LTC2990IMS#TR [Linear]
IC 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO10, PLASTIC, MSOP-10, Power Management Circuit;型号: | LTC2990IMS#TR |
厂家: | Linear |
描述: | IC 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO10, PLASTIC, MSOP-10, Power Management Circuit 光电二极管 |
文件: | 总24页 (文件大小:231K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
LTC2990
2
Quad I C Voltage, Current
and Temperature Monitor
FEATURES
DESCRIPTION
The LTC®2990 is used to monitor system temperatures,
n
Measures Voltage, Current and Temperature
2
n
Measures Two Remote Diode Temperatures
voltages and currents. Through the I C serial interface,
n
±±0.5C ꢀAAuraAc, ±0±65C Resolution (Tcp)
the device can be configured to measure many combi-
nations of internal temperature, remote temperature,
n
±ꢁ5C ꢂnternal Temperature Sensor (Tcp)
n
14-Bit ADC Measures Voltage/Current
remote voltage, remote current and internal V . The
CC
n
3V to 5.5V Supply Operating Voltage
internal 10ppm/°C reference minimizes the number of
supporting components and area required. Selectable
address and configurable functionality give the LTC2990
flexibility to be incorporated in various systems needing
temperature, voltage or current data. The LTC2990 fits
well in systems needing sub-millivolt voltage resolution,
1% current measurement and 1°C temperature accuracy
or any combination of the three.
n
Four Selectable Addresses
n
Internal 10ppm/°C Voltage Reference
n
10-Lead MSOP Package
APPLICATIONS
n
Temperature Measurement
n
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.
Supply Voltage Monitoring
n
Current Measurement
n
Remote Data Acquisition
n
Environmental Monitoring
TYPICAL APPLICATION
Voltage, Current, Temperature Monitor
Temperature Total Unadjusted Error
R
SENSE
1.0
2.5V
I
LOAD
5V
0.5
V
T
V1
V2
V3
CC
REMOTE
SDA
SCL
ADR0
ADR1
0
–0.5
–1.0
LTC2990
T
REMOTE
V4
2990 TA01a
GND
T
INTERNAL
MEASURES: TWO SUPPLY VOLTAGES,
SUPPLY CURRENT, INTERNAL AND
REMOTE TEMPERATURES
–25
0
50
75 100 125
–50
25
T
(°C)
AMB
2990 TA01b
2990fc
1
LTC2990
ABSOLUTE MAXIMUM RATINGS
PIN CONFIGURATION
(Note ꢁ)
TOP VIEW
Supply Voltage V ................................... –0.3V to 6.0V
CC
V1
V2
1
2
3
4
5
10
9
V
CC
Input Voltages V1, V2, V3, V4, SDA, SCL,
ADR1
ADR0
SCL
V3
8
ADR1, ADR2..................................–0.3V to (V + 0.3V)
CC
V4
GND
7
6
Operating Temperature Range
SDA
LTC2990C................................................ 0°C to 70°C
LTC2990I.............................................–40°C to 85°C
Storage Temperature Range .................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec)...................300°C
MS PACKAGE
10-LEAD PLASTIC MSOP
T
= 125°C, θ = 150°C/W
JA
JMAX
ORDER INFORMATION
LEꢀD FREE FꢂNꢂSH
LTC2990CMS#PBF
LTC2990IMS#PBF
LEꢀD BꢀSED FꢂNꢂSH
LTC2990CMS
TꢀPE ꢀND REEL
PꢀRT MꢀRKꢂNG*
LTDSQ
PꢀCKꢀGE DESCRꢂPTꢂON
10-Lead Plastic MSOP
10-Lead Plastic MSOP
PꢀCKꢀGE DESCRꢂPTꢂON
10-Lead Plastic MSOP
10-Lead Plastic MSOP
TEMPERꢀTURE RꢀNGE
0°C to 70°C
LTC2990CMS#TRPBF
LTC2990IMS#TRPBF
TꢀPE ꢀND REEL
LTDSQ
–40°C to 85°C
PꢀRT MꢀRKꢂNG*
LTDSQ
TEMPERꢀTURE RꢀNGE
0°C to 70°C
LTC2990CMS#TR
LTC2990IMS#TR
LTC2990IMS
LTDSQ
–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.
Contact LTC Marketing for parts trimmed to ideality factors other than 1.004.
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/
ELECTRICAL CHARACTERISTICS The l denotes the speAifiAations whiAh applc over the full operating
temperature range, otherwise speAifiAations are at Tꢀ = 2.5C0 VCC = 303V, unless otherwise noted0
SYMBOL
General
PꢀRꢀMETER
CONDꢂTꢂONS
MꢂN
TYP
MꢀX
UNꢂTS
l
l
l
l
V
Input Supply Range
Input Supply Current
Input Supply Current
Input Supply Undervoltage Lockout
2.9
5.5
1.8
5
V
CC
2
I
I
During Conversion, I C Inactive
1.1
1
2.1
mA
μA
V
CC
2
Shutdown Mode, I C Inactive
SD
V
1.3
2.7
CC(UVL)
Measurement ꢀAAuraAc
T
Internal Temperature Total Unadjusted
Error
0.5
1
3.5
1.5
°C
°C
°C
INT(TUE)
T
T
= 0°C to 85°C
= –40°C to 0°C
AMB
AMB
3
l
T
Remote Diode Temperature Total
Unadjusted Error
0.5
°C
η = 1.004 (Note 4)
RMT(TUE)
l
l
l
V
V
V
V
Voltage Total Unadjusted Error
CC
0.1
0.1
0.2
0.25
0.25
0.75
%
%
%
CC(TUE)
V1 Through V4 Total Unadjusted Error
Differential Voltage Total Unadjusted Error –300mV ≤ V ≤ 300mV
V1 – V2 or V3 – V4
n(TUE)
DIFF(TUE)
D
l
l
V
V
V
V
V
Maximum Differential Voltage
Differential Voltage Common Mode Range
Differential Voltage LSB Weight
Single-Ended Voltage LSB Weight
Temperature LSB Weight
Temperature Noise
–300
0
300
mV
V
μV
μV
Deg
DIFF(MAX)
DIFF(CMR)
LSB(DIFF)
V
CC
19.42
305.18
0.0625
0.2
0.05
LSB(SINGLE-ENDED)
LSB(TEMP)
NOISE
Celsius or Kelvin
Celsius or Kelvin
T
°RMS
°/√Hz
T
= 46ms (Note 2)
MEAS
2990fc
2
LTC2990
ELECTRICAL CHARACTERISTICS The l denotes the speAifiAations whiAh applc over the full operating
temperature range, otherwise speAifiAations are at Tꢀ = 2.5C0 VCC = 303V, unless otherwise noted0
SYMBOL
Res
INL
PꢀRꢀMETER
Resolution (No Missing Codes)
Integral Nonlinearity
CONDꢂTꢂONS
(Note 2)
MꢂN
14
TYP
MꢀX
UNꢂTS
Bits
l
l
2.9V ≤ V ≤ 5.5V, V
= 1.5V
CC
IN(CM)
(Note 2)
Single-Ended
Differential
–2
–2
2
2
LSB
LSB
C
V1 Through V4 Input Sampling
Capacitance
V1 Through V4 Input Average Sampling
Current
(Note 2)
0.35
0.6
pF
μA
nA
IN
I
I
0V ≤ V ≤ 3V (Note 2)
N
IN(AVG)
l
V1 Through V4 Input Leakage Current
0V ≤ V ≤ V
–10
10
DC_LEAK(VIN)
N
CC
Measurement Delac
, T , T
V1, V2, V3, V4
l
l
l
l
l
T
Per Configured Temperature Measurement (Note 2)
37
1.2
1.2
1.2
46
1.5
1.5
1.5
55
1.8
1.8
1.8
167
ms
ms
ms
ms
ms
INT R1 R2
Single-Ended Voltage Measurement
Differential Voltage Measurement
(Note 2) Per Voltage, Two Minimum
