LTC1864L/LTC1865L
µPower,
3V, 16-Bit, 150ksps
1- and 2-Channel ADCs in MSOP
FEATURES
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DESCRIPTIO
16-Bit 150ksps ADCs in MSOP Package
Single 3V Supply
Low Supply Current: 450µA (Typ)
Auto Shutdown Reduces Supply Current
to 10µA at 1ksps
True Differential Inputs
1-Channel (LTC1864L) or 2-Channel (LTC1865L)
Versions
SPI/MICROWIRE
TM
Compatible Serial I/O
16-Bit Upgrade to 12-Bit LTC1285/LTC1288
Pin Compatible with 12-Bit LTC1860L/LTC1861L
No Minimum Data Transfer Rate
The LTC
®
1864L/LTC1865L are 16-bit A/D converters that
are offered in MSOP and SO-8 packages and operate on a
single 3V supply. At 150ksps, the supply current is only
450µA. The supply current drops at lower speeds because
the LTC1864L/LTC1865L automatically power down
between conversions. These 16-bit switched capacitor
successive approximation ADCs include sample-and-holds.
The LTC1864L has a differential analog input with an
external reference pin. The LTC1865L offers a software-
selectable 2-channel MUX and an external reference pin on
the MSOP version.
The 3-wire, serial I/O, small MSOP or SO-8 package and
extremely high sample rate-to-power ratio make these
ADCs ideal choices for compact, low power, high speed
systems.
These ADCs can be used in ratiometric applications or
with external references. The high impedance analog
inputs and the ability to operate with reduced spans down
to 1V full scale allow direct connection to signal sources
in many applications, eliminating the need for external
gain stages.
, LTC and LT are registered trademarks of Linear Technology Corporation.
MICROWIRE is a trademark of National Semiconductor Corporation.
APPLICATIO S
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High Speed Data Acquisition
Portable or Compact Instrumentation
Low Power Battery-Operated Instrumentation
Isolated and/or Remote Data Acquisition
TYPICAL APPLICATIO
Supply Current vs Sampling Frequency
Single 3V Supply, 150ksps, 16-Bit Sampling ADC
1µF
SUPPLY CURRENT (µA)
1000
CONV LOW = 2µs
T
A
= 25°C
V
CC
= 2.7V
3V
100
LTC1864L
1
2
ANALOG INPUT
0V TO 3V
3
4
V
REF
IN
+
IN
–
GND
V
CC
SCK
SDO
CONV
8
7
6
5
1864 TA01
10
SERIAL DATA LINK TO
ASIC, PLD, MPU, DSP
OR SHIFT REGISTERS
1
0.1
0.01
0.1
100
1
10
SAMPLING FREQUENCY (kHz)
U
1000
1864L/65L TA02
U
U
sn18645L 18645Lfs
1
LTC1864L/LTC1865L
ABSOLUTE
AXI U
RATI GS
Supply Voltage (V
CC
) ................................................. 7V
Ground Voltage Difference
AGND, DGND LTC1865L MSOP Package .........
±0.3V
Analog Input ............... (GND – 0.3V) to (V
CC
+ 0.3V)
Digital Input ................................ (GND – 0.3V) to 7V
Digital Output .............. (GND – 0.3V) to (V
CC
+ 0.3V)
Power Dissipation .............................................. 400mW
PACKAGE/ORDER I FOR ATIO
TOP VIEW
V
REF
IN
+
IN¯
GND
1
2
3
4
8
7
6
5
V
CC
SCK
SDO
CONV
ORDER PART
NUMBER
TOP VIEW
MS8 PACKAGE
8-LEAD PLASTIC MSOP
LTC1864LCMS8
LTC1864LIMS8
LTC1864LACMS8
LTC1864LAIMS8
MS8 PART MARKING
LTC7
ORDER PART
NUMBER
T
JMAX
= 150°C,
θ
JA
= 210°C/W
TOP VIEW
V
REF
1
IN
+
2
IN
–
3
GND 4
8 V
CC
7 SCK
6 SDO
5 CONV
LTC1864LCS8
LTC1864LIS8
LTC1864LACS8
LTC1864LAIS8
S8 PART MARKING
1864L
1864LI
1864LA
864LAI
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 150°C,
θ
JA
= 175°C/W
Consult LTC Marketing for parts specified with wider operating temperature ranges.
