LTC1863/LTC1867
12-/16-Bit, 8-Channel
200ksps ADCs
FEATURES
s
s
s
DESCRIPTIO
s
s
s
s
s
s
s
s
Sample Rate: 200ksps
16-Bit No Missing Codes and
±2LSB
Max INL
8-Channel Multiplexer with:
Single Ended or Differential Inputs and
Unipolar or Bipolar Conversion Modes
SPI/MICROWIRE
TM
Serial I/O
Signal-to-Noise Ratio: 89dB
Single 5V Operation
On-Chip or External Reference
Low Power: 1.3mA at 200ksps, 0.76mA at 100ksps
Sleep Mode
Automatic Nap Mode Between Conversions
16-Pin Narrow SSOP Package
The LTC
®
1863/LTC1867 are pin-compatible, 8-channel
12-/16-bit A/D converters with serial I/O, and an internal
reference. The ADCs typically draw only 1.3mA from a
single 5V supply.
The 8-channel input multiplexer can be configured for
either single-ended or differential inputs and unipolar
or bipolar conversions (or combinations thereof). The
automatic nap and sleep modes benefit power sensitive
applications.
The LTC1867’s DC performance is outstanding with a
±2LSB
INL specification and no missing codes over tem-
perature. The signal-to-noise ratio (SNR) for the LTC1867
is typically 89dB, with the internal reference.
Housed in a compact, narrow 16-pin SSOP package, the
LTC1863/LTC1867 can be used in space-sensitive as well
as low-power applications.
, LTC and LT are registered trademarks of Linear Technology Corporation.
MICROWIRE is a trademark of National Semiconductor Corp.
APPLICATIO S
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s
s
s
s
Industrial Process Control
High Speed Data Acquisition
Battery Operated Systems
Multiplexed Data Acquisition Systems
Imaging Systems
BLOCK DIAGRA
1
2
3
4
5
6
7
8
Integral Nonlinearity vs Output Code
(LTC1867)
2.0
CH0
CH1
CH2
CH3
CH4
CH5
CH6
CH7/COM
LTC1863/LTC1867 16 V
DD
15
GND
14
SDI
13
12-/16-BIT
+
SERIAL
SDO
200ksps
12
PORT
–
SCK
ADC
11
CS/CONV
10
V
REF
INTERNAL
2.5V REF
9
18637 BD
1.5
1.0
INL (LBS)
ANALOG
INPUT
MUX
0.5
0
– 0.5
– 1.0
REFCOMP
– 1.5
– 2.0
0
16384
32768
49152
OUTPUT CODE
65536
18637 GO1
U
18637f
W
U
1
LTC1863/LTC1867
ABSOLUTE
(Notes 1, 2)
AXI U RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW
CH0 1
CH1 2
CH2 3
CH3 4
CH4 5
CH5 6
CH6 7
CH7/COM 8
16 V
DD
15 GND
14 SDI
13 SDO
12 SCK
11 CS/CONV
10 V
REF
9
REFCOMP
Supply Voltage (V
DD
) ................................... –0.3V to 6V
Analog Input Voltage
CH0-CH7/COM (Note 3) .......... – 0.3V to (V
DD
+ 0.3V)
V
REF
, REFCOMP (Note 4)......... – 0.3V to (V
DD
+ 0.3V)
Digital Input Voltage (SDI, SCK, CS/CONV)
(Note 4) .................................................– 0.3V to 10V
Digital Output Voltage (SDO) ....... – 0.3V to (V
DD
+ 0.3V)
Power Dissipation .............................................. 500mW
Operating Temperature Range
LTC1863C/LTC1867C/LTC1867AC .......... 0°C to 70°C
LTC1863I/LTC1867I/LTC1867AI ........ – 40°C to 85°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
ORDER PART
NUMBER
LTC1863CGN
LTC1863IGN
LTC1867CGN
LTC1867IGN
LTC1867ACGN
LTC1867AIGN
GN PART MARKING
1863
1867
GN PACKAGE
16-LEAD NARROW PLASTIC SSOP
T
JMAX
= 110°C,
θ
JA
= 95°C/W
Consult LTC Marketing for parts specified with wider operating temperature ranges.
