Document
LTC2991 Octal I2C Voltage, Current, and Temperature Monitor
FEATURES
n Measures Voltage, Current, Temperature n Measures Four Remote Diode Temperatures n 0.7°C (Typ) Accuracy, 0.06°C Resolution n 1°C (Typ) Internal Temperature Sensor n Series Resistance Cancellation n 14-Bit ADC Measures Voltage/Current n PWM Temperature Output n 3V to 5.5V Supply Operating Voltage n Eight Selectable Addresses n Internal 10ppm/°C Voltage Reference n V1 to V8 Inputs ESD Rated to 6kV HBM n 16-Lead MSOP Package
APPLICATIONS
n Temperature Measurement n Supply Voltage Monitoring n Current Measurement n Remote Data Acquisition n Environmental Monitoring
DESCRIPTION
The LTC®2991 is used to monitor system temperatures, voltages and currents. Through the I2C serial interface, the eight monitors can individually measure supply voltages and can be paired for differential measurements of current sense resistors or temperature sensing transistors. Additional measurements include internal temperature and internal VCC. The internal 10ppm reference minimizes the number of supporting components and area required. Selectable address and configurable functionality give the LTC2991 flexibility to be incorporated in various systems needing temperature, voltage or current data. The LTC2991 fits well in systems needing submillivolt voltage resolution, 1% current measurement and 1°C temperature accuracy or any combination of the three.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and Easy Drive is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
5V
3.3V
2.5V
1.2V
RSENSE
3.3V I/O 2.5V I/O
1.2V CORE
I2C
2-WIRE INTERFACE
TAMBIENT
VCC V1
V2 V3 V4
SDA SCL ADR0 ADR1 ADR2
LTC2991
V5 V6
V7
GND
V8 PWM
2991 TA01a
FPGA
FPGA TEMPERATURE
BOARD TEMPERATURE TO FAN
TERROR (°C)
Temperature Total Unadjusted Error
1.00
0.75
0.50 0.25
TREMOTE
0 –0.25
TINTERNAL
–0.50
–0.75
–1.00 –50 –25 0
25 50 75 TAMBIENT (°C)
100 125 150
2991 TA01b
For more information www.linear.com/LTC2991
2991ff
1
LTC2991
ABSOLUTE MAXIMUM RATINGS
(Note 1)
Supply Voltage (VCC)................................. –0.3V to 6.0V Input Voltages V1, V2, V3, V4, V5, V6, V7, V8, SCL, ADR0, ADR1, ADR2...............–0.3V to (VCC + 0.3V) Output Voltage PWM.....................–0.3V to (VCC + 0.3V) Output Voltage SDA...................................... –0.3V to 6V Operating Temperature Range LTC2991C................................................. 0°C to 70°C LTC2991I..............................................–40°C to 85°C Storage Temperature Range................... –65°C to 150°C Lead Temperature (Soldering, 10 sec) MS Package........................................................... 300°C
PIN CONFIGURATION
TOP VIEW
V1 1 V2 2 V3 3 V4 4 V5 5 V6 6 V7 7 V8 8
16 15
AVCDCR2
14 ADR1
13 ADR0
12 PWM
11 SCL
10 SDA
9 GND
MS PACKAGE 16-LEAD PLASTIC MSOP
TJMAX = 125°C, θJA = 120°C/W
ORDER INFORMATION
LEAD FREE FINISH
TAPE AND REEL
PART MARKING*
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LTC2991CMS#PBF
LTC2991CMS#TRPBF 2991
16-Lead Plastic MSOP
0°C to 70°C
LTC2991IMS#PBF
LTC2991IMS#TRPBF
2991
16-Lead Plastic MSOP
–40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/. Some packages are available in 500 unit reels through designated sales channels with #TRMPBF suffix.
E LECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C, VCC = 3.3V, unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN TYP MAX
General
VCC Input Supply Range
ICC Input Supply Current
ISD Input Supply Current
VCC(UVL)
Input Supply Undervoltage Lockout
Measurement Accuracy
l 2.9
5.5
During Conversion, I2C Inactive
l
1.1 1.5
Shutdown Mode, I2C Inactive
l
16
l 1.3 2.0 2.6
TINTERNAL(TUE) TRMT(TUE)
Internal Temperature Total Unadjusted Error Remote Diode Temperature Total Unadjusted Error
η = 1.004
±1 ±3.5 l ±0.7 ±1.5
VCC(TUE)
VCC Voltage Total Unadjusted Error
2.9V ≤ 5.5V
l ±0.05 ±0.25
VN(TUE) VDIFF(TUE)
V1 Through V8 Total Unadjusted Error Differential Voltage Total Unadjusted Error V1 – V2, V3 – V4, V5 – V6, V7 – V8
0V ≤ 4.9V –300mV≤ VD ≤300mV
l ±0.05 ±0.25 l ±0.1 ±0.75
VDIFF(MAX) VOFFSET_DIFF VOFFSET_SE
Full-Scale Differential Voltage Differential Offset Single-Ended Offset
V1 through V8 = 0V V1 through V8 = 0V
l –312.5
312.5
l –12.5
0
12.5
l –6
0
6
UNITS
V mA µA
V
°C °C
% % %
mV LSB LSB
2991ff
2 For more information www.linear.