|
|
PDF LTC1419 Data sheet ( Hoja de datos )
| Número de pieza | LTC1419 | |
| Descripción | 14-Bit/ 800ksps Sampling A/D Converter with Shutdown | |
| Fabricantes | Linear Technology | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de LTC1419 (archivo pdf) en la parte inferior de esta página. Total 20 Páginas | ||
|
No Preview Available !
LTC1419
14-Bit, 800ksps Sampling
A/D Converter with Shutdown
FEATURES
■ Sample Rate: 800ksps
■ Power Dissipation: 150mW
■ 81.5dB S/(N + D) and 93dB THD
■ No Missing Codes
■ No Pipeline Delay
■ Nap and Sleep Shutdown Modes
■ Operates with 2.5V Internal 15ppm/°C
Reference or External Reference
■ True Differential Inputs Reject Common Mode Noise
■ 20MHz Full-Power Bandwidth Sampling
■ Bipolar Input Range: ±2.5V
■ 28-Pin SSOP and SO Packages
U
APPLICATIO S
■ Telecommunications
■ Digital Signal Processing
■ Multiplexed Data Acquisition Systems
■ High Speed Data Acquisition
■ Spectrum Analysis
■ Imaging Systems
DESCRIPTIO
The LTC®1419 is a 1µs, 800ksps, 14-bit sampling
A/D converter that draws only 150mW from ±5V supplies.
This easy-to-use device includes a high dynamic range
sample-and-hold and a precision reference. Two digitally
selectable power shutdown modes provide flexibility for
low power systems.
The LTC1419 has a full-scale input range of ±2.5V. Out-
standing AC performance includes 81.5dB S/(N + D) and
93dB THD with a 100kHz input; 80dB S/(N + D) and 86dB
THD at the Nyquist input frequency of 400kHz.
The unique differential input sample-and-hold can acquire
single-ended or differential input signals up to its 20MHz
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 data ready signal (BUSY)
ease connections to FIFOs, DSPs and microprocessors.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners. Protected by U.S. Patents
including 5581252.
TYPICAL APPLICATIO
VREF
OUTPUT
2.50V
1µF
800kHz, 14-Bit Sampling A/D Converter
LTC1419
5V
DIFFERENTIAL 1
28
ANALOG INPUT
(–2.5V TO 2.5V)
2
3
+AIN
–AIN
4 VREF
REFCOMP
AVDD
DVDD
VSS
BUSY
27
26
25
–5V
10µF
10µF
5 24
10µF
AGND
CS
6
D13(MSB)
7
23
CONVST
22
µP CONTROL
LINES
D12 RD
8 21
D11 SHDN
9 20
D10 D0
10 19
D9 D1
14-BIT
PARALLEL
11
D8
12
18
D2
17
BUS D7
D3
13 16
D6 D4
14 15
DGND
D5
Effective Bits and Signal-to-(Noise + Distortion)
vs Input Frequency
14
13
12
11
10
9
8
7
6
5
4
3 fSAMPLE = 800kHz
2
1k 10k
100k
INPUT FREQUENCY (Hz)
86
80
74
68
62
1M 2M
1419 TA02
1419 TA01
1419fb
1
1 page  
TYPICAL PERFORMANCE CHARACTERISTICS
LTC1419
S/(N + D) vs Input Frequency
and Amplitude
90
80 VIN = 0dB
70 VIN = –20dB
60
50
40
30
VIN = –60dB
20
10
0
1k
10k
100k
1M 2M
INPUT FREQUENCY (Hz)
1419 G01
Spurious-Free Dynamic Range
vs Input Frequency
0
–10
–20
–30
– 40
–50
– 60
–70
–80
– 90
–100
–110
10k
100k
INPUT FREQUENCY (Hz)
1M 2M
1419 G04
Integral Nonlinearity
vs Output Code
1.0
0.5
0
– 0.5
– 1.0
0
4096
8192 12288
OUTPUT CODE
16384
1419 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
1419 G02
Intermodulation Distortion Plot
0
fSAMPLE = 800kHz
fIN1 = 95.8984375kHz
– 20 fIN2 = 104.1015625kHz
– 40
– 60
– 80
– 100
– 120
0
50 100 150 200 250 300 350 400
FREQUENCY (kHz)
1419 G05
Power Supply Feedthrough
vs Ripple Frequency
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
– 100
1k
VDD VSS
DGND
10k
100k
1M 2M
RIPPLE FREQUENCY (Hz)
1419 G08
Distortion vs Input Frequency
0
–10
–20
–30
–40
–50
–60
–70
–80 THD
–90
– 100
– 110
1k
3RD
10k 100k
INPUT FREQUENCY (Hz)
2ND
1M 2M
1419 G03
Differential Nonlinearity
vs Output Code
1.0
0.5
0
– 0.5
– 1.0
0
4096
8192 12288
OUTPUT CODE
16384
1419 G06
Input Common Mode Rejection
vs Input Frequency
80
70
60
50
40
30
20
10
0
1 10 100 1000 10000
INPUT FREQUENCY (Hz)
1419 G09
1419fb
5
5 Page 
LTC1419
APPLICATIONS INFORMATION
many applications. For example, Figure 7 shows a 1000pF
capacitor from + AIN to ground and a 100Ω source resistor
to limit the input bandwidth to 1.6MHz. The 1000pF
capacitor also acts as a charge reservoir for the input
sample-and-hold and isolates the ADC input from sam-
pling glitch sensitive circuitry. High quality capacitors and
resistors should be used since these components can add
distortion. NPO and silver mica type dielectric capacitors
have excellent linearity. Carbon surface mount resistors can
also generate distortion from self heating and from damage
that may occur during soldering. Metal film surface mount
resistors are much less susceptible to both problems.
