™ analog-to-digital converter with patented Easy Drive™
technology. The patented sampling scheme eliminates
dynamic input current errors and the shortcomings of on-
chip buffering through automatic cancellation of differential
input current. This allows large external source impedances
and input signals, with rail-to-rail input range to be directly
digitized while maintaining exceptional DC accuracy.
The LTC2480 includes on-chip programmable gain and
an oscillator. The LTC2480 can be configured to provide a
programmable gain from 1 to 256 in 8 steps, measure an
external signal or internal temperature sensor and reject
line frequencies. 50Hz, 60Hz or simultaneous 50Hz/60Hz
line frequency rejection can be selected as well as a 2x
speed-up mode.
The LTC2480 allows a wide common mode input range
(0V to V
CC
) independent of the reference voltage. The
reference can be as low as 100mV or can be tied directly
to V
CC
. The LTC2480 includes an on-chip trimmed oscil-
lator eliminating the need for external crystals or oscil-
lators. Absolute accuracy and low drift are automatically
maintained through continuous, transparent, offset and
full-scale calibration.
L,
LT, LTC and LTM, Linear Technology and the Linear logo are registered trademarks and
No Latency
∆Σ
and Easy Drive are trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners. Patents pending.
n
n
n
n
n
n
n
n
n
n
n
Extended Temperature Range of –40°C to 125°C
Easy Drive Technology Enables Rail-to-Rail Inputs
with Zero Differential Input Current
Directly Digitizes High Impedance Sensors with
Full Accuracy
Programmable Gain from 1 to 256
GND to V
CC
Input/Reference Common Mode Range
Programmable 50Hz, 60Hz or Simultaneous
50Hz/60Hz Rejection Mode
2ppm (0.25LSB) INL, No Missing Codes
1ppm Offset and 15ppm Full-Scale Error
Selectable 2x Speed Mode (15Hz Using Internal
Oscillator)
No Latency: Digital Filter Settles in a Single Cycle
Single Supply 2.7V to 5.5V Operation
Internal Oscillator
Available in a Tiny (3mm
×
3mm) 10-Lead
DFN Package and 10-Lead MSOP Package
APPLICATIONS
n
n
n
n
n
n
n
Direct Sensor Digitizer
Weight Scales
Direct Temperature Measurement
Strain Gauge Transducers
Instrumentation
Industrial Process Control
DVMs and Meters
TYPICAL APPLICATION
V
CC
0.1µF
10k
SENSE
10k
V
IN–
0.1µF
I
DIFF
= 0
V
REF
LTC2480
GND
f
O
V
CC
1µF
SDI
SDO
SCK
CS
2480 TA01
+FS Error vs R
SOURCE
at IN
+
and IN
–
V
CC
= 5V
60 V
REF
= 5V
V
IN+
= 3.75V
V
IN–
= 1.25V
40
f
O
= GND
20 T
A
= 25°C
0
–20
–40
–60
–80
1
10
1k
R
SOURCE
( )
100
10k
100k
2480 TA04
80
+FS ERROR (ppm)
V
IN+
C
IN
= 1µF
4-WIRE
SPI INTERFACE
2480fe
For more information
www.linear.com/LTC2480
1
LTC2480
ABSOLUTE MAXIMUM RATINGS
(Notes 1, 2)
Supply Voltage (V
CC
) to GND ...................... –0.3V to 6V
Analog Input Voltage to GND ....... –0.3V to (V
CC
+ 0.3V)
Reference Input Voltage to GND .. –0.3V to (V
