FEATURES
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LTC2453
Easy-to-Use, Ultra-Tiny,
Differential, 16-Bit
ΔΣ
ADC
With I
2
C Interface
DESCRIPTION
The LTC
®
2453 is an ultra-tiny, fully differential, 16-bit,
analog-to-digital converter. The LTC2453 uses a single
2.7V to 5.5V supply and communicates through an I
2
C
interface. The ADC is available in an 8-pin, 3mm
×
2mm
DFN package. It includes an integrated oscillator that does
not require any external components. It uses a delta-sigma
modulator as a converter core and has no latency for
multiplexed applications. The LTC2453 includes a pro-
prietary input sampling scheme that reduces the average
input sampling current several orders of magnitude lower
than conventional delta-sigma converters. Additionally,
due to its architecture, there is negligible current leakage
between the input pins.
The LTC2453 can sample at 60 conversions per second,
and due to the very large oversampling ratio, has ex-
tremely relaxed antialiasing requirements. The LTC2453
includes continuous internal offset and full-scale calibration
algorithms which are transparent to the user, ensuring
accuracy over time and over the operating temperature
range. The converter has external REF
+
and REF
–
pins
and the differential input voltage range can extend up to
±(V
REF+
– V
REF–
).
Following a single conversion, the LTC2453 can auto-
matically enter a sleep mode and reduce its power to less
than 0.2μA. If the user reads the ADC once a second, the
LTC2453 consumes an average of less than 50μW from
a 2.7V supply.
Integral Nonlinearity, V
CC
= 3V
2.0
1.5
V
CC
= 3V
V
REF+
= 3V
V
REF–
= 0V
±V
CC
Differential Input Range
16-Bit Resolution (Including Sign), No Missing
Codes
2LSB Offset Error
4LSB Full-Scale Error
60 Conversions Per Second
Single Conversion Settling Time for Multiplexed
Applications
Single-Cycle Operation with Auto Shutdown
800μA Supply Current
0.2μA Sleep Current
Internal Oscillator—No External Components
Required
2-Wire I
2
C Interface
Ultra-Tiny 3mm
×
2mm DFN Package
APPLICATIONS
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System Monitoring
Environmental Monitoring
Direct Temperature Measurements
Instrumentation
Industrial Process Control
Data Acquisition
Embedded ADC Upgrades
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Protected by U.S. Patents, including 6208279, 6411242, 7088280, 7164378.
TYPICAL APPLICATION
2.7V TO 5.5V
0.1μF
0.1μF
IN
+
10k
10k
IN
–
10k
R
0.1μF
REF
–
REF
+
V
CC
SCL
LTC2453
SDA
2-WIRE I
2
C
INTERFACE
10μF
INL (LSB)
1.0
0.5
0
–0.5
–1.0
T
A
= –45°C, 25°C, 90°C
GND
–1.5
–2.0
2453 TA01
–3
–2
–1
1
2
0
DIFFERENTIAL INPUT VOLTAGE (V)
3
2453 G02
2453f
1
LTC2453
ABSOLUTE MAXIMUM RATINGS
(Notes 1, 2)
PIN CONFIGURATION
TOP VIEW
GND 1
REF
–
Supply Voltage (V
CC
) ................................... –0.3V to 6V
Analog Input Voltage (V
IN+
, V
IN–
) .. –0.3V to (V
CC
+ 0.3V)
Reference Voltage (V
REF+
, V
REF–
) .. –0.3V to (V
CC
+ 0.3V)
Digital Voltage (SDA, SCL) ............ –0.3V to (V
CC
+ 0.3V)
Storage Temperature Range................... –65°C to 150°C
Operating Temperature Range
LTC2453C ................................................ 0°C to 70°C
LTC2453I ............................................. –40°C to 85°C
8
9
7
6
5
SDA
SCL
IN
+
IN
–
2
3
REF
+
V
CC
4
DD8 PACKAGE
8-LEAD (3mm
×
2mm) PLASTIC DFN
C/I GRADE T
JMAX
= 125°C,
θ
JA
= 76°C/W (NOTE 4)
EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
Lead Free Finish
TAPE AND REEL (MINI)
TAPE AND REEL
PART MARKING*
PACKAGE DESCRIPTION
TEMPERATURE RANGE
0°C to 70°C
–40°C to 85°C
LTC2453CDDB#TRMPBF
LTC2453CDDB#TRPBF
LDBQ
8-Lead Plastic (3mm
×
2mm) DFN
LTC2453IDDB#TRMPBF
LTC2453IDDB#TRPBF
LDBQ
8-Lead Plastic (3mm
×
2mm) DFN
TRM = 500 pieces. *Temperature grades are identified by a label on the shipping container.
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on lead based finish parts.
