|
|
PDF LTC1569C Data sheet ( Hoja de datos )
| Número de pieza | LTC1569C | |
| Descripción | Linear Phase/ DC Accurate/ Tunable/ 10th Order Lowpass Filter | |
| Fabricantes | Linear Technology | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de LTC1569C (archivo pdf) en la parte inferior de esta página. Total 12 Páginas | ||
|
No Preview Available !
LTC1569-7
Linear Phase, DC Accurate,
Tunable, 10th Order Lowpass Filter
FEATURES
s One External R Sets Cutoff Frequency
s Root Raised Cosine Response
s Up to 300kHz Cutoff on a Single 5V Supply
s Up to 150kHz Cutoff on a Single 3V Supply
s 10th Order, Linear Phase Filter in an SO-8
s DC Accurate, VOS(MAX) = 5mV
s Low Power Modes
s Differential or Single-Ended Inputs
s 80dB CMRR (DC)
s 80dB Signal-to-Noise Ratio, VS = 5V
s Operates from 3V to ±5V Supplies
U
APPLICATIO S
s Data Communication Filters for 3V Operation
s Linear Phase and Phase Matched Filters for I/Q
Signal Processing
s Pin Programmable Cutoff Frequency Lowpass Filters
DESCRIPTIO
The LTC®1569-7 is a 10th order lowpass filter featuring
linear phase and a root raised cosine amplitude response.
The high selectivity of the LTC1569-7 combined with its
linear phase in the passband makes it suitable for filtering
both in data communications and data acquisition sytems.
Furthermore, its root raised cosine response offers the
optimum pulse shaping for PAM data communications.
The filter attenuation is 50dB at 1.5 • fCUTOFF, 60dB at 2 •
fCUTOFF, and in excess of 80dB at 6 • fCUTOFF. DC-accuracy-
sensitive applications benefit from the 5mV maximum DC
offset.
The LTC1569-7 is the first sampled data filter which does
not require an external clock yet its cutoff frequency can be
set with a single external resistor with a typical accuracy
of 3.5% or better. The external resistor programs an
internal oscillator whose frequency is divided by either 1,
4 or 16 prior to being applied to the filter network. Pin 5
determines the divider setting. Thus, up to three cutoff
frequencies can be obtained for each external resistor
value. Using various resistor values and divider settings,
the cutoff frequency can be programmed over a range of
seven octaves. Alternatively, the cutoff frequency can be
set with an external clock and the clock-to-cutoff fre-
quency ratio is 32:1. The ratio of the internal sampling rate
to the filter cutoff frequency is 64:1.
The LTC1569-7 is fully tested for a cutoff frequency of
256kHz/128kHz with single 5V/3V supply although up to
300kHz cutoff frequencies can be obtained.
The LTC1569-7 features power savings modes and it is
available in an SO-8 surface mount package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATION
Single 3V Supply, 128kHz/32kHz/8kHz Lowpass Filter
3V
3.48k
2k
VIN 1 IN+
OUT 8 VOUT
2 IN–
V+ 7 REXT = 10k
LTC1569-7
3 GND
RX 6
1µF
4 V–
1/16
DIV/CLK 5
1/4
EASY TO SET fCUTOFF:
1/1
fCUTOFF = 128kHz (10k/REXT)
1, 4 OR 16
3V
1µF
3V
100pF
1569-7 TA01
Frequency Response, fCUTOFF = 128kHz/32kHz/8kHz
0
–20
–40
–60
–80
–100
1
10 100
FREQUENCY (kHz)
1000
1569-7 TA01a
1
1 page  
LTC1569-7
PIN FUNCTIONS
IN +/IN – (Pins 1, 2): Signals can be applied to either or
both input pins. The DC gain from IN + (Pin 1) to OUT
(Pin␣ 8) is 1.0, and the DC gain from Pin 2 to Pin 8 is –1. The
input range, input resistance and output range are de-
scribed in the Applications Information section. Input
voltages which exceed the power supply voltages should
be avoided. Transients will not cause latchup if the current
into/out of the input pins is limited to 20mA.
GND (Pin 3): The GND pin is the reference voltage for the
filter and should be externally biased to 2V (1.11V) to
maximize the dynamic range of the filter in applications
using a single 5V (3V) supply. For single supply operation,
the GND pin should be bypassed with a quality 1µF
ceramic capacitor to V – (Pin 4). The impedance of the
circuit biasing the GND pin should be less than 2kΩ as the
GND pin generates a small amount of AC and DC current.
For dual supply operation, connect Pin␣ 3 to a high quality
DC ground. A ground plane should be used. A poor ground
will increase DC offset, clock feedthrough, noise and
distortion.
