channel, 12-bit successive approximation ADCs with an I
2
C
compatible serial interface. These ADCs include an internal
reference and a fully differential sample-and-hold circuit
to reduce common-mode noise. The LTC2301/LTC2305
operate from an internal clock to achieve a fast 1.3μs
conversion time.
The LTC2301/LTC2305 operate from a single 5V supply
and draw just 300μA at a throughput rate of 1ksps. The
ADC enters nap mode when not converting, reducing the
power dissipation.
The LTC2301/LTC2305 are available in small 12-pin
4mm
×
3mm DFN and 12-pin MSOP packages. The in-
ternal 2.5V reference further reduces PCB board space
requirements.
The low power consumption and small size make the
LTC2301/LTC2305 ideal for battery operated and portable
applications, while the 2-wire I
2
C compatible serial interface
makes these ADCs a good match for space-constrained
systems.
12-Bit I
2
C ADC Famly
Input Channels
Part Number
1
LTC2301
2
LTC2305
8
LTC2309
12-Bit Resolution
Low Power: 1.5mW at 1ksps, 35μW Sleep Mode
14ksps Throughput Rate
Internal Reference
Low Noise: SNR = 73.5dB
Guaranteed No Missing Codes
Single 5V Supply
2-wire I
2
C Compatible Serial Interface with 9
Addresses Plus One Global for Synchronization
Fast Conversion Time: 1.3μs
1-Channel (LTC2301) and 2-Channel (LTC2305)
Versions
Unipolar or Bipolar Input Ranges (Software
Selectable)
Internal Conversion Clock
Guaranteed Operation from –40°C to 125°C
(MSOP Package)
12-Pin 4mm
×
3mm DFN and 12-Pin MSOP
Packages
APPLICATIONS
n
n
n
n
n
n
Industrial Process Control
Motor Control
Accelerometer Measurements
Battery Operated Instruments
Isolated and/or Remote Data Acquisition
Power Supply Monitoring
L,
LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
BLOCK DIAGRAM
5V
10μF
LTC2301
LTC2305
CH0(IN
+
)
ANALOG INPUT
0V TO 4.096V UNIPOLAR CH1(IN
+
)
±2.048V BIPOLAR
ANALOG
INPUT
MUX
+
–
V
DD
0.1μF
AD1
AD0
SCL
SDA
V
REF
2.2μF
Integral Nonlinearity vs Output Code (LTC2305)
1.00
0.75
0.50
INL (LSB)
REFCOMP
10μF
0.25
0.00
–0.25
–0.50
–0.75
–1.00
0
1024
2048
3072
OUTPUT CODE
4096
23015 TA01b
12-BIT
SAR ADC
I
2
C
PORT
INTERNAL
2.5V REF
PIN NAMES IN PARENTHESES
REFER TO LTC2301
GND
23015 TA01a
0.1μF
23015f
1
LTC2301/LTC2305
ABSOLUTE MAXIMUM RATINGS
(Notes 1,2)
Supply Voltage (V
DD
) ................................ –0.3V to 6.0V
Analog Input Voltage
CH0(IN
+
), CH1(IN
–
), REF,
REFCOMP .....................(GND – 0.3V) to (V
DD
+ 0.3V)
Digital Input Voltage..........(GND – 0.3V) to (V
DD
+ 0.3V)
Digital Output Voltage .......(GND – 0.3V) to (V
DD
+ 0.3V)
Power Dissipation ...............................................500mW
Operating Temperature Range
LTC2301C/LTC2305C ............................... 0°C to 70°C
LTC2301I/LTC2305I.............................. –40°C to 85°C
LTC2301H/LTC2305H (Note 13) ......... –40°C to 125°C
Storage Temperature Range................... –65°C to 150°C
PIN CONFIGURATION
LTC2305
GND
SDA
SCL
GND
CH0
CH1
1
2
3
4
5
6
13
TOP VIEW
12 AD0
11 AD1
10 V
DD
9
8
7
GND
REFCOMP
V
REF
LTC2301
GND
SDA
SCL
GND
IN
+
TOP VIEW
1
2
3
4
5
6
13
12 AD0
11 AD1
10 V
DD
9
8
7
GND
REFCOMP
V
REF
IN
–
DE PACKAGE
12-LEAD (4mm
×
3mm) PLASTIC DFN
T
JMAX
= 150°C,
θ
JA
= 43°C/W
