LTC2946
Wide Range I
2
C Power,
Charge and Energy Monitor
FEATURES
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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 I
2
C interface.
The LTC2946 I
2
C interface includes separate data input
and output pins for use with standard or opto-isolated I
2
C
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.
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Rail-to-Rail Input Range: 0V to 100V
Wide Input Supply Range: 2.7V to 100V
Shunt Regulator for Supplies >100V
Δ∑ ADC with Less Than ±0.4% Total
Unadjusted Error
12-Bit Resolution for Current and Voltages
±1% Accurate Power and Energy Measurements
±0.6% Accurate Current and Charge Measurements
Additional ADC Input Monitors an External Voltage
Internal ±5% or External Time Bases
Continuous Scan and Snapshot Modes
Stores Minimum and Maximum Values
Alerts When Limits Exceeded
Split SDA Pin Eases Opto-Isolation
Shutdown Mode with I
Q
< 40µA
Available in 4mm × 3mm DFN and 16-Lead
MSOP Packages
APPLICATIONS
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Telecom Infrastructure
Industrial Equipment
General Purpose Energy Measurement
TYPICAL APPLICATION
Wide Range Power, Charge and Energy
Monitor with Onboard ADC and I
2
C
V
IN
4V TO 100V
V
DD
0.1µF
NINE I
2
C
ADDRESSES
ACCUMULATION
ENABLE
INTV
CC
ADR1
ADR0
GND
GPIO2
CLKIN
LTC2946
0.02
SENSE
+
SENSE
–
GPIO3
SCL
SDAI
SDAO
ADIN
GPIO1
CLKOUT
TO
LOAD
ALERT
ADC TUE (%)
I
2
C
INTERFACE
MEASURED
VOLTAGE
GENERAL
PURPOSE
OUTPUT
0.10
ADC Total Unadjusted Error (ADIN)
0.05
0
–0.05
OPTIONAL
CRYSTAL
TIMEBASE
–0.10
2946 TA01a
0
1024
2048
CODE
3072
4096
2946 TA01b
2946fa
For more information
www.linear.com/LTC2946
1
LTC2946
ABSOLUTE MAXIMUM RATINGS
(Notes 1, 2)
V
DD
Voltage.............................................. –0.3V to 100V
SENSE
+
Voltage ...........................................–1V to 100V
SENSE
–
Voltage .....–1V or SENSE
+
– 1V to SENSE
+
+ 1V
INTV
CC
Voltage
(Note 3) ...................–0.3V to Lesser of 5.8V, V
DD
+ 0.3V
ADR1, ADR0, ADIN, SDAO,
SDAO,
GPIO1 TO GPIO3
Voltages ....................................................... –0.3V to 7V
CLKOUT Voltage ........................–0.3V to INTV
CC
+ 0.3V
CLKIN Voltage ........................................... –0.3V to 5.5V
INTV
CC
Clamp Current ...........................................35mA
SCL, SDAI Voltages (Note 4) ..................... –0.3V to 5.9V
SCL, SDAI Clamp Current ........................................5mA
Operating Temperature Range
LTC2946C ................................................ 0°C to 70°C
LTC2946I .............................................–40°C to 85°C
LTC2946H .......................................... –40°C to 125°C
LTC2946MP ...................................... –55°C TO 125°C
Storage Temperature Range .................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec)
MS Package Only .............................................. 300°C
PIN CONFIGURATION
LTC2946
V
DD
INTV
CC
GPIO1
GPIO2
GPIO3
SDAO
SDAI
SCL
1
2
3
4
5
6
7
8
17
GND
TOP VIEW
16 SENSE
+
15 SENSE
–
14 ADR1
13 ADIN
12 ADR0
11 GND