CO VERTER A D
PARAMETER
Resolution
No Missing Codes Resolution
INL
Transition Noise
Gain Error
ULTIPLEXER CHARACTERISTICS
●
The
●
denotes specifications which apply over the full operating temperature range, otherwise specifications are T
A
= 25°C.
V
CC
= 2.7V, V
REF
= 2.5V, f
SCK
= f
SCK(MAX)
as defined in Recommended Operating Conditions, unless otherwise noted.
CONDITIONS
●
●
(Note 3)
2
U
U
W
W W
U
W U
W
(Notes 1, 2)
Operating Temperature Range
LTC1864LC/LTC1865LC/
LTC1864LAC/LTC1865LAC .................... 0°C to 70°C
LTC1864LI/LTC1865LI/
LTC1864LAI/LTC1865LAI ................. – 40°C to 85°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
ORDER PART
NUMBER
CONV
CH0
CH1
AGND
DGND
1
2
3
4
5
10
9
8
7
6
V
REF
V
CC
SCK
SDO
SDI
MS PACKAGE
10-LEAD PLASTIC MSOP
T
JMAX
= 150°C,
θ
JA
= 210°C/W
LTC1865LCMS
LTC1865LIMS
LTC1865LACMS
LTC1865LAIMS
MS PART MARKING
LTJ4
ORDER PART
NUMBER
TOP VIEW
CONV 1
CH0 2
CH1 3
GND 4
8 V
CC
7 SCK
6 SDO
5 SDI
LTC1865LCS8
LTC1865LIS8
LTC1865LACS8
LTC1865LAIS8
S8 PART MARKING
1865L
1865LI
1865LA
865LAI
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 150°C,
θ
JA
= 175°C/W
U
LTC1864L/LTC1865L
MIN
TYP
MAX
16
14
±8
2
LTC1864LA/LTC1865LA
MIN
TYP
MAX
16
15
±6
2
±20
UNITS
Bits
Bits
LSB
LSB
RMS
mV
●
●
±20
sn18645L 18645Lfs
LTC1864L/LTC1865L
CO VERTER A D
PARAMETER
Offset Error
Input Differential Voltage
Range
Absolute Input Range
V
REF
Input Range
Analog Input Leakage Current
C
IN
Input Capacitance
The
●
denotes specifications which apply over the full operating temperature range, otherwise specifications are T
A
= 25°C.
V
CC
= 2.7V, V
REF
= 2.5V, f
SCK
= f
SCK(MAX)
as defined in Recommended Operating Conditions, unless otherwise noted.
CONDITIONS
●
DY A IC ACCURACY
T
A
= 25°C. V
CC
= 3V, V
REF
= 3V, f
SAMPLE
= 150kHz, unless otherwise noted.
SYMBOL PARAMETER
SNR
THD
Signal-to-Noise Ratio
1kHz Input Signal
Total Hamonic Distortion Up to 5th Harmonic 1kHz Input Signal
Full Power Bandwidth
Full Linear Bandwidth
S/(N + D)
≥
75dB
S/(N + D) Signal-to-Noise Plus Distortion Ratio
CONDITIONS
LTC1864L/LTC1865L
MIN
TYP
MAX
82
82
92
10
20
UNITS
dB
dB
dB
MHz
kHz
DIGITAL A D DC ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
V
IH
V
IL
I
IH
I
IL
V
OH
V
OL
I
OZ
I
SOURCE
I
SINK
I
REF
I
CC
P
D
High Level Input Voltage
Low Level Input Voltage
High Level Input Current
Low Level Input Current
High Level Output Voltage
Low Level Output Voltage
Hi-Z Output Leakage
Output Source Current
Output Sink Current
Reference Current (LTC1864L SO-8 and
MSOP, LTC1865L MSOP)
Supply Current
Power Dissipation
CONDITION
V
CC
= 3.3V
V
CC
= 2.7V
V
IN
= V
CC
V
IN
= 0V
V
CC
= 2.7V, I
O
= 10µA
V
CC
= 2.7V, I
O
= 360µA
V
CC
= 2.7V, I
O
= 400µA
CONV = V
CC
V
OUT
= 0V
V
OUT
= V
CC
CONV = V
CC
f
SMPL
= f
SMPL(MAX)
CONV = V
CC
After Conversion
f
SMPL
= f
SMPL(MAX)
f
SMPL
= f
SMPL(MAX)
The
●
denotes specifications which apply
over the full operating temperature range, otherwise specifications are T
A
= 25°C. V
CC
= 2.7V, V
REF
= 2.5V, unless otherwise noted.
