參數(shù)資料
型號(hào): AD7482
廠商: Analog Devices, Inc.
元件分類: ADC
英文描述: 3MSPS, 12-Bit SAR ADC
中文描述: 3MSPS,12位SAR ADC
文件頁(yè)數(shù): 11/16頁(yè)
文件大小: 1498K
代理商: AD7482
REV. 0
AD7482
–11–
OFFSET/OVERRANGE
The AD7482 provides a
±
8% overrange capability as well as a
programmable offset register. The overrange capability is achieved
by the use of a 13th bit (D12) and the CLIP input. If the CLIP
input is at logic high and the contents of the offset register are
zero, then the AD7482 operates as a normal 12-bit ADC. If the
input voltage is greater than the full-scale voltage, the data output
from the ADC will be all
1s.
Similarly, if the input voltage is
lower than the zero-scale voltage, the data output from the ADC
will be all
0s.
In this case, D12 acts as an overrange indicator. It
is set to
1
if the analog input voltage is outside the nominal 0 V
to 2.5 V range.
If the offset register contains any value other than
0,
the
contents of the register are added to the SAR result at the end
of conversion. This has the effect of shifting the transfer function
of the ADC as shown in Figure 11 and Figure 12. However,
it should be noted that with the CLIP input set to logic high,
the maximum and minimum codes that the AD7482 will output
will be 0xFFF and 0x000, respectively. Further details are given
in Table I and Table II.
Figure 11 shows the effect of writing a positive value to the offset
register. If, for example, the contents of the offset register
contained the value 256, then the value of the analog input
voltage for which the ADC would transition from reading all
0s
to 000...001 (the bottom reference point) would be:
(
The analog input voltage for which the ADC would read full-
scale (0xFFF) in this example would be:
(
0 5
256
155 944
.
.
LSB
LSB
mV
)
=
2 5
1 5
.
256
2 3428
.
.
V
LSB
LSB
V
)
=
ANALOG INPUT
0V
1LSB = V
REF
/4096
0
000...000
A
111...111
111...110
000...001
000...010
111...000
011...111
+V
REF
– 1.5LSB
Figure 11. Transfer Characteristic with Positive Offset
The effect of writing a negative value to the offset register is
shown in Figure 12. If a value of
128 was written to the offset
register, the bottom end reference point would now occur at:
Following this, the analog input voltage needed to produce a
full-scale (0xFFF) result from the ADC would now be:
0 5
128
78 43
.
.
– –
LSB
LSB
mV
)
=
2 5
1 5
.
128
2 5772
.
.
– –
V
LSB
LSB
V
)
=
000...000
0V
A
ANALOG INPUT
111...111
111...110
000...001
000...010
111...000
011...111
0.5LSB
–OFFSET
+V
REF
– 1.5LSB
–OFFSET
1LSB = V
REF
/4096
Figure 12. Transfer Characteristic with Negative Offset
Table I shows the expected ADC result for a given analog input
voltage with different offset values and with CLIP tied to logic
high. The combined advantages of the offset and overrange
features of the AD7482 are shown clearly in Table II. It shows
the same range of analog input and offset values as Table I but
with the clipping feature disabled.
Table I. Clipping Enabled (CLIP = 1)
Offset
V
IN
200 mV
155.94 mV
0 V
+78.43 mV
+2.3428 V
+2.5 V
+2.5772 V
+2.7 V
–128
0
+256
ADC DATA, D[0:11]
D12
0
0
0
0
3710
3967
4095
4095
0
0
0
128
3838
4095
4095
4095
0
0
256
384
4095
4095
4095
4095
1 1 1
1 1 0
1 0 0
0 0 0
0 0 0
0 0 1
0 1 1
1 1 1
Table II. Clipping Disabled (CLIP = 0)
Offset
V
IN
200 mV
155.94 mV
0 V
+78.43 mV
+2.3428 V
+2.5 V
+2.5772 V
+2.7 V
–128
ADC DATA, D[0:12]
0
+256
456
384
128
0
3710
3968
4095
4552
328
256
0
128
3838
4096
4223
4680
72
0
256
384
4094
4352
4479
4936
Values from
327 to +327 may be written to the offset register.
These values correspond to an offset of
±
200 mV. A write to the
offset register is performed by writing a 13-bit word to the part
as detailed in the Parallel Interface section. The 10 LSBs of the
13-bit word contain the offset value, while the 3 MSBs must
be set to
0.
Failure to write zeros to the 3 MSBs may result
in the incorrect operation of the device.
相關(guān)PDF資料
PDF描述
AD7482AST 3MSPS, 12-Bit SAR ADC
AD7482BST 1.5Gbps Serial ATA-Compatible Mux/Buffer with Loopback and Equalization
AD7490 16-Channel, 1 MSPS, 12-Bit ADC with Sequencer in 28-Lead TSSOP
AD7490BCP 16-Channel, 1 MSPS, 12-Bit ADC with Sequencer in 28-Lead TSSOP
AD7490BRU 16-Channel, 1 MSPS, 12-Bit ADC with Sequencer in 28-Lead TSSOP
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD7482AST 制造商:Rochester Electronics LLC 功能描述:12 BIT 3.5 MEG ADC IC - Tape and Reel 制造商:Analog Devices 功能描述:IC 12BIT ADC SMD 7482 LQFP48
AD7482ASTZ 功能描述:IC ADC 12BIT SAR 3MSPS 48LQFP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 模數(shù)轉(zhuǎn)換器 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:2,500 系列:- 位數(shù):12 采樣率(每秒):3M 數(shù)據(jù)接口:- 轉(zhuǎn)換器數(shù)目:- 功率耗散(最大):- 電壓電源:- 工作溫度:- 安裝類型:表面貼裝 封裝/外殼:SOT-23-6 供應(yīng)商設(shè)備封裝:SOT-23-6 包裝:帶卷 (TR) 輸入數(shù)目和類型:-
AD7482BST 制造商:Analog Devices 功能描述:ADC Single SAR 3Msps 12-bit Parallel 48-Pin LQFP 制造商:Rochester Electronics LLC 功能描述:12 BIT 3.5 MEG ADC IC - Tape and Reel 制造商:Analog Devices 功能描述:A/D Converter (A-D) IC
AD7482BSTZ 功能描述:IC ADC 12BIT SAR 3MSPS 48-LQFP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 模數(shù)轉(zhuǎn)換器 系列:- 其它有關(guān)文件:TSA1204 View All Specifications 標(biāo)準(zhǔn)包裝:1 系列:- 位數(shù):12 采樣率(每秒):20M 數(shù)據(jù)接口:并聯(lián) 轉(zhuǎn)換器數(shù)目:2 功率耗散(最大):155mW 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:48-TQFP 供應(yīng)商設(shè)備封裝:48-TQFP(7x7) 包裝:Digi-Reel® 輸入數(shù)目和類型:4 個(gè)單端,單極;2 個(gè)差分,單極 產(chǎn)品目錄頁(yè)面:1156 (CN2011-ZH PDF) 其它名稱:497-5435-6
AD7484 制造商:AD 制造商全稱:Analog Devices 功能描述:3MSPS, 14-Bit SAR ADC