EVALA5970D STMicroelectronics, EVALA5970D Datasheet - Page 28

• Manufacturer Part Number: EVALA5970D
• Description: Power Management Modules & Development Tools EVAL BOARD A5970D Auto Grade
• Manufacturer: STMicroelectronics
• Type: DC/DC Switching Converters, Regulators & Controllersr

Specifications of EVALA5970D

• Input Voltage: 4.4 V to 36 V
• Output Voltage: 1.235 V to 35 V
• Board Size: 23 mm x 20 mm
• Product: Power Management Modules
• Supply Current: 1 A
• Dimensions: 23 mm x 20 mm
• For Use With/related Products: AN1330
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Compensation network with MLCC (multiple layer ceramic capacitor) at the output
7
7.1
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Compensation network with MLCC (multiple layer
ceramic capacitor) at the output
MLCCs with values in the range of 10 µF-22 µF and rated voltages in the range of 10 V-25 V
are available today at relatively low cost from many manufacturers.
These capacitors have very low ESR values (a few mΩ) and thus are occasionally used for
the output filter in order to reduce the voltage ripple and the overall size of the application.
However, a very low ESR value affects the compensation of the loop (see
the
may be required.
system with ceramic capacitors at the output (the optimum component value depends on
the application).
Figure 29. MLCC compensation network example
External SOFT_START network
At the start-up, the device can quickly increase the current up to the current limit in order to
charge the output capacitor. If a soft ramp-up of the output voltage is required, an external
soft-start network can be implemented as shown in
The capacitor C is charged up to an external reference (through R), and the B
COMP pin.
This clamps the duty cycle, limiting the slew rate of the output voltage.
loop) and in order to keep the system stable, a more complicated compensation network
Figure 29
shows an example of a compensation network that stabilizes the
Figure
30.
Section 4: Closing
JT
clamps the
AN1330