V1 – V2, V3 – V4
(Note 2)
(Note 2)
(Note 2)
V
V
Measurement
CC
CC
Max Delay
Mode[4:0] = 11101, T , T , T , V
INT R1 R2 CC
Vꢁ, V3 Output (Remote Diode Mode Onlc)
l
l
I
V
Output Current
Output Voltage
Remote Diode Mode
260
350
V
CC
μA
V
OUT
0
OUT
2
ꢂ C ꢂnterfaAe
l
l
l
l
l
l
l
V
V
V
V
V
ADR0, ADR1 Input Low Threshold Voltage Falling
ADR0, ADR1 Input High Threshold Voltage Rising
0.3 • V
V
V
V
V
V
ADR(L)
ADR(H)
OL1
CC
0.7 • V
0.7 • V
CC
CC
SDA Low Level Maximum Voltage
Maximum Low Level Input Voltage
Minimum High Level Input Voltage
SDA, SCL Input Current
I = –3mA, V = 2.9V to 5.5V
SDA and SCL Pins
SDA and SCL Pins
0.4
O
CC
0.3 • V
IL
CC
IH
I
I
0 < V
,
< V
CC
1
1
μA
μA
SDAI,SCLI
SDA SCL
Maximum ADR0, ADR1 Input Current
ADR0 or ADR1 Tied to V or GND
CC
ADR(MAX)
2
ꢂ C Timing (Note 2)
f
t
t
t
Maximum SCL Clock Frequency
Minimum SCL Low Period
Minimum SCL High Period
Minimum Bus Free Time Between Stop/
Start Condition
400
kHz
μs
ns
SCL(MAX)
LOW
1.3
600
1.3
HIGH
μs
BUF(MIN)
t
t
Minimum Hold Time After (Repeated)
Start Condition
Minimum Repeated Start Condition Set-Up
Time
600
600
ns
ns
HD,STA(MIN)
SU,STA(MIN)
t
t
t
t
t
Minimum Stop Condition Set-Up Time
Minimum Data Hold Time Input
Minimum Data Hold Time Output
Minimum Data Set-Up Time Input
Maximum Suppressed Spike Pulse Width
SCL, SDA Input Capacitance
600
0
900
100
250
10
ns
ns
ns
ns
ns
pF
SU,STO(MIN)
HD,DATI(MIN)
HD,DATO(MIN)
SU,DAT(MIN)
SP(MAX)
300
50
C
X
Note ꢁ: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 4: Trimmed to an ideality factor of 1.004 at 25°C. Remote diode
temperature drift (TUE) verified at diode voltages corresponding to
the temperature extremes with the LTC2990 at 25°C. Remote diode
temperature drift (TUE) guaranteed by characterization over the LTC2990
operating temperature range.
Note 2: Guaranteed by design and not subject to test.
Note 3: Integral nonlinearity is defined as the deviation of a code from a
straight line passing through the actual endpoints of the transfer curve.
The deviation is measured from the center of the quantization band.
2990fc
3
LTC2990
Tꢀ = 2.5C, VCC = 303V unless otherwise noted
TYPICAL PERFORMANCE CHARACTERISTICS
Measurement Delac Variation
Supplc Current vs Temperature
Shutdown Current vs Temperature
vs T Normalized to 303V, 2.5C
1200
1150
1100
1050
1000
950
3.5
3.0
4
V
CC
= 5V
V
= 5V
3
CC
2.5
V
CC
= 5V
2
1
2.0
1.5
1.0
0.5
V
= 3.3V
CC
V
CC
= 3.3V
V
CC
= 3.3V
0
0
–1
–25
0
150
–50
25 50 75 100 125
(°C)
–25
0
150
–50
25 50 75 100 125
(°C)
–25
0
150
–50
25 50 75 100 125
(°C)
T
T
T
AMB
AMB
AMB
2990 G02
2990 G01
2990 G03
VCC TUE
Single-Ended VX TUE
Differential Voltage TUE
0.10
0.05
0
0.10
0.05
0
1.0
0.5
V
CC
= 5V
0
V
CC
= 3.3V
–0.05
–0.10
–0.05
–0.10
–0.5
–1.0
–25
0
150
–25
0
150
–50
25 50 75 100 125
(°C)
–25
0
150
–50
25 50 75 100 125
–50
25 50 75 100 125
(°C)
T
T
(°C)
T
AMB
AMB
AMB
2990 G05
2990 G04
2990 G06
Remote Diode Error with LTC299±
at 2.5C, 9±5C
Remote Diode Error with LTC299±
at Same Temperature as Diode
TꢂNTERNꢀL Error
4
3
1.00
0.75
0.50
0.25
0.6
0.4
LTC2990
AT 25°C
2
0.2
1
0
LTC2990
AT 90°C
–0.25
0
0
–0.2
–0.4
–0.6
–1
–2
–0.50
–0.75
–1.00
–3
–25
0
150
–25
0
150
–50
25 50 75 100 125
–50
25 50 75 100 125
(°C)
–25
0
150
–50
25 50 75 100 125
T
(°C)
T
AMB
BATH TEMPERATURE (°C)
AMB
2990 G07
2990 G09
2990 G08
2990fc
4
LTC2990
TYPICAL PERFORMANCE CHARACTERISTICS Tꢀ = 2.5C, VCC = 303V unless otherwise noted
Single-Ended Noise
Single-Ended Transfer FunAtion
Single-Ended ꢂNL
6
4000
1.0
0.5
0
4800 READINGS
3500
3000
5
4
3
2
1
V
CC
= 5V
V
CC
= 3.3V
V
CC
= 3.3V
2500
2000
1500
1000
500
V
CC
= 5V
–0.5
0
–1.0
–1
0
0
1
2
3
(V)
4
5
–2
–1
1
2
3
3
5
6
–3
0
–1 –0
1
2
4
V
X
LSBs (305.18μV/LSB)
V
(V)
X
2990 G12
2990 G10
2990 G11
LTC299± Differential Noise
Differential Transfer FunAtion
Differential ꢂNL
2
1
500
400
300
200
100
0
0.4
0.3
800 READINGS
0.2
0.1
0
0
–0.1
–0.2
–0.3
–0.4
–1
–2
0
0.2
–0.4
0.4
0
–0.2
–4 –3 –2 –1
1
2
3
0
0.1
–0.4 –0.3 –0.2 –0.1
0.2 0.3 0.4
V
IN
(V)
LSBs (19.42μV/LSB)
V1-V2 (V)
2990 G15
2990 G13
2990 G14
TꢂNT Noise
Remote Diode Noise
POR Thresholds vs Temperature
500
400
300
200
100
0
600
500
400
300
200
100
0
2.6
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
1000 READINGS
1000 READINGS
V
CC
RISING
V
CC
FALLING
–0.75 –0.5 –0.25
0
(°C)
0.25 0.5 0.75
–0.75 –0.5 –0.25
0
0.25 0.5 0.75
50 75
(°C)
–50 –25
0
25
T
100 125 150
(°C)
AMB
2990 G16
2990 G17
2990 G18
2990fc
5
LTC2990
PIN FUNCTIONS
SDꢀ (Pin 6): Serial Bus Data Input and Output. In the
transmitter mode (Read), the conversion result is output
through the SDA pin, while in the receiver mode (Write),
the device configuration bits are input through the SDA
pin. At data input mode, the pin is high impedance; while
at data output mode, it is an open-drain N-channel driver
andthereforeanexternalpull-upresistororcurrentsource
Vꢁ (Pin ꢁ): First Monitor Input. This pin can be config-
ured as a single-ended input or the positive input for a
differential or remote diode temperature measurement (in
combination with V2). When configured for remote diode
temperature, this pin will source a current.
V2 (Pin 2): Second Monitor Input. This pin can be con-
figured as a single-ended input or the negative input for a
differential or remote diode temperature measurement (in
combination with V1). When configured for remote diode
temperature, this pin will have an internal termination,
while the measurement is active.
to V is needed.
CC
SCL (Pin 7): Serial Bus Clock Input. The LTC2990 can
only act as a slave and the SCL pin only accepts external
serial clock. The LTC2990 does not implement clock
stretching.
