LTC1418
Low Power, 14-Bit, 200ksps
ADC with Serial and Parallel I/O
FEATURES
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DESCRIPTION
The
LTC
®
1418
is a low power, 200ksps, 14-bit A/D con-
verter. Data output is selectable for 14-bit parallel or serial
format. This versatile device can operate from a single 5V
or ±5V supply. An onboard high performance sample-and-
hold, a precision reference and internal timing minimize
external circuitry requirements. The low 15mW power
dissipation is made even more attractive with two user
selectable power shutdown modes.
The LTC1418 converts 0V to 4.096V unipolar inputs from
a single 5V supply and ±2.048V bipolar inputs from ±5V
supplies. DC specs include ±1.25LSB INL, ±1LSB DNL
and no missing codes over temperature. Outstanding AC
performance includes 82dB S/(N + D) and 94dB THD at
the Nyquist input frequency of 100kHz.
The flexible output format allows either parallel or serial
I/O. The SPI/MICROWIRE compatible serial I/O port can
operate as either master or slave and can support clock
frequencies from DC to 10MHz. A separate convert start
input and a data ready signal (BUSY) allow easy control
of conversion start and data transfer.
L,
LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
Single Supply 5V or ±5V Operation
Sample Rate: 200ksps
±1.25LSB INL and ±1LSB DNL Max
Power Dissipation: 15mW (Typ)
Parallel or Serial Data Output
No Missing Codes Over Temperature
Power Shutdown: Nap and Sleep
External or Internal Reference
Differential High Impedance Analog Input
Input Range: 0V to 4.096V or ±2.048V
81.5dB S/(N + D) and –94dB THD at Nyquist
28-Lead SSOP Package
APPLICATIONS
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Remote Data Acquisition
Battery Operated Systems
Digital Signal Processing
Isolated Data Acquisition Systems
Audio and Telecom Processing
Medical Instrumentation
TYPICAL APPLICATION
Low Power, 200kHz, 14-Bit Sampling A/D Converter
5V
10 F
V
DD
LTC1418
A
IN
+
Typical INL Curve
1.0
SER/PAR
D13
0.5
INL (LSBs)
A
IN–
S/H
14-BIT ADC
14
REFCOMP
10 F
4.096V
BUFFER
SELECTABLE
SERIAL/
PARALLEL
PORT
D5
D4 (EXTCLKIN)
D3 (SCLK)
D2 (CLKOUT)
D1 (D
OUT
)
D0 (EXT/INT)
BUSY
CS
RD
CONVST
SHDN
1418 TA01
0
–0.5
V
REF
1 F
8k
2.5V
REFERENCE
TIMING AND
LOGIC
–1.0
0
4096
8192
OUTPUT CODE
12288
16384
1418 TA02
AGND
V
SS
(0V OR – 5V)
DGND
1418fa
For more information
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1
LTC1418
ABSOLUTE MAXIMUM RATINGS
(Note 1, 2)
PACKAGE/ORDER INFORMATION
TOP VIEW
A
IN+
A
IN –
V
REF
REFCOMP
AGND
D13 (MSB)
D12
D11
D10
1
2
3
4
5
6
7
8
9
28 V
DD
27 V
SS
26
BUSY
25
CS
24
CONVST
23
RD
22
SHDN
21 SER/PAR
20 D0 (EXT/INT)
19 D1 (D
OUT
)
18 D2 (CLKOUT)
17 D3 (SCLK)
16 D4 (EXTCLKIN)
15 D5
OBSOLETE PACKAGE
N PACKAGE
28-LEAD NARROW PDIP
Supply Voltage (V
DD
) .................................................6V
Negative Supply Voltage (V
SS
)
Bipolar Operation Only ............................. –6V to GND
Total Supply Voltage (V
DD
to V
SS
)
Bipolar Operation Only ......................................... 12V
Analog Input Voltage (Note 3)
Unipolar Operation ................... –0.3V to (V
DD
+ 0.3V)
Bipolar Operation ...........(V
SS
– 0.3V) to (V
