STEVAL-ISA052V1 STMicroelectronics, STEVAL-ISA052V1 Datasheet - Page 31

• 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
7.1.5
Table 8.
Current sensing and current limit
The PM6675S switching controller uses a valley current sensing algorithm to properly
handle the current limit protection and the inductor current zero-crossing information. The
current is detected during the conduction time of the low-side MOSFET. The current sensing
element is the on-resistance of the low-side switch. The sensing scheme is visible in
Figure 40
Figure 40. Current sensing scheme
An internal 100 µA current source is connected to C
input of the positive current limit comparator. When the voltage drop developed across the
sensing parameter equals the voltage drop across the programming resistor R
controller skips subsequent cycles until the overcurrent condition is detected or the output
UV protection latches off the device (see
protections on page 34
Referring to
without the need for an external sensing resistor. The on-resistance of the MOSFET is
affected by temperature drift and nominal value spread of the parameter itself; this must be
considered during the R
V
V
VSEL
VSEL
VSEL
.
> 4.3 V
< 3.7 V
Figure 40
Mode-of-operation settings summary
PM6675S
V
1V <V
< 0.5 V
V
1V <V
V
PM6675
PM6675
, the R
NOSKIP
NOSKIP
NOSKIP
).
PGND
PGND
ILIM
NOSKIP
NOSKIP
setting resistor design.
DS(on)
NOSKIP
HGATE
HGATE
PHASE
PHASE
LGATE
LGATE
< 0.5 V
> 4.2 V
> 4.2 V
CSNS
CSNS
< 3.5 V
< 3.5 V
sensing technique allows high efficiency performance
100µA·
100µA·
Section 7.1.11: Switching section OV and UV
R
R
ILIM
ILIM
VOUT
1.5 V
V
V
ADJ
IN
IN
I
I
SNS
VALLEY
VALLEY
pin that is also the non-inverting
·
·
R
R
Forced-PWM
Non-audible pulse-skip
Pulse-skip
Forced-PWM
Non-audible pulse-skip
Pulse-skip
DSon
DSon
V
V
OUT
OUT
Operating mode
Device description
ILIM
, the
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