I2C System Monitor

I2C System Monitor
Power
Supply
V1
I 2C
V2
LTC2990
FPGA
V3
Temp.
Diode
V4
Measures:
External Temperature
Differential Voltage
Internal Temperature
Rail-to-Rail Current
Single-Ended Voltage
Internal VCC
Accurately Measure Temperature, Voltage and Current
The LTC 2990 is a temperature, voltage and current monitor for 3V to 5.5V systems which integrates a 14-bit ADC, 10ppm/°C
reference and I2C interface to provide submillivolt voltage resolution, as well as accuracy of ±1°C internally and ±0.5°C
remotely when making temperature measurements. Unlike traditional temperature monitors that rely on single-ended inputs for
measurements, the LTC2990 uses four differential inputs to measure multiple parameters simultaneously.
®
Features
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Measures Voltage, Current and Temperature
Measures Two Remote Diode Temperatures
±1°C Accuracy, 0.06°C Resolution
±2°C Internal Temperature Sensor
14-Bit ADC Measures Voltage/Current
3V to 5.5V Supply Operating Voltage
Four Selectable Addresses
Internal 10ppm/°C Voltage Reference
10-Lead MSOP Package
Applications
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Temperature Measurement
Supply Voltage Monitoring
Inductor DCR Compensation
Current Measurement
Remote Data Acquisition
Environmental Monitoring
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered
trademarks of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
Demo Board
REMOTE
DIODE
SENSORS
VCC
MODE
V1
GND
V2
SCL
CONTROL
LOGIC
V3
MUX
SDA
I2C
ADC
V4
ADR0
ADR1
UV
INTERNAL
SENSOR
VCC
UNDERVOLTAGE
DETECTOR
REFERENCE
Built-In Configurability
Uncompromised Accuracy
Accessibility in Mind
Four multifunction differential voltage
pins to measure combinations of
external temperature, single-ended
voltage, differential voltage and railto-rail current, while also measuring
the LTC2990’s own internal VCC and
temperature. Take Celsius or Kelvin
temperature measurements. No
inflexible dedicated temperature or
voltage pins.
The 14-bit Δ∑ ADC and 10ppm/°C
voltage reference minimize component
count and board space, while enabling
the LTC2990 to achieve exceptional
accuracy and resolution: ±1°C ACC
(0.06°C RES) for external temperature,
±2°C ACC (0.06°C RES) for internal
temperature, ±0.1% ACC (305µV RES)
for internal VCC , ±0.1% ACC (305µV
RES) for external single-ended voltage,
and ±0.5% ACC (19µV RES) for
differential voltage or current.
The LTC2990’s I2C serial interface
supports data rates up to 100kbps
in standard mode and 400kbps in
fast mode. An undervoltage detector
inhibits communication if the supply
voltage drops below 2.0V, and
shutting down the LTC2990 results
in only 1µA of input supply current.
Access various registers to select the
configuration of the LTC2990, trigger
start or repeated conversions, query
results and even determine if existing
data is new or old.
External Temperature
x1
x2
x1
x1
x1
3
x1
x1
x1
4
x1
x1
x1
5
x1
x1
x4
6
x1
x1
x2
7
x1
x1
x2
8
x1
x1
x2
9
x1
x1
x1
10
x1
x1
x2
x1
x1
x1
1.0
MS PACKAGE
10-LEAD PLASTIC MSOP
0.5
TUE (°C)
Internal Temperature
x1
2
Temperature Total Unadjusted Error
Rail-to-Rail Current
Internal VCC
1
Differential Voltage
Configuration
Single-Ended Voltage
10 Possible Sensing Configurations
V1
V2
V3
V4
GND
TREMOTE
1
2
3
4
5
10
9
8
7
6
VCC
ADR1
ADR0
SCL
SDA
0
–0.5
x1
x1
x2
–1.0
0
25
50
75
100
125
TAMB (°C)
www.linear.com/2990 n 1-800-4-LINEAR
0810A