V3 (Pin 3): Third Monitor Input. This pin can be config-
ured as a single-ended input or the positive input for a
differential or remote diode temperature measurement (in
combination with V4). When configured for remote diode
temperature, this pin will source a current.
ꢀDR±(Pin8):SerialBusAddressControlInput.TheADR0
2
pin is an address control bit for the device I C address.
See Table 2.
ꢀDRꢁ (Pin 9): Serial Bus Address Control Input. The
V4 (Pin 4): Fourth Monitor Input. This pin can be config-
ured as a single-ended input or the negative input for a
differential or remote diode temperature measurement (in
combination with V3). When configured for remote diode
temperature, this pin will have an internal termination,
while the measurement is active.
2
ADR1 pin is an address control bit for the device I C
address. See Table 2.
V
(Pin ꢁ±): Supply Voltage Input.
CC
GND (Pin .): Device Circuit Ground. Connect this pin to a
ground plane through a low impedance connection.
2990fc
6
LTC2990
FUNCTIONAL DIAGRAM
REMOTE
DIODE
SENSORS
V
10
5
CC
MODE
V1
GND
1
V2
SCL
SDA
2
CONTROL
LOGIC
7
6
8
9
V3
3
MUX
2
ADC
ADR0
ADR1
I C
V4
4
UV
INTERNAL
SENSOR
V
CC
UNDERVOLTAGE
DETECTOR
REFERENCE
2990 FD
TIMING DIAGRAM
SDAI/SDAO
t
SP
t
t
t
SU, DAT
t
t
SU,STA
BUF
HD, DATO,
HD, DATI
t
HD, STA
t
SU, STO
t
SP
2990 TD
SCL
t
HD, STA
START
CONDITION
REPEATED START
CONDITION
STOP
CONDITION
START
CONDITION
2990fc
7
LTC2990
OPERATION
The LTC2990 monitors voltage, current, internal and
threshold. During an undervoltage condition, the part is in
a reset state, and the data and control registers are placed
in the default state of 00h.
remote temperatures. It can be configured through an
2
I C interface to measure many combinations of these pa-
rameters. Single or repeated measurements are possible.
Remote temperature measurements use a transistor as
a temperature sensor, allowing the remote sensor to be a
discreteNPN(ex.MMBT3904)oranembeddedPNPdevice
in a microprocessor or FPGA. The internal ADC reference
minimizes the number of support components required.
Remotediodemeasurementsareconductedusingmultiple
ADC conversions and source currents to compensate for
sensor series resistance. During temperature measure-
ments, the V2 or V4 terminal of the LTC2990 is terminated
with a diode. The LTC2990 is calibrated to yield the correct
temperature for a remote diode with an ideality factor of
1.004. See the applications section for compensation of
sensor ideality factors other than the factory calibrated
value of 1.004.
The Functional Diagram displays the main components of
the device. The input signals are selected with an input
MUX, controlled by the control logic block. The control
logic uses the mode bits in the control register to manage
the sequence and types of data acquisition. The control
logic also controls the variable current sources during
remote temperature acquisition. The order of acquisitions
2
TheLTC2990communicatesthroughanI Cserialinterface.
The serial interface provides access to control, status and
2
data registers. I C defines a 2-wire open-drain interface
supporting multiple slave devices and masters on a single
bus. The LTC2990 supports 100kbits/s in the standard
mode and up to 400kbit/s in fast mode. The four physical
is fixed: T
, V1, V2, V3, V4 then V . The ADC
INTERNAL
CC
performs the necessary conversion(s) and supplies the
data to the control logic for further processing in the case
of temperature measurements, or routing to the appropri-
ate data register for voltage and current measurements.
Current and temperature measurements, V1 – V2 or V3
– V4, are sampled differentially by the internal ADC. The
2
addressessupportedarelistedinTable2.TheI Cinterface
is used to trigger single conversions, or start repeated
conversions by writing to a dedicated trigger register. The
data registers contain a destructive-read status bit (data
valid), which is used in repeated mode to determine if
the register’s contents have been previously read. This
bit is set when the register is updated with new data, and
cleared when read.
2
I C interface supplies access to control, status and data
registers. The ADR1 and ADR0 pins select one of four
2
possible I C addresses (see Table 2). The undervoltage
2
detector inhibits I C communication below the specified
APPLICATIONS INFORMATION
Figure 1 is the basic LTC2990 application circuit.
Power Up
R
SENSE
The V pin must exceed the undervoltage (UV) thresh-
CC
15mΩ
2.5V
5V
old of 2.5V to keep the LTC2990 out of power-on reset.
Power-on reset will clear all of the data registers and the
control register.
I
LOAD
0.1μF
2-WIRE
MMBT3904
V
V1
V2
V3
CC
SDA
SCL
ADR0
ADR1
2
I C
INTERFACE
LTC2990
GND
470pF
Temperature Measurements
V4
2990 F01
The LTC2990 can measure internal temperature and up
to two external diode or transistor sensors. During tem-
perature conversion, current is sourced through either
the V1 or the V3 pin to forward bias the sensing diode.
Figure ꢁ
2990fc
8
LTC2990
APPLICATIONS INFORMATION
Table ꢁ0 ReAommended Transistors to Be Used as Temperature
Sensors
The change in sensor voltage per degree temperature
change is 275μV/°C, so environmental noise must be kept
to a minimum. Recommended shielding and PCB trace
considerations are illustrated in Figure 2.
MꢀNUFꢀCTURER
PꢀRT NUMBER
PꢀCKꢀGE
Fairchild Semiconductor
MMBT3904
FMMT3904
SOT-23
SOT-23
The diode equation:
Central Semiconductor
CMPT3904
CET3904E
SOT-23
SOT-883L
⎛ ⎞
k • T
q
IC
Diodes, Inc.
On Semiconductor
NXP
MMBT3904
MMBT3904LT1
MMBT3904
MMBT3904
UMT3904
SOT-23
SOT-23
SOT-23
SOT-23
SC-70
VBE = η•
•ln
(1)
⎜ ⎟
I
⎝ ⎠
S
can be solved for T, where T is Kelvin degrees, I is a
S
Infineon
process dependent factor on the order of 1E-13, η is the
diode ideality factor, k is Boltzmann’s constant and q is
the electron charge.
Rohm
the diode sensor can be considered a temperature scaling
factor. The temperature error for a 1% accurate ideality
factorerroris1%oftheKelvintemperature.Thus,at25°C,
or298K, a+1%accurateidealityfactorerroryieldsa+2.98
degree error. At 85°C or 358K, a +1% error yields a 3.6
degree error. It is possible to scale the measured Kelvin
or Celsius temperature measured using the LTC2990 with
a sensor ideality factor other than 1.004, to the correct
value. The scaling Equations (3) and (4) are simple, and
can be implemented with sufficient precision using 16-bit
fixed-point math in a microprocessor or microcontroller.
VBE •q
T =
(2)
⎛ ⎞
IC
η•k•In
⎜ ⎟
I
⎝ ⎠
S
The LTC2990 makes differential measurements of diode
voltage to calculate temperature. Proprietary techniques
allow for cancellation of error due to series resistance.
0.1μF
GND SHIELD
LTC2990
TRACE
V1
V2
V3
V4
V
CC
ADR1
ADR0
SCL
Factory Ideality Calibration Value:
η
CAL
= 1.004
470pF
GND SDA
Actual Sensor Ideality Value:
NPN SENSOR
2990 F02
η
ACT
Figure 20 ReAommended PCB Lacout
Compensated Kelvin Temperature:
ꢂdealitc FaAtor SAaling
ηCAL
(3)
(4)
T
=
• T
K _MEAS
K _COMP
ηACT
Compensated Celsius Temperature
The LTC2990 is factory calibrated for an ideality factor of
1.004, which is typical of the popular MMBT3904 NPN
transistor. The semiconductor purity and wafer-level pro-
cessing limits device-to-device variation, making these
devicesinterchangeable(typically<0.5°C)fornoadditional
cost. Several manufacturers supply suitable transistors,
somerecommendedsourcesarelistedinTable1. Discrete
2-terminal diodes are not recommended as temperature
sensors. Whileanidealityfactorvalueof1.004istypicalof
target sensors, small deviations can yield significant tem-
perature errors. Contact LTC Marketing for parts trimmed
to ideality factors other than 1.004. The ideality factor of
⎡
⎤
ηCAL
TC_COMP
=
• T
+273 – 273
(
)
⎢
⎣
⎥
C_MEAS
η
ACT
⎦
A 16-bit unsigned number is capable of representing the
ratio η /η
in a range of 0.00003 to 1.99997, by
CAL ACT
15
multiplying the fractional ratio by 2 . The range of scal-
ing encompasses every conceivable target sensor value.