EXPOSED PAD (PIN 13) IS GND, MUST BE SOLDERED TO PCB
DE PACKAGE
12-LEAD (4mm
×
3mm) PLASTIC DFN
T
JMAX
= 150°C,
θ
JA
= 43°C/W
EXPOSED PAD (PIN 13) IS GND, MUST BE SOLDERED TO PCB
LTC2305
GND
SDA
SCL
GND
CH0
CH1
1
2
3
4
5
6
TOP VIEW
12
11
10
9
8
7
AD0
AD1
V
DD
GND
REFCOMP
V
REF
LTC2301
GND
SDA
SCL
GND
IN
+
IN
–
1
2
3
4
5
6
TOP VIEW
12
11
10
9
8
7
AD0
AD1
V
DD
GND
REFCOMP
V
REF
MS PACKAGE
12-LEAD PLASTIC MSOP
T
JMAX
= 150°C,
θ
JA
= 130°C/W
MS PACKAGE
12-LEAD PLASTIC MSOP
T
JMAX
= 150°C,
θ
JA
= 130°C/W
ORDER INFORMATION
LEAD FREE FINISH
LTC2301CDE#PBF
LTC2301IDE#PBF
LTC2305CDE#PBF
LTC2305IDE#PBF
LTC2301CMS#PBF
LTC2301IMS#PBF
LTC2301HMS#PBF
LTC2305CMS#PBF
TAPE AND REEL
LTC2301CDE#TRPBF
LTC2301IDE#TRPBF
LTC2305CDE#TRPBF
LTC2305IDE#TRPBF
LTC2301CMS#TRPBF
LTC2301IMS#TRPBF
LTC2301HMS#TRPBF
LTC2305CMS#TRPBF
PART MARKING*
2301
2301
2305
2305
2301
2301
2301
2305
PACKAGE DESCRIPTION
12-Lead (3mm
×
4mm) Plastic DFN
12-Lead (3mm
×
4mm) Plastic DFN
12-Lead (3mm
×
4mm) Plastic DFN
12-Lead (3mm
×
4mm) Plastic DFN
12-Lead Plastic MSOP
12-Lead Plastic MSOP
12-Lead Plastic MSOP
12-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
0°C to 70°C
–40°C to 85°C
–40°C to 125°C
0°C to 70°C
23015f
2
LTC2301/LTC2305
ORDER INFORMATION
LEAD FREE FINISH
LTC2305IMS#PBF
LTC2305HMS#PBF
TAPE AND REEL
LTC2305IMS#TRPBF
LTC2305HMS#TRPBF
PART MARKING*
2305
2305
PACKAGE DESCRIPTION
12-Lead Plastic MSOP
12-Lead Plastic MSOP
TEMPERATURE RANGE
–40°C to 85°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.
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/
CONVERTER AND MULTIPLEXER CHARACTERISTICS
The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T
A
= 25°C. (Note 4)
PARAMETER
Resolution (No Missing Codes)
Integral Linearity Error
Differential Linearity Error
Bipolar Zero Error
Bipolar Zero Error Drift
Unipolar Zero Error
Unipolar Zero Error Drift
Unipolar Zero Error Match (LTC2305)
Bipolar Full-Scale Error
Bipolar Full-Scale Error Drift
Unipolar Full-Scale Error
Unipolar Full-Scale Error Drift
Unipolar Full-Scale Error Match (LTC2305)
External Reference (Note 7)
REFCOMP = 4.096V (Note 7)
External Reference
External Reference (Note 7)
REFCOMP = 4.096V (Note 7)
External Reference
l
l
l
l
CONDITIONS
l
MIN
12
l
l
l
l
TYP
±0.4
±0.3
±0.5
0.002
±0.7
0.002
±0.1
±1
±0.9
0.05
±0.5
±0.7
0.05
±0.1
MAX
±1
±1
±8
±6
±1
±10
±9
±10
±6
±2
UNITS
Bits
LSB
LSB
LSB
LSB/°C
LSB
LSB/°C
LSB
LSB
LSB
LSB/°C
LSB
LSB
LSB/°C
LSB
(Note 5)
(Note 6)
(Note 6)
ANALOG INPUT
SYMBOL
V
IN
+
V
IN
–
V
IN
+ – V
IN
–
I
IN
C
IN
CMRR
PARAMETER
The
l
denotes the specifications which apply over the full operating temperature range, otherwise
specifications are at T
A
= 25°C. (Note 4)
CONDITIONS
(Note 8)
Unipolar (Note 8)
Bipolar (Note 8)
V
IN
= V
IN
+ – V
IN
– (Unipolar)
V
IN
= V
IN
+ – V
IN
– (Bipolar)
Sample Mode
Hold Mode
l
l
l
l
MIN
–0.05
–0.05
–0.05
TYP
MAX
REFCOMP
0.25 • REFCOMP
0.75 • REFCOMP
UNITS
V
V
V
V
V
Absolute Input Range (CH0, CH1, IN+)
Absolute Input Range (CH0, CH1, IN–)
Input Differential Voltage Range
Analog Input Leakage Current
Analog Input Capacitance
Input Common Mode Rejection Ratio
0 to REFCOMP
±REFCOMP/2
±1
55
5
70
μA
pF
pF
dB
23015f
3
LTC2301/LTC2305
DYNAMIC ACCURACY
SYMBOL
SINAD
SNR
THD
SFDR
PARAMETER
