LINEAR TECHNOLOGY LTC1864, LTC1865 Technical data
查询LTC1864ACMS8供应商
FEATURES
LTC1864/LTC1865
µPower, 16-Bit, 250ksps
1- and 2-Channel ADCs in MSOP
U
DESCRIPTIO
■
16-Bit 250ksps ADCs in MSOP Package
■
Single 5V Supply
■
Low Supply Current: 850µA (Typ)
■
Auto Shutdown Reduces Supply Current
to 2µA at 1ksps
■
True Differential Inputs
■
1-Channel (LTC1864) or 2-Channel (LTC1865)
Versions
■
SPI/MICROWIRETM Compatible Serial I/O
■
16-Bit Upgrade to 12-Bit LTC1286/LTC1298
■
Pin Compatible with 12-Bit LTC1860/LTC1861
U
APPLICATIO S
■
High Speed Data Acquisition
■
Portable or Compact Instrumentation
■
Low Power Battery-Operated Instrumentation
■
Isolated and/or Remote Data Acquisition
The LTC®1864/LTC1865 are 16-bit A/D converters that are
offered in MSOP and SO-8 packages and operate on a
single 5V supply. At 250ksps, the supply current is only
850µA. The supply current drops at lower speeds because
the LTC1864/LTC1865 automatically power down
between conversions. These 16-bit switched capacitor
successive approximation ADCs include sample-and-holds.
The LTC1864 has a differential analog input with an
adjustable reference pin. The LTC1865 offers a softwareselectable 2-channel MUX and an adjustable 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.
TYPICAL APPLICATIO
Single 5V Supply, 250ksps, 16-Bit Sampling ADC
1µF
LTC1864
ANALOG INPUT
0V TO 5V
1
V
REF
2
+
IN
3
–
IN
4
GND
V
SCK
SDO
CONV
8
CC
7
6
5
1864 TA01
U
5V
SERIAL DATA LINK TO
ASIC, PLD, MPU, DSP
OR SHIFT REGISTERS
Supply Current vs Sampling Frequency
1000
100
10
1
SUPPLY CURRENT (µA)
0.1
0.01
0.01
0.1
SAMPLING FREQUENCY (kHz)
10
1
100
1864 TA02
1000
sn18645 18645fs
1
LTC1864/LTC1865
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
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
WWWU
ABSOLUTE AXI U RATI GS
Supply Voltage (VCC) ................................................. 7V
Ground Voltage Difference
AGND, DGND LTC1865 MSOP Package ........... ±0.3V
Analog Input ............... (GND – 0.3V) to (V
Digital Input ................................ (GND – 0.3V) to 7V
Digital Output .............. (GND – 0.3V) to (V
Power Dissipation.............................................. 400mW
CC
CC
(Notes 1, 2)
+ 0.3V)
+ 0.3V)
Operating Temperature Range
LTC1864C/LTC1865C/
LTC1864AC/LTC1865AC ........................ 0°C to 70°C
LTC1864I/LTC1865I/
LTC1864AI/LTC1865AI ..................... –40°C to 85°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
UU
W
PACKAGE/ORDER I FOR ATIO
ORDER PART
TOP VIEW
V
1
REF
+
2
IN
3
IN¯
4
GND
MS8 PACKAGE
8-LEAD PLASTIC MSOP
= 150°C, θJA = 210°C/W
T
JMAX
TOP VIEW
1
V
REF
+
2
IN
–
3
IN
4
GND
S8 PACKAGE
8-LEAD PLASTIC SO
T
= 150°C, θJA = 175°C/W
JMAX
Consult LTC Marketing for parts specified with wider operating temperature ranges.
