SMM205 Datasheet, PDF (1/20 Pages) Summit Microelectronics, Inc. – Dual Channel Supply Voltage Marginer and Active DC Output Controller

SMM205
Preliminary Information¹ (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
• I²C 2-wire serial bus for programming
configuration and monitoring status.
• 28 lead QFN package
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
I²C
BUS
WP#
SDA
SCL
A0
A1
A2
FILT_CAP
TRIM_CAPA
TRIM_CAPB
External or
Internal
VREF
VDD_CAP
TRIMA
VMA
SMM205
COMP1
VREF_CNTL
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 I²C 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 I²C 2-wire data bus. The I²C 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.
Vin V+
DC/DC
Trim ^V–
On/Off
V1
GND
Processor
UV
Vin V+
V2
DC/DC
Trim ^V–
On/Off
READY
START
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 [phone] • FAX [phone]
2069 1.4 6/23/03
www.summitmicro.com
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