SMM605 SUMMIT Microelectronics, Inc:, SMM605 Datasheet - Page 2

• Manufacturer Part Number: SMM605
• Description: Six-channel Supply Voltage Marginer And Active Dc Output Controller
• Manufacturer: SUMMIT Microelectronics, Inc:

Figure 2 – Example Power Supply Margining using the SMM605. The waveform on the left is margin low to
high from 1.6V to 2.0V and the waveform on the right is margin high to nominal from 2.0V to 1.8V. The ADOC
function guarantees the output level to be within ±0.2% maximum with a ±0.1% external reference. The
bottom waveform is the READY signal indicating margin is complete.
GENERAL DESCRIPTION
The SMM605 is capable of controlling the DC output of
up to six DC/DC Modules, switching regulators or LDOs
that use a trim/adjust pin and automatically change the
level using a unique Active DC Output Control
(ADOC
standard 2-wire I
used to set the nominal DC output voltage as well as
the margin high and low settings. The part actively
controls the programmed set levels to maintain tight
control over load variations and voltage drops at the
point of load. The margin range will vary depending on
the supply manufacturer and model but the normal
range is 10% adjustment around the nominal output
setting. However, the SMM605 has the capability to
margin from 0.35V to VDD. The user can set the
desired voltage settings (nominal, margin high and
margin low) into the EE memory array for the device.
Then, volatile registers are used to select one of these
settings. These registers are accessed over the I
bus.
In normal operation, Active DC Output Control is set to
adjust the nominal output voltage of the converter.
Typical converter accuracy ratings range from ±2% to
±5% of their output voltage.
Output Control feature of the SMM605 can increase the
accuracy to ±0.1% (±0.2% Max.). This high accuracy
control of the converter output voltage is extremely
important in low voltage applications where deviations
in power supply voltage can result in lower system
performance. Active DC Output Control can also be
used for margining a supply during system test or may
be turned off by de-selecting the function in the Control
Register.
Summit Microelectronics, Inc
TM
). The ADOC function is programmable over a
2
C serial data interface and can be
Using the Active DC
2064 1.2 09/20/06
2
C
The margin high and margin low voltage settings can
range from 0.35V to VDD around the converters’
nominal output voltage setting depending on the
specified margin range of the DC-DC converter. When
the SMM605 receives the command to margin, the
Active DC Output Control will adjust the supply to the
selected margin voltage. Once the supply has reached
its margined set point, the Ready bit in the status
register will set and the READY pin will go active. If
Active DC Control is disabled, a margined supply can
return to its nominal voltage by writing to the margin
command register.
In order to obtain maximum accuracy, the SMM605
requires an external voltage reference.
reference with ±0.1% accuracy will enable an overall
±0.2% accuracy for the device. A configuration option
also exists so that an internal voltage reference can be
used, but with less accuracy. Total accuracy using the
internal reference is ±0.5%.
The SMM605 has additional filter pins to filter unwanted
switching regulator noise.
FILT_CAP.
The SMM605 can be powered from either the 12VIN
supply pin (6V to 14V range) via an internal regulator or
the VDD supply pin (+2.7 to 5.5V range), see Figure 3.
Programming of the SMM605 is performed over the
industry standard I
status register is available to read the state of the part
and a Write Protect bit is available to prevent writing to
the
configuration
2
C 2-wire serial data interface. A
registers
They are VDD_CAP and
Preliminary Information
and
SMM605
EE
An external
memory.
2