digital converters with an integrated precision reference.
They use a single 2.7V to 5.5V supply and communicate
through an SPI Interface. The LTC2460 is single-ended
with a 0V to V
REF
input range and the LTC2462 is dif-
ferential with a ±V
REF
input range. Both ADC’s include
a 1.25V integrated reference with 2ppm/°C drift per-
formance and 0.1% initial accuracy. The converters are
available in a 12-pin DFN 3mm
×
3mm package or an
MSOP-12 package. They include an integrated oscillator
and perform conversions with no latency for multiplexed
applications. The LTC2460/LTC2462 include a proprietary
input sampling scheme that reduces the average input
current several orders of magnitude when compared to
conventional delta sigma converters.
Following a single conversion, the LTC2460/LTC2462
automatically power down the converter and can also be
configured to power down the reference. When both the
ADC and reference are powered down, the supply current
is reduced to 200nA.
The LTC2460/LTC2462 can sample at 60 conversions per
second, and due to the very large oversampling ratio,
have extremely relaxed antialiasing requirements. Both
include continuous internal offset and fullscale calibration
algorithms which are transparent to the user, ensuring ac-
curacy over time and the operating temperature range.
16-Bit Resolution, No Missing Codes
Internal Reference, High Accuracy 10ppm/°C (Max)
Single-Ended (LTC2460) or Differential (LTC2462)
2LSB Offset Error
0.01% Gain Error
60 Conversions Per Second
Single Conversion Settling Time for Multiplexed
Applications
Single-Cycle Operation with Auto Shutdown
1.5mA Supply Current
2μA (Max) Sleep Current
Internal Oscillator—No External Components
Required
SPI Interface
Ultra-Tiny 12-Lead 3mm
×
3mm DFN and MSOP
Packages
APPLICATIONS
n
n
n
n
n
n
n
System Monitoring
Environmental Monitoring
Direct Temperature Measurements
Instrumentation
Industrial Process Control
Data Acquisition
Embedded ADC Upgrades
L,
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
REFERENCE OUTPUT VOLTAGE (V)
1.2520
1.2515
1.2510
1.2505
1.2500
1.2495
1.2490
1.2485
1.2480
–50
0.1μF
0.1μF
IN
+
LTC2462
IN
–
10k
0.1μF
R
REF
–
REFOUT
0.1μF
COMP V
CC
SCK
SDO
CS
GND
24602 TA01a
V
REF
vs Temperature
0.1μF
10μF
10k
10k
SPI
INTERFACE
–30
–10 10
30
50
TEMPERATURE (°C)
70
90
24602 TA01b
24602f
1
LTC2460/LTC2462
ABSOLUTE MAXIMUM RATINGS
(Notes 1, 2)
Supply Voltage (V
CC
) ................................... –0.3V to 6V
Analog Input Voltage
(IN
+
, IN
–
, IN, REF
–
,
COMP REFOUT) ............................ –0.3V to (V
