SMM105
Preliminary Information
1
(See Last Page)
Single-Channel Supply Voltage Marginer and Active DC Output Controller
FEATURES & APPLICATIONS
•
Extremely accurate (±0.1%) Active
DC Output Control (ADOC
TM
)
•
ADOC Automatically adjusts supply output
voltage level under all DC 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 pad QFN or 25 ball
Ultra
CSP
TM
(Chip-Scale)
package
INTRODUCTION
The SMM105 actively controls the output voltage level
of a DC/DC converter that uses a Trim or VADJ/FB pin
to adjust the output. An Active DC Output Control
(ADOC
TM
) 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 SMM105 will
check 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 SMM105 ADOC will continue 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
12VIN (6V to 15V)
3.3/5Vin (2.7V to 5.5V)
12VIN
WP#
SDA
I
2
C
BUS
SCL
A2
A1
A0
VDD_CAP
VM
COMP1
OV
uP/
DSP/
FPGA/
ASIC
TRIM
VDD
TRIM_CAP
FILT_CAP
VIN
DC/DC
Converter
TRIM
ON/OFF
V+
V-
1.2 VIN
GND
SMM105
Internal or
External
Voltage
Reference
COMP2
VREF_CNTL
READY
START
GND
FAULT#
UV
FAULT#
READY
POWER GOOD
Figure 1 – Applications Schematic using the SMM105 Controller to actively control the DC output level
(ADOC) of a DC/DC Converter as well as margin control. The SMM105 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. 2005 •
1717 Fox Drive • San Jose CA 95131 • Phone 408 436-9890 • FAX 408 436-9897
2068 1.8 09/20/05
www.summitmicro.com
1
SUMMIT [ SUMMIT MICROELECTRONICS, INC. ]
