EVALA5970D STMicroelectronics, EVALA5970D Datasheet - Page 19

• 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

AN1330
5.2
Table 4.
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. A 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. Moreover the GND pin of the device is connected to the ground plane
directly with VIA on the bottom side of the PCB.
Figure 13. Layout example
Coiltronics
BI
Murata
Panasonic
Sumida
Epcos
Wurth Elektronik
Manufacturer
MINIMUN SIZE OF FEEDBACK
PIN CONNECTIONS TO AVOID
PICKUP
CONNECTION TO
GROUNDPLANE
THROUGH VIA
Inductor selection (continued)
VERY SMALL HIGH CURRENT
CIRCULATING PATH TO MINIMIZE
RADIATION AND HIGH FREQUENCY
RESONANCE PROBLEMS
Figure 13
Vin
R2
R1
to output voltage
ELLATV
HM76-2
HM76-3
B82476
LQN6C
744561
Series
UP1B
UP2B
CR75
Cin
below.
5
8
L5970
4
1
D
Inhibit signal
COMPENSATION NETWORK FAR
FROM HIGH CURRENT PATHS
Inductor value (µH)
AM00012v1
22 to 33
33 to 47
22 to 33
33 to 47
22 to 33
22 to 47
22 to 33
33 to 47
33 to 47
Cout
L
Gnd
Vout
Application information
OUTPUT CAPACITOR
DIRECTLY CONNECTED
TO HEAVY GROUND
Saturation current (A)
1.4 to 2.05
0.9 to 1.2
1.2 to 1.5
1 to 1.2
1.7 to 2
1 to 1.2
2 to 2.5
1.6 to 2
1.6 to 2
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