CO VERTER CHARACTERISTICS
The
q
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. With external reference (Notes 5, 6)
PARAMETER
Resolution
No Missing Codes
Integral Linearity Error
Differential Linearity Error
Transition Noise
Offset Error
Offset Error Match
Offset Error Drift
Gain Error
Gain Error Match
Gain Error Tempco
Power Supply Sensitivity
Internal Reference
External Reference
V
DD
= 4.75V – 5.25V
±15
±2.7
±1
Unipolar
Bipolar
Unipolar (Note 8)
Bipolar
Unipolar
Bipolar
±0.5
±6
±6
±1
±15
±2.7
±5
q
q
CONDITIONS
q
q
LTC1863
MIN
TYP
MAX
12
12
±1
±1
±1
0.1
±3
±4
±1
±1
LTC1867
MIN
TYP
MAX
16
15
±4
±4
–2
0.74
±32
±64
±2
±2
±0.5
±96
±96
±4
3
LTC1867A
MIN
TYP
MAX
16
16
±2
±2.5
–1
0.74
±32
±64
±2
±2
±0.5
±64
±64
±2
±15
±2.7
±5
1.75
UNITS
Bits
Bits
LSB
LSB
LSB
LSB
RMS
LSB
LSB
LSB
LSB
ppm/°C
LSB
LSB
LSB
ppm/°C
ppm/°C
LSB
Unipolar (Note 7)
Bipolar
q
q
q
DY A IC ACCURACY
SYMBOL
SNR
S/(N+D)
PARAMETER
Signal-to-Noise Ratio
Signal-to-(Noise + Distortion) Ratio
(Note 5)
CONDITIONS
1kHz Input Signal
1kHz Input Signal
LTC1863
MIN
TYP
MAX
73.6
73.5
LTC1867/LTC1867A
MIN
TYP
MAX
89
88
UNITS
dB
dB
18637f
2
U
W
U
U
W W
W
W U
U
LTC1863/LTC1867
DY A IC ACCURACY
SYMBOL
THD
PARAMETER
Total Harmonic Distortion
Peak Harmonic or Spurious Noise
Channel-to-Channel Isolation
Full Power Bandwidth
The
q
denotes the specifications which apply over the full operating temperature range, otherwise
specifications are at T
A
= 25°C. (Note 5)
SYMBOL
PARAMETER
Analog Input Range
C
IN
t
ACQ
Analog Input Capacitance for CH0 to
CH7/COM
Sample-and-Hold Acquisition Time
Input Leakage Current
On Channels, CHX = 0V or V
DD
CONDITIONS
Unipolar Mode (Note 9)
Bipolar Mode
Between Conversions (Sample Mode)
During Conversions (Hold Mode)
q
q
q
q
A ALOG I PUT
I TER AL REFERE CE CHARACTERISTICS
PARAMETER
V
REF
Output Voltage
V
REF
Output Tempco
V
REF
Line Regulation
V
REF
Output Resistance
REFCOMP Output Voltage
CONDITIONS
I
OUT
= 0
I
OUT
= 0
4.75V
≤
V
DD
≤
5.25V
I
OUT
≤0.1mA
I
OUT
= 0
DIGITAL I PUTS A D DIGITAL OUTPUTS
SYMBOL
V
IH
V
IL
I
IN
C
IN
V
OH
V
OL
I
SOURCE
I
SINK
PARAMETER
High Level Input Voltage
Low Level Input Voltage
Digital Input Current
Digital Input Capacitance
High Level Output Voltage (SDO)
Low Level Output Voltage (SDO)
Output Source Current
Output Sink Current
Hi-Z Output Leakage
Hi-Z Output Capacitance
Data Format
CONDITIONS
V
DD
= 5.25V
V
DD
= 4.75V
V
IN
= 0V to V
DD
The
q
denotes the specifications which apply over the
full operating temperature range, otherwise specifications are at T
A
= 25°C. (Note 5)
LTC1863/LTC1867/LTC1867A
MIN
TYP
MAX
q
q
q
U
U
U
U
W U
U
(Note 5)