CC
+ 0.3V)
,
Digital Voltage
(V
SDI
, V
SDO
, V
SCK
, V
CS
) ................. –0.3V to (V
CC
+ 0.3V)
Storage Temperature Range................... –65°C to 150°C
Operating Temperature Range
LTC2460C/LTC2462C ............................... 0°C to 70°C
LTC2460I/LTC2462I.............................. –40°C to 85°C
PIN CONFIGURATION
LTC2462
TOP VIEW
REFOUT
COMP
CS
SDI
SCK
SDO
1
2
3
4
5
6
12 V
CC
11 GND
10 IN
–
9 IN
+
8 REF
–
7 GND
REFOUT
COMP
CS
SDI
SCK
SDO
1
2
3
4
5
6
TOP VIEW
12
11
10
9
8
7
V
CC
GND
IN
–
IN
+
REF
–
GND
LTC2462
DD PACKAGE
12-LEAD (3mm 3mm) PLASTIC DFN
T
JMAX
= 125°C,
θ
JA
= 43°C/W
EXPOSED PAD (PIN 13) PCB GROUND CONNECTION OPTIONAL
LTC2460
TOP VIEW
REFOUT
COMP
CS
SDI
SCK
SDO
1
2
3
4
5
6
12 V
CC
11 GND
10 GND
9 IN
8 REF
–
7 GND
LTC2460
MS PACKAGE
12-LEAD PLASTIC MSOP
T
JMAX
= 125°C,
θ
JA
= 120°C/W
TOP VIEW
REFOUT
COMP
CS
SDI
SCK
SDO
1
2
3
4
5
6
12
11
10
9
8
7
V
CC
GND
GND
IN
REF
–
GND
DD PACKAGE
12-LEAD (3mm 3mm) PLASTIC DFN
T
JMAX
= 125°C,
θ
JA
= 43°C/W
EXPOSED PAD (PIN 13) PCB GROUND CONNECTION OPTIONAL
MS PACKAGE
12-LEAD PLASTIC MSOP
T
JMAX
= 125°C,
θ
JA
= 120°C/W
ORDER INFORMATION
LEAD FREE FINISH
LTC2460CDD#PBF
LTC2460IDD#PBF
LTC2460CMS#PBF
LTC2460IMS#PBF
LTC2462CDD#PBF
LTC2462IDD#PBF
LTC2462CMS#PBF
LTC2462IMS#PBF
TAPE AND REEL
LTC2460CDD#TRPBF
LTC2460IDD#TRPBF
LTC2460CMS#TRPBF
LTC2460IMS#TRPBF
LTC2462CDD#TRPBF
LTC2462IDD#TRPBF
LTC2462CMS#TRPBF
LTC2462IMS#TRPBF
PART MARKING*
LFDQ
LFDQ
2460
2460
LDXM
LDXM
2462
2462
PACKAGE DESCRIPTION
12-Lead Plastic (3mm × 3mm) DFN
12-Lead Plastic (3mm × 3mm) DFN
12-Lead Plastic MSOP-12
12-Lead Plastic MSOP-12
12-Lead Plastic (3mm × 3mm) DFN
12-Lead Plastic (3mm × 3mm) DFN
12-Lead Plastic MSOP-12
12-Lead Plastic MSOP-12
TEMPERATURE RANGE
0°C to 70°C
–40°C to 85°C
0°C to 70°C
–40°C to 85°C
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.
Consult LTC Marketing for information on non-standard 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/
24602f
2
LTC2460/LTC2462
ELECTRICAL CHARACTERISTICS
PARAMETER
Resolution (No Missing Codes)
Integral Nonlinearity
Offset Error
Offset Error Drift
Gain Error
Gain Error Drift
Includes Contributions of ADC and Internal Reference
Includes Contributions of ADC and Internal Reference
C-Grade
I-Grade
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 2)
CONDITIONS
(Note 3)
(Note 4)
l
l
l
MIN
16
TYP
1
2
0.02
±0.01
±2
±5
2.2
80
MAX
10
10
±0.25
±10
UNITS
Bits
LSB
LSB
LSB/°C
% of FS
ppm/°C
ppm/°C
μV
RMS
dB
Transition Noise
Power Supply Rejection DC
ANALOG INPUTS
specifications are at T
A
= 25°C.
