1
LTC1864L/LTC1865L
18645Lf
APPLICATIO S
U
FEATURES
DESCRIPTIO
U
TYPICAL APPLICATIO
U
Power, 3V, 16-Bit, 150ksps
1- and 2-Channel ADCs in MSOP
Single 3V Supply, 150ksps, 16-Bit Sampling ADC
Supply Current vs Sampling Frequency
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
450
A. 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.
s
16-Bit 150ksps ADCs in MSOP Package
s
Single 3V Supply
s
Low Supply Current: 450
A (Typ)
s
Auto Shutdown Reduces Supply Current
to 10
A at 1ksps
s
True Differential Inputs
s
1-Channel (LTC1864L) or 2-Channel (LTC1865L)
Versions
s
SPI/MICROWIRE
TM
Compatible Serial I/O
s
16-Bit Upgrade to 12-Bit LTC1285/LTC1288
s
Pin Compatible with 12-Bit LTC1860L/LTC1861L
s
No Minimum Data Transfer Rate
, LTC and LT are registered trademarks of Linear Technology Corporation.
s
High Speed Data Acquisition
s
Portable or Compact Instrumentation
s
Low Power Battery-Operated Instrumentation
s
Isolated and/or Remote Data Acquisition
1
2
3
4
8
7
6
5
V
REF
IN
+
IN
GND
V
CC
SCK
SDO
CONV
LTC1864L
1864 TA01
ANALOG INPUT
0V TO 3V
3V
1
F
SERIAL DATA LINK TO
ASIC, PLD, MPU, DSP
OR SHIFT REGISTERS
MICROWIRE is a trademark of National Semiconductor Corporation.
SAMPLING FREQUENCY (kHz)
0.1
SUPPLY CURRENT (
A)
1
10
100
1000
0.01
1
10
1000
1864L/65L TA02
0.1
100
CONV LOW = 2
s
T
A
= 25
C
V
CC
= 2.7V
2
LTC1864L/LTC1865L
18645Lf
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
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
(Notes 1, 2)
ORDER PART
NUMBER
MS8 PART MARKING
MS PART MARKING
LTJ4
LTJ5
LTC1865LCMS
LTC1865LIMS
LTC1865LACMS
LTC1865LAIMS
ORDER PART
NUMBER
LTC1864LCMS8
LTC1864LIMS8
LTC1864LACMS8
LTC1864LAIMS8
LTC7
LTC8
T
JMAX
= 150
C,
JA
= 210
C/W
T
JMAX
= 150
C,
JA
= 210
C/W
1
2
3
4
V
REF
IN
+
IN
GND
8
7
6
5
V
CC
SCK
SDO
CONV
TOP VIEW
MS8 PACKAGE
8-LEAD PLASTIC MSOP
ABSOLUTE AXI U RATI GS
W
W
W
U
PACKAGE/ORDER I FOR ATIO
U
U
W
LTC9
LTD1
ORDER PART
NUMBER
S8 PART MARKING
S8 PART MARKING
1864L
1864LI
LTC1864LCS8
LTC1864LIS8
LTC1864LACS8
LTC1864LAIS8
ORDER PART
NUMBER
T
JMAX
= 150
C,
JA
= 175
C/W
1
2
3
4
8
7
6
5
TOP VIEW
S8 PACKAGE
8-LEAD PLASTIC SO
V
REF
IN
+
IN
GND
V
CC
SCK
SDO
CONV
1864LA
864LAI
LTJ6
LTJ7
1865L
1865LI
LTC1865LCS8
LTC1865LIS8
LTC1865LACS8
LTC1865LAIS8
1865LA
865LAI
1
2
3
4
8
7
6
5
TOP VIEW
S8 PACKAGE
8-LEAD PLASTIC SO
CONV
CH0
CH1
GND
V
CC
SCK
SDO
SDI
T
JMAX
= 150
C,
JA
= 175
C/W
1
2
3
4
5
CONV
CH0
CH1
AGND
DGND
10
9
8
7
6
V
REF
V
CC
SCK
SDO
SDI
TOP VIEW
MS PACKAGE
10-LEAD PLASTIC MSOP
q
LTC1864L/LTC1865L LTC1864LA/LTC1865LA
PARAMETER
CONDITIONS
MIN
TYP
MAX
MIN
TYP
MAX
UNITS
Resolution
q
16
16
Bits
No Missing Codes Resolution
q
14
15
Bits
INL
(Note 3)
q
8
6
LSB
Transition Noise
2
2
LSB
RMS
Gain Error
q
20
20
mV
CO VERTER A D ULTIPLEXER CHARACTERISTICS
U
W
U
Consult LTC Marketing for parts specified with wider operating temperature ranges.