The ideality factor scaling granularity yields a worst-case
temperatureerrorof0.01°at125°C.Multiplyingthis16-bit
2990fc
9
LTC2990
APPLICATIONS INFORMATION
R
unsigned number and the measured Kelvin (unsigned)
temperature represented as a 16-bit number, yields a
32-bit unsigned result. To scale this number back to a
13-bit temperature (9-bit integer part, and a 4-bit frac-
SENSE
0V – V
CC
I
LOAD
V1
V2
15
LTC2990
tional part), divide the number by 2 per Equation (5).
Similarly, Celsius coded temperature values can be scaled
using 16-bit fixed-point arithmetic, using Equation (6).
In both cases, the scaled result will have a 9-bit integer
(d[12:4]) and the 4LSBs (d[3:0]) representing the 4-bit
fractional part. To convert the corrected result to decimal,
2990 F03
Figure 30 Simplified Current Sense SAhematiA
ential input signal during a conversion is (V – 1.49V)
IN
• 0.34[μA/V]. The maximum source impedance to yield
14-bit results with, 1/2LSB full-scale error is ~50Ω. In
order to achieve high accuracy 4-point, or Kelvin con-
nected measurements of the sense resistor differential
voltage are necessary.
4
divide the final result by 2 or 16, as you would the reg-
ister contents. If ideality factor scaling is implemented
in the target application, it is beneficial to configure the
LTC2990 for Kelvin coded results to limit the number of
math operations required in the target processor.
In the case of current measurements, the external sense
resistor is typically small, and determined by the full-scale
input voltage of the LTC2990. The full-scale differential
voltage is 0.300V. The external sense resistance is then a
⎛
⎞
ηCAL
Unsigned
215
T
(
)
⎜
⎝
⎟
⎠
K _MEAS
η
ACT
(5)
(6)
T
=
=
K _COMP
215
functionofthemaximummeasurablecurrent,orR
EXT_MAX
⎛
⎞
ηCAL
Unsigned
215 TC_MEAS +273.15 • 24
(
)
⎜
⎝
⎟
(
)
= 0.300V/I
. For example, if you wanted to measure a
MAX
η
ACT
⎠
TC_COMP
current range of 5A, the external shunt resistance would
215
equal 0.300V/5A = 60mΩ.
– 273.15 • 24
Thereexistsawaytoimprovethesenseresistor’sprecision
usingtheLTC2990.TheLTC2990measuresbothdifferential
voltage and remote temperature. It is therefore, possible
to compensate for the absolute resistance tolerance of the
senseresistorandthetemperaturecoefficientofthesense
resistor in software. The resistance would be measured
by running a calibrated test current through the discrete
resistor. The LTC2990 would measure both the differential
voltage across this resistor and the resistor temperature.
Sampling Currents
Single-ended voltage measurements are directly sampled
by the internal ADC. The average ADC input current is a
function of the input applied voltage as follows:
I
= (V – 1.49V) • 0.17[μA/V]
IN
IN(AVG)
Inputs with source resistance less than 200Ω will yield
full-scalegainerrorsduetosourceimpedanceof<1/2LSB
for 14-bit conversions. The nominal conversion time is
1.5ms for single-ended conversions.
From this measurement, R and T in the equation be-
O
O
low would be known. Using the two equations, the host
microprocessor could compensate for both the absolute
tolerance and the TCR.
Current Measurements
R = R • [1 + α(T – T )]
The LTC2990 has the ability to perform 14-bit current
measurements with the addition of a current sense resis-
tor (see Figure 3).
T
O
O
where:
α = +3930 ppm/°C for copper trace
α = 2 to ~+200ppm/°C for discrete R
In order to achieve accurate current sensing a few de-
tails must be considered. Differential voltage or current
measurements are directly sampled by the internal ADC.
The average ADC input current for each leg of the differ-
(7)
(8)
I = (V1 – V2)/R
T
2990fc
10
LTC2990
APPLICATIONS INFORMATION
DeviAe Configuration
accessed. Bit 6 of the register is a sensor-shorted alarm.
This bit of the corresponding register will be high if the
remote sensor diode differential voltage is below 0.14V.
The LTC2990 internal bias circuitry maintains this voltage
above this level during normal operating conditions. Bit 5
of the register is a sensor open alarm. This bit of the cor-
respondingregisterwillbehighiftheremotesensordiode
The LTC2990 is configured by writing the control register
through the serial interface. Refer to Table 5 for control
register bit definition. The device is capable of many ap-
plication configurations including voltage, temperature
and current measurements. It is possible to configure the
device for single or repeated acquisitions. For repeated
acquisitions,onlytheinitialtriggerisrequiredandnewdata
is written over the old data. Acquisitions are frozen during
serial read data transfers to prevent the upper and lower
data bytes for a particular measurement from becoming
out of sync. Internally, both the upper and lower bytes
are written at the same instant. Since serial data transfer
timeout is not implemented, failure to terminate a read
operation will yield an indefinitely frozen wait state. The
device can also make single measurements, or with one
trigger,allofthemeasurementsfortheconfiguration.When
the device is configured for multiple measurements, the
order of measurements is fixed. As each new data result
is ready, the MSB of the corresponding data register is
set, and the corresponding status register bit is set. These
bits are cleared when the corresponding data register is
addressed. The configuration register value at power-up
yields the measurement of only the internal temperature
sensor, if triggered. The four input pins V1 through V4 will
be in a high impedance state, until configured otherwise,
and a measurement triggered.
differential voltage is above 1.0V . The LTC2990 internal
DC
biascircuitrymaintainsthisvoltagebelowthislevelduring
normal operating conditions. The two sensor alarms are
only valid after a completed conversion indicated by the
data_valid bit being high. Bit 4 through Bit 0 of the MSB
register are the conversion result bits D[12:8], in two’s
compliment format. Note in Kelvin results, the result will
alwaysbepositive. TheLSBregistercontainstemperature
result bits D[7:0]. To convert the register contents to
temperature, use the following equation:
T = D[12:0]/16.
See Table 10 for conversion value examples.
Voltage/Current:Voltageresultsarereportedintworespec-
tive registers, an MSB and LSB register. The Voltage MSB
result register most significant bit (Bit 7) is the data_valid
bit, which indicates whether the current register contents
have been accessed since the result was written to the
register. This bit will be set when the register contents are
new, and cleared when accessed. Bit 6 of the MSB register
is the sign bit, Bits 5 though 0 represent bits D[13:8] of
the two’s complement conversion result. The LSB register
holds conversion bits D[7:0]. The LSB value is different
for single-ended voltage measurements V1 through V4,
and differential (current measurements) V1 – V2 and V3
– V4. Single-ended voltages are limited to positive values
intherange0Vto3.5V. Differentialvoltagescanhaveinput
values in the range of –0.300V to 0.300V.
