SMM205
Preliminary Information
1
(See Last Page)
Dual Channel Supply Voltage Marginer and Active DC Output Controller
FEATURES & APPLICATIONS
•
Extremely accurate (±0.1%) Active
DC Output Control (ADOC)
•
ADOC Automatically adjusts supply output
voltage level under all load conditions
•
Capable of margining supplies with trim inputs
using either positive or negative trim pin control
•
Wide Margin/ADOC range from 0.3V to VDD
•
Uses either an internal or external VREF
•
Operates from any intermediate bus supply
from 8V to 15V and from 2.7V to 5.5V
•
Programmable START and READY pins
•
Two programmable general purpose monitor
sensors – UV and OV with FAULT Output Flag
•
General Purpose 1k EEPROM with Write Protect
•
I
2
C 2-wire serial bus for programming
configuration and monitoring status.
•
28 lead QFN package
INTRODUCTION
The SMM205 actively controls the output voltage level
of two DC/DC converters that use a Trim or VADJ/FB
pin to adjust the output. An Active DC Output Control
(ADOC) feature is used during normal operation to
maintain extremely accurate settings of supply
voltages and, during system test, to control margining
of the supplies using I
2
C commands. Total accuracy
with a ±0.1% external reference is ±0.2%, and ±0.5%
using the internal reference. The device can margin
supplies with either positive or negative trim pin control
within a range of 0.3V to VDD. The SMM105 supply
can be from 12V, 8V, 5V or 3.3V to as low as 2.7V to
accommodate any intermediate bus supply.
The voltage settings (margin high/low and nominal)
are programmed into nonvolatile memory through the
industry standard I
2
C 2-wire data bus. The I
2
C bus is
also used to enable margin high, margin low, ADOC or
normal operation. When margining, the SMM205
checks the voltage output of the converter and make
adjustments to the trim pin via a feedback loop to bring
the voltage to the margin setting. A margining status
register is set to indicate that the system is ready for
test. The SMM205 ADOC continues to monitor and
adjust the channel output at the specified level.
Applications
•
In-system test and control of Point-of-Load
(POL) Power Supplies for Multi-voltage
Processors, DSPs and ASICs
•
Enterprise and edge routers, servers, Storage
Area Networks
SIMPLIFIED APPLICATIONS DRAWING
6V to 15V
2.7V to 5.5V
Intermediate
Bus Voltage
(IBA
I
2
C
BUS
12VIN
WP#
SDA
SCL
A0
A1
A2
VDD
FILT_CAP
TRIM_CAPA
TRIM_CAPB
Vin
V+
V1
GND
Processor
DC/DC
V–
Trim
On/Off
VDD_CAP
TRIMA
VMA
UV
Vin
V+
V2
SMM205
External or
Internal
VREF
COMP1
VREF_CNTL
DC/DC
V–
Trim
On/Off
READY
START
FAULT#
TRIMB
VMB
COMP2
OV
Figure 1 – Applications Schematic showing the SMM205 ADOC actively control the DC output level of 2
DC/DC Converters as well as provide margin control. The SMM205 can operate over a wide supply range
Note: This is an applications example only. Some pins, components and values are not shown.
© SUMMIT
Microelectronics, Inc. 2003 •
1717 Fox Drive • San Jose CA 95131 • Phone 408 436-9890 • FAX 408 436-9897
2069 1.4 6/23/03
www.summitmicro.com
GND
1
SUMMIT [ SUMMIT MICROELECTRONICS, INC. ]
