|
|
PDF LTC1560-1IS8 Data sheet ( Hoja de datos )
| Número de pieza | LTC1560-1IS8 | |
| Descripción | 1MHz/500kHz Continuous Time/ Low Noise/ Lowpass Elliptic Filter | |
| Fabricantes | Linear Technology | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de LTC1560-1IS8 (archivo pdf) en la parte inferior de esta página. Total 8 Páginas | ||
|
No Preview Available !
LTC1560-1
1MHz/500kHz
Continuous Time,
Low Noise, Lowpass Elliptic Filter
FEATURES
s 5th Order, 1MHz Elliptic Filter in SO-8 Package
s Pin Selectable 1MHz/500kHz Cutoff Frequency
s Signal-to-Noise Ratio (SNR): 75dB
s Signal-to-Noise Ratio with – 63dB THD: 69dB
s Passband Ripple (fCUTOFF = 1MHz): ±0.3dB
s Stopband Attenuation Better Than 60dB
s No External Components Required
U
APPLICATIONS
s Antialiasing Filters
s Smoothing or Reconstruction Filters
s Communication Filters
DESCRIPTION
The LTC®1560-1 is a 5th order, continuous-time, lowpass
filter. The elliptic transfer function of the LTC1560-1 was
carefully chosen to reach a compromise between selectiv-
ity, for antialiasing applications, and transient response.
The filter cutoff frequency, fCUTOFF, is pin selectable to
either 500kHz (Pin 5 to V +) or 1MHz (Pin 5 to V –). When
programmed for 1MHz, the passband ripple is typically
±0.2dB up to 0.55fCUTOFF and ±0.3dB to 0.9fCUTOFF. The
transition band gain is – 24dB at 1.4fCUTOFF and – 51dB at
2fCUTOFF. Stopband attenuation is 63dB at 2.43fCUTOFF and
above, remaining at least 60dB to 10MHz with proper
board layout. When the LTC1560-1 is programmed for
fCUTOFF = 500kHz, the filter response closely follows the
1MHz case with the exception of passband flatness near
the cutoff frequency; the gain at fCUTOFF is – 1.3dB.
The LTC1560-1, unlike other high frequency filters, is
designed for low noise and low distortion. With a 1VRMS
input signal, the signal-to-noise ratio is 69dB and the THD
is – 63dB. The maximum SNR of 75dB is obtained with a
2.1VRMS input signal. This results in – 46dB THD.
The LTC1560-1 operates with ±5V supplies, has a power
saving mode and is available in an SO-8 surface mount
package.
Other cutoff frequencies from 450kHz to 1.5MHz can be
obtained. Demo board DC135A is available for the
LTC1560-1. For more information please contact LTC
Marketing.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATION
– 5V
0.1µF
1MHz/500kHz Elliptic Lowpass Filter
VIN
0.01µF
1
GND
8
VOUT
2
VIN
7
SHDN
3
LTC1560-1
GND V +
6
4 V–
5
0.5fC / fC
VOUT
(OR – 5V)
0.1µF
5V
0.01µF
– 5V
1MHz
5V
500kHz
1560-1 TA01
Frequency Response
10
0
–10
– 20
– 30
– 40
– 50
– 60
– 70
– 80
fCUTOFF = 1MHz/500kHz
– 90
0.1 1
FREQUENCY (MHz)
10
1560-1 TA02
1
1 page  
LTC1560-1
PIN FUNCTIONS
GND (Pins 1, 3): Analog Ground Pins. The quality of the
analog ground can affect the filter performance. For dual
supply operation the analog ground pin should be con-
nected to an analog ground plane surrounding the pack-
age. The analog ground plane should be connected to a
digital ground plane (if any) at a single point. For single
supply operation, the analog ground pin should be biased
at one-half the power supply across the device (see
Figure 1) and the analog ground plane should then be
connected to V – (Pin 4).
VIN (Pin 2): The filter input is internally connected to the
inverting input of a high frequency op amp through an 8k
resistor.
V –, V + (Pins 4, 6): Power Supply Pins. The negative and
positive power supply (Pins 4 and 6 respectively) should
be decoupled with a 0.1µF capacitor in parallel with a
0.01µF. Both capacitors should be types designed for
decoupling video frequencies and they should be placed
as close as possible to the power supply pins of the filter.
Parallel routing of high frequency signal paths should be
avoided; they will couple into the device’s power supply
pins and cause gain inaccuracy and stopband degrada-
tion. The power supplies can be applied in any order, that
is, the positive supply can be applied before the negative
supply and vice versa. Switching power supplies are not
recommended.
0.5fC/fC (Pin 5): By tying Pin 5 high the filter cutoff
frequency is internally programmed for 500kHz. By tying
Pin 5 low the cutoff frequency will switch to 1MHz. Pin 5
should not be left floating. The logic threshold of Pin 5 is
approximately 0.4 times the total power supply across the
device.
SHDN (Pin 7): Shutdown. Under normal operating condi-
tions, Pin 7 should be shorted either to the analog ground
(Pin 1) or to V – (Pin 4). If Pin 7 is pulled high to V +, the filter
operation will stop and the IC will be placed in a power
saving mode. The power supply current will then be
reduced to 1mA. For a ±5V supply, the logic threshold of
Pin 7 is 2.5V. Pin 7 is internally connected to the analog
ground pin via a 50k resistor.
VOUT (Pin 8): The filter output pin can sink or source 1mA.
The total harmonic distortion of the filter will degrade
when driving coaxial cables or loads less than 10k without
an output buffer.
V+
10k
0.1µF
0.01µF
1µF 0.01µF 10k
1
GND
8
VOUT
2
VIN VIN
7
SHDN
3
LTC1560-1
GND V +
6
4 V–
5
0.5fC / fC
ANALOG GROUND PLANE
VOUT
GND OR V+
SYSTEM GROUND
DIGITAL GROUND
PLANE
1560-1 F01
Figure 1. Connections for Single Supply Operation
5
5 Page | ||
| Páginas | Total 8 Páginas | |
| PDF Descargar | [ Datasheet LTC1560-1IS8.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| LTC1560-1IS8 | 1MHz/500kHz Continuous Time/ Low Noise/ Lowpass Elliptic Filter | 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 |