STEVAL-ISA052V1 STMicroelectronics, STEVAL-ISA052V1 Datasheet - Page 46

• 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

Application information
8.1.6
46/53
VOUT current limit setting
The valley current limit is set by R
current. The valley of the inductor current I
Equation 46
The output current limit depends on the current ripple as shown in
Figure 48. Valley current limit waveforms
As the valley threshold is fixed, the greater the current ripple, the greater the DC output
current will be. If an output current limit greater than I
range is required, the minimum current ripple must be considered in the previous formula.
Then the resistor R
Equation 47
where R
temperature effect and the worst case value in R
The accuracy of the valley current also depends on the offset of the internal comparator (±5
mV).
The negative valley-current limit (if the device works in forced-PWM mode) is given by:
Equation 48
DSon
is the drain-source on-resistance of the low-side switch. Consider the
MAX LOAD 1
Current
Valley current limit
CSNS
Inductor current
is:
I
CSNS
Lvalley
R
CSNS
I
NEG
and must be chosen to support the maximum load
=
I
=
LOAD
Lvalley
MAX LOAD 2
=
R
DSon
110
R
(max)
100
DSon
DSon
is:
mV
⋅
uA
I
Lvalley
−
LOAD
calculation (typically +0.4 % / °C).
∆
2
I
L
(max) over all the input voltage
Inductor current
Figure 48
Time
:
PM6675S