LTC1864L/LTC1865L
MIN
TYP
MAX
●
●
●
●
●
●
●
●
W U
(Note 4)
U
W U
U
ULTIPLEXER CHARACTERISTICS
LTC1864L/LTC1865L
MIN
TYP
MAX
±2
0
– 0.05
– 0.05
1
●
LTC1864LA/LTC1865LA
MIN
TYP
MAX
±2
0
– 0.05
– 0.05
1
12
5
±5
V
REF
V
CC
+ 0.05
V
CC
/2
V
CC
±1
UNITS
mV
V
V
V
V
µA
pF
pF
±5
V
REF
V
CC
+ 0.05
V
CC
/2
V
CC
±1
V
IN
= IN
+
– IN
–
IN
+
Input
IN
–
Input
LTC1864L SO-8 and MSOP, LTC1865L MSOP
In Sample Mode
During Conversion
●
12
5
UNITS
V
V
µA
µA
V
V
1.9
0.45
2.5
– 2.5
2.3
2.1
2.6
2.45
0.3
±3
– 6.5
6.5
V
µA
mA
mA
●
●
●
●
0.001
0.01
0.5
0.45
1.22
3
0.1
10
1.0
µA
mA
µA
mA
mW
sn18645L 18645Lfs
3
LTC1864L/LTC1865L
RECO
V
CC
f
SCK
t
CYC
t
SMPL
t
suCONV
t
hDI
t
suDI
t
WHCLK
t
WLCLK
t
WHCONV
t
WLCONV
t
hCONV
full operating temperature range, otherwise specifications are T
A
= 25°C.
SYMBOL PARAMETER
Supply Voltage
Clock Frequency
Total Cycle Time
Analog Input Sampling Time (Note 5)
Setup Time CONV↓ Before First SCK↑
(See Figure 1)
Hold Time SDI After SCK↑
Setup Time SDI Stable Before SCK↑
SCK High Time
SCK Low Time
CONV High Time Between Data
Transfer Cycles
CONV Low Time During Data Transfer
Hold Time CONV Low After Last SCK↑
LTC1865L
LTC1865L
f
SCK
= f
SCK(MAX)
f
SCK
= f
SCK(MAX)
LTC1864L
LTC1865L
CONDITIONS
E DED OPERATI G CO DITIO S
The
●
denotes specifications which apply over the full operating temperature
range, otherwise specifications are T
A
= 25°C. V
CC
= 2.7V, V
REF
= 2.5V, f
SCK
= f
SCK(MAX)
as defined in Recommended Operating
Conditions, unless otherwise noted.
SYMBOL
t
CONV
t
dDO
t
dis
t
en
t
hDO
t
r
t
f
PARAMETER
Conversion Time (See Figure 1)
Delay Time, SCK↓ to SDO Data Valid
Delay Time, CONV↑ to SDO Hi-Z
Delay Time, CONV↓ to SDO Enabled
Time Output Data Remains
Valid After SCK↓
SDO Rise Time
SDO Fall Time
C
LOAD
= 20pF
C
LOAD
= 20pF
C
LOAD
= 20pF
C
LOAD
= 20pF
C
LOAD
= 20pF
CONDITIONS
●
●
●
●
●
●
TI I G CHARACTERISTICS
f
SMPL(MAX)
Maximum Sampling Frequency
Note 1:
Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2:
All voltage values are with respect to GND.