CONDITIONS
1kHz Input Signal, Up to 5th Harmonic
1kHz Input Signal
100kHz Input Signal
–3dB Point
LTC1863
MIN
TYP
MAX
–94.5
–94.5
–100
1.25
LTC1867/LTC1867A
MIN
TYP
MAX
– 95
– 95
–117
1.25
UNITS
dB
dB
dB
MHz
U
LTC1863/LTC1867/LTC1867A
MIN
TYP
MAX
0-4.096
±2.048
32
4
1.5
1.1
±1
UNITS
V
V
pF
pF
µs
µA
U
(Note 5)
LTC1863/LTC1867/LTC1867A
MIN
TYP
MAX
2.480
2.500
±15
0.43
6
4.096
2.520
UNITS
V
ppm/°C
mV/V
kΩ
V
UNITS
V
V
µA
pF
V
V
2.4
0.8
±10
2
4.75
4.74
0.05
0.10
–32
19
0.4
V
DD
= 4.75V, I
O
= –10µA
V
DD
= 4.75V, I
O
= –200µA
V
DD
= 4.75V, I
O
= 160µA
V
DD
= 4.75V, I
O
= 1.6mA
SDO = 0V
SDO = V
DD
CS/CONV = High, SDO = 0V or V
DD
CS/CONV = High (Note 10)
Unipolar
Bipolar
q
q
4
V
V
mA
mA
q
q
±10
15
Straight Binary
Two’s Complement
µA
pF
18637f
3
LTC1863/LTC1867
POWER REQUIRE E TS
SYMBOL
V
DD
I
DD
PARAMETER
Supply Voltage
Supply Current
The
q
denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. (Note 5)
CONDITIONS
(Note 9)
f
SAMPLE
= 200ksps
NAP Mode
SLEEP Mode
q
q
q
P
DISS
Power Dissipation
The
q
denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. (Note 5)
SYMBOL
f
SAMPLE
t
CONV
t
ACQ
f
SCK
t
1
t
2
t
3
t
4
t
5
t
6
t
7
t
8
PARAMETER
Maximum Sampling Frequency
Conversion Time
Acquisition Time
SCK Frequency
CS/CONV High Time
SDO Valid After SCK↓
SDO Valid Hold Time After SCK↓
SDO Valid After CS/CONV↓
SDI Setup Time Before SCK↑
SDI Hold Time After SCK↑
SLEEP Mode Wake-Up Time
Bus Relinquish Time After CS/CONV↑
C
REFCOMP
= 10µF, C
VREF
= 2.2µF
C
L
= 25pF
q
TI I G CHARACTERISTICS
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 (unless otherwise
noted).
Note 3:
When these pin voltages are taken below GND or above V
DD
, they
will be clamped by internal diodes. This product can handle input currents
of greater than 100mA without latchup.
Note 4:
When these pin voltages are taken below GND, they will be
clamped by internal diodes. This product can handle input currents of
greater than 100mA below GND without latchup. These pins are not
clamped to V
DD
.
Note 5:
V
DD
= 5V, f
SAMPLE
= 200ksps at 25°C, t
r
= t
f
= 5ns and
V
IN
– = 2.5V for bipolar mode unless otherwise specified.
4
U W
LTC1863/LTC1867/LTC1867A
MIN
TYP
MAX
4.75
1.3
150
0.2
6.5
5.25
1.8
3
9
UNITS
V
mA
µA
µA
mW
UW
CONDITIONS
q
q
q
LTC1863/LTC1867/LTC1867A
MIN
TYP
MAX
200
3
1.5
40
5
15
10
1.1
40
100
13
11
10
–6
4
60
20
40
30
22
3.5
UNITS
kHz
µs
µs
MHz
ns
ns
ns
ns
ns
ns
ms
ns
Short CS/CONV Pulse Mode
C
L
= 25pF (Note 11)
C
L
= 25pF
C
L
= 25pF
q
q
q
q
q
q
Note 6:
Linearity, offset and gain error specifications apply for both
unipolar and bipolar modes. The INL and DNL are tested in bipolar mode.
