Complete Three-in-One DDR
Power Solution With BF_CUT
POWER MANAGEMENT
Description
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.
SC2516
Features
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
Typical Application Circuit
1
FBVDDQ
SS/EN
VTT
5
VDDQ
6
7
8
VDDQ
9
10
11
2
3
4
COMP
FBVDDQ
SS/EN
VTTGND
VTT
VDDQ
AGND
VTTFB
REFSENS
TH _PAD
FB_GMCH
SS_GMCH
PGND
BG
TG
BST
5VSBY
COMP_GMCH
BF_CUT
TG_GMCH
BG_GMCH
GND_GMCH
POK
22
21
20
19
18
17
16
15
14
13
12
GMCH
Latched BF_CUT
3VCC
5VSBY
FBVDDQ
VDDQ
FB_GMCH
ATXPWR_OK
FB_GMCH
23
SC2516
Revision 8, May. 2005
1
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