™ 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, a
temperature sensor 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
ΔΣ
and Easy Drive are trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners. Patents pending.
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
Integrated Temperature Sensor
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
1μF
10k
SENSE
10k
SDI
SDO
LTC2480
V
IN–
GND
f
O
SCK
CS
2480 TA01
+FS Error vs R
SOURCE
at IN
+
and IN
–
V
CC
= 5V
V
REF
= 5V
60
V
IN+
= 3.75V
–
40 V
IN
= 1.25V
f
O
= GND
T
A
= 25°C
20
0
–20
–40
–60
–80
1
10
1k
R
SOURCE
(Ω)
100
10k
100k
2480 TA04
80
+FS ERROR (ppm)
I
DIFF
= 0
1μF
V
IN+
V
REF
V
CC
C
IN
= 1μF
4-WIRE
SPI INTERFACE
2480fb
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
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
SDI
V
CC
V
REF
IN
+
IN
–
1
2
3
4
5
TOP VIEW
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
TAPE AND REEL
LTC2480CDD#TRPBF
LTC2480IDD#TRPBF
LTC2480CMS#TRPBF
LTC2480IMS#TRPBF
PART MARKING*
LBJY
LBJY
LTCWB
LTCWB
PACKAGE DESCRIPTION
10-Lead (3mm
×
3mm) Plastic DFN
10-Lead (3mm
×
3mm) Plastic DFN
10-Lead Plastic MSOP
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
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/
2480fb
2
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
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
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
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
0.1
MAX
10
2.5
25
l
25
0.1
15
Output Noise
Internal PTAT Signal
Internal PTAT Temperature Coefficient
Programmable Gain
0.6
420
1.4
1
256
UNITS
Bits
ppm of V
REF
ppm of V
REF
μV
nV/°C
ppm of V
REF
ppm of
V
REF
/°C
ppm of V
REF
ppm of
V
REF
/°C
ppm of V
REF
ppm of V
REF
ppm of V
REF
μV
RMS
mV
mV/°C
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
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
5V ≤ V
CC
≤ 5.5V, V
REF
= 5V, GND ≤ IN
–
= IN
+
≤ V
CC
(Note 13)
(Note 15)
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
UNITS
Bits
ppm of V
REF
ppm of V
REF
mV
nV/°C
ppm of V
REF
ppm of
V
REF
/°C
0.1
25
0.1
0.84
1
128
ppm of V
REF
ppm of
V
REF
/°C
μV
RMS
2480fb
3
LTC2480
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Notes 3, 4)
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)
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, 8)
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
l
l
l
l
l
CONVERTER CHARACTERISTICS
MIN
140
140
140
110
110
87
120
TYP
MAX
UNITS
dB
dB
dB
120
120
dB
dB
dB
140
120
120
120
dB
dB
dB
dB
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
PARAMETER
High Level Input Voltage
CS,
f
O
, SDI
Low Level Input Voltage
CS,
f
O
, SDI
High Level Input Voltage
SCK
CONDITIONS
2.7V ≤ V
CC
≤ 5.5V
2.7V ≤ V
CC
≤ 5.5V
2.7V ≤ V
CC
≤ 5.5V (Note 10)
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
TYP
MAX
UNITS
V
V
CC
– 0.5
0.5
V
CC
– 0.5
V
V
2480fb
4
LTC2480
ANALOG INPUTS AND DIGITAL OUTPUTS
V
IL
I
IN
I
IN
C
IN
C
IN
V
OH
V
OL
V
OH
V
OL
I
OZ
Low Level Input Voltage
SCK
Digital Input Current
CS,
f
O
, SDI
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)
2.7V ≤ V
CC
≤ 5.5V (Note 10)
0V ≤ V
IN
≤ V
CC
0V ≤ V
IN
≤ V
CC
(Note 10)
l
l
l
0.5
–10
–10
10
10
V
CC
– 0.5
0.4
V
CC
– 0.5
0.4
–10
10
10
10
V
μA
μA
pF
pF
V
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)
SYMBOL
V
CC
I
CC
CONDITIONS
l
l
l
MIN
2.7
TYP
160
1
MAX
5.5
250
2
UNITS
V
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
Logic analyzers are widely used tools in digital design verification and debugging. They can verify the proper functioning of digital circuits and help users identify and troubleshoot faults. They ...[详细]
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