STEVAL-ISA052V1 STMicroelectronics, STEVAL-ISA052V1 Datasheet - Page 39

• Manufacturer Part Number: STEVAL-ISA052V1
• Description: KIT EVAL PM6675S HE CTLR 2A REG
• Manufacturer: STMicroelectronics

Specifications of STEVAL-ISA052V1

• Main Purpose: DC/DC, Step Down with LDO
• Outputs And Type: 2, Non-Isolated
• Voltage - Output: 1.5V, 0.6 ~ 3.3V
• Current - Output: 10A, 2A
• Voltage - Input: 4.5 ~ 28 V
• Regulator Topology: Buck
• Board Type: Fully Populated
• Utilized Ic / Part: PM6675
• Product: Power Management Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Frequency - Switching: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 497-8426

PM6675S
Table 10.
R1 (kΩ)
330
330
330
330
330
330
where
Equation 28a
Equation 28b
Referring to the typical application schematic (figure in cover page and
expression is then:
Equation 29
The switching frequency directly affects two parameters:
●
●
Even if the switching frequency is theoretically independent from battery and output
voltages, parasitic parameters involved in power path (like MOSFETs on-resistance and
inductor DCR) introduce voltage drops responsible for a slight dependence on load current.
In addition, the internal delay is cause of a light dependence from input voltage.
Typical values for switching frequency selection
Inductor size: greater frequencies mean smaller inductances. In notebook applications,
real estate solutions (i.e. low-profile power inductors) are mandatory also with high
saturation and r.m.s. currents.
Efficiency: switching losses are proportional to the frequency. Generally, higher
frequencies imply lower efficiency.
R2 (kΩ)
11
13
15
18
20
22
f
SW
=
K
α
α
OSC
OSC
α
OSC
OUT
Approx switching frequency (kHz)
=
=
=
R
V
V
1
V
R
V
OSC
SNS
OUT
+
IN
2
R
2
⋅
K
OSC
1
250
300
350
400
450
500
Application information
Figure 33
), the final
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