DataSheetWiki


SC480 fiches techniques PDF

Semtech Corporation - Complete DDR1/2/3 Memory Power Supply

Numéro de référence SC480
Description Complete DDR1/2/3 Memory Power Supply
Fabricant Semtech Corporation 
Logo Semtech Corporation 





1 Page

No Preview Available !





SC480 fiche technique
POWER MANAGEMENT
Description
The SC480 is a combination switching regulator and
linear source/sink regulator intended for DDR1/2/3
memory systems. The purpose of the switching regulator
is to generate the supply voltage, VDDQ, for the memory
system. It is a pseudo-xed frequency constant on-
time controller designed for high efciency, superior DC
accuracy, and fast transient response. The purpose of the
linear source/sink regulator is to generate the memory
termination voltage, VTT, with the ability to source and
www.DatasSihneket4aU3.cAompeak current.
For the VDDQ regulator, the switching frequency is constant
until a step in load or line voltage occurs at which time the
pulse density, i.e., frequency, will increase or decrease to
counter the transient change in output or input voltage.
After the transient, the frequency will return to steady-state
operation. At lighter loads, the selectable Power-Save
Mode enables the PWM converter to reduce its switching
frequency and improve efciency. The integrated gate
drivers feature adaptive shoot-through protection and
soft-switching. Additional features include cycle-by-cycle
current limiting, digital soft-start, over-voltage and under-
voltage protection and a power good ag.
For the VTT regulator, the output voltage tracks REF,
which is ½ VDDQ to provide an accurate termination
voltage. The VTT output is generated from a 1.2V to VDDQ
input by a linear source/sink regulator which is designed
for high DC accuracy, fast transient response, and low
external component count. All three outputs (VDDQ, VTT
and REF) are actively discharged when VDDQ is disabled,
reducing external component count and cost. The SC480
is available in a 24-pin MLPQ (4x4 mm) package.
Typical Application Circuit
SC480
Complete DDR1/2/3
Memory Power Supply
Features
‹ Constant On-Time Controller for Fast Dynamic
Response on VDDQ
‹ DDR1/DDR2/DDR3 Compatible
‹ VDDQ = Fixed 1.8V or 2.5V, or Adjustable from
1.5V to 3.0V
‹ 1% Internal Reference (2% System Accuracy)
‹ Resistor Programmable On-Time for VDDQ
‹ VCCA/VDDP Range = 4.5V to 5.5V
‹ VIN Range = 2.5V to 25V
‹ VDDQ DC Current Sense Using Low-Side RDS(ON)
Sensing or External RSENSE in Series with Low-Side
FET
‹ Cycle-by-Cycle Current Limit for VDDQ
‹ Digital Soft-Start for VDDQ
‹ Analog Soft-Start for VTT/REF
‹ Smart Over-Voltage VDDQ Protection Against Source-
Current Loads
‹ Combined EN and PSAVE Pin for VDDQ
‹ Over-Voltage/Under-Voltage Fault Protection
‹ Power Good Output
‹ Separate VCCA and VDDP Supplies
‹ VTT/REF Range = 0.75V – 1.5V
‹ VTT Source/Sink 3A Peak
‹ Internal Resistor Divider for VTT/REF
‹ VTT is High Impedance in S3
‹ VDDQ, VTT, REF Are Actively Discharged in S4/S5
‹ 24 Lead MLPQ (4x4 mm) Lead-Free Package
‹ Fully WEEE and RoHS Compliant
Applications
¡ Notebook Computers
¡ CPU I/O Supplies
¡ Handheld Terminals and PDAs
¡ LCD Monitors
¡ Network Power Supplies
VTT
VBAT
VDDQ
C4
10uF
C5
10uF
R1
1Meg
VTTSNS
C7
1nF
REF
R6
10R
C9
1uF
5V
C1
1uF
C10
1uF
D1
1 PGND2
2 VTTS
3 VSSA
4 TON
5 REF
6 VCCA
U1
SC480
VDDQ
C8
0.1uF
C2
0.1uF
VBAT
C3
2x10uF
Q1
Q2
PGND1 18
PGND1
ILIM
17
16
RILIM
15
VDDP
VDDP 14
PGD 13
PAD PAD
R4
VDDQ
L1
C6
+
PGOOD
R7 10R
EN/PSV
VTT_EN
5V
C11
1uF
November 3, 2006
1
www.semtech.com

PagesPages 25
Télécharger [ SC480 ]


Fiche technique recommandé

No Description détaillée Fabricant
SC480 Complete DDR1/2/3 Memory Power Supply Semtech Corporation
Semtech Corporation
SC4806 Multiple Function Double Ended PWM Controller Semtech Corporation
Semtech Corporation
SC4808A High Performance Dual Ended PWM Controller Semtech Corporation
Semtech Corporation
SC4808B High Performance Dual Ended PWM Controller Semtech Corporation
Semtech Corporation

US18650VTC5A

Lithium-Ion Battery

Sony
Sony
TSPC106

PCI Bus Bridge Memory Controller

ATMEL
ATMEL
TP9380

NPN SILICON RF POWER TRANSISTOR

Advanced Semiconductor
Advanced Semiconductor


www.DataSheetWiki.com    |   2020   |   Contactez-nous  |   Recherche