The
q
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.
3
LTC1864L/LTC1865L
18645Lf
LTC1864L/LTC1865L
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
SNR
Signal-to-Noise Ratio
82
dB
S/(N + D) Signal-to-Noise Plus Distortion Ratio
1kHz Input Signal
82
dB
THD
Total Hamonic Distortion Up to 5th Harmonic 1kHz Input Signal
92
dB
Full Power Bandwidth
10
MHz
Full Linear Bandwidth
S/(N + D)
75dB
20
kHz
PARAMETER
CONDITIONS
MIN
TYP
MAX
MIN
TYP
MAX
UNITS
Offset Error
q
2
5
2
5
mV
Input Differential Voltage
V
IN
= IN
+
IN
q
0
V
REF
0
V
REF
V
Range
Absolute Input Range
IN
+
Input
0.05
V
CC
+ 0.05
0.05
V
CC
+ 0.05
V
IN
Input
0.05
V
CC
/2
0.05
V
CC
/2
V
V
REF
Input Range
LTC1864L SO-8 and MSOP, LTC1865L MSOP
1
V
CC
1
V
CC
V
Analog Input Leakage Current
(Note 4)
q
1
1
A
C
IN
Input Capacitance
In Sample Mode
12
12
pF
During Conversion
5
5
pF
DY
A
IC ACCURACY
U
W
DIGITAL A D DC ELECTRICAL CHARACTERISTICS
U
The
q
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.
CO VERTER A D ULTIPLEXER CHARACTERISTICS
U
W
U
T
A
= 25
C. V
CC
= 3V, V
REF
= 3V, f
SAMPLE
= 150kHz, unless otherwise noted.
LTC1864L/LTC1865L
SYMBOL
PARAMETER
CONDITION
MIN
TYP
MAX
UNITS
V
IH
High Level Input Voltage
V
CC
= 3.3V
q
1.9
V
V
IL
Low Level Input Voltage
V
CC
= 2.7V
q
0.45
V
I
IH
High Level Input Current
V
IN
= V
CC
q
2.5
A
I
IL
Low Level Input Current
V
IN
= 0V
q
2.5
A
V
OH
High Level Output Voltage
V
CC
= 2.7V, I
O
= 10
A
q
2.3
2.6
V
V
CC
= 2.7V, I
O
= 360
A
q
2.1
2.45
V
V
OL
Low Level Output Voltage
V
CC
= 2.7V, I
O
= 400
A
q
0.3
V
I
OZ
Hi-Z Output Leakage
CONV = V
CC
q
3
A
I
SOURCE
Output Source Current
V
OUT
= 0V
6.5
mA
I
SINK
Output Sink Current
V
OUT
= V
CC
6.5
mA
I
REF
Reference Current (LTC1864L SO-8 and
CONV = V
CC
q
0.001
3
A
MSOP, LTC1865L MSOP)
f
SMPL
= f
SMPL(MAX)
q
0.01
0.1
mA
I
CC
Supply Current
CONV = V
CC
After Conversion
q
0.5
10
A
f
SMPL
= f
SMPL(MAX)
q
0.45
1.0
mA
P
D
Power Dissipation
f
SMPL
= f
SMPL(MAX)
1.22
mW
LTC1864L/LTC1865L
LTC1864LA/LTC1865LA
The
q
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.