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
PARAMETER
Resolution (No Missing Codes)
Integral Nonlinearity
Offset Error
Offset Error Drift
Gain Error
Gain Error Drift
Transition Noise
Power Supply Rejection DC
The
●
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Note 2)
CONDITIONS
(Note 3)
(Note 4)
●
●
●
●
MIN
16
TYP
2
2
0.02
0.01
0.02
1.4
80
MAX
10
10
0.02
UNITS
Bits
LSB
LSB
LSB/°C
% of FS
LSB/°C
μV
RMS
dB
2453f
2
LTC2453
ANALOG INPUTS AND REFERENCES
SYMBOL
V
IN+
V
IN–
V
REF+
V
REF–
V
OR+
, V
UR+
V
OR–
, V
UR–
C
IN
I
DC_LEAK(IN+)
I
DC_LEAK(IN–)
PARAMETER
Positive Input Voltage Range
Negative Input Voltage Range
Positive Reference Voltage Range
Negative Reference Voltage Range
Overrange/Underrange Voltage, IN
+
Overrange/Underrange Voltage, IN–
IN
+
, IN
–
Sampling Capacitance
IN
+
DC Leakage Current
IN
–
DC Leakage Current
V
IN
= GND (Note 8)
V
IN
= V
CC
(Note 8)
V
IN
= GND (Note 8)
V
IN
= V
CC
(Note 8)
V
REF
= 3V (Note 8)
●
●
●
●
●
The
●
denotes the specifications which apply over the full
operating temperature range, otherwise specifications are at T
A
= 25°C.
CONDITIONS
●
●
MIN
0
0
V
CC
– 2.5
0
TYP
MAX
V
CC
V
CC
V
CC
V
CC
– 2.5
UNITS
V
V
V
V
LSB
LSB
pF
V
REF+
– V
REF–
≥ 2.5V
V
REF+
– V
REF–
≥ 2.5V
V
REF
= 5V, V
IN–
= 2.5V (See Figure 2)
V
REF
= 5V, V
IN+
= 2.5V (See Figure 2)
●
●
8
8
0.35
–10
–10
–10
–10
–10
1
1
1
1
1
50
10
10
10
10
10
nA
nA
nA
nA
nA
nA
I
DC_LEAK(REF+, REF–)
REF
+
, REF
–
DC Leakage Current
I
CONV
Input Sampling Current (Note 5)
POWER REQUIREMENTS
SYMBOL
V
CC
I
CC
PARAMETER
Supply Voltage
Supply Current
Conversion
Sleep
The
●
denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C.
CONDITIONS
●
●
●
MIN
2.7
TYP
MAX
5.5
UNITS
V
μA
μA
800
0.2
1200
0.6
I
2
C INPUTS AND OUTPUTS
SYMBOL
V
IH
V
IL
I
I
V
HYS
V
OL
I
IN
C
I
C
B
PARAMETER
High Level Input Voltage
Low Level Input Voltage
Digital Input Current
The
●
denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. (Notes 2, 7)
CONDITIONS
●
●
●
MIN
0.7V
CC
TYP
MAX
0.3V
CC
UNITS
V
V
μA
V
V
μA
pF
pF
–10
0.05V
CC
10
0.4
1
Hysteresis of Schmidt Trigger Inputs
Low Level Output Voltage (SDA)
Input Leakage
Capacitance for Each I/O Pin
Capacitance Load for Each Bus Line
(Note 3)
I = 3mA
0.1V
CC
≤ V
IN
≤ V
CC
●
●
●
●
●
10
400
2453f
3
LTC2453
I
2
C TIMING CHARACTERISTICS
SYMBOL
t
CONV
f
SCL
t
HD(SDA)
t
LOW
t
HIGH
t
SU(STA)
t
HD(DAT)
t
SU(DAT)
t
r
t
f
t
SU(STO)
t
BUF
t
OF
t
SP
PARAMETER
Conversion Time
SCL Clock Frequency
Hold Time (Repeated) START Condition
LOW Period of the SCL Pin
HIGH Period of the SCL Pin
Set-Up Time for a Repeated START Condition
Data Hold Time
Data Set-Up Time
Rise Time for SDA/SCL Signals
Fall Time for SDA/SCL Signals
Set-Up Time for STOP Condition
Bus Free Time Between a Stop and Start Condition
Output Fall Time V
IHMIN
to V
ILMAX
Input Spike Suppression
Bus Load C
B
10pF to
400pF (Note 6)
(Note 6)
(Note 6)
The
●
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Notes 2, 7)
CONDITIONS
●
●
●
●
●
●
●
●
●
●
●
●
●
●
MIN
13
0
0.6
1.3
0.6
0.6
0
100
20 + 0.1C
B
20 + 0.1C
B
0.6
1.3
20 + 0.1C
B
TYP
16.6
MAX
23
400
UNITS
ms
kHz
μs
μs
μs
μs
0.9
300
300
μs
ns
ns
ns
μs
μs
250
50
ns
ns
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 voltage values are with respect to GND. V
CC
= 2.7V to 5.5V
unless otherwise specified.