PARAMETER
SYMBOL
V
IN+
V
IN–
V
IN
V
OR+
, V
UR+
V
OR–
, V
UR–
C
IN
The
l
denotes the specifications which apply over the full operating temperature range, otherwise
CONDITIONS
LTC2462
LTC2462
LTC2460
V
IN–
= 0.625V (See Figure 3)
V
IN+
= 0.625V (See Figure 3)
V
IN
= GND (Note 8)
V
IN
= V
CC
(Note 8)
V
IN
= GND (Note 8)
V
IN
= V
CC
(Note 8)
l
l
l
l
l
l
l
l
MIN
0
0
0
TYP
MAX
V
REF
V
REF
V
REF
UNITS
V
V
V
LSB
LSB
pF
Positive Input Voltage Range
Negative Input Voltage Range
Input Voltage Range
Overrange/Underrange Voltage, IN
+
Overrange/Underrange Voltage, IN–
IN
+
, IN
–
, IN Sampling Capacitance
8
8
0.35
–10
–10
–10
–10
1.247
1
1
1
1
50
1.25
±2
±5
–90
l
l
I
DC_LEAK(IN+, IN–, IN)
IN
+
, IN
–
DC Leakage Current (LTC2462)
IN DC Leakage Current (LTC2460)
I
DC_LEAK(IN–)
I
CONV
V
REF
IN
–
DC Leakage Current
Input Sampling Current (Note 5)
Reference Output Voltage
Reference Voltage Coefficient
10
10
10
10
1.253
±10
nA
nA
nA
nA
nA
V
ppm/°C
ppm/°C
dB
mA
μA
mV/mA
nV/√Hz
(Note 11)
C-Grade
I-Grade
2.7V ≤ V
CC
≤ 5.5V
V
CC
= 5.5, Forcing Output to GND
V
CC
= 5.5, Forcing Output to GND
2.7V ≤ V
CC
≤ 5.5V, I
OUT
= 100μA Sourcing
,
,
C
COMP
= 0.1μF C
REFOUT
= 0.1μF At f = 1kHz
l
Reference Line Regulation
Reference Short Circuit Current
COMP Pin Short Circuit Current
Reference Load Regulation
Reference Output Noise Density
35
200
3.5
30
The
l
denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C.
SYMBOL
V
CC
I
CC
PARAMETER
Supply Voltage
Supply Current
Conversion
Nap
Sleep
CONDITIONS
l
l
l
l
POWER REQUIREMENTS
MIN
2.7
TYP
MAX
5.5
UNITS
V
mA
μA
μA
24602f
1.5
800
0.2
2.5
1500
2
3
LTC2460/LTC2462
operating temperature range,otherwise specifications are at T
A
= 25°C. (Note 2)
SYMBOL
V
IH
V
IL
I
IN
C
IN
V
OH
V
OL
I
OZ
PARAMETER
High Level Input Voltage
Low Level Input Voltage
Digital Input Current
Digital Input Capacitance
High Level Output Voltage
Low Level Output Voltage
Hi-Z Output Leakage Current
I
O
= –800μA
I
O
= 1.6mA
l
l
l
DIGITAL INPUTS AND DIGITAL OUTPUTS
The
l
denotes the specifications which apply over the full
CONDITIONS
l
l
l
MIN
V
CC
– 0.3
TYP
MAX
0.3
UNITS
V
V
μA
pF
V
–10
10
V
CC
– 0.5
10
0.4
–10
10
V
μA
TIMING CHARACTERISTICS
The
l
denotes the specifications which apply over the full operating temperature
range,otherwise specifications are at T
A
= 25°C.
SYMBOL
t
CONV
f
SCK
t
lSCK
t
hSCK
t
1
t
2
t
3
t
KQ
t
4
t
5
PARAMETER
Conversion Time
SCK Frequency Range
SCK Low Period
SCK High Period
CS
Falling Edge to SDO Low Z
CS
Rising Edge to SDO High Z
CS
Falling Edge to SCK Falling Edge
SCK Falling Edge to SDO Valid
SDI Setup Before SCK↑
SDI Hold After SCK↑
(Note 7)
(Note 3)
(Note 3)
(Notes 7, 8)
(Notes 7, 8)
CONDITIONS
l
l
l
l
l
l
l
l
l
l
MIN
13
250
250
0
0
100
0
100
100
TYP
16.6
MAX
23
2
UNITS
ms
MHz
ns
ns
100
100
100
ns
ns
ns
ns
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
REFCM
= V
REF
/2, FS = 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:
CS
= V
CC
. A positive current is flowing into the DUT pin.
Note 6:
SCK = V
CC
or GND. SDO is high impedance.
Note 7:
See Figure 4.
Note 8:
See Figure 5.
Note 9:
Input sampling current is the average input current drawn from the
input sampling network while the LTC2460/LTC2462 is actively sampling
the input.
Note 10:
A positive current is flowing into the DUT pin.
Note 11:
Temperature coefficient is calculated by dividing the maximum
change in output voltage by the specified temperature range.