CC
+ 0.3V)
Digital Input Voltage to GND ........ –0.3V to (V
CC
+ 0.3V)
Digital Output Voltage to GND ...... –0.3V to (V
CC
+ 0.3V)
Operating Temperature Range
LTC2480C ............................................... 0°C to 70°C
LTC2480I ............................................ –40°C to 85°C
LTC2480H ........................................ –40°C to 125°C
Storage Temperature Range.................. –65°C to 125°C
PIN CONFIGURATION
TOP VIEW
SDI
V
CC
V
REF
IN
+
IN
–
1
2
3
4
5
11
GND
10 f
O
9 SCK
8 GND
7 SDO
6
CS
TOP VIEW
SDI
V
CC
V
REF
IN
+
IN
–
1
2
3
4
5
10
9
8
7
6
f
O
SCK
GND
SDO
CS
DD PACKAGE
10-LEAD (3mm
×
3mm) PLASTIC DFN
T
JMAX
= 125°C,
θ
JA
= 43°C/W
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
MS PACKAGE
10-LEAD PLASTIC MSOP
T
JMAX
= 125°C,
θ
JA
= 120°C/W
ORDER INFORMATION
LEAD FREE FINISH
LTC2480CDD#PBF
LTC2480IDD#PBF
LTC2480CMS#PBF
LTC2480IMS#PBF
LTC2480HDD#PBF
LTC2480HMS#PBF
TAPE AND REEL
LTC2480CDD#TRPBF
LTC2480IDD#TRPBF
LTC2480CMS#TRPBF
LTC2480IMS#TRPBF
LTC2480HDD#TRPBF
LTC2480HMS#TRPBF
PART MARKING*
LBJY
LBJY
LTCWB
LTCWB
LBJY
LTCWB
PACKAGE DESCRIPTION
10-Lead (3mm
×
3mm) Plastic DFN
10-Lead (3mm
×
3mm) Plastic DFN
10-Lead Plastic MSOP
10-Lead Plastic MSOP
10-Lead (3mm
×
3mm) Plastic DFN
10-Lead Plastic MSOP
TEMPERATURE RANGE
0°C to 70°C
–40°C to 85°C
0°C to 70°C
–40°C to 85°C
–40°C to 125°C
–40°C to 125°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/
2480fe
2
For more information
www.linear.com/LTC2480
LTC2480
ELECTRICAL CHARACTERISTICS (NORMAL SPEED)
The
l
denotes the specifications which
apply over the full operating temperature range, otherwise specifications are at T
A
= 25°C. (Notes 3, 4)
CONDITIONS
0.1 ≤ V
REF
≤ V
CC
, –FS ≤ V
IN
≤ +FS (Note 5)
5V ≤ V
CC
≤ 5.5V, V
REF
= 5V, V
IN(CM)
= 2.5V (Note 6)
2.7V ≤ V
CC
≤ 5.5V, V
REF
= 2.5V, V
IN(CM)
= 1.25V (Note 6)
2.5V ≤ V
REF
≤ V
CC
, GND ≤ IN
+
= IN
–
≤ V
CC
(Note 14)
2.5V ≤ V
REF
≤ V
CC
, GND ≤ IN
+
= IN
–
≤ V
CC
2.5V ≤ V
REF
≤ V
CC
, IN
+
= 0.75V
REF
, IN
–
= 0.25V
REF
2.5V ≤ V
REF
≤ V
CC
, IN
+
= 0.75V
REF
, IN
–
= 0.25V
REF
(H-Grade)
2.5V ≤ V
REF
≤ V
CC
, IN
+
= 0.75V
REF
, IN
–
= 0.25V
REF
2.5V ≤ V
REF
≤ V
CC
, IN
+
= 0.75V
REF
, IN
–
= 0.25V
REF
2.5V ≤ V
REF
≤ V
CC
, IN
+
= 0.75V
REF
, IN
–
= 0.25V
REF
(H-Grade)
2.5V ≤ V
REF
≤ V
CC
, IN
+
= 0.75V
REF
, IN
–
= 0.25V
REF
5V ≤ V
CC
≤ 5.5V, V
REF
= 2.5V, V
IN(CM)
= 1.25V
5V ≤ V
CC
≤ 5.5V, V
REF
= 5V, V
IN(CM)
= 2.5V
2.7V ≤ V
CC
≤ 5.5V, V
REF
= 2.5V, V
IN(CM)
= 1.25V
5V ≤ V
CC
≤ 5.5V, V
REF
= 5V, GND ≤ IN
–
= IN
+
≤ V
CC
(Note 13)
T
A
= 27°C
l
l
l
l
l
l
l
l
PARAMETER
Resolution (No Missing Codes)
Integral Nonlinearity
Offset Error
Offset Error Drift
Positive Full-Scale Error
Positive Full-Scale Error Drift
Negative Full-Scale Error
Negative Full-Scale Error Drift
Total Unadjusted Error
MIN
16
TYP
2
1
0.5
10
MAX
10
2.5
25
40
UNITS