Signal-to-(Noise + Distortion) Ratio
Signal-to-Noise Ratio
Total Harmonic Distortion
Spurious Free Dynamic Range
Channel-to-Channel Isolation
Full Linear Bandwidth
–3dB Input Linear Bandwidth
Aperture Delay
Transient Response
Full-Scale Step
The
l
denotes the specifications which apply over the full operating temperature range,
otherwise specifications are at T
A
= 25°C and A
IN
= –1dBFS. (Notes 4,9)
CONDITIONS
f
IN
= 1kHz
f
IN
= 1kHz
f
IN
= 1kHz
f
IN
= 1kHz, First 5 Harmonics
f
IN
= 1kHz
f
IN
= 1kHz
(Note 10)
l
l
l
l
MIN
71
71
79
TYP
73.4
73.5
–91
92
–109
700
25
13
240
MAX
UNITS
dB
dB
–77
dB
dB
dB
kHz
MHz
ns
ns
INTERNAL REFERENCE CHARACTERISTICS
The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T
A
= 25°C. (Notes 4)
PARAMETER
V
REF
Output Voltage
V
REF
Output Tempco
V
REF
Output Impedance
V
REFCOMP
Output Voltage
V
REF
Line Regulation
CONDITIONS
I
OUT
= 0
I
OUT
= 0
–0.1mA ≤ I
OUT
≤ 0.1mA
I
OUT
= 0
V
DD
= 4.75V to 5.25V
l
MIN
2.46
TYP
2.50
±25
8
4.096
0.8
MAX
2.54
UNITS
V
ppm/°C
kΩ
V
mV/V
I
2
C INPUTS AND DIGITAL OUTPUTS
The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T
A
= 25°C. (Notes 4)
SYMBOL PARAMETER
V
IH
V
IL
V
IHA
V
ILA
R
INH
R
INL
R
INF
I
I
V
HYS
V
OL
t
OF
t
SP
C
CAX
High Level Input Voltage
Low Level Input Voltage
High Level Input Voltage for Address Pins A1, A0
Low Level Input Voltage for Address Pins A1, A0
Resistance from A1, A0 to V
DD
to Set Chip
Address Bit to 1
Resistance from A1, A0 to GND to Set Chip
Address Bit to 0
Resistance from A1, A0 to GND or V
DD
to Set
Chip Address Bit to Float
Digital Input Current
Hysteresis of Schmitt Trigger Inputs
Low Level Output Voltage (SDA)
Output Fall Time V
IN(MIN)
to V
IL(MAX)
Input Spike Suppression
External Capacitance Load on Chip Address Pins
(A1, A0) for Valid Float
V
IN
= V
DD
(Note 8)
I = 3mA
Bus Load C
B
10pF to 400pF (Note 11)
CONDITIONS
l
l
l
l
l
l
l
l
l
l
l
l
l
MIN
2.85
TYP
MAX
1.5
UNITS
V
V
V
V
kΩ
kΩ
MΩ
4.75
0.25
10
10
2
–10
0.25
0.4
20 + 0.1C
B
250
50
10
10
μA
V
V
ns
ns
pF
23015f
4
LTC2301/LTC2305
POWER REQUIREMENTS
SYMBOL
V
DD
I
DD
PARAMETER
Supply Voltage
Supply Current
Nap Mode
Sleep Mode
Power Dissipation
Nap Mode
Sleep Mode
14ksps Sample Rate
SLP Bit = 0, Conversion Done
SLP Bit = 1, Conversion Done
14ksps Sample Rate
SLP Bit = 0, Conversion Done
SLP Bit = 1, Conversion Done
The
l
denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. (Note 4)
CONDITIONS
l
l
l
l
l
l
l
MIN
4.75
TYP
5
2.3
225
7
11.5
1.125
35
MAX
5.25
3.5
400
15
17.5
2
75
UNITS
V
mA
μA
μA
mW
mW
μW
P
D
I
2
C TIMING CHARACTERISTICS
SYMBOL
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
PARAMETER
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 Second Start
Condition
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Note 4)
CONDITIONS
l
l
l
l
l
l
l
l
l
l
l
MIN
0.6
1.3
0.6
0.6
0
100
20 + 0.1C
B
20 + 0.1C
B
0.6
1.3
TYP
MAX
400
UNITS
kHz
μs
μs
μs
μs
0.9
300
300
μs
ns
ns
ns
μs
μs
(Note 11)
(Note 11)
ADC TIMING CHARACTERISTICS
SYMBOL
f
SMPL
t
CONV
t
ACQ
t
REFWAKE
PARAMETER
Throughput Rate (Successive Reads)
Conversion Time
Acquisition Time
REFCOMP Wakeup Time (Note 12)
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
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