8
7
6
5
8
7
6
5
V
CC
SCK
SDO
CONV
V
SCK
SDO
CONV
CC
NUMBER
LTC1864CMS8
LTC1864IMS8
LTC1864ACMS8
LTC1864AIMS8
MS8 PART MARKING
LTHQ
ORDER PART
NUMBER
LTC1864CS8
LTC1864IS8
LTC1864ACS8
LTC1864AIS8
S8 PART MARKING
1864
1864I
1864A
1864AI
T
= 150°C, θJA = 210°C/W
JMAX
T
= 150°C, θJA = 175°C/W
JMAX
ORDER PART
NUMBER
LTC1865CMS
LTC1865IMS
LTC1865ACMS
LTC1865AIMS
MS PART MARKING
LTHS
ORDER PART
NUMBER
LTC1865CS8
LTC1865IS8
LTC1865ACS8
LTC1865AIS8
S8 PART MARKING
1865
1865I
1865A
1865AI
W
U
U
CO VERTER A D ULTIPLEXER CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25°C.
VCC = 5V, V
PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS
Resolution ● 16 16 Bits
No Missing Codes Resolution ● 14 15 Bits
INL (Note 3) ● ±8 ±6 LSB
Transition Noise 1.1 1.1 LSB
Gain Error ● ±20 ±20 mV
2
REF
= 5V, f
SCK
= f
SCK(MAX)
as defined in Recommended Operating Conditions, unless otherwise noted.
LTC1864/LTC1865 LTC1864A/LTC1865A
RMS
sn18645 18645fs
LTC1864/LTC1865
W
U
U
CO VERTER A D ULTIPLEXER CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25°C.
VCC = 5V, V
PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS
Offset Error LTC1864 SO-8 and MSOP, LTC1865 MSOP ● ±2 ±5 ±2 ±5mV
Input Differential Voltage Range VIN = IN+ – IN
Absolute Input Range IN+ Input –0.05 VCC + 0.05 –0.05 VCC + 0.05 V
V
Input Range LTC1864 SO-8 and MSOP, 1 V
REF
Analog Input Leakage Current (Note 4) ● ±1 ±1 µA
CIN Input Capacitance In Sample Mode 12 12 pF
U
REF
= 5V, f
W
SCK
= f
SCK(MAX)
as defined in Recommended Operating Conditions, unless otherwise noted.
LTC1864/LTC1865 LTC1864A/LTC1865A
LTC1865 SO-8 ● ±3 ±7 ±3 ±7mV
–
–
Input –0.05 VCC/2 – 0.05 VCC/2 V
IN
LTC1865 MSOP
During Conversion 5 5 pF
● 0V
REF
CC
0V
1VCCV
REF
V
DY A IC ACCURACY
TA = 25°C. VCC = 5V, V
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
SNR Signal-to-Noise Ratio 87 dB
S/(N + D) Signal-to-Noise Plus Distortion Ratio 10kHz Input Signal 83 dB
THD Total Hamonic Distortion Up to 5th Harmonic 10kHz Input Signal 88 dB
Full Power Bandwidth 20 MHz
Full Linear Bandwidth S/(N + D) ≥ 75dB 125 kHz
REF
= 5V, f
= 250kHz, unless otherwise noted.
SAMPLE
100kHz Input Signal 76 dB
100kHz Input Signal 77 dB
LTC1864/LTC1865
U
DIGITAL A D DC ELECTRICAL CHARACTERISTICS
over the full operating temperature range, otherwise specifications are TA = 25°C. VCC = 5V, V
SYMBOL PARAMETER CONDITION MIN TYP MAX UNITS
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 VCC = 5.25V ● 2.4 V
Low Level Input Voltage VCC = 4.75V ● 0.8 V
High Level Input Current VIN = V
Low Level Input Current VIN = 0V ● –2.5 µA
High Level Output Voltage VCC = 4.75V, IO = 10µA ● 4.5 4.74 V
Low Level Output Voltage VCC = 4.75V, IO = 1.6mA ● 0.4 V
Hi-Z Output Leakage CONV = V
Output Source Current V
Output Sink Current V
Reference Current (LTC1864 SO-8 and CONV = V
MSOP, LTC1865 MSOP) f
Supply Current CONV = V
Power Dissipation f
CC
= 4.75V, IO = 360µA ● 2.4 4.72 V
V
CC
CC
= 0V –25 mA
OUT
= V
OUT
CC
CC
= f
SMPL
SMPL(MAX)
After Conversion ● 0.001 3 µA
CC
= f
f
SMPL
SMPL(MAX)
= f
SMPL
SMPL(MAX)
The ● denotes specifications which apply
= 5V, unless otherwise noted.