10 CLKOUT
9 CLKIN
TOP VIEW
V
DD
INTV
CC
GPIO1
GPIO2
GPIO3
SDAO
SDAI
SCL
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
SENSE
+
SENSE
–
ADR1
ADIN
ADR0
GND
CLKOUT
CLKIN
DE PACKAGE
16-LEAD (4mm
×
3mm) PLASTIC DFN
T
JMAX
= 125°C,
θ
JA
= 43°C/W, E PAD GND SOLDERED DOWN
EXPOSED PAD (PIN 17) IS GND, PCB GND CONNECTION IS OPTIONAL
LTC2946-1
TOP VIEW
V
DD
INTV
CC
GPIO1
GPIO2
GPIO3
SDAO
SDAI
SCL
1
2
3
4
5
6
7
8
17
GND
16 SENSE
+
15 SENSE
–
14 ADR1
13 ADIN
12 ADR0
11 GND
10 CLKOUT
9 CLKIN
MS PACKAGE
16-LEAD PLASTIC MSOP
T
JMAX
= 125°C,
θ
JA
= 120°C/W
TOP VIEW
V
DD
INTV
CC
GPIO1
GPIO2
GPIO3
SDAO
SDAI
SCL
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
SENSE
+
SENSE
–
ADR1
ADIN
ADR0
GND
CLKOUT
CLKIN
MS PACKAGE
16-LEAD PLASTIC MSOP
T
JMAX
= 125°C,
θ
JA
= 120°C/W
DE PACKAGE
16-LEAD (4mm
×
3mm) PLASTIC DFN
T
JMAX
= 125°C,
θ
JA
= 43°C/W, E PAD GND SOLDERED DOWN
EXPOSED PAD (PIN 17) IS GND, PCB GND CONNECTION IS OPTIONAL
2946fa
2
For more information
www.linear.com/LTC2946
LTC2946
ORDER INFORMATION
LEAD FREE FINISH
TAPE AND REEL
PART MARKING
LTC2946CDE#PBF
LTC2946CDE#TRPBF
2946
LTC2946IDE#PBF
LTC2946IDE#TRPBF
2946
LTC2946HDE#PBF
LTC2946HDE#TRPBF
2946
LTC2946CDE-1#PBF
LTC2946CDE-1#TRPBF
29461
LTC2946IDE-1#PBF
LTC2946IDE-1#TRPBF
29461
LTC2946HDE-1#PBF
LTC2946HDE-1#TRPBF
29461
LTC2946CMS#PBF
LTC2946CMS#TRPBF
2946
LTC2946IMS#PBF
LTC2946IMS#TRPBF
2946
LTC2946HMS#PBF
LTC2946HMS#TRPBF
2946
LTC2946MPMS#PBF
LTC2946MPMS#TRPBF
2946
LTC2946CMS-1#PBF
LTC2946CMS-1#TRPBF
29461
LTC2946IMS-1#PBF
LTC2946IMS-1#TRPBF
29461
LTC2946HMS-1#PBF
LTC2946HMS-1#TRPBF 29461
LTC2946MPMS-1#PBF
LTC2946MPMS-1#TRPBF 29461
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on nonstandard lead based finish parts.
PACKAGE DESCRIPTION
16-Lead (4mm × 3mm) Plastic DFN
16-Lead (4mm × 3mm) Plastic DFN
16-Lead (4mm × 3mm) Plastic DFN
16-Lead (4mm × 3mm) Plastic DFN
16-Lead (4mm × 3mm) Plastic DFN
16-Lead (4mm × 3mm) Plastic DFN
16-Lead Plastic MSOP
16-Lead Plastic MSOP
16-Lead Plastic MSOP
16-Lead Plastic MSOP
16-Lead Plastic MSOP
16-Lead Plastic MSOP
16-Lead Plastic MSOP
16-Lead Plastic MSOP
TEMPERATURE RANGE
0°C to 70°C
–40°C to 85°C
–40°C to 125°C
0°C to 70°C
–40°C to 85°C
–40°C to 125°C
0°C to 70°C
–40°C to 85°C
–40°C to 125°C
–55°C to 125°C
0°C to 70°C
–40°C to 85°C
–40°C to 125°C
–55°C to 125°C
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/
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
DD
is from 4V to 100V, unless otherwise noted. (Note 2)
SYMBOL
Supplies
V
DD
V
CC
I
DD
I
CC
V
CC(LDO)
ΔV
CC(LDO)
V
CCZ
ΔV
CCZ
V
CC(UVL)
V
DD(UVL)
V
DDI2C(RST)
V
CCI2C(RST)
SENSE Inputs
I
SENSE
+
(HI)
I
SENSE
–
(HI)
I
SENSE
+
(LO)
48V SENSE
+
Input Current
48V SENSE
–
Input Current
0V SENSE
+
Source Current
SENSE
+
, SENSE
–
, V
DD
= 48V
Shutdown
SENSE
+
, SENSE
–
, V
DD
= 48V
Shutdown
SENSE
+
, SENSE
–
= 0V, V
DD
= 48V
Shutdown
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ELECTRICAL CHARACTERISTICS
PARAMETER
V
DD
Input Supply Voltage
INTV
CC
Input Supply Voltage
V
DD
Supply Current
INTV
CC
Supply Current
INTV
CC
Linear Regulator Voltage
INTV
CC
Linear Regulator Load Regulation
