
SMM764 
Four-Channel Active DC Output Controller, Monitor, Marginer and Sequencer with Sequence-Link
FEATURES & APPLICATIONS  
Preliminary Information 
1
(See Last Page)
 SUMMIT 
Microelectronics, Inc. 
2004  1717 Fox Drive  San Jose CA 95131  Phone 408 436-9890  FAX 408 436-9897  
The Summit Web Site can be accessed by “right” or “l(fā)eft” mouse clicking on the link:
http://www.summitmicro.com/
2098 1.1  6/29/2005                                                                                                 
1
 
 Extremely accurate (±0.2%) output voltages      
    using Active DC Output Control (ADOC) 
 
 Sequence-Link provides sequencing of up to     
    46 channels 
 
ADOC automatically adjusts supply output 
    voltage level under all DC load conditions 
 
Monitors, controls and margins up to 4 supplies        
    from 0.3V to 5.5V 
 
Programmable power-on/-off sequencing 
 
Operates from any intermediate bus supply  
from 6V to 14V and from 2.7V to 5.5V 
 
Monitors 12V input VDD and temperature sensor 
 
Wide margin/ADOC range from 0.3v to VDD 
 
Monitors two general-purpose 10-bit ADC inputs 
 
I
2
C 2-wire serial bus for programming 
configuration and monitoring status, including 
10-bit ADC conversion results 
 
2 programmable Under Voltage  (UV) and Over  
    Voltage (OV) threshold limits for each of 9  
    monitored inputs 
 
2k-bit general purpose nonvolatile memory  
Applications 
 
Monitor/control distributed and POL supplies 
 
Multi-voltage processors, DSPs, ASICSs used in 
telecom, CompactPCI or server systems 
 SIMPLIFIED APPLICATIONS DRAWING
The SMM764 is an Active DC Output power supply 
Controller (ADOC
) that monitors, margins, and 
cascade sequences. The ADOC feature is unique and 
maintains extremely accurate settings of system 
supply voltages to within ±0.2% under full load. The 
SMM764 actively controls up to 4 DC/DC converters 
and can be linked with up to 7 other Sequence-Link 
devices to accommodate sequencing of up to 46 
channels. Control of the DC-DC converters is 
accomplished through the use of a Trim or Regulator 
VADJ/FB pin to adjust the output voltage.  For system 
test, the part also controls margining of the supplies 
using I
C commands. It can margin supplies with 
either positive or negative control within a range of 
0.3V to VDD, depending on the specified range of the 
converter. The SMM764 also intelligently sequences 
or cascades the power supplies on and off in any 
order using enable outputs with programmable 
polarity. It can operate off any intermediate bus supply 
ranging from 6V to 14V or from 5.5V to as low as 2.7V. 
The part monitors 4 power supply channels as well as 
VDD, 12V input, two general-purpose analog inputs 
and an internal temperature sensor using a 10-bit 
ADC.  The 10-bit ADC can measure the value on any 
one of the monitor channels and output the data via 
the I
C bus. A host system can communicate with the 
SMM764 status register, margining and utilize 2K-bits 
of nonvolatile memory. 
TRIM
B
PUP
B
VM
B
TRIM_CAP
B
CAP
B
TRIM
A
PUP
A
VM
A
TRIM_CAP
A
CAP
A
SMM764
μ
P/
ASIC
V
R
H
M
3.3VIN (+2.7V to +5.5V Range)
RESET#
READY
HEALTHY
1
12VIN (+6V to +14V Range)
External
or
Internal
TEMP
SENSOR
AIN1
2.5VIN
1.2VIN
12V
3.3V
SDA
SCL
A2
I
2
C
BUS
VREF
VIN
TRIM
Vout
DC/DC
Converter A
ON/OFF
VIN
TRIM
Vout
DC/DC
Converter B
ON/OFF
External or
Internal
REFERENCE
Environmental
SENSOR
AIN2
DC/DC
Converter C,
DC/DC
Converter D,
2 of 4 DC-DC
Converters shown
SEQ_LINK
T
L
Figure 1 – Applications schematic using the SMM764 controller to actively control the output levels of up 
to 4 DC/DC converters while also providing power-on/off, cascade sequencing and output margining. 
Note:  This is an applications example only. Some pins, components and values are not shown. 
INTRODUCTION