DD
+ 0.3V)
Digital Input Voltage (Note 4)
Unipolar Operation ................................. –0.3V to 10V
Bipolar Operation .........................(V
SS
– 0.3V) to 10V
Digital Output Voltage
Unipolar Operation ................... –0.3V to (V
DD
+ 0.3V)
Bipolar Operation ...........(V
SS
– 0.3V) to (V
DD
+ 0.3V)
Power Dissipation .............................................. 500mW
Operation Temperature Range
LTC1418C ................................................. 0°C to 70°C
LTC1418I ..............................................–40°C to 85°C
Storage Temperature Range .................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec)................... 300°C
D9 10
D8 11
D7 12
D6 13
DGND 14
G PACKAGE
28-LEAD PLASTIC SSOP
T
JMAX
= 110°C,
θ
JA
= 95°C/W (G)
T
JMAX
= 110°C,
θ
JA
= 100°C/W (N)
ORDER INFORMATION
LEAD FREE FINISH
LTC1418ACG#PBF
LTC1418CG#PBF
LTC1418AIG#PBF
LTC1418IG#PBF
LTC1418ACN#PBF
LTC1418CN#PBF
LTC1418AIN#PBF
LTC1418IN#PBF
TAPE AND REEL
LTC1418ACG#TRPBF
LTC1418CG#TRPBF
LTC1418AIG#TRPBF
LTC1418IG#TRPBF
LTC1418ACN#TRPBF
LTC1418CN#TRPBF
LTC1418AIN#TRPBF
LTC1418IN#TRPBF
PART MARKING
1418ACG
1418CG
1418AIG
1418IG
1418ACN
1418CN
1418AIN
1418IN
PACKAGE DESCRIPTION
28-Lead Plastic SSOP
28-Lead Plastic SSOP
28-Lead Plastic SSOP
28-Lead Plastic SSOP
OBSOLETE PACKAGE
28-Lead PDIP
28-Lead PDIP
28-Lead PDIP
28-Lead PDIP
0°C to 70°C
0°C to 70°C
–40°C to 85°C
–40°C to 85°C
TEMPERATURE RANGE
0°C to 70°C
0°C to 70°C
–40°C to 85°C
–40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on nonstandard 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/
2
1418fa
For more information
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LTC1418
temperature range, otherwise specifications are at T
A
= 25°C. (Notes 5, 6)
PARAMETER
Resolution (No Missing Codes)
Integral Linearity Error
Differential Linearity Error
Offset Error
Full-Scale Error
Full-Scale Tempco
(Note 8)
Internal Reference
External Reference = 2.5V
I
OUT(REF)
= 0, Internal Reference, Commercial
I
OUT(REF)
= 0, Internal Reference, Industrial
I
OUT(REF)
= 0, External Reference
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CONVERTER CHARACTERISTICS
The
l
denotes the specifications which apply over the full operating
LTC1418
CONDITIONS
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LTC1418A
MAX
±2
±1.5
±20
±60
±30
MIN
14
TYP
±0.5
±0.35
±2
±20
±5
±10
±20
±1
MAX
±1.25
±1
±10
±60
±15
±45
UNITS
Bits
LSB
LSB
LSB
LSB
LSB
ppm/°C
ppm/°C
ppm/°C
MIN
13
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TYP
±0.8
±0.7
±5
±10
±5
±15
±5
(Note 7)
The
l
denotes the specifications which apply over the full operating temperature range, otherwise
specifications are at T
A
= 25°C. (Note 5)
SYMBOL PARAMETER
V
IN
I
IN
C
IN
t
ACQ
Analog Input Range (Note 9)
Analog Input Leakage Current
Analog Input Capacitance
Sample-and-Hold Acquisition Time
CONDITIONS
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4.75V ≤ V
DD
≤ 5.25V (Unipolar)
4.75V ≤ V
DD
≤ 5.25V, –5.25V ≤ V
SS
≤ –4.75V (Bipolar)
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ANALOG INPUT
MIN
TYP
0 to 4.096
±2.048
MAX
UNITS
V
V
CS
= High
Between Conversions (Sample Mode)
During Conversions (Hold Mode)