V –/V + (Pins 4, 7): For 3V, 5V and ±5V applications a
quality 1µF ceramic bypass capacitor is required from V +
(Pin 7) to V – (Pin 4) to provide the transient energy for the
internal clock drivers. The bypass should be as close as
possible to the IC. In dual supply applications (Pin 3 is
grounded), an additional 0.1µF bypass from V + (Pin 7) to
GND (Pin 3) and V – (Pin 4) to GND (Pin 3) is recom-
mended.
The maximum voltage difference between GND (Pin 3) and
V + (Pin 7) should not exceed 5.5V.
DIV/CLK (Pin 5): DIV/CLK serves two functions. When the
internal oscillator is enabled, DIV/CLK can be used to
engage an internal divider. The internal divider is set to 1:1
when DIV/CLK is shorted to V – (Pin 4). The internal divider
is set to 4:1 when DIV/CLK is allowed to float (a 100pF
bypass to V – is recommended). The internal divider is set
to 16:1 when DIV/CLK is shorted to V + (Pin 7). In the
divide-by-4 and divide-by-16 modes the power supply
current is reduced by typically 60%.
When the internal oscillator is disabled (RX shorted
to V –) DIV/CLK becomes an input pin for applying an
external clock signal. For proper filter operation, the clock
waveform should be a squarewave with a duty cycle as
close as possible to 50% and CMOS voltages levels (see
Electrical Characteristics section for voltage levels). DIV/
CLK pin voltages which exceed the power supply voltages
should be avoided. Transients will not cause latchup if the
fault current into/out of the DIV/CLK pin is limited to 40mA.
RX (Pin 6): Connecting an external resistor between the RX
pin and V + (Pin 7) enables the internal oscillator. The value
of the resistor determines the frequency of oscillation. The
maximum recommended resistor value is 40k and the
minimum is 3.8k/8k (single 5V/3V supply). The internal
oscillator is disabled by shorting the RX pin to V – (Pin 4).
(Please refer to the Applications Information section.)
OUT (Pin 8): Filter Output. This pin can drive 10kΩ and/or
40pF loads. For larger capacitive loads, an external 100Ω
series resistor is recommended. The output pin can ex-
ceed the power supply voltages by up to ±2V without
latchup.
BLOCK DIAGRA
IN+ 1
IN– 2
GND 3
V– 4
10TH ORDER
LINEAR PHASE
FILTER NETWORK
POWER
CONTROL
DIVIDER/
BUFFER
PRECISION
OSCILLATOR
8 OUT
7 V+
6 RX
REXT
5 DIV/CLK
1569-7 BD
5
5 Page 
TYPICAL APPLICATION
Dual 5V Supply Operation,
DC Coupled Filter with External Clock Source
VIN 1 IN+
2 IN–
OUT 8 VOUT
fCUTOFF = fCLK/32
V+ 7
5V
LTC1569-7
3 GND
RX 6
0.1µF
0.1µF
–5V 4 V– DIV/CLK 5
5V
0V
fCLK ≤ 10MHz
1569-7 TA05
1µF
LTC1569-7
Single 5V Supply Operation, DC Coupled Input,
128kHz Cutoff Frequency
5V
2.49k
1.65k
VIN 1 IN+
2 IN–
OUT 8 VOUT
V+ 7 REXT = 10k
LTC1569-7
3 GND
RX 6
1µF
4 V–
DIV/CLK 5
( )( )128kHz
fCUTOFF =
n=1
10k
REXT
n = 1, 4, 16 FOR PIN 5 AT
GROUND, OPEN, V+
5V
1µF
1569-7 TA06
PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted.
S8 Package
8-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
0.189 – 0.197*
(4.801 – 5.004)
8 765
0.228 – 0.244
(5.791 – 6.197)
0.150 – 0.157**
(3.810 – 3.988)
0.010
(0.254
–
–
0.020
0.508)
×
45°
0.008 – 0.010
(0.203 – 0.254)
1
0°– 8° TYP
0.053 – 0.069
(1.346 – 1.752)
2
0.016 – 0.050
0.406 – 1.270
0.014 – 0.019
(0.355 – 0.483)
*DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
**DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
34
0.004 – 0.010
(0.101 – 0.254)
0.050
(1.270)
TYP
SO8 0996
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
11
11 Page | ||
| Páginas | Total 12 Páginas | |
| PDF Descargar | [ Datasheet LTC1569C.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| LTC1569-6 | Linear Phase/ DC Accurate/ Low Power/ 10th Order Lowpass Filter | Linear Technology |
| LTC1569-7 | Linear Phase/ DC Accurate/ Tunable/ 10th Order Lowpass Filter | Linear Technology |
| LTC1569C | Linear Phase/ DC Accurate/ Tunable/ 10th Order Lowpass Filter | Linear Technology |
| LTC1569CS8-6 | Linear Phase/ DC Accurate/ Low Power/ 10th Order Lowpass 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 |