NX9415CMTR Microsemi Analog Mixed Signal Group, NX9415CMTR Datasheet - Page 10

• Manufacturer Part Number: NX9415CMTR
• Description: IC BUCK SYNC ADJ 5A MCM-24L
• Manufacturer: Microsemi Analog Mixed Signal Group
• Type: Step-Down (Buck)r

Specifications of NX9415CMTR

• Internal Switch(s): Yes
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: Adj to 0.8V
• Current - Output: 5A
• Frequency - Switching: 200kHz ~ 2.2MHz
• Voltage - Input: 9 ~ 22 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 24-VQFN Exposed Pad, 24-HVQFN, 24-SQFN, 24-DHVQFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -

compensator is
the compensator of transconductance amplifier must
sat i sf y t hi s condi t i on: R
able if R
Rev.1.2
12/28/09
For the voltage amplifier, the transfer function of
Figure 10 - Bode plot of Type III compensator
To achieve the same effect as voltage amplifier,
V
Zin
loop gain
compensator
V
OUT
Figure 9 - Type III compensator using
C3
1
R3
power stage
e
||R
F
2
||R
Z1
Z
Z
Vout
3
in
>>1/gm can be met at the same time.
f
F
R2
R1
20dB/decade
F
Z2
LC
transconductance amplifier
4
>>2/gm. And it would be desir-
Vref
Fb
C2
F
C1
O
Zf
gm
F
40dB/decade
R4
P2
F
P1
F
Ve
S
F
ESR
B. Type II compensator design
circuit without feedback as shown in figure 12. R
introduce a zero to cancel the double pole effect. C
introduces a pole to suppress the switching noise. The
following equations show the compensator pole zero lo-
cation and constant gain.
F
LC
<F
Figure 11 - Bode plot of Type II compensator
Type II compensator can be realized by simple RC
For this type of compensator, F
ESR
F =
F
Gain=g
<<F
p
z
loop gain
2
power stage
compensator
O
2
<=1/10~1/5F
m
F
Z
1
R
R +R
1
R
F
3
1
R
3
LC
1
C
F
C
2
1
ESR
2
s.
40dB/decade
R
20dB/decade
3
F F
O
... (7)
... (8)
... (9)
O
Gain
has to satisfy
P
NX9415
3
and C
10
1
2