Data Format
The data registers are broken into 8-bit upper and lower
bytes. Voltage and current conversions are 14-bits. The
upper bits in the MSB registers provide status on the
resulting conversions. These status bits are different for
temperature and voltage conversions:
Temperature: Temperature conversions are reported as
Celsius or Kelvin results described in Tables 8 and 9,
each with 0.0625 degree-weighted LSBs. The format is
controlled by the control register, Bit 7. All temperature
Use the following equations to convert the register values
(see Table 10 for examples):
V
V
V
V
= D[14:0] • 305.18μV, if Sign = 0
= (D[14:0] +1) • –305.18μV, if Sign = 1
= D[14:0] • 19.42μV, if Sign = 0
= (D[14:0] +1) • –19.42μV, if Sign = 1
SINGLE-ENDED
SINGLE-ENDED
DIFFERENTIAL
DIFFERENTIAL
formats, T , T and T are controlled by this bit. The
INT R1
R2
Temperature MSB result register most significant bit
(Bit 7) is the DATA_VALID bit, which indicates whether
the current register contents have been accessed since
the result was written to the register. This bit will be set
when new data is written to the register, and cleared when
Current = D[13:0] • 19.42μV/R
, if Sign = 0
SENSE
Current = (D[13:0] +1) • –19.42μV/R
, if Sign = 1
SENSE
2990fc
11
LTC2990
APPLICATIONS INFORMATION
where R
<1Ω.
is the current sensing resistor, typically
STꢀRT and STOP Conditions
SENSE
When the bus is idle, both SCL and SDA must be high. A
bus master signals the beginning of a transmission with
a START condition by transitioning SDA from high to low
while SCL is high. When the bus is in use, it stays busy
if a repeated START (SR) is generated instead of a STOP
condition. The repeated START (SR) conditions are func-
tionally identical to the START (S). When the master has
finished communicating with the slave, it issues a STOP
condition by transitioning SDA from low to high while SCL
is high. The bus is then free for another transmission.
V :TheLTC2990measuresV .Toconvertthecontentsof
CC
CC
the V register to voltage, use the following equation:
CC
V
= 2.5 + D[13:0] • 305.18μV
CC
Digital ꢂnterfaAe
The LTC2990 communicates with a bus master using a
2
two-wire interface compatible with the I C Bus and the
2
SMBus, an I C extension for low power devices.
The LTC2990 is a read-write slave device and supports
SMBusbusReadByteDataandWriteByteData,ReadWord
Data and Write Word Data commands. The data formats
for these commands are shown in Tables 3 though 10.
2
ꢂ C DeviAe ꢀddressing
Four distinct bus addresses are configurable using the
ADR0-ADR1 pins. There is also one global sync address
availableatEEhwhichprovidesaneasywaytosynchronize
The connected devices can only pull the bus wires LOW
and can never drive the bus HIGH. The bus wires are
externally connected to a positive supply voltage via a
current source or pull-up resistor. When the bus is free,
2
multiple LTC2990s on the same I C bus. This allows write
only access to all 2990s on the bus for simultaneous trig-
gering. Table 2 shows the correspondence between ADR0
and ADR1 pin states and addresses.
2
bothlinesareHIGH. DataontheI Cbuscanbetransferred
at rates of up to 100kbit/s in the standard mode and up to
2
ꢀAknowledge
400kbit/s in the fast mode. Each device on the I C bus is
recognized by a unique address stored in that device and
can operate as either a transmitter or receiver, depending
on the function of the device. In addition to transmitters
and receivers, devices can also be considered as masters
or slaves when performing data transfers. A master is
the device which initiates a data transfer on the bus and
generates the clock signals to permit that transfer. At the
same time any device addressed is considered a slave.
The acknowledge signal is used for handshaking between
thetransmitterandthereceivertoindicatethatthelastbyte
of data was received. The transmitter always releases the
SDA line during the acknowledge clock pulse. When the
slave is the receiver, it must pull down the SDA line so that
it remains LOW during this pulse to acknowledge receipt
of the data. If the slave fails to acknowledge by leaving
SDA HIGH, then the master can abort the transmission by
generatingaSTOPcondition.Whenthemasterisreceiving
data from the slave, the master must pull down the SDA
line during the clock pulse to indicate receipt of the data.
After the last byte has been received the master will leave
the SDA line HIGH (not acknowledge) and issue a STOP
condition to terminate the transmission.
The LTC2990 can only be addressed as a slave. Once ad-
dressed, it can receive configuration bits or transmit the
last conversion result. Therefore the serial clock line SCL
is an input only and the data line SDA is bidirectional. The
device supports the standard mode and the fast mode for
data transfer speeds up to 400kbit/s. The Timing Diagram
shows the definition of timing for fast/standard mode
Write ProtoAol
2
devices on the I C bus. The internal state machine cannot
2
updateinternaldataregistersduringanI Creadoperation.
The master begins communication with a START condi-
tion followed by the seven bit slave address and the R/W#
bit set to zero. The addressed LTC2990 acknowledges
the address and then the master sends a command byte
which indicates which internal register the master wishes
2990fc
2
The state machine pauses until the I C read is complete.
It is therefore, important not to leave the LTC2990 in this
state for long durations, or increased conversion latency
will be experienced.
12
LTC2990
APPLICATIONS INFORMATION
to write. The LTC2990 acknowledges the command byte
and then latches the lower four bits of the command byte
into its internal Register Address pointer. The master then
delivers the data byte and the LTC2990 acknowledges
once more and latches the data into its internal register.
The transmission is ended when the master sends a STOP
condition. If the master continues sending a second data
byte, as in a Write Word command, the second data byte
willbeacknowledgedbytheLTC2990andwrittentothenext
register in sequence, if this register has write access.
Control Register
The control register (Table 5) determines the selected
measurement mode of the device. The LTC2990 can be
configured to measure voltages, currents and tempera-
tures.Thesemeasurementscanbesingle-shotorrepeated
measurements. Temperatures can be set to report in
Celsius or Kelvin temperature scales. The LTC2990 can be
configuredtorunparticularmeasurements, orallpossible
measurementspertheconfigurationspecifiedbythemode
bits. The power-on default configuration of the control
register is set to 0x00, which translates to a repeated
measurement of the internal temperature sensor, when
triggered. This mode prevents the application of remote
diode test currents on pins V1 and V3, and remote diode
terminations on pins V2 and V4 at power-up.
Read ProtoAol
ThemasterbeginsareadoperationwithaSTARTcondition
followed by the seven bit slave address and the R/W# bit
settozero.TheaddressedLTC2990acknowledgesthisand
then the master sends a command byte which indicates
which internal register the master wishes to read. The
LTC2990acknowledgesthisandthenlatchesthelowerfour
bitsofthecommandbyteintoitsinternalRegisterAddress
pointer.ThemasterthensendsarepeatedSTARTcondition
followed by the same seven bit address with the R/W# bit
now set to one. The LTC2990 acknowledges and sends
the contents of the requested register. The transmission
is ended when the master sends a STOP condition. The
register pointer is automatically incremented after each
byte is read. If the master acknowledges the transmitted
data byte, as in a Read Word command, the LTC2990
will send the contents of the next sequential register as
the second data byte. The byte following register 0x0F is
register 0x00, or the status register.
Status Register
The status register (Table 4) reports the status of a par-
ticular conversion result. When new data is written into a
particular result register, the corresponding DATA_VALID
bit is set. When the register is addressed by the I
face, the status bit (as well as the DATA_VALID bit in the
respectiveregister)iscleared.Thehostcanthendetermine
if the current available register data is new or stale. The
busy bit, when high, indicates a single-shot conversion is
in progress. The busy bit is always high during repeated
mode, after the initial conversion is triggered.
