參數(shù)資料
型號(hào): MAX1275AETC+
廠商: Maxim Integrated Products
文件頁(yè)數(shù): 18/18頁(yè)
文件大?。?/td> 0K
描述: IC ADC 12BIT 1.8MSPS 12-TQFN
產(chǎn)品培訓(xùn)模塊: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
標(biāo)準(zhǔn)包裝: 75
位數(shù): 12
采樣率(每秒): 1.8M
數(shù)據(jù)接口: MICROWIRE?,QSPI?,串行,SPI?
轉(zhuǎn)換器數(shù)目: 1
功率耗散(最大): 45mW
電壓電源: 模擬和數(shù)字
工作溫度: -40°C ~ 85°C
安裝類型: 表面貼裝
封裝/外殼: 12-WQFN 裸露焊盤
供應(yīng)商設(shè)備封裝: 12-TQFN-EP(4x4)
包裝: 管件
輸入數(shù)目和類型: 1 個(gè)差分,雙極
MAX1274/MAX1275
1.8Msps, Single-Supply, Low-Power,
True-Differential, 12-Bit ADCs
_______________________________________________________________________________________
9
Detailed Description
The MAX1274/MAX1275 use an input T/H and succes-
sive-approximation register (SAR) circuitry to convert
an analog input signal to a digital 12-bit output. The
serial interface requires only three digital lines (SCLK,
CNVST, and DOUT) and provides easy interfacing to
microprocessors (Ps) and DSPs. Figure 3 shows the
simplified internal structure for the MAX1274/MAX1275.
True-Differential Analog Input T/H
The equivalent circuit of Figure 4 shows the input archi-
tecture of the MAX1274/MAX1275, which is composed
of a T/H, a comparator, and a switched-capacitor digi-
tal-to-analog converter (DAC). The T/H enters its track-
ing mode on the 14th SCLK rising edge of the previous
conversion. Upon power-up, the T/H enters its tracking
mode immediately. The positive input capacitor is con-
nected to AIN+. The negative input capacitor is con-
nected to AIN-. The T/H enters its hold mode on the
falling edge of CNVST and the difference between the
sampled positive and negative input voltages is con-
verted. The time required for the T/H to acquire an input
signal is determined by how quickly its input capaci-
tance is charged. If the input signal’s source imped-
ance is high, the acquisition time lengthens. The
acquisition time, tACQ, is the minimum time needed for
the signal to be acquired. It is calculated by the follow-
ing equation:
tACQ
≥ 9 × (RS + RIN) × 16pF
where RIN = 200
Ω, and RS is the source impedance of
the input signal.
Note: tACQ is never less than 104ns and any source
impedance below 12
Ω does not significantly affect the
ADC’s AC performance.
Input Bandwidth
The ADC’s input-tracking circuitry has a 20MHz small-
signal bandwidth, making it is possible to digitize high-
speed transient events and measure periodic
signals with bandwidths exceeding the ADC’s sam-
pling rate by using undersampling techniques. To
avoid high-frequency signals being aliased into the fre-
quency band of interest, anti-alias filtering is recom-
mended.
Analog Input Protection
Internal protection diodes that clamp the analog input
to VDD and GND allow the analog input pins to swing
from GND - 0.3V to VDD + 0.3V without damage. Both
inputs must not exceed VDD or be lower than GND for
accurate conversions.
RGND
AIN+
GND
DOUT
SCLK
CNVST
CONTROL
LOGIC AND
TIMING
AIN-
VL
VDD
REF
12-BIT
SAR
ADC
MAX1274
MAX1275
T/H
OUTPUT
BUFFER
Figure 3. Functional Diagram
CIN+
RIN+
RIN-
CIN-
VAZ
AIN+
AIN-
CONTROL
LOGIC
CAPACITIVE
DAC
COMP
CIN+
RIN+
RIN-
CIN-
VAZ
AIN+
AIN-
CONTROL
LOGIC
CAPACITIVE
DAC
COMP
ACQUISITION MODE
HOLD/CONVERSION MODE
Figure 4. Equivalent Input Circuit
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MAX1275AETC+ 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 12-Bit 1.8Msps 5.25V Precision ADC RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 結(jié)構(gòu):Sigma-Delta 轉(zhuǎn)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(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-32
MAX1275AETC+T 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 12-Bit 1.8Msps 5.25V Precision ADC RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 結(jié)構(gòu):Sigma-Delta 轉(zhuǎn)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(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-32
MAX1275AETC-T 功能描述:模數(shù)轉(zhuǎn)換器 - ADC RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 結(jié)構(gòu):Sigma-Delta 轉(zhuǎn)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(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-32
MAX1275BCTC 功能描述:模數(shù)轉(zhuǎn)換器 - ADC RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 結(jié)構(gòu):Sigma-Delta 轉(zhuǎn)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(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-32
MAX1275BCTC+ 功能描述:模數(shù)轉(zhuǎn)換器 - ADC Integrated Circuits (ICs) RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 結(jié)構(gòu):Sigma-Delta 轉(zhuǎn)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(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-32