EVALA5970AD STMicroelectronics, EVALA5970AD Datasheet - Page 24

• Manufacturer Part Number: EVALA5970AD
• Description: BOARD EVAL FOR A5970AD REG
• Manufacturer: STMicroelectronics

Specifications of EVALA5970AD

• Main Purpose: DC/DC, Step Down
• Outputs And Type: 1, Non-Isolated
• Voltage - Output: 1.235 ~ 35V
• Current - Output: 1A
• Voltage - Input: 4 ~ 36V
• Regulator Topology: Buck
• Frequency - Switching: 500kHz
• Board Type: Fully Populated
• Utilized Ic / Part: A5970AD
• Product: Power Management Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Application information
8.2
8.3
24/42
Layout considerations
The layout of switching DC-DC converters is very important to minimize noise and
interference. Power-generating portions of the layout are the main cause of noise and so
high switching current loop areas should be kept as small as possible and lead lengths as
short as possible.
High impedance paths (in particular the feedback connections) are susceptible to
interference, so they should be as far as possible from the high current paths. An layout
example is provided in
The input and output loops are minimized to avoid radiation and high frequency resonance
problems. The feedback pin connections to the external divider are very close to the device
to avoid pick-up noise.
Figure 13. Layout example
Thermal considerations
The dissipated power of the device is tied to three different sources:
●
Equation 22
Where D is the duty cycle of the application. Note that the duty cycle is theoretically given by
the ratio between V
Conduction losses due to the not insignificant R
OUT
Figure 13
and V
IN
Doc ID 14661 Rev 4
P
, but in practice it is substantially higher than this value to
ON
below.
A5970AD
=
R
DSON
•
(
I
OUT
)
DSON
2
•
D
, which are equal to:
A5970AD