2
C inter-
a6-a0
b7-b0
b7-b0
1-7
8
9
1-7
8
9
1-7
8
9
P
S
START
ADDRESS
R/W
ACK
DATA
ACK
DATA
ACK
STOP
2990 F04
Figure 40 Data Transfer Over ꢂ2C or SMBus
S
ADDRESS W#
10011a1:a0
A
0
COMMAND
A
0
DATA
b7:b0
A
0
P
0
XXXXXb3:b0
FROM MASTER TO SLAVE
FROM SLAVE TO MASTER
A: ACKNOWLEDGE (LOW)
A#: NOT ACKNOWLEDGE (HIGH)
R: READ BIT (HIGH)
W#: WRITE BIT (LOW)
S: START CONDITION
P: STOP CONDITION
2990 F05
Figure .0 LTC299± Serial Bus Write Bcte ProtoAol
2990fc
13
LTC2990
APPLICATIONS INFORMATION
S
ADDRESS W#
A
0
COMMAND
A
0
DATA
b7:b0
A
0
DATA
b7:b0
A
0
P
10011a1:a0
0
XXXXXb3:b0
2990 F06
Figure 60 LTC299± Serial Bus Repeated Write Bcte ProtoAol
S
ADDRESS W#
10011a1:a0
A
0
COMMAND
A
0
S
ADDRESS
R
1
A
0
DATA A#
b7:b0
P
0
XXXXXb3:b0
10011a1:a0
1
2990 F07
Figure 70 LTC299± Serial Bus Read Bcte ProtoAol
S
ADDRESS W#
10011a1:a0
A
0
COMMAND
A
0
S
ADDRESS
R
1
A
0
DATA
b7:b0
A
0
DATA A#
b7:b0
P
0
XXXXXb3:b0
10011a1:a0
1
2990 F08
Figure 80 LTC299± Serial Bus Repeated Read Bcte ProtoAol
Table 20 ꢂ2C Base ꢀddress
2
2
HEX ꢂ C BꢀSE ꢀDDRESS
BꢂNꢀRY ꢂ C BꢀSE ꢀDDRESS
ꢀDRꢁ
ꢀDR±
98h
1001 100X*
1001 101X*
1001 110X*
1001 111X*
1110 1110
0
0
1
1
0
1
0
1
9Ah
9Ch
9Eh
EEh
Global Sync Address
*X = R/W Bit
Table 30 LTC299± Register ꢀddress and Contents
†
REGꢂSTER ꢀDDRESS*
REGꢂSTER NꢀME
STATUS
REꢀD/WRꢂTE
DESCRꢂPTꢂON
00h
01h
02h
03h
04h
05h
06h
07h
08h
09h
0Ah
0Bh
0Ch
0Dh
0Eh
0Fh
R
Indicates BUSY State, Conversion Status
Controls Mode, Single/Repeat, Celsius/Kelvin
Triggers an Conversion
CONTROL
TRIGGER**
N/A
R/W
R/W
Unused Address
T
(MSB)
(LSB)
R
R
R
R
R
R
R
R
R
R
R
R
Internal Temperature MSB
INT
T
Internal Temperature LSB
INT
V1 (MSB)
V1 (LSB)
V2 (MSB)
V2 (LSB)
V3 (MSB)
V3 (LSB)
V4 (MSB)
V4 (LSB)
V1, V1 – V2 or T MSB
R1
V1, V1 – V2 or T LSB
R1
V2, V1 – V2 or T MSB
R1
V2, V1 – V2 or T LSB
R1
V3, V3 – V4 or T MSB
R2
V3, V3 – V4 or T LSB
R2
V4, V3 – V4 or T MSB
R2
V4, V3 – V4 or T LSB
R2
V
(MSB)
(LSB)
V
CC
V
CC
MSB
LSB
CC
V
CC
*Register Address MSBs b7-b4 are ignored.
**Writing any value triggers a conversion. Data Returned reading this register address is the Status register.
†
Power-on reset sets all registers to 00h.
2990fc
14
LTC2990
APPLICATIONS INFORMATION
Table 40 STꢀTUS Register (Default ±x±±)
BꢂT
b7
b6
b5
b4
b3
b2
b1
b0
NꢀME
OPERꢀTꢂON
0
Always Zero
V
CC
Ready
1 = V Register Contains New Data, 0 = V Register Read
CC CC
V4 Ready
1 = V4 Register Contains New Data, 0 = V4 Register Read
1 = V3 Register Contains New Data, 0 = V3 Register Data Old
1 = V2 Register Contains New Data, 0 = V2 Register Data Old
1 = V1 Register Contains New Data, 0 = V1 Register Data Old
V3, T , V3 – V4 Ready
R2
V2 Ready
V1, T , V1 – V2 Ready
R1
T
Ready
1 = T Register Contains New Data, 0 = T Register Data Old
INT INT
INT
Busy*
1= Conversion In Process, 0 = Acquisition Cycle Complete
*In Repeat mode, Busy = 1 always
Table .0 CONTROL Register (Default ±x±±)
BꢂT
b7
NꢀME
OPERꢀTꢂON
Temperature Format
Temperature Reported In; Celsius = 0 (Default), Kelvin = 1
Repeated Acquisition = 0 (Default), Single Acquisition = 1
Reserved
b6
Repeat/Single
b5
Reserved
b[4:3]
Mode [4:3]
Mode Description
0
0
1
0
1
Internal Temperature Only (Default)
0
T
T
, V1 or V1 – V2 Only per Mode [2:0]
, V3 or V3 – V4 Only per Mode [2:0]
R1
1
1
R2
All Measurements per Mode [2:0]
Mode Description
b[2:0]
Mode [2:0]
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
V1, V2, T (Default)
R2
V1 – V2, T
R2
V1 – V2, V3, V4
T
T
T
, V3, V4
R1
, V3 – V4
R1
, T
R1 R2
V1 – V2, V3 – V4
V1, V2, V3, V4
2990fc
15
LTC2990
APPLICATIONS INFORMATION
Table 60 Voltage/Current Measurement MSB Data Register
Format
BꢂT 7
BꢂT 6
BꢂT .
BꢂT 4
BꢂT 3
BꢂT 2
BꢂT ꢁ
BꢂT ±
DV*
Sign
D13
D12
D11
D10
D9
D8
*Data Valid is set when a new result is written into the register. Data Valid
2
is cleared when this register is addressed (read) by the I C inteface.
Table 70 Voltage/Current Measurement LSB Data Register
Format
BꢂT 7
BꢂT 6
BꢂT .
BꢂT 4
BꢂT 3
BꢂT 2
BꢂT ꢁ
BꢂT ±
D7
D6
D5
D4
D3
D2
D1
D0
Table 80 Temperature Measurement MSB Data Register Format
BꢂT 7
BꢂT 6
BꢂT .
BꢂT 4
BꢂT 3
BꢂT 2
BꢂT ꢁ
BꢂT ±
†
DV*
SS**
SO
D12
D11
D10
D9
D8
*DATA_VALID is set when a new result is written into the register.
2
DATA_VALID is cleared when this register is addressed (read) by the I C
interface.
**Sensor Short is high if the voltage measured on V1 is too low
during temperature measurements. This signal is always low for T
measurements.
INT
†
Sensor Open is high if the voltage measured on V1 is excessive
during temperature measurements. This signal is always low for T
measurements.
INT
Table 90 Temperature Measurement LSB Data Register Format
BꢂT 7
BꢂT 6
BꢂT .