Note 7:
Integral nonlinearity is defined as the 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 8:
Unipolar offset is the offset voltage measured from +1/2LSB
when the output code flickers between 0000 0000 0000 0000 and
0000 0000 0000 0001 for LTC1867 and between 0000 0000 0000 and
0000 0000 0001 for LTC1863. Bipolar offset is the offset voltage
measured from –1/2LSB when output code flickers between 0000 0000
0000 0000 and 1111 1111 1111 1111 for LTC1867, and between
0000 0000 0000 and 1111 1111 1111 for LTC1863.
Note 9:
Recommended operating conditions. The input range of
±2.048V
for bipolar mode is measured with respect to V
IN
– = 2.5V.
Note 10:
Guaranteed by design, not subject to test.
Note 11:
t
2
of 25ns maximum allows f
SCK
up to 20MHz for rising capture
with 50% duty cycle and f
SCK
up to 40MHz for falling capture (with 3ns
setup time for the receiving logic).
18637f
LTC1863/LTC1867
TYPICAL PERFOR A CE CHARACTERISTICS
Integral Nonlinearity vs
Output Code
2.0
1.5
1.0
DNL (LSB)
INL (LSB)
0.5
0
– 0.5
– 1.0
– 1.5
– 2.0
0
16384
32768
49152
OUTPUT CODE
65536
18637 GO1
0
– 0.5
– 1.0
COUNTS
4096 Points FFT Plot (f
IN
= 1kHz)
0
–20
–40
AMPLITUDE (dB)
–60
–80
–100
–120
–140
0
25
50
FREQUENCY (kHz)
18637 G04
–40
AMPLITUDE (dB)
–60
–80
–100
–120
–140
RESULTING AMPLITUDE ON
SELECTED CHANNEL (dB)
SNR = 88.8dB
SINAD = 87.9dB
THD = 95dB
f
SAMPLE
= 200ksps
INTERNAL REFERENCE
75
Signal-to-Noise Ratio vs
Frequency
100
90
80
AMPLITUDE (dB)
AMPLITUDE (dB)
70
60
50
40
30
20
1
10
INPUT FREQUENCY (kHz)
100
18637 G07
70
60
50
40
30
20
1
10
INPUT FREQUENCY (kHz)
100
18637 G08
AMPLITUDE (dB)
U W
(LTC1867)
Differential Nonlinearity vs
Output Code
2.0
1.5
1.0
0.5
2000
2500
Histogram for 4096 Conversions
2152
1500
1000
935
579
500
– 1.5
– 2.0
0
16384
32768
49152
OUTPUT CODE
65536
18637 GO2
276
0
1
26
–2
–1
0
CODE
18637 GO3
122
1
2
5
3
0
4
–4 –3
4096 Points FFT Plot (f
IN
= 1kHz,
REFCOMP = External 5V)
0
–20
SNR = 90dB
SINAD = 88.5dB
THD = 94dB
f
SAMPLE
= 200ksps
V
REF
= 0V
REFCOMP = EXT 5V
–80
–90
–100
–110
–120
Crosstalk vs Input Frequency
ADJACENT PAIR
NONADJACENT PAIR
–130
–140
100
0
25
50
FREQUENCY (kHz)
75
100
18637 G05
1
10
100
1000
ACTIVE CHANNEL INPUT FREQUENCY (kHz)
18637 G06
Signal-to-(Noise + Distortion) vs
Input Frequency
100
90
80
–20
–30
–40
–50
–60
–70
–80
–90
–100
Total Harmonic Distortion vs
Input Frequency
1
10
INPUT FREQUENCY (kHz)
100
18637 G09
18637f
5
