FEATURES
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LTC2453
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 or 8-pin, 3mm
×
3mm TSOT 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 proprietary 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 algo-
rithms 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.
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±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 8-Pin 3mm
×
2mm DFN
and TSOT23 Packages
APPLICATIONS
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System Monitoring
Environmental Monitoring
Direct Temperature Measurements
Instrumentation
Industrial Process Control
Data Acquisition
Embedded ADC Upgrades
L,
LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. No Latency
ΔΣ
is a trademark 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
2.0
1.5
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)
0.5
0
–0.5
–1.0
GND
–1.5
2453 TA01
Integral Nonlinearity, V
CC
= 3V
V
CC
= 3V
V
REF+
= 3V
V
REF–
= 0V
1.0
T
A
= –45°C, 25°C, 90°C
–2.0
–3
1
2
0
DIFFERENTIAL INPUT VOLTAGE (V)
–2
–1
3
2453 TA01b
2453fb
1
LTC2453
ABSOLUTE MAXIMUM RATINGS
(Notes 1, 2)
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
PIN CONFIGURATION
TOP VIEW
GND 1
REF
–
2
REF
+
8
9
7
6
5
SDA
SCL
IN
+
TOP VIEW
GND 1
REF¯ 2
REF
+
3
VCC 4
8 SDA
7 SCL
6 IN
+
5 IN¯
3
V
CC
4
IN
–
DDB PACKAGE
8-LEAD (3mm × 2mm) PLASTIC DFN
C/I GRADE T
JMAX
= 125°C,
θ
JA
= 76°C/W
EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB
TS8 PACKAGE
8-LEAD PLASTIC TSOT-23
C/I GRADE T
JMAX
= 125°C,
θ
JA
= 140°C/W
ORDER INFORMATION
Lead Free Finish
TAPE AND REEL (MINI)
LTC2453CDDB#TRMPBF
LTC2453IDDB#TRMPBF
LTC2453CTS8#TRMPBF
LTC2453ITS8#TRMPBF
TAPE AND REEL
LTC2453CDDB#TRPBF
LTC2453IDDB#TRPBF
LTC2453CTS8#TRPBF
LTC2453ITS8#TRPBF
PART MARKING*
LDBQ
LDBQ
LTDCG
LTDCG
PACKAGE DESCRIPTION
8-Lead Plastic (3mm
×
2mm) DFN
8-Lead Plastic (3mm
×
2mm) DFN
8-Lead Plastic TSOT-23
8-Lead Plastic TSOT-23
TEMPERATURE RANGE
0°C to 70°C
–40°C to 85°C
0°C to 70°C
–40°C to 85°C
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
l
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)
l
l
l
l
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
2453fb
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)
l
l
l
l
l
The
l
denotes the specifications which apply over the full
operating temperature range, otherwise specifications are at T
A
= 25°C.
CONDITIONS
l
l
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)
l
l
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
l
denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C.
CONDITIONS
l
l
l
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
l
denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. (Notes 2, 7)
CONDITIONS
l
l
l
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
≤ 0.9V
CC
l
l
l
l
l
10
400
2453fb
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
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Notes 2, 7)
CONDITIONS
l
l
l
l
l
l
l
l
l
l
l
l
l
l
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
2453fb
4
LTC2453
TYPICAL PERFORMANCE CHARACTERISTICS
Offset Error vs Temperature
5
4
OFFSET ERROR (LSB)
GAIN ERROR (LSB)
3
2
1
V
CC
= V
REF+
= 5V
0
–1
–50
5
(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
4
V
CC
= V
REF+
= 3V
V
CC
= V
REF+
= 4.1V
V
CC
= V
REF+
= 3V
V
CC
= V
REF
+
= 4.1V
3
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
–100
–25
0
25
50
TEMPERATURE (°C)
75
100
2453 G10
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
2453fb
5