Shunt Regulator Voltage at INTV
CC
Shunt Regulator Load Regulation
INTV
CC
Supply Undervoltage Lockout
V
DD
Supply Undervoltage Lockout
V
DD
I
2
C Logic Reset
INTV
CC
I
2
C Logic Reset
CONDITIONS
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MIN
4
2.7
TYP
MAX
100
5.8
UNITS
V
V
mA
μA
mA
μA
V
mV
V
mV
V
V
V
V
V
DD
= 48V, INTV
CC
Open
Shutdown
INTV
CC
= V
DD
= 5V
Shutdown
8V < V
DD
< 100V, I
LOAD
= 0mA
8V < V
DD
< 100V, I
LOAD
= 0mA to 10mA
V
DD
= 48V, I
CC
= 1mA
V
DD
= 48V, I
CC
= 1mA to 35mA
INTV
CC
Rising, V
DD
= INTV
CC
V
DD
Rising, INTV
CC
Open
V
DD
Falling, INTV
CC
Open
INTV
CC
Falling, V
DD
= INTV
CC
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0.9
15
0.7
15
4.4
5.8
2.3
2.4
1.7
1.7
5
100
6.3
2.6
2.8
2.1
2.1
100
1.3
40
1.0
40
5.4
200
6.7
250
2.69
3
150
1
20
1
–10
–1
µA
µA
µA
µA
µA
µA
2946fa
For more information
www.linear.com/LTC2946
3
LTC2946
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
DD
is from 4V to 100V, unless otherwise noted. (Note 2)
SYMBOL
I
SENSE(LO)–
PARAMETER
0V SENSE
–
Source Current
CONDITIONS
SENSE
+
, SENSE
–
= 0V, V
DD
= 48V
Shutdown
(Note 7)
ΔSENSE (C-, I-Grade)
ΔSENSE (H-, MP-Grade)
SENSE
+
, V
DD
(C-, I-Grade)
SENSE
+
, V
DD
(H-, MP-Grade)
ADIN (C-, I-Grade)
ADIN (H-, MP-Grade)
ΔSENSE (C-, I-Grade)
ΔSENSE (H-, MP-Grade)
SENSE
+
, V
DD
(C-, I-Grade)
SENSE
+
, V
DD
(H-, MP-Grade)
ADIN (C-, I-Grade)
ADIN (H-, MP-Grade)
ΔSENSE
SENSE
+
, V
DD
ADIN
ΔSENSE (C-, I-Grade)
ΔSENSE (H-, MP-Grade)
SENSE
+
, V
DD
ADIN
ΔSENSE
SENSE
+
, V
DD
ADIN
ΔSENSE
SENSE
+
, V
DD
ADIN
ΔSENSE
SENSE
+
, V
DD
, ADIN
V
DD
= 48V, ADIN = 3V
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ELECTRICAL CHARACTERISTICS
MIN
TYP
MAX
–5
–1
UNITS
µA
µA
Bits
ADC (SENSE
+
, SENSE
–
= 0V, 100V) (Note 5)
RES
TUE
Resolution (No missing codes)
Total Unadjusted Error (Note 6)
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12
±0.6
±0.7
±0.4
±0.5
±0.3
±0.4
103
103.1
102.8
102.9
2.054
2.056
V
FS
Full-Scale Voltage
101.8
101.7
102
101.9
2.042
2.04
LSB
V
OS
LSB Step Size
Offset Error
102.4
102.4
102.4
102.4
2.048
2.048
25
25
0.5
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l
l
l
l
l
l
INL
σ
τ
t
CONV
R
ADIN
V
CLKIN(TH)
f
CLKIN(MAX)
I
CLKIN(IN)
I
CLKOUT
V
GPIO(TH)
V
GPIO(HYST)
V
GPIO(OL)
I
GPIO(IN)
V
ADR(H)
V
ADR(L)
I
ADR(IN)
I
ADR(IN,Z)
V
OD(OL)
I
SDA,SCL(IN)
Integral Nonlinearity
Transition Noise (Note 7)
Conversion Time (Snapshot Mode)
ADIN Input Resistance
CLKIN Input Threshold
Maximum CLKIN Frequency
CLKIN Input Current
CLKOUT Output Current
GPIO Input Threshold
GPIO Input Hysteresis
GPIO Output Low Voltage
GPIO Input Leakage Current
ADR0, ADR1 Input High Threshold
ADR0, ADR1 Input Low Threshold
ADR0, ADR1 Input Current
Allowable Leakage When Open
SDAO,
SDAO,
Output Low Voltage
SDAI, SDAO,
SDAO,
SCL Input Current
±2.1
±3.1
±1.5
±1.1
±2.5
±2
±2
1.2
0.3
10
65.6
32.8
10
1
5
–70
1.06
–100
1.22
36
0.15
0
1.9
0.3
2.4
0.6
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l
l
62.4
31.2
3
0.7
25
68.8
34.4
%
%
%
%
%
%
mV
mV
V
V
V
V
µV
mV
mV
LSB
LSB
LSB
LSB
LSB
LSB
LSB
µV
RMS
mV
RMS
µV
RMS
ms
ms
MΩ
V
MHz
μA
μA
V
mV
V
μA
V
V
μA
μA