Bits
ppm of V
REF
ppm of V
REF
µV
nV/°C
ppm of V
REF
ppm of V
REF
ppm of
V
REF
/°C
0.1
25
40
0.1
15
ppm of V
REF
ppm of V
REF
ppm of
V
REF
/°C
ppm of V
REF
ppm of V
REF
ppm of V
REF
µV
RMS
Output Noise
Internal PTAT Signal
Programmable Gain
0.6
390
1
450
256
mV
ELECTRICAL CHARACTERISTICS (2X SPEED)
The
l
denotes the specifications which apply over the
full operating temperature range, otherwise specifications are at T
A
= 25°C. (Notes 3, 4)
CONDITIONS
0.1 ≤ V
REF
≤ V
CC
, –FS ≤ V
IN
≤ +FS (Note 5)
5V ≤ V
CC
≤ 5.5V, V
REF
= 5V, V
IN(CM)
= 2.5V (Note 6)
2.7V ≤ V
CC
≤ 5.5V, V
REF
= 2.5V, V
IN(CM)
= 1.25V (Note 6)
2.5V ≤ V
REF
≤ V
CC
, GND ≤ IN
+
= IN
–
≤ V
CC
(Note 14)
2.5V ≤ V
REF
≤ V
CC
, GND ≤ IN
+
= IN
–
≤ V
CC
2.5V ≤ V
REF
≤ V
CC
, IN
+
= 0.75V
REF
, IN
–
= 0.25V
REF
2.5V ≤ V
REF
≤ V
CC
, IN
+
= 0.75V
REF
, IN
–
= 0.25V
REF
(H-Grade)
2.5V ≤ V
REF
≤ V
CC
, IN
+
= 0.75V
REF
, IN
–
= 0.25V
REF
2.5V ≤ V
REF
≤ V
CC
, IN
+
= 0.75V
REF
, IN
–
= 0.25V
REF
2.5V ≤ V
REF
≤ V
CC
, IN
+
= 0.75V
REF
, IN
–
= 0.25V
REF
(H-Grade)
2.5V ≤ V
REF
≤ V
CC
, IN
+
= 0.75V
REF
, IN
–
= 0.25V
REF
5V ≤ V
CC
≤ 5.5V, V
REF
= 5V, GND ≤ IN
–
= IN
+
≤ V
CC
(Note 13)
(Note 15)
l
l
l
l
l
l
l
l
PARAMETER
Resolution (No Missing Codes)
Integral Nonlinearity
Offset Error
Offset Error Drift
Positive Full-Scale Error
Positive Full-Scale Error Drift
Negative Full-Scale Error
Negative Full-Scale Error Drift
Output Noise
Programmable Gain
MIN
16
TYP
2
1
0.5
100
MAX
10
2
25
40
UNITS
Bits
ppm of V
REF
ppm of V
REF
mV
nV/°C
ppm of V
REF
ppm of V
REF
ppm of
V
REF
/°C
0.1
25
40
0.1
0.84
1
128
ppm of V
REF
ppm of V
REF
ppm of
V
REF
/°C
µV
RMS
2480fe
For more information
www.linear.com/LTC2480
3
LTC2480
CONVERTER CHARACTERISTICS
PARAMETER
Input Common Mode Rejection DC
Input Common Mode Rejection
50Hz ±2%
Input Common Mode Rejection
60Hz ±2%
Input Normal Mode Rejection
50Hz ±2%
Input Normal Mode Rejection
60Hz ±2%
Input Normal Mode Rejection
50Hz/60Hz ±2%
Reference Common Mode
Rejection DC
Power Supply Rejection DC
Power Supply Rejection, 50Hz ±2%
Power Supply Rejection, 60Hz ±2%
CONDITIONS
2.5V ≤ V
REF
≤ V
CC
, GND ≤ IN
–
= IN
+
≤ V
CC
(Note 5)
2.5V ≤ V
REF
≤ V
CC
, GND ≤ IN
–
= IN
+
≤ V
CC
(Note 5)
2.5V ≤ V
REF
≤ V
CC
, GND ≤ IN
–
= IN
+
≤ V
CC
(Note 5)
l
l
l
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Notes 3, 4)
MIN
140
140
140
110
104
110
104
87
120
140
120
120
120
120
120
TYP
MAX
UNITS
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
l
2.5V ≤ V
REF
≤ V
CC
, GND ≤ IN
–
= IN
+
≤ V
CC
(Notes 5, 7)
2.5V ≤ V
REF
≤ V
CC
, GND ≤ IN
–
= IN
+
≤ V
CC
(Notes 5, 7) (H-Grade)
l
l
2.5V ≤ V
REF
≤ V
CC
, GND ≤ IN
–
= IN
+
≤ V
CC
(Notes 5, 8)
–
= IN
+
≤ V (Notes 5, 8) (H-Grade)
l
2.5V ≤ V
REF
≤ V
CC
, GND ≤ IN
CC
2.5V ≤ V
REF
≤ V
CC
, GND ≤ IN
–
= IN
+
≤ V
CC
(Notes 5, 9)
2.5V ≤ V
REF
≤ V
CC
, GND ≤ IN
–
= IN
+
≤ V
CC
(Note 5)
V
REF
