LTC1416
Low Power 14-Bit, 400ksps
Sampling ADC
FEATURES
s
s
s
s
s
s
s
s
s
s
s
DESCRIPTIO
Sample Rate: 400ksps
Power Dissipation: 70mW
Guaranteed
±
1.5LSB DNL,
±
2LSB INL (Max)
80.5dB S/(N + D) and 93dB THD at 100kHz
80dB S/(N + D) and 90dB THD at Nyquist
Nap and Sleep Shutdown Modes
Operates with Internal or External Reference
True Differential Inputs Reject Common Mode Noise
15MHz Full Power Bandwidth Sampling
±2.5V
Bipolar Input Range
28-Pin SSOP Package
The LTC
®
1416 is a 2.2µs, 400ksps, 14-bit sampling A/D
converter that draws only 70mW from
±5V
supplies. This
easy-to-use device includes a high dynamic range sample-
and-hold and a precision reference. Two digitally select-
able power shutdown modes provide flexibility for low
power systems.
The LTC1416’s full-scale input range is
±2.5V.
Maximum
DC specifications include
±2LSB
INL,
±1.5LSB
DNL over
temperature. Outstanding AC performance includes 80.5dB
S/(N + D) and 93dB THD with a 100kHz input, and 80dB
S/(N + D) and 90dB THD at the Nyquist input frequency of
200kHz.
The unique differential input sample-and-hold can ac-
quire single-ended or differential input signals up to its
15MHz bandwidth. The 60dB common mode rejection
allows users to eliminate ground loops and common
mode noise by measuring signals differentially from the
source.
The ADC has a
µP
compatible, 14-bit parallel output port.
There is no pipeline delay in the conversion results. A
separate convert start input and a data ready signal
(BUSY) ease connections to FIFOs, DSPs and micropro-
cessors.
APPLICATI
s
s
s
s
s
s
S
Telecommunications
Digital Signal Processing
Multiplexed Data Acquisition Systems
High Speed Data Acquisition
Spectrum Analysis
Imaging Systems
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATI
10µF
AV
DD
DV
DD
Complete, 70mW, 14-Bit ADC with 80.5dB S/(N + D)
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
1k
Effective Bits and
Signal-to-(Noise + Distortion)
vs Input Frequency
86
80
74
68
62
SIGNAL/(NOISE + DISTORTION) (dB)
LTC1416
A
IN+
S/H
A
IN–
REFCOMP
22µF
V
REF
1µF
V
SS
10µF –5V
BUFFER
4k
2.5V
REFERENCE
TIMING
AND
LOGIC
14-BIT ADC
14
EFFECTIVE BITS
OUTPUT
BUFFERS
•
•
•
D13 (MSB)
D0 (LSB)
BUSY
CS
CONVST
RD
SHDN
f
SAMPLE
= 400kHz
10k
100k
INPUT FREQUENCY (Hz)
1M 2M
1416 TA02
AGND
DGND
1416 TA01
U
NYQUIST
FREQUENCY
UO
UO
1
LTC1416
ABSOLUTE
AXI U
RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW
A
IN+
1
A
IN–
2
28 AV
DD
27 DV
DD
26 V
SS
25 BUSY
24 CS
23 CONVST
22 RD
21 SHDN
20 D0
19 D1
18 D2
17 D3
16 D4
15 D5
AV
DD
= DV
DD
= V
DD
(Notes 1, 2)
Supply Voltage (V
DD
) ................................................ 6V
Negative Supply Voltage (V
SS
)................................ – 6V
Total Supply Voltage (V
DD
to V
SS
) .......................... 12V
Analog Input Voltage
(Note 3) ......................... (V
SS
– 0.3V) to (V
DD
+ 0.3V)
Digital Input Voltage (Note 4) ..........(V
SS
– 0.3V) to 10V
Digital Output Voltage ....... (V
SS
– 0.3V) to (V
DD
+ 0.3V)
Power Dissipation ............................................. 500mW
Operating Temperature Range
Commercial ............................................ 0°C to 70°C
Industrial ........................................... – 40°C to 85°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
ORDER
PART NUMBER
LTC1416CG
LTC1416IG
V
REF
3
REFCOMP 4
AGND 5
D13(MSB) 6
D12 7
D11 8
D10 9
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
Consult factory for Military grade parts and for A grade parts.