4
LTC1864L/LTC1865L
18645Lf
LTC1864L/LTC1865L
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
CC
Supply Voltage
2.7
3.6
V
f
SCK
Clock Frequency
q
DC
8
MHz
t
CYC
Total Cycle Time
16 SCK + t
CONV
s
t
SMPL
Analog Input Sampling Time (Note 5)
LTC1864L
16
SCK
LTC1865L
14
SCK
t
suCONV
Setup Time CONV
Before First SCK
60
ns
(See Figure 1)
t
hDI
Hold Time SDI After SCK
LTC1865L
30
ns
t
suDI
Setup Time SDI Stable Before SCK
LTC1865L
30
ns
t
WHCLK
SCK High Time
f
SCK
= f
SCK(MAX)
45%
1/f
SCK
t
WLCLK
SCK Low Time
f
SCK
= f
SCK(MAX)
45%
1/f
SCK
t
WHCONV
CONV High Time Between Data
t
CONV
s
Transfer Cycles
t
WLCONV
CONV Low Time During Data Transfer
16
SCK
t
hCONV
Hold Time CONV Low After Last SCK
26
ns
LTC1864L/LTC1865L
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
t
CONV
Conversion Time (See Figure 1)
q
3.7
4.66
s
f
SMPL(MAX)
Maximum Sampling Frequency
q
150
kHz
t
dDO
Delay Time, SCK
to SDO Data Valid
C
LOAD
= 20pF
45
55
ns
q
60
ns
t
dis
Delay Time, CONV
to SDO Hi-Z
q
55
120
ns
t
en
Delay Time, CONV
to SDO Enabled
C
LOAD
= 20pF
q
35
120
ns
t
hDO
Time Output Data Remains
C
LOAD
= 20pF
q
5
15
ns
Valid After SCK
t
r
SDO Rise Time
C
LOAD
= 20pF
25
ns
t
f
SDO Fall Time
C
LOAD
= 20pF
12
ns
RECO
E
DED OPERATI
G CO DITIO
S
U
U
U
U
W
W
TI I G CHARACTERISTICS
U
W
The
q
denotes specifications which apply over the
full operating temperature range, otherwise specifications are T
A
= 25
C.
The
q
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.
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.
5
LTC1864L/LTC1865L
18645Lf
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
Supply Current vs Sampling
Frequency
Supply Current vs Temperature
Sleep Current vs Temperature
Reference Current vs
Sampling Rate
Reference Current vs
Temperature
Reference Current vs
Reference Voltage
Typical INL Curve
Typical DNL Curve
Analog Input Leakage Current vs
Temperature
SAMPLING FREQUENCY (kHz)
0.1
SUPPLY CURRENT (
A)
1
10
100
1000
0.01
1
10
1000
1864L/65L G01
1864L/65L G02
1864L/65L G03
0.1
100
CONV LOW = 2
s
T
A
= 25
C
V
CC
= 2.7V
TEMPERATURE (
C)
50
SUPPLY CURRENT (
A)
600
500
400
300
200
100
0
25
75
25
0
50
100
125
f
S
= 150kHz
V
CC
= 2.7V
V
REF
= 2.5V
TEMPERATURE (
C)
50
SHUTDOWN CURRENT (
A)
20
15
10
5
0
25
75
25
0
50
100
125
f
S
= 150kHz
V
CC
= 2.7V
V
REF
= 2.5V
SAMPLING FREQUENCY (kHz)
0
REFERENCE CURRENT (
A)
25
50
75
100
1864L/65L G04
125
10
9
8
7
6
5
4
3
2
1
0
150
CONV LOW = 2
s
T
A
= 25
C
V
CC
= 2.7V
V
REF
= 2.5V
TEMPERATURE (
C)
50
REFERENCE CURRENT (
A)
25
20
15
10
5
0
25
75
1864L/65L G05
25
0
50
100
125
f
S
= 150kHz
V
CC
= 2.7V
V
REF
= 2.5V
REFERENCE VOLTAGE (V)
0
REFERENCE CURRENT (
A)
0.5
1.0
2.0
1.5
3.0
2.5
1864L/65L G06
3.5
25
20
15
10
5
0
4.0
f
S
= 150kHz
T
A
= 25
C
V
CC
= 3.6V
TEMPERATURE (
C)
50
ANALOG INPUT LEAKAGE (nA)
100
75
50
25
0
25
75
1864L/65L G09
25
0
50
100
125
CONV = 0V
V
CC
= 2.7V
V
REF
= 2.5V
CODE
0
INL ERROR (LSBs)
0
2
65536
1865 G02
2
4
16384
32768
49152
4
V
CC
= 2.7V
V
REF
= 2.5V
f
S
= 150kHz
CODE
0
DNL ERROR (LSBs)
0
1
65536
1865 G03
1
2
16384
32768
49152
2
V
CC
= 2.7V
V
REF
= 2.5V
f
S
= 150kHz
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