BꢂT 4
BꢂT 3
BꢂT 2
BꢂT ꢁ
BꢂT ±
D7
D6
D5
D4
D3
D2
D1
D0
2990fc
16
LTC2990
APPLICATIONS INFORMATION
Table ꢁ±0 Conversion Formats
VOLTꢀGE FORMꢀTS
Single-Ended
SꢂGN
0
BꢂNꢀRY VꢀLUE D[ꢁ3:±]
11111111111111
10110011001101
01111111111111
00000000000000
11110000101001
11111111111111
10110011001101
10000000000000
00000000000000
10000000000000
00001110101000
00000000000000
10110011001101
10000000000000
00001010001111
VOLTꢀGE
>5
LSB = 305.18μV
0
3.500
0
2.500
0
0.000
1
–0.300
>0.318
+0.300
+0.159
0.000
Differential
0
LSB = 19.42μV
0
0
0
1
–0.159
–0.300
<–0.318
1
1
V
= Result + 2.5V
0
V
CC
V
CC
= 6V
= 5V
CC
LSB = 305.18μV
0
0
V
CC
= 2.7V
TEMPERꢀTURE FORMꢀTS
FORMꢀT
Celsius
Celsius
Celsius
Celsius
Kelvin
BꢂNꢀRY VꢀLUE D[ꢁ2:±]
0011111010000
0000110010001
0000110010000
1110110000000
1100011100010
1000100010010
0111010010010
TEMPERꢀTURE
+125.0000
+25.0625
+25.0000
–40.0000
398.1250
273.1250
233.1250
Temperature Internal, T or T
R1
R2
LSB = 0.0625 Degrees
Kelvin
Kelvin
2990fc
17
LTC2990
TYPICAL APPLICATIONS
Computer Voltage and Temperature Monitoring
High Voltage/Current and Temperature Monitoring
R
1mΩ
1%
12V
5V
SENSE
V
IN
3.3V
5V TO 105V
10.0k
1%
30.1k
1%
I
R
20Ω
1%
LOAD
IN
0A TO 10A
0.1μF
10.0k
1%
10.0k
1%
0.1μF
+IN
–INS
–
+
–INF
V
–
+
MICROPROCESSOR
V
V
V1
V2
V3
CC
2-WIRE
V
REG
SDA
SCL
ADR0
ADR1
2
I C
LTC2990
GND
470pF
INTERFACE
V4
OUT
LTC6102HV
0.1μF
2990 TA03
R
4.99k
1%
OUT
200k
1%
0.1μF
VOLTꢀGE, CURRENT ꢀND TEMPERꢀTURE CONFꢂGURꢀTꢂON:
CONTROL REGISTER: 0x58
T
REG 4, 5
REG 6, 7
REG 8, 9
REG A, B
REG E, F
0.0625°C/LSB
0.61mVLSB
4.75k
1%
AMB
V1 (+5)
V2(+12)
1.22mV/LSB
T
0.0625°C/LSB
2.5V + 305.18μV/LSB
PROCESSOR
V
CC
5V
0.1μF
MMBT3904
V
V1
V2
V3
CC
2-WIRE
SDA
SCL
ADR0
ADR1
2
I C
LTC2990
GND
470pF
INTERFACE
V4
2990 TA02
ALL CAPACITORS 20%
VOLTꢀGE, CURRENT ꢀND TEMPERꢀTURE CONFꢂGURꢀTꢂON:
CONTROL REGISTER: 0x58
T
REG 4, 5
REG 6, 7
REG 8, 9
REG A, B
REG E, F
0.0625°C/LSB
13.2mVLSB
1.223mA/LSB
0.0625°C/LSB
2.5V + 305.18μV/LSB
AMB
V
LOAD
V2(I
)
LOAD
T
REMOTE
V
CC
Motor ProteAtion/Regulation
LOAD
= I • V
0.1Ω
1%
PWR
MOTOR CONTROL VOLTAGE
0V TO 5V
DC
DC
0A TO 2.2A
5V
0.1μF
V
V1
V2
V3
CC
MMBT3904
MOTOR
2-WIRE
SDA
SCL
ADR0
ADR1
2
I C
LTC2990
GND
INTERFACE
470pF
MOTOR
V4
T
2990 TA04
T
INTERNAL
CURRENT ꢀND TEMPERꢀTURE CONFꢂGURꢀTꢂON:
VOLTꢀGE ꢀND TEMPERꢀTURE CONFꢂGURꢀTꢂON:
CONTROL REGISTER: 0x59
CONTROL REGISTER: 0x58
T
REG 4, 5
REG 6, 7
REG A, B
REG E, F
0.0625°C/LSB
194μA/LSB
T
AMB
REG 4, 5
REG 8, 9
REG A, B
REG E, F
0.0625°C/LSB
305.18μVLSB
0.0625°C/LSB
AMB
I
V
MOTOR
MOTOR
CC
MOTOR
T
MOTOR
CC
T
0.0625°C/LSB
2.5V + 305.18μV/LSB
V
V
2.5V + 305.18μV/LSB
2990fc
18
LTC2990
TYPICAL APPLICATIONS
Large Motor ProteAtion/Regulation
LOAD
ꢀꢁꢀ*ꢀtꢀ7
PWR
0.01Ω
MOTOR CONTROL VOLTAGE
0V TO 40V
1W, 1%
0A TO 10A
71.5k
1%
71.5k
1%
10.2k
1%
10.2k
1%
5V
0.1μF
V
V1 V2
CC
MMBT3904
MOTOR
2-WIRE
SDA
SCL
ADR0
ADR1
V3
2
I C
LTC2990
INTERFACE
470pF
MOTOR
V4
GND
T
2990 TA05
T
INTERNAL
VOLTꢀGE ꢀND TEMPERꢀTURE CONFꢂGURꢀTꢂON:
CURRENT ꢀND TEMPERꢀTURE CONFꢂGURꢀTꢂON:
CONTROL REGISTER: 0x58
CONTROL REGISTER: 0x59
T
REG 4, 5
REG 8, 9
REG A, B
REG E, F
0.0625°C/LSB
2.44mVLSB
T
AMB
REG 4, 5
REG 6, 7
REG A, B
REG E, F
0.0625°C/LSB
15.54mA/LSB
AMB
V
I
MOTOR
MOTOR
MOTOR
MOTOR
CC
T
0.0625°C/LSB
2.5V + 305.18μV/LSB
T
0.0625°C/LSB
2.5V + 305.18μV/LSB
V
V
CC
Fan/ꢀir Filter/Temperature ꢀlarm
3.3V
MMBT3904
FAN
22Ω
0.125W
470pF
3.3V
0.1μF
HEATER ENABLE
V
MMBT3904
FAN
V1
V2
V3
CC
TEMPERATURE FOR:
GOOD FAN
2-WIRE
SDA
SCL
ADR0
ADR1
2
I C
LTC2990
GND
22Ω
0.125W
INTERFACE
470pF
BAD FAN
V4
HEATER
T
INTERNAL
NDS351AN
HEATER ENABLE
2 SECOND PULSE
2990 TA06
CONTROL REGISTER: 0x5D
T
T
T
REG 4, 5
REG 6, 7
REG A, B
REG E, F
0.0625°C/LSB
AMB
R1
R2
0.0625°C/LSB
0.0625°C/LSB
2.5V + 305.18μV/LSB
V
CC
2990fc
19
LTC2990
TYPICAL APPLICATIONS
Batterc Monitoring
BATTERY I AND V MONITOR
15mΩ*
CHARGING
CURRENT
5V
0.1μF
V
V1
V2
V3
CC
MMBT3904
2-WIRE
SDA
SCL
ADR0
ADR1
2
V(t)
T(t)
I(t)
+
I C
LTC2990
GND
NiMH
BATTERY
INTERFACE
470pF
• • •
100%
100%
100%
V4
T
BATT
2990 TA07
T
*IRC LRF3W01R015F
INTERNAL
VOLTꢀGE ꢀND TEMPERꢀTURE CONFꢂGURꢀTꢂON:
CURRENT ꢀND TEMPERꢀTURE CONFꢂGURꢀTꢂON:
CONTROL REGISTER: 0x58
CONTROL REGISTER: 0x59
T
AMB
REG 4, 5
REG 8, 9
REG A, B
REG E, F
0.0625°C/LSB
305.18μVLSB
T
REG 4, 5
REG 6, 7
REG A, B
REG E, F
0.0625°C/LSB
1.295mA/LSB
AMB
BAT
V
I
BAT
BAT
T
0.0625°C/LSB
2.5V + 305.18μV/LSB
T
0.0625°C/LSB
2.5V + 305.18μV/LSB
BAT
V
V
CC
CC
Wet-Bulb PscAhrometer
5V
0.1μF
MMBT3904
V2
MMBT3904
V
CC
V1
SDA
SCL
V3
μC
LTC2990
470pF
470pF
$T
ADR0
ADR1
V4
2990 TA08
GND
T
DRY
T
WET
T
INTERNAL
FAN: SUNON
KDE0504PFB2
DAMP MUSLIN
CONTROL REGISTER: 0x5D
FAN
T
AMB
T
WET
T
DRY
REG 4, 5
REG 6, 7
REG A, B
REG E, F
0.0625°C/LSB
0.0625°C/LSB
0.0625°C/LSB
WATER
RESERVOIR
5V
V
CC
2.5V + 305.18μV/LSB
NDS351AN
FAN ENABLE
REFERENCES:
http://en.wikipedia.org/wiki/Hygrometer
http://en.wikipedia.org/wiki/Psychrometrics
Wind DireAtion/ꢂnstrumentation
3.3V
μC
0.1μF
MMBT3904 3.3V MMBT3904
V
V1
V2
V3
CC
SDA
SCL
ADR0
ADR1
LTC2990
470pF
470pF
V4
2990 TA11
GND
HEATER
