SC2516 Datasheet, PDF (1/15 Pages) Semtech Corporation – Complete Three-in-One DDR Power Solution With BF_CUT

POWER MANAGEMENT
SC2516
Complete Three-in-One DDR
Power Solution With BF_CUT
Description
Features
The SC2516 is a fully integrated, Three-in-One DDR Con-
troller supplying power to the VDDQ, VTT and GMCH
rails. Two synchronous buck controller provide the VDDQ
and GMCH at high efficiency, while an internal linear regu-
lator supplies the termination voltage with 1.8A(min)
Source/Sink capability.
The SC2516 uses the Intel^® defined Latched BF_Cut
signal to comply with motherboard state transitions. The
regulator uses the 5VDUAL rail to supply VDDQ under all
motherboard states, via the VDDQ switcher. The GMCH
regulator is slaved off the 5V main regulator, using a sepa-
rate UVLO on that rail. Additional logic and supervisory
circuitry complete the functionality of this single chip DDR
power solution in compliance with ACPI requirements.
The MLP package with a copper pad provides excellent
thermal impedance while keeping small footprint. VDDQ
short circuit protection along with VTT current limit as
well as two independent thermal shutdown circuits as-
sure safe operation under all fault conditions.
Typical Application Circuit
‹ Uses Latched BF_Cut from Intel Glue Chip to
control regulators
‹ External VDDQ divider allows DDRI or DDRII Com-
patibility
‹ High efficiency VDDQ switcher
‹ External GMCH divider allows 1.5V or 1.25V pro-
gramming
‹ High efficiency GMCH switcher supplies pro-
grammed output from the 5V or 3.3V rail
‹ Single chip solution complies fully with ACPI power
sequencing specifications
‹ 1.8A (min) VTT Source/Sink capability
‹ High current 1Amp gate driver for VDDQ switcher
‹ Independent thermal shutdown for VTT
‹ Fast transient response
‹ Space saving 22-pin MLP package with copper
thermal pad for heatsinking to PC Board
Applications
‹ Power Solution for DDR memory per Intel
motherboard specification
‹ High speed data line termination
12VCC
5Vdual
FBVDDQ
SS/EN
VTT
VDDQ
VDDQ
1 _COMP
2 _FBVDDQ
3
SS/EN
4 _VTTGND
5 _VTT
6 _VDDQ
7 _AGND
8 _VTTFB
9 _REFSENS
10 _{FB_GMCH}
11 _{SS_GMCH}
PGND ²²
BG ²¹
20
TG
BST ¹⁹
5VSBY ¹⁸
COMP_GMCH ¹⁷
BF_CUT ¹⁶
TG_GMCH ¹⁵
BG_GMCH ¹⁴
GND_GMCH ¹³
POK ¹²
FB_GMCH
SC2516
ATXPWR_OK
5VSBY
Latched BF_CUT
3VCC
VDDQ
FBVDDQ
GMCH
FB_GMCH
Revision 8, May. 2005
1
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