V
REF
= V
REF+
– V
REF–
, V
REFCM
= (V
REF+
+ V
REF–
)/2, FS = V
REF+
– V
REF–
;
V
IN
= V
IN+
– V
IN–
, –V
REF
≤ V
IN
≤ V
REF
; V
INCM
= (V
IN+
+ V
IN–
)/2.
Note 3.
Guaranteed by design, not subject to test.
Note 4.
Integral nonlinearity is defined as the deviation of a code from a
straight line passing through the actual endpoints of the transfer curve.
Guaranteed by design and test correlation.
Note 5.
Input sampling current is the average input current drawn from
the input sampling network while the LTC2453 is converting.
Note 6.
C
B
= capacitance of one bus line in pF.
Note 7.
All values refer to V
IH(MIN
) and V
IL(MAX)
levels.
Note 8.
A positive current is flowing into the DUT pin.
TYPICAL PERFORMANCE CHARACTERISTICS
Integral Nonlinearity, V
CC
= 5V
2.0
1.5
1.0
INL (LSB)
INL (LSB)
0.5
0
–0.5
–1.0
–1.5
–2.0
–5 –4 –3 –2 –1 0 1 2 3 4
DIFFERENTIAL INPUT VOLTAGE (V)
5
T
A
= –45°C, 25°C, 90°C
V
CC
= 5V
V
REF+
= 5V
V
REF–
= 0V
2.0
1.5
1.0
V
CC
= 3V
V
REF+
= 3V
V
REF–
= 0V
(T
A
= 25°C, unless otherwise noted)
Maximum INL vs Temperature
2.0
V
CC
= V
REF+
= 5V, 4.1V, 3V
Integral Nonlinearity, V
CC
= 3V
1.5
INL (LSB)
T
A
= –45°C, 25°C, 90°C
0.5
0
–0.5
–1.0
–1.5
–2.0
–3
1.0
0.5
1
2
0
DIFFERENTIAL INPUT VOLTAGE (V)
–2
–1
3
2453 G02
0
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
2453 G03
2453 G01
2453f
4
LTC2453
TYPICAL PERFORMANCE CHARACTERISTICS
Offset Error vs Temperature
5
4
OFFSET ERROR (LSB)
3
2
1
V
CC
= V
REF
0
–1
–50
+
= 5V
(T
A
= 25°C, unless otherwise noted)
Transition Noise vs Temperature
3.0
2.5
2.0
1.5
1.0
0.5
0
–50
V
CC
= 4.1V
Gain Error vs Temperature
5
4
GAIN ERROR (LSB)
V
CC
= V
REF+
= 3V
V
CC
= V
REF
+
= 4.1V
3
V
CC
= V
REF+
= 3V
V
CC
= V
REF
+
= 4.1V
2
TRANSITION NOISE RMS (μV)
V
CC
= 5V
V
CC
= 3V
1
V
CC
= V
REF+
= 5V
–25
0
25
50
TEMPERATURE (°C)
75
100
2453 G04
0
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
2453 G05
–25
0
25
50
TEMPERATURE (°C)
75
100
2453 G06
Transition Noise vs Output Code
3.0
2.5
2.0
1.5
1.0
0.5
0
–32768
V
CC
= V
REF+
= 5V
V
CC
= V
REF+
= 3V
1200
Conversion Mode Power Supply
Current vs Temperature
250
60Hz OUTPUT SAMPLE RATE
CONVERSION CURRENT (μA)
1000
800
600
400
200
0
–50
V
CC
= 3V
V
CC
= 4.1V
SLEEP CURRENT (nA)
V
CC
= 5V
200
Sleep Mode Power Supply
Current vs Temperature
TRANSITION NOISE RMS (μV)
V
CC
= 5V
150
V
CC
= 4.1V
100
50
V
CC
= 3V
–16384
0
16384
OUTPUT CODE
32768
2453 G07
–25
0
25
50
TEMPERATURE (°C)
75
100
2453 G08
0
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
2453 G09
Average Power Dissipation vs
Temperature, V
CC
= 3V
10000
AVERAGE POWER DISSIPATION (μW)
0
Power Supply Rejection vs
Frequency at V
CC
21
V
CC
= 4.1V
V
REF+
= 2.7V
V
REF–
= 0V
V
IN+
= 1V
V
IN–
= 2V
20
CONVERSION TIME (ms)
Conversion Time vs Temperature
1000
25Hz OUTPUT SAMPLE RATE
REJECTIOIN (dB)
–20
V
CC
= 3V
19
V
CC
= 4.1V
18
V
CC
= 5V
17
16
15
10Hz OUTPUT SAMPLE RATE
100
1Hz OUTPUT SAMPLE RATE
–40
–60
10
–80
1
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
2453 G10
–100
1
10
100 1k 10k 100k
FREQUENCY AT V
CC
(Hz)
1M
10M
14
–50
–25
50
25
0
TEMPERATURE (°C)
75
100
2453 G12
2453 G11
2453f
5
