LTC2975_15 Datasheet, PDF (1/104 Pages) Linear Technology – 4-Channel PMBus Power System Manager Featuring Accurate Input Current and Energy Measurement

LTC2975
4-Channel PMBus Power
System Manager Featuring Accurate
Input Current and Energy Measurement
Features
Description
nn _{Sequence, Trim, Margin and Supervise Four Power}
Supplies
nn _{Manage Faults, Monitor Telemetry and Create Fault Logs}
nn _{PMBus™ Compliant Command Set}
nn _{Supported by LTpowerPlay™ GUI}
nn _{Margin or Trim Supplies to Within 0.25% of Target}
nn _{Monitor Input Current (±1%) and Accumulate Energy}
nn _{Fast OV/UV and OC Supervisors Per Channel}
nn _{Coordinate Sequencing and Fault Management}
Across Multiple LTC PSM Devices
nn _{Automatic Fault Logging to Internal EEPROM}
nn _{Operate Autonomously Without Additional Software}
nn _{External Temperature and Input Voltage Supervisors}
nn _{Accurate Monitoring of Four Output Voltages, Four}
Output Currents, Four External Temperatures, Input
Voltage and Current, and Internal Die Temperature
nn _I²_{C/SMBus Serial Interface}
nn _{Can Be Powered from 3.3V, or 4.5V to 15V}
nn _{Pin-Compatible to the LTC2974}
nn _{Available in 64-Lead 9mm × 9mm QFN Package}
Applications
nn _{Computers and Network Servers}
nn _{Industrial Test and Measurement}
nn _{High Reliability Systems}
nn _{Video and Medical Imaging}
The LTC^®2975 is a 4-channel Power System Manager used
to sequence, trim (servo), margin, supervise, manage
faults, provide telemetry and create fault logs. PMBus
commands support power supply sequencing, precision
point-of-load voltage adjustment and margining. DACs use
a proprietary soft-connect algorithm to minimize supply
disturbances. Supervisory functions include over and under
current, voltage and temperature threshold limits for four
power supply output channels as well as over and under
voltage threshold limits for a single power supply input
channel. Programmable fault responses can disable the
power supplies with optional retry after a fault is detected.
Faults that disable a power supply can automatically trigger
black box EEPROM storage of fault status and associated
telemetry. An internal 16-bit ADC monitors four output
voltages, four output currents, four external temperatures,
input voltage and current, and die temperature. Input power,
energy, and output power is also calculated. A program-
mable watchdog timer monitors microprocessor activity
for a stalled condition and resets the microprocessor if
necessary. A single wire bus synchronizes power supplies
across multiple LTC Power System Management (PSM)
devices. Configuration EEPROM supports autonomous
operation without additional software.
L, LT, LTC, LTM, Linear Technology, the Linear logo, µModule and PolyPhase are registered
trademarks and LTpowerPlay is a trademark of Linear Technology Corporation. PMBus is
a trademark of SMIF, Inc. All other trademarks are the property of their respective owners.
Protected by U.S. Patents including 7382303, 7420359 and 8648623.
Typical Application
4-Channel PMBus Power System Manager with Input Energy Metering
4.5V < V_IBUS < 15V
OV
PMBus
INTERFACE
TO/FROM
OTHER
DEVICES
V_PWR
V_{IN_SNS}
AUXFAULTB
V_{IN_SNS_CAP}
V_DD33**
I_{IN_SNSP}
I_{IN_SNSM}
I_SENSEP0
I_SENSEM0
V_DAC0
V_SENSEP0
SDA
LTC2975*
SCL
ALERTB
CONTROL0
FAULTB0
FAULTB1
V_SENSEM0
V_{OUT_EN0}
T_SENSE0
SHARE_CLK
ASEL0
PWRGD
ASEL1
WP _GND WDI/RESETB
LOAD
R30
R20
R10
MMBT3906
V_IN
I^–
I⁺ DC/DC
CONVERTER
TG
SW
BG
V_FB
SGND
RUN/SS
GND
TO µP
RESETB
INPUT
0.1µF
WATCHDOG
TIMER INTERRUPT
2975 TA01a
*SOME DETAILS OMITTED FOR CLARITY
ONLY ONE OF FOUR CHANNELS SHOWN
**LTC2975 MAY ALSO BE POWERED
DIRECTLY FROM EXTERNAL 3.3V SUPPLY
For more information www.linear.com/LTC2975
Power Measurement Error
2
Mfr_ein_config_iin_range = Medium
V_{IIN_SNS} = 50mV
V_{VIN_SNS} = 12V
1
0
–1
6 TYPICAL PARTS
–2
–50 –25 0 25 50 75 100
TEMPERATURE (°C)
2975 TA01b
2975f
1