CO VERTER CHARACTERISTICS
PARAMETER
Resolution (No Missing Codes)
Integral Linearity Error
Differential Linearity Error
Offset Error
Full-Scale Error
Full-Scale Tempco
(Note 8)
(Note 7)
CONDITIONS
With Internal Reference (Notes 5, 6)
MIN
q
q
q
q
TYP
±0.8
±0.7
±5
±20
±10
±15
MAX
±2
±1.5
±20
±60
±40
UNITS
Bits
LSB
LSB
LSB
LSB
LSB
ppm/°C
13
Internal Reference
External Reference = 2.5V
I
OUT(REF)
= 0
A ALOG I PUT
SYMBOL PARAMETER
V
IN
I
IN
C
IN
t
ACQ
t
AP
t
jitter
CMRR
(Note 5)
CONDITIONS
4.75V
≤
V
DD
≤
5.25V, – 5.25V
≤
V
SS
≤
– 4.75V
CS = High
Between Conversions
During Conversions
(Note 9)
q
q
q
MIN
TYP
±2.5
MAX
±1
UNITS
V
µA
pF
pF
Analog Input Range (Note 9)
Analog Input Leakage Current
Analog Input Capacitance
Sample-and-Hold Acquisition Time
Sample-and-Hold Aperture Delay Time
Sample-and-Hold Aperture Delay Time Jitter
Analog Input Common Mode Rejection Ratio
15
5
100
–1.5
2
400
ps
RMS
dB
– 2.5V < (A
IN–
= A
IN+
) < 2.5V
60
2
U
ns
ns
W
U
U
W W
W
U
U
U
LTC1416
DY A IC ACCURACY
SYMBOL
S/(N + D)
THD
SFDR
IMD
PARAMETER
I TER AL REFERE CE CHARACTERISTICS
PARAMETER
V
REF
Output Voltage
V
REF
Output Tempco
V
REF
Line Regulation
V
REF
Output Resistance
COMP Output Voltage
CONDITIONS
I
OUT
= 0
I
OUT
= 0
4.75V
≤
V
DD
≤
5.25V
– 5.25V
≤
V
SS
≤
– 4.75V
– 0.1mA
≤
I
OUT
≤
0.1mA
I
OUT
= 0
DIGITAL I PUTS A D DIGITAL OUTPUTS
SYMBOL PARAMETER
V
IH
V
IL
I
IN
C
IN
V
OH
High Level Input Voltage
Low Level Input Voltage
Digital Input Current
Digital Input Capacitance
High Level Output Voltage
V
DD
= 4.75V
I
OUT
= – 10µA
I
OUT
= – 200µA
V
DD
= 4.75V
I
OUT
= 160µA
I
OUT
= 1.6mA
V
OUT
= 0V to V
DD
, CS High
CS High (Note 9 )
V
OUT
= 0V
V
OUT
= V
DD
CONDITIONS
V
DD
= 5.25V
V
DD
= 4.75V
V
IN
= 0V to V
DD
V
OL
Low Level Output Voltage
I
OZ
C
OZ
I
SOURCE
I
SINK
Hi-Z Output Leakage D13 to D0
Hi-Z Output Capacitance D13 to D0
Output Source Current
Output Sink Current
POWER REQUIRE E TS
SYMBOL PARAMETER
V
DD
V
SS
I
DD
Positive Supply Voltage
Negative Supply Voltage
Positive Supply Current
Nap Mode
Sleep Mode
Negative Supply Current
Nap Mode
Sleep Mode
I
SS
U W
U
U
U
W U
U
(Note 5)
CONDITIONS
100kHz Input Signal
200kHz Input Signal
100kHz Input Signal, First 5 Harmonics
200kHz Input Signal, First 5 Harmonics
100kHz Input Signal
f
IN1
= 87.01172kHz, f
IN2
= 113.18359kHz
(S/(N + D)
≥
77dB)
q
q
q
MIN
77
TYP
80.5
80
– 93
– 90
– 95
– 90
15
0.8
MAX
UNITS
dB
dB
Signal-to-(Noise + Distortion) Ratio
Total Harmonic Distortion
Spurious-Free Dynamic Range
Intermodulation Distortion
Full Power Bandwidth
Full Linear Bandwidth
– 86
– 86
dB
dB
dB
dB
MHz
MHz
U
(Note 5)
MIN
2.480
TYP
2.500
±15
0.05
0.05
4
4.06
MAX
2.520
UNITS
V
ppm/°C
LSB/V
LSB/V
kΩ
V
(Note 5)
MIN
q
q
q
TYP
MAX
0.8
±10
UNITS
V
V
µA
pF
V
V
V
V
µA
pF
mA
mA
2.4
5
4.5
q
4.0
0.05
0.10
q
q
q
0.4
±10
15
– 10
10
(Note 5)
CONDITIONS
(Note 10)
(Note 10)
q
MIN
4.75
– 4.75
TYP
MAX
5.25
– 5.25
UNITS
V
V
mA
mA
µA
mA
µA
µA
SHDN = 0V, CS = 0V
SHDN = 0V, CS = 5V
q
7
0.8
1
7
20
15
10
1.2
10
SHDN = 0V, CS = 0V
SHDN = 0V, CS = 5V
3
LTC1416
POWER REQUIRE E TS
SYMBOL
P
DISS
PARAMETER
Power Dissipation
Power Dissipation, Nap Mode
Power Dissipation, Sleep Mode
TI I G CHARACTERISTICS
SYMBOL
f
SAMPLE(MAX)
t
CONV
t
ACQ
t
ACQ+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 + Conversion Time
CS to RD Setup Time
CS↓ to CONVST↓ Setup Time
CS↓ to SHDN↓ Setup Time
SHDN↑ to CONVST↓ Wake-Up Time
CONVST Low Time
CONVST to BUSY Delay
Data Ready Before BUSY↑
Delay Between Conversions
Wait Time RD↓ After BUSY↑
Data Access Time After RD↓
t
11
Bus Relinquish Time
t
12
t
13
RD Low Time
CONVST High Time
The
q
denotes specifications which apply over the full operating
temperature range; all other limits and typicals at T
A
= 25°C.
