- 您现在的位置：买卖IC网 > PDF目录2012 > MAX7480ESA+T (Maxim Integrated Products)IC FILTER LOWPASS 8TH 8-SOIC PDF资料下载
参数资料
| 型号： | MAX7480ESA+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 7/8页 |
| 文件大小： | 0K |
| 描述： | IC FILTER LOWPASS 8TH 8-SOIC |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| 滤波器类型： | 巴特沃斯，低通开关电容器 |
| 频率 - 截止或中心： | 2kHz |
| 滤波器数： | 4 |
| 滤波器阶数： | 8th |
| 电源电压： | 4.5 V ~ 5.5 V |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 8-SOIC（0.154"，3.90mm 宽） |
| 供应商设备封装： | 8-SOIC |
| 包装： | 带卷 (TR) |
MAX7480
8th-Order, Lowpass, Butterworth,
Switched-Capacitor Filter
_______________________________________________________________________________________
7
Clock Signal
External Clock
The MAX7480 SCF is designed for use with external
clocks that have a 40% to 60% duty cycle. When using
an external clock with these devices, drive CLK with a
CMOS gate powered from 0 to VDD. Varying the rate of
the external clock adjusts the corner frequency of the
filter as follows:
fC = fCLK / 100
Internal Clock
When using the internal oscillator, connect a capacitor
(COSC) between CLK and ground. The value of the
capacitor determines the oscillator frequency as follows:
Minimize the stray capacitance at CLK so that it does
not affect the internal oscillator frequency. Vary the rate
of the internal oscillator to adjust the filter’s corner fre-
quency by a 100:1 clock to corner-frequency ratio. For
example, an internal oscillator frequency of 100kHz
produces a nominal corner frequency of 1kHz.
Input Impedance vs. Clock Frequencies
The MAX7480’s input impedance is effectively that of a
switched-capacitor resistor, and is inversely proportion-
al to frequency. The input impedance values deter-
mined below represent the average input impedance,
since the input current is not continuous. As a rule, use
a driver with an output impedance less than 10% of the
filter’s input impedance. Estimate the input impedance
of the filter using the following formula:
where fCLK = clock frequency and CIN = 2.31pF.
Low-Power Shutdown Mode
This device features a shutdown mode that is activated
by driving SHDN low. In shutdown mode, the filter’s sup-
ply current reduces to 0.2A (typ) and its output
becomes high impedance. For normal operation, drive
SHDN high or connect to VDD.
___________Applications Information
Offset and Common-Mode
Input Adjustment
The voltage at COM sets the common-mode input volt-
age and is biased at mid-supply with an internal resis-
tor-divider. Bypass COM with a 0.1F capacitor and
connect OS to COM. For applications requiring offset
adjustment or DC level shifting, apply an external bias
voltage through a resistor-divider network to OS, as
shown in Figure 3. (Note: Do not leave OS unconnect-
ed.) The output voltage is represented by this equation:
VOUT = (VIN - VCOM) + VOS
with VCOM = VDD / 2 (typical), where (VIN - VCOM) is
lowpass-filtered by the SCF and VOS is added at the
output stage. See the
Electrical Characteristics for the
voltage range of COM and OS. Changing the voltage
on COM or OS significantly from mid-supply reduces
the filter’s dynamic range.
Power Supplies
The MAX7480 operates from a single +5V supply.
Bypass VDD to GND with a 0.1F capacitor. If dual
supplies (±2.5V) are required, connect COM to system
ground and connect GND to the negative supply.
Figure 4 shows an example of dual-supply operation.
Single- and dual-supply performances are equivalent.
For either single- or dual-supply operation, drive CLK
and SHDN from GND (V- in dual-supply operation) to
VDD. For ±5V dual-supply applications, use the
MAX291–MAX297.
Input Signal Amplitude Range
The optimal input signal range is determined by observ-
ing the voltage level at which the total harmonic distor-
tion plus noise (THD+N) is minimized for a given corner
frequency. The
Typical Operating Characteristics
shows a graph of the device’s THD+N response as the
input signal’s peak-to-peak amplitude is varied. This
measurement is made with OS and COM biased at mid-
supply.
Z
1
f
C
IN
CLK
IN
= ()
f
(kHz)
C
; C
in pF
OSC
3
OSC
=
53 10
VDD
VSUPPLY
IN
CLK
GND
INPUT
OUTPUT
50k
OUT
0.1
F
0.1
F
0.1
F
CLOCK
SHDN
COM
OS
MAX7480
Figure 3. Offset Adjustment Circuit
相关PDF资料 |
PDF描述 |
|---|---|
| MAX7491EEE+T | IC FILTER SW CAP DUAL 16-QSOP |
| MAX9501EEE+ | IC FILTER HDTV 16-QSOP |
| MAX9526AEI/V+T | IC VID DECODER NTSC/PAL 28QSOP |
| MAX98088EWY+T | IC CODEC AUDIO FLEXSOUND 63WLP |
| MAX98089ETN+ | IC CODEC AUDIO FLEXSOUND 56TQFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX7481ETI+ | 制造商:Maxim Integrated Products 功能描述:HIGH-SPEED, LOW-VOLTAGE, 0.7O CMOS ANALOG SWITCHES/MULTIPLEX - Rail/Tube 制造商:Rochester Electronics LLC 功能描述: |
| MAX7482ETI+ | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
| MAX748AC/D | 功能描述:直流/直流开关转换器 1.7mA Quiescent Current-Mode PWM DC-DC Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| MAX748AC/D DIE | 制造商:Maxim Integrated Products 功能描述: |
| MAX748ACPA | 功能描述:直流/直流开关转换器 3.3V Step-Down DC/DC Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
发布紧急采购，3分钟左右您将得到回复。