Commercial
Industrial
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±1
25
5
µA
pF
pF
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300
300
1000
1000
ns
ns
DYNAMIC ACCURACY
The
l
denotes the specifications which apply over the full operating temperature range,
otherwise specifications are at T
A
= 25°C. (Note 5)
PARAMETER
Signal-to-Noise Plus Distortion Ratio
Total Harmonic Distortion
Spurious Free Dynamic Range
Intermodulation Distortion
Full Power Bandwidth
Full Linear Bandwidth
S/(N + D) ≥ 77dB
SYMBOL
S/(N + D)
THD
SFDR
IMD
CONDITIONS
97.5kHz Input Signal
100kHz Input Signal, First 5 Harmonics
100kHz Input Signal
f
IN1
= 97.7kHz, f
IN2
= 104.2kHz
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MIN
79
86
TYP
81.5
–94
95
–90
5
0.5
MAX
–86
UNITS
dB
dB
dB
dB
MHz
MHz
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3
LTC1418
INTERNAL REFERENCE CHARACTERISTICS
PARAMETER
V
REF
Output Voltage
V
REF
Output Tempco
V
REF
Line Regulation
V
REF
Output Resistance
CONDITIONS
I
OUT
= 0
I
OUT
= 0, Commercial
I
OUT
= 0, Industrial
4.75V ≤ V
DD
≤ 5.25V
–5.25V ≤ V
SS
≤ –4.75V
0.1mA ≤ | I
OUT
| ≤ 0.1mA
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The
l
denotes the specifications which apply over the
full operating temperature range, otherwise specifications are at T
A
= 25°C. (Note 5)
MIN
2.480
TYP
2.500
±10
±20
0.05
0.05
8
MAX
2.520
±45
UNITS
V
ppm/°C
ppm/°C
LSB/V
LSB/V
kΩ
DIGITAL INPUTS AND OUTPUTS
SYMBOL
V
IH
V
IL
I
IN
C
IN
V
OH
V
OL
I
OZ
C
OZ
I
SOURCE
I
SINK
PARAMETER
High Level Input Voltage
Low Level Input Voltage
Digital Input Current
Digital Input Capacitance
High Level Output Voltage
Low Level Output Voltage
Hi-Z Output Leakage D13 to D0
Hi-Z Output Capacitance D13 to D0
Output Source Current
Output Sink Current
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Note 5)
CONDITIONS
V
DD
= 5.25V
V
DD
= 4.75V
V
IN
= 0V to V
DD
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
V
OUT
= 0V to V
DD
,
CS
High
CS
High (Note 9)
V
OUT
= 0V
V
OUT
= V
DD
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MIN
2.4
TYP
MAX
0.8
±10
UNITS
V
V
µA
pF
V
V
1.4
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4.0
4.74
0.05
0.10
0.4
±10
15
V
V
µA
pF
mA
mA
–10
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POWER REQUIREMENTS
SYMBOL
V
DD
V
SS
I
DD
PARAMETER
Positive Supply Voltage (Notes 10, 11)
Negative Supply Voltage (Note 10)
Positive Supply Current
Nap Mode
Sleep Mode
I
SS
Negative Supply Current
Nap Mode
Sleep Mode
The
l
denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. (Note 5)
CONDITIONS
Bipolar Only (V
SS
= 0V for Unipolar)
Unipolar,
RD
High (Note 5 )
Bipolar,
RD
High (Note 5)
SHDN
= 0V,
CS
= 0V (Note 12)
SHDN
= 0V,
CS
= 5V (Note 12)
Bipolar,
RD
High (Note 5)
SHDN
= 0V,
CS
= 0V (Note 12)
SHDN
= 0V,
CS
= 5V (Note 12)
Unipolar
Bipolar
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MIN
4.75
–4.75
TYP
MAX
5.25
–5.25
UNITS
V
V
mA
µA
µA
mA
µA
µA
mW
mW
3.0
3.9
570
2
1.4
0.1
0.1
15.0
26.5
4.3
4.5
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1.8
P
DIS
Power Dissipation
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21.5
31.5
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LTC1418