Note 3:
Integral nonlinearity is defined as deviation of a code from a
straight line passing through the actual endpoints of the transfer curve.
The deviation is measured from the center of the quantization band.
Note 4:
Channel leakage current is measured while the part is in sample
mode.
Note 5:
Assumes f
SCK
= f
SCK(MAX)
In the case of the LTC1864L SCK does
not have to be clocked during this time if the SDO data word is not
desired. In the case of the LTC1865L a minimum of 2 clocks are required
on the SCK input after CONV falls to configure the MUX during this time.
4
U
U
U
U WW
The
●
denotes specifications which apply over the
LTC1864L/LTC1865L
MIN
TYP
MAX
2.7
●
UNITS
V
MHz
µs
SCK
SCK
ns
ns
ns
1/f
SCK
1/f
SCK
µs
SCK
ns
3.6
8
DC
16 • SCK + t
CONV
16
14
60
30
30
45%
45%
t
CONV
16
26
UW
LTC1864L/LTC1865L
MIN
TYP
MAX
3.7
150
45
55
35
5
15
25
12
55
60
120
120
4.66
UNITS
µs
kHz
ns
ns
ns
ns
ns
ns
ns
sn18645L 18645Lfs
LTC1864L/LTC1865L
TYPICAL PERFOR A CE CHARACTERISTICS
Supply Current vs Sampling
Frequency
1000
CONV LOW = 2µs
T
A
= 25°C
V
CC
= 2.7V
600
500
f
S
= 150kHz
V
CC
= 2.7V
V
REF
= 2.5V
SHUTDOWN CURRENT (µA)
SUPPLY CURRENT (µA)
SUPPLY CURRENT (µA)
100
10
1
0.1
0.01
0.1
100
1
10
SAMPLING FREQUENCY (kHz)
Reference Current vs
Sampling Rate
10
9
CONV LOW = 2µs
T
A
= 25°C
V
CC
= 2.7V
V
REF
= 2.5V
25
REFERENCE CURRENT (µA)
REFERENCE CURRENT (µA)
7
6
5
4
3
2
1
0
0
25
75
100
125
50
SAMPLING FREQUENCY (kHz)
150
15
REFERENCE CURRENT (µA)
8
Typical INL Curve
4
V
CC
= 2.7V
V
REF
= 2.5V
f
S
= 150kHz
2
1
2
ANALOG INPUT LEAKAGE (nA)
DNL ERROR (LSBs)
INL ERROR (LSBs)
0
–2
–4
0
16384
32768
CODE
49152
U W
1864L/65L G01
1864L/65L G04
1865 G02
Supply Current vs Temperature
20
Sleep Current vs Temperature
f
S
= 150kHz
V
CC
= 2.7V
V
REF
= 2.5V
15
400
300
200
100
0
–50 –25
10
5
1000
50
25
75
0
TEMPERATURE (°C)
100
125
0
–50 –25
50
25
75
0
TEMPERATURE (°C)
100
125
1864L/65L G02
1864L/65L G03
Reference Current vs
Temperature
25
f
S
= 150kHz
V
CC
= 2.7V
V
REF
= 2.5V
Reference Current vs
Reference Voltage
f
S
= 150kHz
T
A
= 25°C
V
CC
= 3.6V
20
20
15
10
10
5
5
0
–50 –25
0
50
25
75
0
TEMPERATURE (°C)
100
125
0
0.5
1.0 1.5 2.0 2.5 3.0
REFERENCE VOLTAGE (V)
3.5
4.0
1864L/65L G05
1864L/65L G06
Typical DNL Curve
100
V
CC
= 2.7V
V
REF
= 2.5V
f
S
= 150kHz
Analog Input Leakage Current vs
Temperature
CONV = 0V
V
CC
= 2.7V
V
REF
= 2.5V
75
0
50
–1
25
65536
–2
0
16384
32768
CODE
49152
65536
1865 G03
0
–50 –25
50
25
75
0
TEMPERATURE (°C)
100
125
1864L/65L G09
sn18645L 18645Lfs
5
FPGA/CPLD
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