A5975DTR STMicroelectronics, A5975DTR Datasheet - Page 19
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A5975DTR
Manufacturer Part Number
A5975DTR
Description
IC REG SW STEP-DOWN 3A 8SOIC
Manufacturer
STMicroelectronics
Series
-r
Type
Step-Down (Buck), PWMr
Datasheet
1.A5975DTR.pdf
(50 pages)
Specifications of A5975DTR
Internal Switch(s)
Yes
Synchronous Rectifier
No
Number Of Outputs
1
Voltage - Output
1.235 V ~ 35 V
Current - Output
3A
Frequency - Switching
250kHz
Voltage - Input
4 V ~ 36 V
Operating Temperature
-40°C ~ 125°C
Mounting Type
Surface Mount
Package / Case
8-SOIC (0.154", 3.90mm Width) Exposed Pad
Lead Free Status / Rohs Status
Lead free / RoHS Compliant
Other names
497-11426-2
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
A5975DTR
Manufacturer:
MICROCHIP
Quantity:
3 000
A5975D
7
7.1
Closing the loop
Figure 9.
Error amplifier and compensation network
The output LC filter of a step-down converter contributes with 180-degree phase shift in the
control loop. For this reason a compensation network between the COMP pin and GROUND
is added. The simplest compensation network, together with the equivalent circuit of the
error amplifier, are shown in
loop gain. CP does not significantly affect system stability but it is useful to reduce the noise
of the COMP pin.
The transfer function of the error amplifier and its compensation network is:
Equation 2
where A
vo
A
0
= G
s ( )
Block diagram of the loop
m
=
· R
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -
s
2
⋅
o
.
R
0
⋅
(
C
0
+
Figure
Doc ID 018760 Rev 1
C
p
) R
⋅
10. R
c
⋅
C
A
c
V0
C
+
and C
s
⋅
(
⋅
1
(
R
+
0
s
C
⋅
⋅
C
R
introduce a pole and a zero in the open
c
c
+
⋅
C
R
c
0
)
⋅
(
C
0
+
C
p
)
+
R
c
⋅
C
Closing the loop
c
)
+
1
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