V
μA
2946fa
CLKIN, CLKOUT, GPIO
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1.3
10
–130
1.32
0.4
±1
2.7
0.9
±13
±7
V
CLKIN
= 5V
V
CLKIN
= 0V, V
CLKOUT
= 0V
V
GPIO
Rising
I
GPIO
= 8mA
V
GPIO
= 5V
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I
2
C Interface (V
DD
= 48V)
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l
ADR0, ADR1 = 0V, 3V
I
SDAO
, I
SDAO
= 8mA
SDAI, SDAO,
SDAO,
SCL = 5V
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l
l
l
0.15
0
0.4
±1
4
For more information
www.linear.com/LTC2946
LTC2946
ELECTRICAL CHARACTERISTICS
SYMBOL
V
SDA,SCL(TH)
V
SDA,SCL(CL)
f
SCL(MAX)
t
LOW
t
HIGH
t
BUF(MIN)
t
HD,STA(MIN)
t
SU,STA(MIN)
t
SU,STO(MIN)
t
HD,DATI(MIN)
t
HD,DATO(MIN)
t
SU,DAT(MIN)
t
SP(MAX)
t
RST
C
X
PARAMETER
SDAI, SCL Input Threshold
SDAI, SCL Clamp Voltage
Maximum SCL Clock Frequency
SCL LOW Period
SCL HIGH Period
Bus Free Time Between
STOP/START Condition
Hold Time After (Repeated) START
Condition
Repeated START Condition
Setup Time
STOP Condition Setup Time
Data Hold Time Input
Data Hold Time Output
Data Setup Time
Maximum Suppressed Spike Pulse Width
Stuck Bus Reset Time
SCL, SDAI Input Capacitance (Note 7)
SCL or SDAI Held Low
I
SDAI
, I
SCL
= 3mA
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
DD
is from 4V to 100V, unless otherwise noted. (Note 2)
CONDITIONS
l
l
MIN
1.5
5.9
400
TYP
1.8
6.4
MAX
2.1
6.9
UNITS
V
V
kHz
I
2
C Interface Timing
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l
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l
l
l
l
0.65
50
0.12
140
30
30
–100
300
50
25
600
30
110
33
5
1.3
600
1.3
600
600
600
0
900
100
250
10
μs
ns
μs
ns
ns
ns
ns
ns
ns
ns
ms
pF
Note 1:
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 2:
All currents into pins are positive. All voltages are referenced to
ground, unless otherwise noted.
Note 3:
An internal shunt regulator limits the INTV
CC
pin to a minimum of
5.8V. Driving this pin to voltages beyond 5.8V may damage the part. This
pin can be safely tied to higher voltages through a resistor that limits the
current below 35mA.
Note 4:
Internal clamps limit the SCL and SDAI pins to a minimum of
5.9V. Driving these pins to voltages beyond the clamp may damage the
part. The pins can be safely tied to higher voltages through resistors that
limit the current below 5mA.
Note 5:
ΔSENSE is defined as V
SENSE+
– V
SENSE –
Note 6:
TUE = (ACTUAL CODE – IDEAL CODE)/4096 • 100% where IDEAL
CODE is derived from a straight line passing through Code 0 at 0V and
theoretical code of 4096 at V
FS
.
Note 7:
Guaranteed by design and not subject to test.
TYPICAL PERFORMANCE CHARACTERISTICS
1000
900
SUPPLY CURRENT (µA)
800
700
26
24
22
20
SHUTDOWN
V
DD
Supply Current
NORMAL
SUPPLY CURRENT (µA)
900
800
700
600
30
25
20
15
INTV
CC
Supply Current
5.2
NORMAL
INTV
CC
VOLTAGE (V)
6
2946 G02
INTV
CC
Load Regulation
5.1
5.0
SHUTDOWN
4.9
0
20
40
60
80
V
DD
SUPPLY VOLTAGE (V)
100
2946 G01
2
3
4
5
INTV
CC
SUPPLY VOLTAGE (V)
4.8
0
2
4
6
LOAD CURRENT (mA)
8
10
2946 G03
2946fa
For more information
www.linear.com/LTC2946
5
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