REF
LTC1864/LTC1865
● 2.5 µA
● ±3 µA
20 mA
● 0.001 3 µA
● 0.05 0.1 mA
● 0.85 1.3 mA
4.25 mW
sn18645 18645fs
3
LTC1864/LTC1865
UUUUWW
RECO E DED OPERATI G CO DITIO S
SCK(MAX)
SCK(MAX)
= 25°C.
A
full operating temperature range, otherwise specifications are T
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
CC
f
SCK
t
CYC
t
SMPL
t
suCONV
t
hDI
t
suDI
t
WHCLK
t
WLCLK
t
WHCONV
t
WLCONV
t
hCONV
Supply Voltage 4.75 5.25 V
Clock Frequency ● DC 20 MHz
Total Cycle Time 16 • SCK + t
Analog Input Sampling Time LTC1864 16 SCK
LTC1865 14 SCK
Setup Time CONV↓ Before First SCK↑ 30 ns
(See Figure 1)
Hold Time SDI After SCK↑ LTC1865 15 ns
Setup Time SDI Stable Before SCK↑ LTC1865 15 ns
SCK High Time f
SCK Low Time f
CONV High Time Between Data t
Transfer Cycles
CONV Low Time During Data Transfer 16 SCK
Hold Time CONV Low After Last SCK↑ 13 ns
SCK
SCK
= f
= f
The ● denotes specifications which apply over the
LTC1864/LTC1865
CONV
40% 1/f
40% 1/f
CONV
µs
SCK
SCK
µs
UW
TI I G CHARACTERISTICS
range, otherwise specifications are TA = 25°C. VCC = 5V, V
Conditions, unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
t
CONV
f
SMPL(MAX)
t
dDO
t
dis
t
en
t
hDO
t
r
t
f
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.
Conversion Time (See Figure 1) ● 2.75 3.2 µs
Maximum Sampling Frequency ● 250 kHz
Delay Time, SCK↓ to SDO Data Valid C
Delay Time, CONV↑ to SDO Hi-Z ● 30 60 ns
Delay Time, CONV↓ to SDO Enabled C
Time Output Data Remains C
Valid After SCK↓
SDO Rise Time C
SDO Fall Time C
The ● denotes specifications which apply over the full operating temperature
= 5V, f
REF
= 20pF 15 20 ns
LOAD
= 20pF ● 30 60 ns
LOAD
= 20pF ● 510 ns
LOAD
= 20pF 8 ns
LOAD
= 20pF 4 ns
LOAD
= f
SCK
SCK(MAX)
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.
as defined in Recommended Operating
LTC1864/LTC1865
● 25 ns
4
sn18645 18645fs
UW
V
REF
(V)
0
REFERENCE CURRENT (µA)
60
50
40
30
20
10
0
1234
1864/65 G06
5
V
CC
= 5V
T
A
= 25°C
f
S
= 250kHz
TEMPERATURE (°C)
–50
ANALOG INPUT LEAKAGE (nA)
100
1864/65 G09
050
100
75
50
25
0
–25 25 75 125
VCC = 5V
V
REF
= 5V
CONV = 0V
TYPICAL PERFOR A CE CHARACTERISTICS
Supply Current vs Sampling
1000
SUPPLY CURRENT (µA)
0.01
100
10
1
0.1
0.01
Frequency
VCC = 5V
= 25°C
T
A
CONV LOW = 800ns
0.1
1.0
SAMPLING FREQUENCY (kHz)
10
100
1000
1864/65 G01
Supply Current vs Temperature
1000
800
600
400
SUPPLY CURRENT (µA)
200
0
–50
0
–25
TEMPERATURE (°C)
VCC = 5V
V
REF
f
SAMPLE
CONV HIGH = 3.2µS
50
25
= 5V
= 250kHz
75
100
1864/65 G02
125
