DRQ-12-42-D48 Datasheet, PDF (8/24 Pages) Murata Power Solutions Inc. – 500W Digital Fully Regulated Intermediate DC-DC Bus Converter

TECHNICAL NOTES
Power Management Overview
The module includes a wide range of readable and configurable power
management features that are easy to implement with a minimum of external
components. Furthermore, the module includes protection features that
continuously protect the load from damage due to unexpected system faults.
The SMBALERT pin alerts the host if there is a fault in the module. The follow-
ing product parameters can continuously be monitored by a host: Vout, Iout,
Vin, Temperature, and Power Good. The module is distributed with a default
configuration suitable for a wide range operation in terms of Vin, Vout, and
load. All power management functions can be reconfigured using the PMBus
interface. The product provides a PMBus digital interface that enables the user
to configure many aspects of the device operation as well as monitor the input
and output parameters. Please contact our FAE for special configurations.
Soft-start Power Up
The default rise time of the ramp up is 20 ms. When starting by applying
input voltage the control circuit boot-up time adds an additional 10 ms delay.
The soft-start power up of the module can be reconfigured using the PMBus
interface.
Over Voltage Protection (OVP)
The module includes over voltage limiting circuitry for protection of the load.
The default OVP limit is 20% above the nominal output voltage. If the output
voltage surpasses the OVP limit, the module can respond in different ways.
The default response from an over voltage fault is to immediately shut down.
The device will continuously check for the presence of the fault condition,
and when the fault condition no longer exists the device will be re-enabled.
The OVP fault level and fault response can be reconfigured using the PMBus
interface.
Over Current Protection (OCP, Current limit)
The module includes current limiting circuitry for protection at continuous over
load. The default setting for the product is hicup mode. The current limit could
be configured by simply setting the IOUT_OC_FAULT_LIMIT to be greater than
the IOUT_OC_WARN_LIMIT. The maximum value that the current limit could be
set is 50A.
Power Good
The module provides Power Good (PG) flag in the Status Word register that
indicates the output voltage is within a specified tolerance of its target level
and no fault condition exists. The Power Good pin default logic is negative and
it can be configured by MFR_PGOOD_POLARITY.
DRQ-12/42-D48 Series
500W Digital Fully Regulated
Intermediate DC-DC Bus Converter
Switching Frequency Adjust Using PMBus
By default the switching frequency is set to 175-250 KHz variable frequency
control. The product is optimized at this frequency but it can be changed to 175
KHz fixed frequency control. The thermal performance can be affected if the
switching frequency is changed when Vin is above 50 Vdc. The following graph
shows Frequency vs. Vin.
250kHZ
235kHZ
220kHZ
205kHZ
190kHZ
175kHZ
50V 52V 54V 56V 59V 61V 64V 66V
Figure 1. Frequency graph
69V 71V
PMBus Interface
This module offers a PMBus digital interface that enables the user to configure
many characteristics of the device operation as well as to monitor the input
and output voltages, output current and device temperature. The module can
be used with any standard two-wire I2C or SMBus host device. In addition, the
module is compatible with PMBus version 1.2 and includes an SMBALERT line
to help alleviate bandwidth limitations related to continuous fault monitoring.
The module supports 100 kHz and 400 kHz bus clock frequency only.
PMBUS Logic Level
Logic high input
Logic low input
Logic high output
Logic low output
MIN.
2
0
2.4
-0.1
NOM.
MAX.
3.3
0.8
3.6
0.4
UNITS
V
V
V
V
Monitoring via PMBus
A system controller (host device) can monitor a wide variety of parameters
through the PMBus interface. The controller can monitor fault conditions by
monitoring the SMBALERT pin, which will be asserted when any number of
pre-configured fault or warning conditions occur. The system controller can
also continuously monitor any number of power conversion parameters includ-
ing but not limited to the following:
• Input voltage
• Output voltage
• Output current
• Module temperature
Software Tools for Design and Production
For these modules, Murata-PS provides software for configuring and monitor-
ing via the PMBus interface. For more information please contact your local
Murata-PS representative.
See http://power.murata.com/datasheet?/data/apnotes/dcan-63.pdf for
Application Note AN-63, Digital DC-DC Evaluation Board User Guide.
See http://power.murata.com/datasheet?/data/apnotes/dcan-64.pdf for Ap-
plication Note AN-64, Murata Power Brick GUI User Guide.
www.murata-ps.com/support
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