10-VFDFN Exposed Pad
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

BD8314NUV
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www.rohm.com
[2]Cs and Rs setting
In the step-up DC/DC converter, the secondary pole point is caused by the coil and capacitor as expressed by the
following equation.
This secondary pole causes a phase rotation of 180°. To secure the stability of the system, put zero points in 2
places to perform compensation.
Zero point by built-in CR
Zero point by Cs
Setting C
It is desirable to set Rs at about 1/20 of (R
Those pole points are summarized in the figure below. The actual frequency property is different from the ideal
calculation because of part constants. If possible, check the phase margin with a frequency analyzer or network
analyzer, etc.. Otherwise, check for the presence or absence of ringing by load response waveform and also
check for the presence or absence of oscillation under a load of an adequate margin.
f
LC

2
π
1
S2

 
LC
D
to be half to 2 times a frequency as large as f
D: ON Duty = ( V
・・・・(4)
fz
fz
Fig. 36 Example of DC/DC converter frequency property
1
1


OUT
2
2
π
π
- V

R
R
(Measured with FRA5097 by NF Corporation)
1
4
1
(3)
IN
C

1
2
) / V
R

3
1
+R

C
13
OUT
S
3
kHz
) to cancel any phase boosting at high frequencies.
(5) (6)
12/15
(4)
・・・・(5)
・・・・(6)
LC
provides an appropriate phase margin.
Technical Note
2010.11 - Rev.C