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 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
DD
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
= – 5V, f
SAMPLE
= 400kHz, t
r
= t
f
= 5ns unless
otherwise specified.
4
U W
(Note 5)
CONDITIONS
q
MIN
TYP
70
4
0.1
MAX
100
6
UNITS
mW
mW
mW
SHDN = 0V, CS = 0V
SHDN = 0V, CS = 5V
UW
(Note 5, see Figures 15 to 21)
CONDITIONS
q
q
MIN
400
1.5
TYP
1.9
100
2
MAX
2.2
400
2.5
UNITS
kHz
µs
ns
µs
ns
ns
ns
(Note 9)
(Notes 9, 10)
(Notes 9, 10)
(Notes 9, 10)
(Note 10)
(Notes 10, 11)
C
L
= 25pF
q
q
q
q
q
0
10
10
400
40
25
50
75
50
40
–5
15
25
35
35
50
20
25
30
100
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
q
q
q
(Note 10)
C
L
= 25pF
q
q
q
C
L
= 100pF
q
20
8
q
q
q
q
0°C
≤
T
A
≤
70°C
– 40°C
≤
T
A
≤
85°C
t
10
40
Note 6:
Linearity, offset and full-scale specifications apply for a single-
ended A
IN+
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 CONVST edge starts a conversion. If CONVST returns
high at a critical point during the conversion it can create small errors. For
best results ensure that CONVST returns high either within 900ns after the
start of the conversion or after BUSY rises.
LTC1416
TYPICAL PERFORMANCE CHARACTERISTICS
S/(N + D) vs Input Frequency
and Amplitude
90
V
IN
= 0dB
SIGNAL-TO-NOISE RATIO (dB)
AMPLITUDE (dB BELOW THE FUNDAMENTAL)
SIGNAL/(NOISE + DISTORTION) (dB)
80
70
60
50
40
30
20
10
0
1k
10k
100k
INPUT FREQUENCY (Hz)
1M 2M
1416 G01
V
IN
= –20dB
V
IN
= –60dB
Spurious-Free Dynamic Range
vs Input Frequency
0
SPURIOUS-FREE DYNAMIC RANGE (dB)
0
–20
–40
–60
–80
–10
–20
AMPLITUDE (dB)
–30
–40
–50
–60
–70
–80
–90
1k
10k
100k
INPUT FREQUENCY (Hz)
1M 2M
1416 G04
DNL ERROR (LSB)
–100
Integral Nonlinearity
vs Output Code
1.0
0
AMPLITUDE OF
POWER SUPPLY FEEDTHROUGH (dB)
–20
–30
–40
–50
–60
–70
–80
–90
1k
DGND (V
IN
= 100mV)
V
SS
(V
IN
= 10mV)
V
DD
(V
IN
= 10mV)
10k
100k
RIPPLE FREQUENCY (Hz)
1M 2M
1416 G08
COMMON MODE REJECTION (dB)
V
OUT
=
±2.5V
V
REF
= 2.5V
0.5
INL ERROR (LSB)
0
–0.5
–1.0
0
4096
8192
OUTPUT CODE
12288
U W
1416 G07
Signal-to-Noise Ratio
vs Input Frequency
90
80
70
60
50
40
30
20
10
0
1k
10k
100k
INPUT FREQUENCY (Hz)
1M 2M
1416 G02
Distortion vs Input Frequency
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
–110
1k
10k
100k
INPUT FREQUENCY (Hz)
1M 2M
1416 G03
THD
3RD
2ND
Intermodulation Distortion Plot
1.0
f
SAMPLE
= 400kHz
f
a
=87.01171876kHz
f
b
=113.1835938kHz
Differential Nonlinearity
vs Output Code
V
OUT
=
±2.5V
V
REF
= 2.5V
0.5
0
–100
–120
–140
0 20 40 60 80 100 120 140 160 180 200
FREQUENCY (Hz)
1416 G05
–0.5
–1.0
0
4096
8192
OUTPUT CODE
12288
16384
1416 G06
Power Supply Feedthrough
vs Ripple Frequency
80
70
60
50
40
30
20
10
0
–10
Input Common Mode Rejection
vs Input Frequency
–100
16384
1k
10k
100k
INPUT FREQUENCY (Hz)
1M 2M
1416 G09
5
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