STEVAL-ISA051V1 STMicroelectronics, STEVAL-ISA051V1 Datasheet - Page 30

• 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

Device description
7.1.4
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Mode-of-operation selection
Figure 35. MODE and DDRSEL multifunction pin configurations
The PM6670S has been designed to satisfy the widest range of applications involving
DDR2/3 memories, SSTL15-18 buses termination and I/O supplies for CPU/chipset. The
device is provided with multilevel pins which allow the user to choose the appropriate
configuration. The MODE pin is used to firstly decide between fixed preset or adjustable
(user defined) output voltages.
When the MODE pin is connected to +5 V, the PM6670S allows setting the VDDQ voltage to
1.8 V or 1.5 V just forcing the DDRSEL multilevel pin to +5 V or to ground respectively (see
Figure 35
In this condition the pulse-skip feature is enabled. This device configuration is suitable for
standard DDR2/3 memory supply applications avoiding the need for an external, high
accuracy, divider for output voltage setting.
Applications requiring different output voltages can be managed by PM6670S simply setting
the adjustable mode. If MODE pin voltage is higher than 4 V, the fixed output mode is
selected. Connecting an external divider to the MODE pin (
negative input of the error amplifier and the output voltage is given by expression (21).
Equation 21
R8
R8
R9
R9
VDDQ
VDDQ
a).
+5V
+5V
(a)
(a)
DDRSEL
DDRSEL
MODE
MODE
Doc ID 14432 Rev 4
PM6670
PM6670
PM6670S
VDDQ
ADJ
=
0
9 .
R9
R9
R8
R8
VDDQ
VDDQ
⋅
R
8
R
+
8
V
V
R
REF
REF
9
Figure 35
+5V
+5V
(b)
(b)
b), it is used as
DDRSEL
DDRSEL
MODE
MODE
PM6670
PM6670
PM6670S
PM6670S