STEVAL-ISA051V1 STMicroelectronics, STEVAL-ISA051V1 Datasheet - Page 31
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STEVAL-ISA051V1
Manufacturer Part Number
STEVAL-ISA051V1
Description
BOARD EVAL PM6670S DDR2/3
Manufacturer
STMicroelectronics
Type
DC/DC Switching Converters, Regulators & Controllersr
Specifications of STEVAL-ISA051V1
Design Resources
STEVAL-ISA051V1 Gerber Files STEVAL-ISA051V1 Schematic STEVAL-ISA051V1 Bill of Material
Main Purpose
Special Purpose DC/DC, DDR Memory Supply
Outputs And Type
4, Non-Isolated
Voltage - Output
1.5V, 1.8V
Voltage - Input
4.5 ~ 28V
Regulator Topology
Buck
Board Type
Fully Populated
Utilized Ic / Part
PM6670
Input Voltage
4.5 V to 28 V
Output Voltage
1.8 V, 1.5 V
Product
Power Management Modules
Silicon Manufacturer
ST Micro
Silicon Core Number
PM6670S
Kit Application Type
Power Management
Application Sub Type
DDR2/3 Memory Power Supply Controller
Kit Contents
Board
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Current - Output
-
Power - Output
-
Frequency - Switching
-
Lead Free Status / Rohs Status
Lead free / RoHS Compliant
For Use With/related Products
PM6670S
Other names
497-8411
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
STEVAL-ISA051V1
Manufacturer:
STMicroelectronics
Quantity:
1
PM6670S
7.1.5
VDDQ output voltage can be set in the range of 0.9 V to 2.6 V. Adjustable mode
automatically switches DDRSEL pin to become the power saving algorithm selector: if tied
to +5 V, the forced-PWM (fixed frequency) control is performed. If grounded or connected to
VREF pin (1.237 V reference voltage), the pulse-skip or non-audible pulse-skip modes are
respectively selected.
Table 8.
Current sensing and current limit
The PM6670S 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 sensed 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 36
Figure 36. Current sensing scheme
An internal 120 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 36
V
V
MODE
MODE
Mode
.
> 4.3 V
< 3.7 V
Mode-of-operation settings summary
1V < V
1V < V
).
PM6670S
PM6670
PM6670
V
V
V
PGND
PGND
DDRSEL
DDRSEL
DDRSEL
DDRSEL
DDRSEL
DDRSEL
<0.5 V
Doc ID 14432 Rev 4
HGATE
HGATE
PHASE
PHASE
LGATE
LGATE
CSNS
CSNS
> 4.2 V
> 4.2 V
< 0.5 V
< 3.5 V
< 3.5 V
100µA·
100µA·
Section 7.1.11: Over voltage and under voltage
R
R
ILIM
ILIM
VDDQ
1.8 V
1.5 V
V
V
ADJ
IN
IN
I
I
VALLEY
VALLEY
SNS
·
·
R
R
pin that is also the non-inverting
DSon
DSon
V
V
OUT
OUT
Non-audible pulse-skip
Operating mode
Forced-PWM
Pulse-skip
Pulse-skip
Device description
ILIM
, the
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