参数资料
型号: MAX1294ACEI
厂商: MAXIM INTEGRATED PRODUCTS INC
元件分类: ADC
英文描述: 420ksps, +5V, 6-/2-Channel, 12-Bit ADCs with +2.5V Reference and Parallel Interface
中文描述: 6-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, PARALLEL ACCESS, PDSO28
封装: 0.150 INCH, 0.025 INCH PITCH, QSOP-28
文件页数: 15/20页
文件大小: 226K
代理商: MAX1294ACEI
M
420ksps, +5V, 6-/2-Channel, 12-Bit ADCs
with +2.5V Reference and Parallel Interface
______________________________________________________________________________________
15
Shutdown Mode
Shutdown mode turns off all chip functions that draw
quiescent current, reducing the typical supply current
to 2μA immediately after the current conversion is com-
pleted. A rising edge on
WR
causes the MAX1294/
MAX1296 to exit shutdown mode and return to normal
operation. To achieve full 12-bit accuracy with a 4.7μF
reference bypass capacitor, 500μs is required after
power-up. Waiting 500μs in standby mode instead of in
full-power mode can reduce power consumption by a
factor of three or more. When using an external refer-
ence, only 50μs is required after power-up. Enter
standby mode by performing a dummy conversion with
the control byte specifying standby mode.
Note:
Bypass capacitors larger than 4.7μF between
REF and GND will result in longer power-up delays.
Transfer Function
Table 5 shows the full-scale voltage ranges for unipolar
and bipolar modes. Figures 8 depicts the nominal
unipolar input/output (I/O) transfer function, and Figure 9
shows the bipolar I/O transfer function. Code transitions
occur halfway between successive-integer LSB values.
Output coding is binary, with 1LSB = (V
REF
/4096).
Maximum Sampling Rate/
Achieving 475ksps
When running at the maximum clock frequency of
7.6MHz, the specified throughput of 420ksps is
achieved by completing a conversion every 18 clock
cycles: one write cycle, three acquisition cycles, 13
conversion cycles, and one read cycle. This assumes
that the results of the last conversion are read before
the next control byte is written. It is possible to achieve
higher throughputs, up to 475ksps, by first writing a
control byte to begin the acquisition cycle of the next
conversion, and then reading the results of the previous
conversion from the bus. This technique (Figure 10)
allows a conversion to be completed every 16 clock
cycles. Note that the switching of the data bus during
Table 5. Full Scale and Zero Scale for Unipolar and Bipolar Operation
111
. . .
111
111
. . .
110
100
. . .
010
100
. . .
001
100
. . .
000
011
. . .
111
011
. . .
110
011
. . .
101
000
. . .
001
000
. . .
000
1
0
INPUT VOLTAGE (LSB)
OUTPUT CODE
ZS = COM
FS = REF + COM
1LSB = 4096
FULL-SCALE
TRANSITION
(COM)
FS - 3/2LSB
FS
2
2048
UNIPOLAR MODE
BIPOLAR MODE
V
REF
+ COM
COM
V
REF
/2 + COM
COM
-V
REF
/2 + COM
Positive Full Scale
Zero Scale
Negative Full Scale
Full Scale
Zero Scale
Figure 8. Unipolar Transfer Functions
011
. . .
111
011
. . .
110
000
. . .
010
000
. . .
001
000
. . .
000
111
. . .
111
111
. . .
110
111
. . .
101
100
. . .
001
100
. . .
000
- FS
COM*
INPUT VOLTAGE (LSB)
OUTPUT CODE
ZS = COM
+FS - 1LSB
+ COM
FS
= REF
2
-FS =
+ COM
-REF
2
1LSB = 4096
*COM V
REF
/2
Figure 9. Bipolar Transfer Functions
相关PDF资料
PDF描述
MAX1294BCEI 420ksps, +5V, 6-/2-Channel, 12-Bit ADCs with +2.5V Reference and Parallel Interface
MAX1296ACEG 420ksps, +5V, 6-/2-Channel, 12-Bit ADCs with +2.5V Reference and Parallel Interface
MAX1296AEEG 420ksps, +5V, 6-/2-Channel, 12-Bit ADCs with +2.5V Reference and Parallel Interface
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相关代理商/技术参数
参数描述
MAX1294ACEI+ 功能描述:模数转换器 - ADC 12-Bit 6Ch 420ksps 5.5V Precision ADC 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
MAX1294ACEI+T 功能描述:模数转换器 - ADC 12-Bit 6Ch 420ksps 5.5V Precision ADC 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
MAX1294ACEI-T 功能描述:模数转换器 - ADC 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
MAX1294AEEI 功能描述:模数转换器 - ADC Integrated Circuits (ICs) 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
MAX1294AEEI+ 功能描述:模数转换器 - ADC 12-Bit 6Ch 420ksps 5.5V Precision ADC 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