75Ω
0.125W
T
INTERNAL
2N7002
HEATER ENABLE
2 SECOND PULSE
CONTROL REGISTER: 0x5D
T
T
T
REG 4, 5
REG 8, 9
REG A, B
REG E, F
0.0625°C/LSB
AMB
R1
R2
0.0625°C/LSB
0.0625°C/LSB
2.5V + 305.18μV/LSB
V
CC
2990fc
20
LTC2990
TYPICAL APPLICATIONS
Liquid-Level ꢂndiAator
3.3V
3.3V
SENSOR HI*
0.1μF
HEATER ENABLE
V
V1
V2
V3
V4
CC
470pF
470pF
SDA
SCL
ADR0
ADR1
SENSOR HI
SENSOR LO
μC
LTC2990
GND
SENSOR LO*
$T = ~2.0°C pp, SENSOR HI
~0.2°C pp, SENSOR LO
T
INTERNAL
NDS351AN
HEATER ENABLE
2 SECOND PULSE
HEATER: 75Ω 0.125W
*SENSOR MMBT3904, DIODE CONNECTED
2290 TA09
CONTROL REGISTER: 0x5D
T
T
T
REG 4, 5
REG 6, 7
REG A, B
REG E, F
0.0625°C/LSB
AMB
HI
0.0625°C/LSB
0.0625°C/LSB
LO
V
CC
2.5V + 305.18μV/LSB
OsAillator/ReferenAe Oven Temperature Regulation
HEATER
= I •V
PWR
0.1Ω
HEATER
VOLTAGE
5V
STYROFOAM
INSULATION
20°C
AMBIENT
0.1μF
V
V1
V2
V3
CC
MMBT3904
HEATER
2-WIRE
SDA
SCL
ADR0
ADR1
2
I C
LTC2990
GND
INTERFACE
470pF
V4
T
OVEN
70°C
OVEN
2990 TA10
T
INTERNAL
HEATER CONSTRUCTION:
HEATER POWER = A • (T
– T
) + B • ∫(T
– T ) dt
SET
AMB
OVEN SET
5FT COIL OF #34 ENAMEL WIRE
~1.6Ω AT 70°C
FEED
FEED
BACK
FORWARD
P
= ~0.4W WITH T = 20°C
HEATER
A
A = 0.004W, B = 0.00005W/DEG-s
VOLTꢀGE ꢀND TEMPERꢀTURE CONFꢂGURꢀTꢂON:
CURRENT ꢀND TEMPERꢀTURE CONFꢂGURꢀTꢂON:
CONTROL REGISTER: 0x58
CONTROL REGISTER: 0x59
T
AMB
REG 4, 5
REG 8, 9
REG A, B
REG E, F
0.0625°C/LSB
305.18μVLSB
T
REG 4, 5
REG 6, 7
REG A, B
REG E, F
0.0625°C/LSB
269μVLSB
AMB
V1, V2
I
HEATER
HEATER
T
0.0625°C/LSB
2.5V + 305.18μV/LSB
T
0.0625°C/LSB
2.5V + 305.18μV/LSB
OVEN
V
V
CC
CC
2990fc
21
LTC2990
PACKAGE DESCRIPTION
Please refer to http://www0linear0Aom/designtools/paAkaging/ for the most reAent paAkage drawings0
MS PaAkage
ꢁ±-Lead PlastiA MSOP
(Reference LTC DWG # 05-08-1661 Rev E)
0.889 p 0.127
(.035 p .005)
5.23
3.20 – 3.45
(.206)
(.126 – .136)
MIN
3.00 p 0.102
(.118 p .004)
(NOTE 3)
0.497 p 0.076
(.0196 p .003)
REF
0.50
(.0197)
BSC
0.305 p 0.038
(.0120 p .0015)
TYP
10 9
8
7 6
RECOMMENDED SOLDER PAD LAYOUT
3.00 p 0.102
(.118 p .004)
(NOTE 4)
4.90 p 0.152
(.193 p .006)
DETAIL “A”
0.254
(.010)
0o – 6o TYP
GAUGE PLANE
1
2
3
4 5
0.53 p 0.152
(.021 p .006)
0.86
(.034)
REF
1.10
(.043)
MAX
DETAIL “A”
0.18
(.007)
SEATING
PLANE
0.17 – 0.27
(.007 – .011)
TYP
0.1016 p 0.0508
(.004 p .002)
0.50
(.0197)
BSC
MSOP (MS) 0307 REV E
NOTE:
1. DIMENSIONS IN MILLIMETER/(INCH)
2. DRAWING NOT TO SCALE
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX
2990fc
22
LTC2990
REVISION HISTORY
REV
DꢀTE
DESCRꢂPTꢂON
PꢀGE NUMBER
2
A
6/11
Revised title of data sheet from “I C Temperature, Voltage and Current Monitor”
Revised Conditions and Values under Measurement Accuracy in Electrical Characteristics section
Revised curve G05 labels in Typical Performance Characteristics section
Revised Applications Information section and renumbered tables and table references
Updated Features section
1
2
4
9 to 17
B
C
8/11
1
10
24
2
Updated Current Measurements section
Updated Related Parts
12/11 Removed conditions for V
Updated Pin 8 description
in Electrical Characteristics
CC(TUE)
6
Removed ° symbol in reference to Kelvin measurements
9
2
Revised Current Measurements, Voltage/Current, I C Device Addressing, Table 2, Table 5, and Table 10 in
Applications Information
10, 11, 12, 14,
15, 17
Revised Typical Applications drawings TA05 and TA11
19, 20
2990fc
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
23
LTC2990
TYPICAL APPLICATION
High Voltage/Current and Temperature Monitoring
R
1mΩ
1%
SENSE
V
IN
5V TO 105V
I
R
20Ω
1%
LOAD
IN
0A TO 10A
0.1μF
+IN
–INS
–
+
–INF
V
–
+
V
V
REG
OUT
LTC6102HV
0.1μF
R
4.99k
1%
OUT
200k
1%
0.1μF
4.75k
1%
5V
0.1μF
MMBT3904
V
V1
V2
V3
CC
2-WIRE
SDA
SCL
ADR0
ADR1
2
I C
LTC2990
GND
470pF
INTERFACE
V4
2990 TA02
ALL CAPACITORS 20%
VOLTꢀGE, CURRENT ꢀND TEMPERꢀTURE CONFꢂGURꢀTꢂON:
CONTROL REGISTER: 0x58
T
REG 4, 5
REG 6, 7
REG 8, 9
REG A, B
REG E, F
0.0625°C/LSB
13.2mVLSB
1.223mA/LSB
0.0625°C/LSB
2.5V + 305.18μV/LSB
AMB
V
LOAD
V2(I
)
LOAD
T
REMOTE
V
CC
RELATED PARTS
PꢀRT NUMBER
DESCRꢂPTꢂON
COMMENTS
2
LTC2991
Octal I C Voltage, Current, Temperature Monitor
Remote and Internal Temperatures, 14-Bit Voltages and
Current, Internal 10ppm/°C Reference
LTC2997
Remote/Internal Temperature Sensor
Temperature to Voltage with Integrated 1.8V Voltage Reference,
1°C Accuracy
LM134
Constant Current Source and Temperature Sensor
Can Be Used as Linear Temperature Sensor
LTC1392
Micropower Temperature, Power Supply and Differential Voltage Complete Ambient Temperature Sensor Onboard
Monitor
™
LTC2487
Internal Temperature Sensor
16-Bit, 2-/4-Channel Delta Sigma ADC with PGA, Easy Drive
2
and I C Interface
LTC6102/LTC6102HV Precision Zero Drift Current Sense Amplifier
5V to 100V, 105V Absolute Maximum (LTC6102HV)
2990fc
LT 1211 REV C • PRINTED IN USA
LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
24
●
●
© LINEAR TECHNOLOGY CORPORATION 2010
(408) 432-1900 FAX: (408) 434-0507 www.linear.com
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