FAIRCHILD FAN5029

FAN5029
8-Bit Programmable 2- to 5-Phase Synchronous
Buck Controller
Features
Description
■ Selectable 2-, 3-, 4-, or 5-phase operation at up to
The FAN5029 is a highly efficient multi-phase synchronous buck switching regulator controller optimized for
converting a 12V main supply into the core supply voltage required by high performance Intel processors. It
uses an internal 8-bit DAC to read voltage identification
(VID) code directly from the processor, which is used to
set the output voltage between 0.5V and 1.6V. It uses a
multi-mode PWM architecture to drive the logic-level outputs at a programmable switching frequency that can be
optimized for VR size and efficiency. The phase relationship of the output signals can be programmed to provide
2-, 3-, 4-, or 5-phase operation, allowing for the construction of up to five complementary buck switching stages.
■
■
■
■
■
■
1 MHz per phase
±8 mV worst-case differential sensing error over
temperature
Logic-level PWM outputs for interface to external
high-power drivers
Active current balancing between all output phases
Built-in power good/crowbar blanking supports on-thefly VID code changes
Digitally programmable 0.5 V to 1.6 V output supports
both VR10 and VR11 specifications
Programmable short circuit protection with programmable latch-off delay
The FAN5029 also includes programmable no-load offset and slope functions to adjust the output voltage as a
function of the load current, so that it is always optimally
positioned for a system transient. The FAN5029 also provides accurate and reliable short circuit protection,
adjustable current limiting, and a delayed Power Good
output that accommodates on-the-fly output voltage
changes requested by the CPU.
Applications
■ Desktop PC/Server power supplies for next generation
Intel processors
VRM
modules
■
FAN5029 is specified over the extended commercial
temperature range of 0°C to +85°C and is available in a
40-lead MLP package.
For more information, please contact
Ron Berthiaume at [email protected]
Related Products
■ FAN5109MX – Dual Bootstrapped 12V MOSFET Driver
■ FAN5068 – DDR-1/DDR-2 plus ACPI Regulator Combo
■ FAN5069 – PWM and LDO Controller Combo
■ FAN6520A – Single Synchronous Buck PWM Controller
©2005 Fairchild Semiconductor Corporation
FAN5029 Product Brief Rev. 1.0.0
1
www.fairchildsemi.com
FAN5029 8-Bit Programmable 2- to 5-Phase Synchronous Buck Controller
December 2005
VCC
RT
RAMPADJ
31
12
13
FAN5029
UVLO
SHUTDOWN
& BIAS
OSCILLATOR
GND 18
CMP
–
CMP
–
CURRENT
BALANCING
CIRCUIT
+
DAC+150mV
CSREF
CMP
–
PWM1
RESET
29 PWM2
RESET
28 PWM3
2 / 3 / 4 / 5-PHASE
DRIVER LOGIC
+
CMP
–
+
–
RESET
27 PWM4
RESET
26
+
CMP
–
DELAY
PWRGD 2
30
+
–
+
DAC-250mV
RESET
+
–
EN 1
OD
SET EN
+
850mV
19
CROWBAR
PWM5
CURRENT
LIMIT
25 SW1
TTSENSE 10
VRHOT 9
24 SW2
THERMAL
THROTTLING
CONTROL
23 SW3
22 SW4
VRFAN 8
21 SW5
17
ILIMIT 11
DELAY
CURRENT
LIMIT
CIRCUIT
7
+
CSCOMP
15 CSREF
–
16 CSSUM
Z
+
14 LLSET
–
COMP 5
–
+
PRECISION
REFERENCE
FBRTN
–
4
FB
6
SS
3
STARTUP
CONTROL
+
Boot Control
DAC
BUFF
VID
DAC
VIDSEL 40
32
33
34
35
36
37
38
39
VID7 VID6 VID5 VID4 VID3 VID2 VID1 VID0
2
FAN5029 Product Brief Rev. 1.0.0
www.fairchildsemi.com
FAN5029 8-Bit Programmable 2- to 5-Phase Synchronous Buck Controller
Block Diagram
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PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY
ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT
CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS.
LIFE SUPPORT POLICY
FAIRCHILDíS PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF FAIRCHILD SEMICONDUCTOR CORPORATION.
As used herein:
2. A critical component is any component of a life
1. Life support devices or systems are devices or
support device or system whose failure to perform can
systems which, (a) are intended for surgical implant into
be reasonably expected to cause the failure of the life
the body, or (b) support or sustain life, or (c) whose
support device or system, or to affect its safety or
failure to perform when properly used in accordance
with instructions for use provided in the labeling, can be
effectiveness.
reasonably expected to result in significant injury to the
user.
PRODUCT STATUS DEFINITIONS
Definition of Terms
Datasheet Identification
Product Status
Definition
Advance Information
Formative or
In Design
This datasheet contains the design specifications for
product development. Specifications may change in
any manner without notice.
Preliminary
First Production
This datasheet contains preliminary data, and
supplementary data will be published at a later date.
Fairchild Semiconductor reserves the right to make
changes at any time without notice in order to improve
design.
No Identification Needed
Full Production
This datasheet contains final specifications. Fairchild
Semiconductor reserves the right to make changes at
any time without notice in order to improve design.
Obsolete
Not In Production
This datasheet contains specifications on a product
that has been discontinued by Fairchild semiconductor.
The datasheet is printed for reference information only.
Rev. I17
3
FAN5029 Product Brief Rev. 1.0.0
www.fairchildsemi.com
FAN5029 8-Bit Programmable 2- to 5-Phase Synchronous Buck Controller
TRADEMARKS