TIMING CHARACTERISTICS
SYMBOL
f
SAMPLE(MAX)
t
CONV
t
ACQ
t
ACQ
+ t
CONV
t
1
t
2
t
3
t
4
t
5
t
6
t
7
t
8
t
9
t
10
PARAMETER
Maximum Sampling Frequency
Conversion Time
Acquisition Time
Acquisition Plus Conversion Time
CS
to
RD
Setup Time
CS↓
to CONVST↓ Setup Time
CS↓
to SHDN↓ Setup Time to Ensure Nap Mode
SHDN↑
to
CONVST↓
Wake-Up Time from Nap Mode
CONVST
Low Time
CONVST
to
BUSY
Delay
Data Ready Before
BUSY↑
Delay Between Conversions
Wait Time
RD↓
After
BUSY↑
Data Access Time After
RD↓
The
l
denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. (Note 5)
CONDITIONS
l
l
l
l
MIN
200
TYP
3.4
0.3
3.7
MAX
4
1
5
UNITS
kHz
µs
µs
µs
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
MHz
MHz
µs
ns
ns
ns
ns
(Notes 9, 10)
(Notes 9, 10)
(Notes 9, 10)
(Note 10)
(Notes 10, 11)
C
L
= 25pF
l
l
l
0
40
40
500
40
20
15
500
–5
35
35
70
l
l
l
(Note 10)
C
L
= 25pF
l
l
l
15
20
l
C
L
= 100pF
t
11
Bus Relinquish Time
Commercial
Industrial
t
12
t
13
t
14
t
15
f
SCLK
f
EXTCLKIN
t
dEXTCLKIN
t
H SCLK
t
L SCLK
t
H EXTCLKIN
t
L EXTCLKIN
RD
Low Time
CONVST
High Time
Delay Time,
SCLK↓
to D
OUT
Valid
Time from Previous Data Remain Valid After SCLK↓
Shift Clock Frequency
External Conversion Clock Frequency
Delay Time,
CONVST↓
to External Conversion Clock Input
SCLK High Time
SCLK Low Time
EXTCLKIN High Time
EXTCLKIN Low Time
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l
l
8
30
40
40
55
20
25
30
t
10
40
15
0
0.03
10
20
250
250
35
25
70
12.5
4.5
533
C
L
= 25pF (Note 9)
C
L
= 25pF (Note 9)
(Notes 9, 10)
(Notes 9, 10)
(Notes 9, 10)
(Notes 9, 10)
(Notes 9, 10)
(Notes 9, 10)
(Notes 9, 10)
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Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2:
All voltage values are with respect to ground with DGND and
AGND wired together (unless otherwise noted).
Note 3:
When these pin voltages are taken below V
SS
or above V
DD
, they
will be clamped by internal diodes. This product can handle input currents
greater than 100mA below V
SS
or above V
CC
without latchup.
Note 4:
When these pin voltages are taken below V
SS
they will be clamped
by internal diodes. This product can handle input currents greater than
100mA below V
SS
without latchup. These pins are not clamped to V
DD
.
Note 5:
V
DD
= 5V, V
SS
= 0V or –5V, f
SAMPLE
= 200kHz, t
r
= t
f
= 5ns unless
otherwise specified.
Note 6:
Linearity, offset and full-scale specifications apply for a single-
ended input with A
IN–
grounded.
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:
Bipolar offset is the offset voltage measured from –0.5LSB when the
output code flickers between 0000 0000 0000 00 and 1111 1111 1111 11.
Note 9:
Guaranteed by design, not subject to test.
Note 10:
Recommended operating conditions.
Note 11:
The falling edge of
CONVST
starts a conversion. If
CONVST
returns high at a critical point during the conversion, it can create small
errors. For best performance ensure that
CONVST
returns high either
within 2.1µs after the conversion starts or after
BUSY
rises.
Note 12:
Pins 16 (D4/EXTCLKIN), 17 (D3/SCLK) and 20 (DO/EXT/INT) at
0V or 5V. See Power Shutdown.
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5