LTC1864/LTC1865
Sleep Current vs Temperature
1000
CONV = V
900
800
700
600
500
400
300
SLEEP CURRENT (nA)
200
100
0
–50
= 5V
CC
0
–25
TEMPERATURE (°C)
50
25
75
100
125
1864/65 G03
Reference Current vs
Sampling Rate
60
VCC = 5V
= 25°C
T
A
50
= 5V
V
REF
CONV LOW = 800ns
40
30
20
REFERENCE CURRENT (µA)
10
0
0
50 100 150 200
SAMPLE RATE (kHz)
Typical INL Curve
4
VCC = 5V
= 25°C
T
A
= 5V
V
REF
2
1864/65 G04
250
Reference Current vs
Temperature
55
V
= 5V
CC
54
= 5V
V
REF
= 250kHz
f
S
53
52
51
50
49
48
REFERENCE CURRENT (µA)
47
46
45
–50
0
–25
TEMPERATURE (°C)
Typical DNL Curve
2
VCC = 5V
= 25°C
T
A
= 5V
V
REF
1
Reference Current vs
Reference Voltage
50
25
75
100
1864/65 G05
125
Analog Input Leakage Current vs
Temperature
0
INL ERROR (LSBs)
–2
–4
0
0
DNL ERROR (LSBs)
–1
16384
32768
CODE
49152
65536
1864/65 G07
–2
0 65536
3276816384
CODE
49152
1864/65 G08
sn18645 18645fs
5
LTC1864/LTC1865
UW
TYPICAL PERFOR A CE CHARACTERISTICS
Change in Offset Error vs
Reference Voltage
75
50
25
0
CHANGE IN OFFSET ERROR (LSB)
–25
1
0
2
REFERENCE VOLTAGE (V)
Change in Gain Error vs
Temperature
5
VCC = 5V
4
= 5V
V
REF
3
2
1
0
–1
–2
–3
CHANGE IN GAIN ERROR (LSB)
–4
–5
–50
–25
25
0
TEMPERATURE (°C)
Change in Gain Error vs
Change in Offset vs Temperature
5
VCC = 5V
= 25°C
T
A
3
4
5
1864/65 G10
VCC = 5V
4
= 5V
V
REF
3
2
1
0
–1
–2
CHANGE IN OFFSET (LSB)
–3
–4
–5
–50
–25
0
TEMPERATURE (°C)
50
25
75
100
1864/65 G11
125
Reference Voltage
20
VCC = 5V
= 25°C
T
15
A
10
5
0
–5
–10
CHANGE IN GAIN ERROR (LSB)
–15
–20
0
2
1
REFERENCE VOLTAGE(V)
4
3
5
1864/65 G12
Histogram of 4096 Conversions
of a DC Input Voltage
1800
127
729
1534
0
1178
1
CODE
1600
1400
1200
1000
800
FREQUENCY
600
400
200
00 1200
50
75
100
1864/65 G13
125
0
–4 –3 –2 –1
VCC = 5V
= 25°C
T
A
= 5V
V
REF
516
2345
1864/65 G14
4096 Point FFT Nonaveraged
0
fS = 203.125kHz
= 99.72763kHz
f
IN
–20
= 5V
V
CC
= 5V
V
REF
–40
= 25°C
T
A
–60
–80
AMPLITUDE (dB)
–100
–120
–140
0
40 60 80 100 120
20
FREQUENCY (kHz)
1864/65 G15
SINAD vs Frequency
100
90
80
70
60
50
SINAD (dB)
40
30
20
10
0
1
6
SNR
SINAD
VCC = 5V
= 5V
V
REF
= 25°C
T
A
= 0dB
V
IN
10 100 1000
FIN (kHz)
1864/5 G16
THD vs Frequency
0
–10
–20
–30
–40
–50
THD (dB)
–60
–70
–80
–90
–100
1
VCC = 5V
= 5V
V
REF
= 25°C
T
A
= 0dB
V
IN
10 100 1000
FIN (kHz)
1864/5 G17
SFDR vs Frequency
100
90
80
70
60
50
SFDR (dB)
40
30
20
10
0
1
VCC = 5V
= 5V
V
REF
= 25°C
T
A
= 0dB
V
IN
10 100 1000
FIN (kHz)
1864/5 G18
sn18645 18645fs
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