sc480imltrt Semtech Corporation, sc480imltrt Datasheet - Page 5

• Manufacturer Part Number: sc480imltrt
• Description: Sc480 Complete Ddr1/2/3 Memory Power Supply
• Manufacturer: Semtech Corporation

TEST CONDITIONS: V
Notes:
1) The VDDQ DC regulation level is higher than the FB error comparator threshold by 50% of the ripple voltage.
2) Using a current sense resistor, this measurement relates to PGND1 minus the source of the low-side MOSFET.
3) clks = switching cycles, consisting of one high side and one low side gate pulse.
4) Guaranteed by design.
5) Thermal shutdown latches both outputs (VTT and VDDQ) off, requiring VCCA or EN/PSV cycling to reset.
6) VTT soft-start ramp rate is limited to 5.5mV/μs typical. If the VDDQ/2 ramp rate is slower than 5.5mV/μsec, the VTT soft-start ramp will follow the VDDQ/2
7) See Shoot-Through Delay Timing Diagram on Page 6.
8) Semtech’s SmartDriver™ FET drive fi rst pulls DH high with a pull-up resistance of 10Ω (typ.) until LX = 1.5V (typ.). At this point, an additional pull-up device is
9) Provided operation below T
POWER MANAGEMENT
Electrical Characteristics (Cont.)
© 2006 Semtech Corp.
Parameter
FB Input Thresholds
FB Logic Input Low
FB Logic Input High
Gate Drives
Shoot-Thru Protection Delay
DL Pull-Down Resistance
DL Sink Current
DL Pull-Up Resistance
DL Source Current
DH Pull-Down Resistance
DH Pull-Up Resistance
DH Sink/Source Current
VTT Pull-Up Resistance
VTT Pull-Down Resistance
VTT Peak Sink/Source Current
ramp.
activated, reducing the resistance to 2Ω (typical). This creates a softer turn-on with minimal power loss, eliminating the need for an external gate or boost
resistor.
increases with temperature, and by available source voltage (typically VDDQ/2).
IN
= 15V, VCCA = VDDP = VTTEN = EN/PSV = 5V, VDDQ = VTTIN = 1.8V, R
(8)
J(MAX)
is maintained. VTT output current is also limited by internal MOSFET resistance which is typically 0.25Ω at 25°C and which
(4)(7)
(9)
VDDQ Set for 2.5V (DDR1)
VDDQ Set for 1.8V (DDR2)
DH High, BST - LX = 5V
DH Low, BST - LX = 5V
DH or DL Rising
VTTS < REF
VTTS > REF
Conditions
V
V
V
DL High
DL Low
DH
DL
DL
= 2.5V
= 2.5V
= 2.5V
5
TON
= 1MΩ. T
Min
AMB
VCCA
25°C
- 0.7
0.25
0.25
Typ
= -40 TO +85C.
0.3
0.8
3.1
1.3
1.3
3.6
30
2
2
2
Max
-40°C to 85°C
Min
2.0
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Max
SC480
Units
ns
V
V
Ω
Ω
Ω
Ω
Ω
Ω
A
A
A
A