LTC2946_15 Datasheet, PDF (1/42 Pages) Linear Technology – Wide Range I2C Power, Charge and Energy Monitor

LTC2946
Wide Range I²C Power,
Charge and Energy Monitor
FEATURES
n _{Rail-to-Rail Input Range: 0V to 100V}
n _{Wide Input Supply Range: 2.7V to 100V}
n _{Shunt Regulator for Supplies >100V}
n _{Δ∑ ADC with Less Than ±0.4% Total}
Unadjusted Error
n _{12-Bit Resolution for Current and Voltages}
n _{±1% Accurate Power and Energy Measurements}
n _{±0.6% Accurate Current and Charge Measurements}
n _{Additional ADC Input Monitors an External Voltage}
n _{Internal ±5% or External Time Bases}
n _{Continuous Scan and Snapshot Modes}
n _{Stores Minimum and Maximum Values}
n _{Alerts When Limits Exceeded}
n _{Split SDA Pin Eases Opto-Isolation}
n _{Shutdown Mode with IQ < 40µA}
n _{Available in 4mm × 3mm DFN and 16-Lead}
MSOP Packages
APPLICATIONS
n _{Telecom Infrastructure}
n _{Industrial Equipment}
n _{General Purpose Energy Measurement}
DESCRIPTION
The LTC^®2946 is a rail-to-rail system monitor that measures
current, voltage, power, charge and energy. It features an
operating range of 2.7V to 100V and includes a shunt regu-
lator for supplies above 100V. The current measurement
common mode range of 0V to 100V is independent of the
input supply. A 12-bit ADC measures load current, input
voltage and an auxiliary external voltage. Load current and
internally calculated power are integrated over an external
clock or crystal or internal oscillator time base for charge
and energy. An accurate time base allows the LTC2946
to provide measurement accuracy of better than ±0.6%
for charge and ±1% for power and energy. Minimum and
maximum values are stored and an overrange alert with
programmable thresholds minimizes the need for software
polling. Data is reported via a standard I²C interface.
The LTC2946 I²C interface includes separate data input
and output pins for use with standard or opto-isolated I²C
connections. The LTC2946-1 has an inverted data output
for use with inverting opto-isolator configurations.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
Hot Swap is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
TYPICAL APPLICATION
Wide Range Power, Charge and Energy
Monitor with Onboard ADC and I²C
V_IN
4V TO 100V
0.1µF
NINE I²C
ADDRESSES
ACCUMULATION
ENABLE
0.02Ω
TO
LOAD
SENSE⁺ SENSE^–
V_DD
GPIO3
ALERT
INTV_CC
SCL
ADR1
SDAI
LTC2946
ADR0
SDAO
GND
ADIN
I²C
INTERFACE
MEASURED
VOLTAGE
GPIO2
CLKIN
GPIO1
CLKOUT
GENERAL
PURPOSE
OUTPUT
OPTIONAL
CRYSTAL
TIMEBASE
2946 TA01a
ADC Total Unadjusted Error (ADIN)
0.10
0.05
0
–0.05
–0.10
0
1024
2048
CODE
3072
4096
2946 TA01b
For more information www.linear.com/LTC2946
2946fa
1