= 2.5V, IN
–
= IN
+
= GND
V
REF
= 2.5V, IN
–
= IN
+
= GND (Notes 7, 9)
V
REF
= 2.5V, IN
–
= IN
+
= GND (Notes 8, 9)
l
l
ANALOG INPUT AND REFERENCE
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Note 3)
PARAMETER
Absolute/Common Mode IN
+
Voltage
Absolute/Common Mode IN
–
Voltage
Full-Scale of the Differential Input (IN
+
– IN
–
)
Least Significant Bit of the Output Code
Input Differential Voltage Range (IN
+
– IN
–
)
Reference Voltage Range
IN
+
Sampling Capacitance
IN
–
Sampling Capacitance
V
REF
Sampling Capacitance
IN
+
DC Leakage Current
IN
–
DC Leakage Current
V
REF
DC Leakage Current
Sleep Mode, IN
+
= GND
Sleep Mode, IN
–
= GND
Sleep Mode, V
REF
= V
CC
l
l
l
l
l
l
l
SYMBOL
IN
+
IN
–
FS
LSB
V
IN
V
REF
C
S
(IN
+
)
C
S
(IN
–
)
C
S
(V
REF
)
I
DC_LEAK
(IN
+
)
I
DC_LEAK
(IN
–
)
I
DC_LEAK
(V
REF
)
CONDITIONS
MIN
GND – 0.3V
GND – 0.3V
0.5V
REF
/GAIN
FS/2
16
–FS
0.1
TYP
MAX
V
CC
+ 0.3V
V
CC
+ 0.3V
UNITS
V
V
V
+FS
V
CC
11
11
11
V
V
pF
pF
pF
–10
–10
–100
1
1
1
10
10
100
nA
nA
nA
ANALOG INPUTS AND DIGITAL OUTPUTS
SYMBOL
V
IH
V
IL
V
IH
V
IL
I
IN
PARAMETER
High Level Input Voltage
CS,
f
O
, SDI
Low Level Input Voltage
CS,
f
O
, SDI
High Level Input Voltage SCK
Low Level Input Voltage SCK
Digital Input Current
CS,
f
O
, SDI
CONDITIONS
2.7V ≤ V
CC
≤ 5.5V (Note 16)
2.7V ≤ V
CC
≤ 5.5V
2.7V ≤ V
CC
≤ 5.5V (Note 10)
2.7V ≤ V
CC
≤ 5.5V (Note 10)
0V ≤ V
IN
≤ V
CC
The
l
denotes the specifications which apply over the
full operating temperature range, otherwise specifications are at T
A
= 25°C. (Note 3)
MIN
l
l
l
l
l
TYP
MAX
0.5
UNITS
V
V
V
V
µA
V
CC
– 0.5
V
CC
– 0.5
0.5
–10
10
2480fe
4
For more information
www.linear.com/LTC2480
LTC2480
ANALOG INPUTS AND DIGITAL OUTPUTS
SYMBOL
I
IN
C
IN
C
IN
V
OH
V
OL
V
OH
V
OL
I
OZ
PARAMETER
Digital Input Current SCK
Digital Input Capacitance
CS,
f
O
, SDI
Digital Input Capacitance SCK
High Level Output Voltage SDO
Low Level Output Voltage SDO
High Level Output Voltage SCK
Low Level Output Voltage SCK
Hi-Z Output Leakage SDO
I
O
= –800µA
I
O
= 1.6mA
I
O
= –800µA
I
O
= 1.6mA
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. (Note 3)
CONDITIONS
0V ≤ V
IN
≤ V
CC
(Note 10)
l
MIN
–10
TYP
10
10
MAX
10
UNITS
µA
pF
pF
V
V
CC
– 0.5
0.4
V
CC
– 0.5
0.4
–10
10
V
V
V
µA
POWER REQUIREMENTS
The
l
denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. (Note 3)
PARAMETER
Supply Voltage
Supply Current
Conversion Mode (Note 12)
Sleep Mode (Note 12)
H-Grade
SYMBOL
V
CC
I
CC
CONDITIONS
l
l
l
l
MIN
2.7
TYP
160
1
MAX
5.5
250
2
20
UNITS
V
µA
µA
µA
TIMING CHARACTERISTICS
SYMBOL
f
EOSC
t
HEO
t
LEO
t
CONV_1
PARAMETER
External Oscillator Frequency Range
External Oscillator High Period
External Oscillator Low Period
Conversion Time for 1x Speed Mode
The
l
denotes the specifications which apply over the full operating temperature
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