参数资料
| 型号： | MAX1494CCJ+T |
| 厂商： | Maxim Integrated |
| 文件页数： | 10/34页 |
| 文件大小： | 0K |
| 描述： | IC ADC W/LCD DRIVER 32-TQFP |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,000 |
| 显示器类型： | LCD |
| 配置： | 7 段 + 2 个信号器 |
| 接口： | 串行 |
| 数字或字符： | A/D，4.5 位数字 |
| 电流 - 电源： | 960µA |
| 电源电压： | 2.7 V ~ 5.25 V |
| 工作温度： | 0°C ~ 70°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 32-LQFP |
| 供应商设备封装： | 32-LQFP（7x7） |
| 包装： | 带卷 (TR) |
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3.5- and 4.5-Digit, Single-Chip ADCs
with LCD Drivers
Detailed Description
The MAX1492/MAX1494 low-power, highly integrated
ADCs with LCD drivers convert a ±2V differential input
voltage (one count is equal to 100μV for the MAX1494
and 1mV for the MAX1492) with a sigma-delta ADC and
output the result to an LCD or μC. An additional
±200mV input range (one count is equal to 10μV for the
MAX1494 and 100μV for the MAX1492) is available to
measure small signals with increased resolution.
The devices operate from a single 2.7V to 5.25V power
supply and offer 3.5-digit (MAX1492) or 4.5-digit
0
-40
-80
-120
-160
(MAX1494) conversion results. An internal 2.048V refer-
ence, an internal charge pump, and a high-accuracy
on-chip oscillator eliminate external components.
-200
0
10
20 30 40
FREQUENCY (Hz)
50
60
The MAX1492 and MAX1494 interface with a μC using
? 1 ( 1 ? z ? N ) ? 4
? ? N ( 1 ? z ? 1 ) ? ?
an SPI/QSPI/MICROWIRE-compatible serial interface.
Data can either be sent directly to the display or to the
μC first for processing before being displayed.
The devices also feature on-chip buffers for the differen-
tial input signal and external reference inputs, allowing
direct interface with high-impedance signal sources. In
addition, they use continuous internal-offset calibration
and offer >100dB of 50Hz and 60Hz line noise rejec-
tion. Other features include data hold and peak hold,
overrange and underrange detection, and a low-battery
monitor.
Analog Input Protection
Internal protection diodes limit the analog input range
from V NEG to (V AVDD + 0.3V). If the analog input
exceeds this range, limit the input current to 10mA.
Internal Analog Input/Reference Buffers
The MAX1492/MAX1494 analog input/reference buffers
Figure 2. Frequency Response of the SINC 4 Filter (Notch at 60Hz)
Digital Filtering
The MAX1492/MAX1494 contain an on-chip digital low-
pass filter that processes the data stream from the
modulator using a SINC 4 ((sinx/x) 4 ) response. The
SINC 4 filter has a settling time of four output data peri-
ods (4 x 200ms).
The MAX1492/MAX1494 have 25% overrange capability
built into the modulator and digital filter.
The digital filter is optimized for f CLK equal to 4.9152MHz.
Lower clock frequencies can be used; however,
50Hz/60Hz noise rejection decreases. The frequency
response of the SINC 4 filter is measured as follows:
H ( z ) = ? ?
?
H ( f ) = ?
sin ? N π
? f ? ? 4
? ?
fm ? ?
sin ? π
? f ? ?
? fm ? ? ?
allow the use of high-impedance signal sources. The
input buffer’s common-mode input range allows the ana-
log inputs and the reference to range from -2.2V to +2.2V.
Modulator
The MAX1492/MAX1494 perform analog-to-digital con-
?
1
? N
?
?
?
?
versions using a single-bit, 3rd-order, sigma-delta mod-
where N is the oversampling ratio, and fm = N
output
ulator. The sigma-delta modulator converts the input
signal into a digital pulse train whose average duty
cycle represents the digitized signal information. The
modulator quantizes the input signal at a much higher
sample rate than the bandwidth of the input.
The MAX1492/MAX1494 modulator provides 3rd-order
frequency shaping of the quantization noise resulting
from the single-bit quantizer. The modulator is fully dif-
ferential for maximum signal-to-noise ratio and mini-
mum susceptibility to power-supply noise. A single-bit
data stream is then presented to the digital filter to
remove the frequency-shaped quantization noise.
data rate = 5Hz.
Filter Characteristics
Figure 2 shows the filter frequency response. The
SINC 4 characteristic -3dB cutoff frequency is 0.228
times the first-notch frequency (5Hz).
The output data rate for the digital filter corresponds
with the positioning of the first notch of the filter’s fre-
quency response. The notches of the SINC 4 filter are
repeated at multiples of the first-notch frequency. The
SINC 4 filter provides an attenuation of better than
100dB at these notches. For example, 50Hz is equal to
10
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| MAX1494EVC16 | 功能描述:模数转换器 - ADC MAX1494C16 EVAL KIT RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32 |
| MAX1494EVKIT | 功能描述:数据转换 IC 开发工具 Evaluation Kit/Evaluation System for the MAX1493 MAX1494 MAX1495 RoHS:否 制造商:Texas Instruments 产品:Demonstration Kits 类型:ADC 工具用于评估:ADS130E08 接口类型:SPI 工作电源电压:- 6 V to + 6 V |
| MAX14950ACTL+ | 功能描述:外围驱动器与原件 - PCI PCIe Gen III Re-Driver RoHS:否 制造商:PLX Technology 工作电源电压: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:FCBGA-1156 封装:Tray |
| MAX14950ACTL+T | 功能描述:外围驱动器与原件 - PCI PCIe Gen III Re-Driver RoHS:否 制造商:PLX Technology 工作电源电压: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:FCBGA-1156 封装:Tray |
| MAX14950CTO+ | 功能描述:外围驱动器与原件 - PCI PCIe Gen III Re-Driver RoHS:否 制造商:PLX Technology 工作电源电压: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:FCBGA-1156 封装:Tray |
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