EVAL5985 STMicroelectronics, EVAL5985 Datasheet - Page 23

• Manufacturer Part Number: EVAL5985
• Description: BOARD EVAL FOR L5985
• Manufacturer: STMicroelectronics
• Type: DC/DC Switching Converters, Regulators & Controllersr

Specifications of EVAL5985

• Main Purpose: DC/DC, Step Down
• Outputs And Type: 1, Non-Isolated
• Voltage - Output: 3.3V
• Current - Output: 2A
• Voltage - Input: 3.3 ~ 18V
• Regulator Topology: Buck
• Frequency - Switching: 500kHz
• Board Type: Fully Populated
• Utilized Ic / Part: L5985
• Input Voltage: 2.9 V to 18 V
• Output Voltage: 0.6 V to 16 V
• Product: Power Management Modules
• Silicon Manufacturer: ST Micro
• Silicon Core Number: L5985
• Kit Application Type: Power Management - Voltage Regulator
• Application Sub Type: Step Down Switching Regulator
• Kit Contents: Board
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: L5985
• Other names: 497-6387; EVAL5985

L5985
Figure 13. Type II compensation network
The singularities of the network are:
In
and the open loop gain (G
Figure 14. Open loop gain: module Bode diagram
The guidelines for positioning the poles and the zeroes and for calculating the component
values can be summarized as follow:
1.
2.
Figure 14
Choose a value for R
and C5 not comparable with parasitic capacitance of the board.
Choose a gain (R
the Bode diagram of the PWM and LC filter transfer function (G
f
Z1
4
/R
=
----------------------------- -
2π R
1
1
LOOP
) in order to have the required bandwidth (BW), that means:
, usually between 1 kΩ and 5 kΩ, in order to have values of C4
⋅
1
Doc ID 13006 Rev 5
4
(f) = G
⋅
C
4
,
PW0
f
P0
· G
=
LC
0
,
(f) · G
f
P1
TYPEII
=
------------------------------------------- -
2π R
⋅
(f)) are drawn.
4
⋅
1
------------------- -
C
C
4
4
Application information
+
⋅
C
C
5
5
PW0
· G
LC
(f))
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