Input Range
The ±2.5V input range of the LTC1419 is optimized for low
noise and low distortion. Most op amps also perform well
over this same range, allowing direct coupling to the
analog inputs and eliminating the need for special transla-
tion circuitry.
Some applications may require other input ranges. The
LTC1419 differential inputs and reference circuitry can
accommodate other input ranges often with little or no
additional circuitry. The following sections describe the
reference and input circuitry and how they affect the input
range.
Internal Reference
The LTC1419 has an on-chip, temperature compensated,
curvature corrected, bandgap reference that is factory
trimmed to 2.500V. It is connected internally to a reference
amplifier and is available at VREF (Pin 3) see Figure 8a. A
5V
VIN
LT1019A-2.5
VOUT
+
ANALOG
INPUT
1
+AIN
2
–AIN
3
VREF
LTC1419
4
REFCOMP
10µF
0.1µF
5
AGND
1419 F08b
Figure 8b. Using the LT1019-2.5 as an External Reference
2k resistor is in series with the output so that it can be
easily overdriven by an external reference or other
circuitry, see Figure 8b. The reference amplifier gains the
voltage at the VREF pin by 1.625 to create the required
internal reference voltage. This provides buffering be-
tween the VREF pin and the high speed capacitive DAC. The
reference amplifier compensation pin (REFCOMP, Pin 4)
must be bypassed with a capacitor to ground. The refer-
ence amplifier is stable with capacitors of 1µF or greater.
For the best noise performance, a 10µF ceramic or 10µF
tantalum in parallel with a 0.1µF ceramic is recommended.
The VREF pin can be driven with a DAC or other means
shown in Figure 9. This is useful in applications where the
peak input signal amplitude may vary. The input span of
the ADC can then be adjusted to match the peak input
signal, maximizing the signal-to-noise ratio. The filtering
of the internal LTC1419 reference amplifier will limit the
bandwidth and settling time of this circuit. A settling time
of 5ms should be allowed for after a reference adjustment.
3 VREF
2.500V
R1
2k BANDGAP
REFERENCE
4.0625V
4 REFCOMP
10µF
5 AGND
REFERENCE
AMP
R2
40k
R3
64k
LTC1419
1419 F08a
Figure 8a. LTC1419 Reference Circuit
LTC1450
ANALOG INPUT
1.25V TO 3V
DIFFERENTIAL
1
+AIN
2
– AIN
LTC1419
1.25V TO 3V 3 VREF
10µF
4
REFCOMP
5
AGND
1419 F09
Figure 9. Driving VREF with a DAC
1419fb
11
11 Page | ||
| Páginas | Total 20 Páginas | |
| PDF Descargar | [ Datasheet LTC1419.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| LTC1410 | 12-Bit/ 1.25Msps Sampling A/D Converter with Shutdown | Linear Technology |
| LTC1410C | 12-Bit/ 1.25Msps Sampling A/D Converter with Shutdown | Linear Technology |
| LTC1410CG | 12-Bit/ 1.25Msps Sampling A/D Converter with Shutdown | Linear Technology |
| LTC1410CSW | 12-Bit/ 1.25Msps Sampling A/D Converter with Shutdown | Linear Technology |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |