LTC2978_15 Datasheet, PDF (1/80 Pages) Linear Technology – Octal Digital Power Supply Manager with EEPROM

NOT RECOMMENDED FOR NEW DESIGNS
Please See LTC2978A for Drop-In Replacement
Features
n _I²_{C/SMBus Serial Interface}
n _{PMBus Compliant Command Set}
n _{Configuration EEPROM with CRC}
n _{Black Box Fault Logging to Internal EEPROM}
n _{Differential Input, 16-Bit ΔΣ ADC with Less Than}
±0.25% of Total Unadjusted Error
n _{Eight Voltage Servos Precisely Adjust Output}
Voltages Using Eight 10-Bit DACs with Soft-Connect
n _{Monitors Eight Output Voltages and One Input}
Voltage and Internal Die Temperature
n _{8-Channel Sequencer}
n _{Programmable Watchdog Timer}
n _{Eight UV/OV VOUT and One VIN Supervisor}
n _{Supports Multi-Channel Fault Management}
n _{Operates Autonomously without Additional Software}
n _{LTC2978 Can Be Powered from 3.3V or 4.5V to 15V}
n _{Available in 64-pin 9mm × 9mm QFN Package}
Applications
n _Computers
n _{Network Servers}
n _{Industrial Test and Measurement}
n _{High Reliability Systems}
n _{Medical Imaging}
n _Video
LTC2978
Octal Digital Power Supply
Manager with EEPROM
Description
The LTC^®2978 is an octal, digital power-supply monitor,
supervisor, sequencer, and margin controller. Eight output
channels can be managed per user defined configura-
tion settings. Supervisory functions include fault OV/UV
threshold limits for eight output channels and one input
channel. Programmable fault dependencies and responses
allow the power supplies to be disabled with optional retry
after a fault has been detected. Serial bus telemetry allows
eight output voltages, one input voltage, die temperature
and fault status to be monitored. In addition, odd num-
bered channels can be configured to measure the voltage
across a current sense resistor. Power supply sequencing,
precision point-of-load voltage adjustment and margining
are supported with PMBus commands. A programmable
watchdog timer monitors microprocessor activity for a
stalled condition and resets the microprocessor if neces-
sary. The 1-wire synchronization bus supports power
supply sequencing across multiple LTC digital power
devices. User programmable parameters can be stored
in EEPROM. Faults and telemetry data can be logged to
EEPROM for diagnostic analysis.
L, LT, LTC, LTM, PolyPhase, Linear Technology and the Linear logo are registered trademarks
and LTpowerPlay ia a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners. Protected by U.S. Patents including 7382303 and 7420359.
Typical Application
Octal Power Supply Controller with PMBus Interface
4.5V < V_IBUS < 15V
3.3V**
TO INTERMEDIATE
BUS CONVERTER ENABLE
PMBus
INTERFACE
WRITE-PROTECT
TO/FROM OTHER
LTC2978s
V_PWR
V_DD33
V_{IN_EN}
V_{IN_SNS}
V_DACP0
V_SENSEP0
SDA ^LTC2978*
SCL
ALERTB
CONTROL0
V_DACM0
V_SENSEM0
V_{OUT_EN0}
WP
PWRGD
WDI/RESETB
FAULTB00
ASEL0
SHARE_CLK
ASEL1
GND
2978 TA01a
V_IN
LOAD
R30
R20
R10
TO µP RESETB INPUT
WATCHDOG
TIMER INTERRUPT
V_OUT
DIGITALLY
MANAGED
POWER
SUPPLY
V_FB
SGND
RUN/SS
GND
*SOME DETAILS OMITTED FOR CLARITY
ONLY ONE OF EIGHT CHANNELS SHOWN
**LTC2978 MAY BE POWERED FROM EITHER AN
EXTERNAL 3.3V SUPPLY OR THE INTERMEDIATE BUS
Typical ADC Total Unadjusted
Error vs Temperature
0.035 _{ADC VIN = 1.8V}
0.030
0.025
0.020
0.015
0.010
0.005
0
–50 –35 –20 –5 10 25 40 55 70 85 100
TEMPERATURE (°C)
2978 TA01b
For more information www.linear.com/LTC2978
2978fd
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