參數資料
型號: MAX1270BEAI
廠商: MAXIM INTEGRATED PRODUCTS INC
元件分類: ADC
英文描述: Multirange, +5V, 8-Channel, Serial 12-Bit ADCs
中文描述: 8-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, SERIAL ACCESS, PDSO28
封裝: 5.3 MM, 0.65 MM PITCH, MO-150, SSOP-28
文件頁數: 9/20頁
文件大?。?/td> 808K
代理商: MAX1270BEAI
M
Multirange, +5V, 8-Channel,
Serial 12-Bit ADCs
_______________________________________________________________________________________
9
Detailed Description
Converter Operation
The MAX1270/MAX1271 multirange, fault-tolerant ADCs
use successive approximation and internal track/hold
(T/H) circuitry to convert an analog signal to a 12-bit
digital output. Figure 3 shows the block diagram of the
MAX1270/MAX1271.
Analog-Input Track/Hold
The T/H enters tracking/acquisition mode on the falling
edge of the sixth clock in the 8-bit input control word,
and enters hold/conversion mode when the timed
acquisition interval (six clock cycles, 3μs minimum)
ends. In internal clock mode, the acquisition is timed by
two external clock cycles and four internal clock cycles.
When operating in bipolar (MAX1270 and MAX1271) or
unipolar mode (MAX1270) the signal applied at the
input channel is rescaled through the resistor-divider
network formed by R1, R2, and R3 (Figure 4); a low
impedance (<4
) input source is recommended to
minimize gain error. When the MAX1271 is configured
for unipolar mode, the channel input resistance (R
IN
)
becomes a fixed 5.12k
(typ). Source impedances
below 15k
(0 to V
REF
) and 5k
(0 to V
REF
/2) do not
significantly affect the AC performance of the ADC.
The acquisition time (t
ACQ
) is a function of the source
output resistance, the channel input resistance, and the
T/H capacitance. Higher source impedances can be
used if an input capacitor is connected between the
analog inputs and AGND. Note that the input capacitor
forms an RC filter with the input source impedance, lim-
iting the ADC’s signal bandwidth.
100k
510k
24k
REFADJ
+5V
MAX1270
MAX1271
0.01
μ
F
CH2
CH3
CH4
CH5
CH6
CH7
REF
CH1
CH0
SHDN
REFADJ
V
DD
AGND
DGND
MAX1270
MAX1271
12-BIT SAR ADC
IN
REF
CLOCK
OUT
T/H
2.5V
REFERENCE
ANALOG
INPUT
MUX
AND SIGNAL
CONDITIONING
Av =
1.638
INT
CLOCK
DIN
SSTRB
DOUT
CS
SCLK
SERIAL INTERFACE LOGIC
10k
+4.096V
0.5mA
DOUT
OR
SSTRB
+5V
a)
HIGH IMPEDANCE TOV
OH
, V
OL
TO
V
OH
AND V
OH
TOHIGH IMPEDANCE
HIGH IMPEDANCE TOV
OH
, V
OL
TO
V
OH
AND V
OH
TOHIGH IMPEDANCE
b)
C
LOAD
C
LOAD
5mA
DOUT
OR
SSTRB
Figure 1. Reference-Adjust Circuit
Figure 3. Block Diagram
Figure 2. Output Load Circuit for Timing Characteristics
相關PDF資料
PDF描述
MAX1271BEAI Multirange, +5V, 8-Channel, Serial 12-Bit ADCs
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相關代理商/技術參數
參數描述
MAX1270BEAI+ 功能描述:模數轉換器 - ADC 12-Bit 8Ch 110ksps 4.18V Precision ADC RoHS:否 制造商:Texas Instruments 通道數量:2 結構:Sigma-Delta 轉換速率:125 SPs to 8 KSPs 分辨率:24 bit 輸入類型:Differential 信噪比:107 dB 接口類型:SPI 工作電源電壓:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-32
MAX1270BEAI+T 功能描述:模數轉換器 - ADC 12-Bit 8Ch 110ksps 4.18V Precision ADC RoHS:否 制造商:Texas Instruments 通道數量:2 結構:Sigma-Delta 轉換速率:125 SPs to 8 KSPs 分辨率:24 bit 輸入類型:Differential 信噪比:107 dB 接口類型:SPI 工作電源電壓:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-32
MAX1270BEAI-T 功能描述:模數轉換器 - ADC RoHS:否 制造商:Texas Instruments 通道數量:2 結構:Sigma-Delta 轉換速率:125 SPs to 8 KSPs 分辨率:24 bit 輸入類型:Differential 信噪比:107 dB 接口類型:SPI 工作電源電壓:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-32
MAX1270BENG 功能描述:模數轉換器 - ADC RoHS:否 制造商:Texas Instruments 通道數量:2 結構:Sigma-Delta 轉換速率:125 SPs to 8 KSPs 分辨率:24 bit 輸入類型:Differential 信噪比:107 dB 接口類型:SPI 工作電源電壓:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-32
MAX1270BENG+ 功能描述:模數轉換器 - ADC 12-Bit 8Ch 110ksps 4.18V Precision ADC RoHS:否 制造商:Texas Instruments 通道數量:2 結構:Sigma-Delta 轉換速率:125 SPs to 8 KSPs 分辨率:24 bit 輸入類型:Differential 信噪比:107 dB 接口類型:SPI 工作電源電壓:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-32