seen by REF
參數(shù)資料
型號: DC746A
廠商: Linear Technology
文件頁數(shù): 21/36頁
文件大小: 0K
描述: BOARD DELTA SIGMA ADC LTC2412
軟件下載: QuikEval System
設(shè)計資源: DC746A Design File
DC746A Schematic
標(biāo)準(zhǔn)包裝: 1
系列: QuikEval™
ADC 的數(shù)量: 1
位數(shù): 24
采樣率(每秒): 7.5
數(shù)據(jù)接口: MICROWIRE?,串行,SPI?
工作溫度: 0°C ~ 70°C
已用 IC / 零件: LTC2412
已供物品:
相關(guān)產(chǎn)品: DC590B-ND - BOARD DEMO USB SERIAL CONTROLLER
LTC2412IGN#PBF-ND - IC ADC 2CH DIFF-IN 24BIT 16SSOP
LTC2412IGN#TRPBF-ND - IC ADC 2CH DIFF-IN 24BIT 16SSOP
LTC2412CGN#TRPBF-ND - IC ADC 2CH DIFF-IN 24BIT 16SSOP
LTC2412CGN#PBF-ND - IC ADC 2CH DIFF-IN 24BIT 16SSOP
LTC2412IGN#TR-ND - IC CONV A/D 24B 2CH DIFF 16-SSOP
LTC2412CGN#TR-ND - IC CONV A/D 24B 2CH DIFF 16-SSOP
LTC2412IGN-ND - IC CONV A/D 24B 2CH DIFF 16-SSOP
LTC2412CGN-ND - IC ADC 2CH DIFF-IN 24BIT 16SSOP
LTC2412
28
2412f
APPLICATIO S I FOR ATIO
WU
U
(50ppm/
°C) are used for the external source impedance
seen by REF+ and REF, the expected drift of the dynamic
current gain error will be insignificant (about 1% of its
value over the entire temperature and voltage range). Even
for the most stringent applications a one-time calibration
operation may be sufficient.
In addition to the reference sampling charge, the reference
pins ESD protection diodes have a temperature dependent
leakage current. This leakage current, nominally 1nA
(
±10nA max), results in a small gain error. A 100 source
resistance will create a 0.05
V typical and 0.5V maxi-
mum full-scale error.
Output Data Rate
When using its internal oscillator, the LTC2412 can pro-
duce up to 7.5 readings per second with a notch frequency
of 60Hz (FO = LOW) and 6.25 readings per second with a
notch frequency of 50Hz (FO = HIGH). The actual output
data rate will depend upon the length of the sleep and data
output phases which are controlled by the user and which
can be made insignificantly short. When operated with an
external conversion clock (FO connected to an external
oscillator), the LTC2412 output data rate can be increased
as desired. The duration of the conversion phase is 20510/
fEOSC. If fEOSC = 153600Hz, the converter behaves as if the
internal oscillator is used and the notch is set at 60Hz.
There is no significant difference in the LTC2412 perfor-
mance between these two operation modes.
An increase in fEOSC over the nominal 153600Hz will
translate into a proportional increase in the maximum
output data rate. This substantial advantage is neverthe-
less accompanied by three potential effects, which must
be carefully considered.
First, a change in fEOSC will result in a proportional change
in the internal notch position and in a reduction of the
converter differential mode rejection at the power line
frequency. In many applications, the subsequent perfor-
mance degradation can be substantially reduced by rely-
ing upon the LTC2412’s exceptional common mode
rejection and by carefully eliminating common mode to
differential mode conversion sources in the input circuit.
The user should avoid single-ended input filters and
should maintain a very high degree of matching and
symmetry in the circuits driving the IN+ and INpins.
Second, the increase in clock frequency will increase
proportionally the amount of sampling charge transferred
through the input and the reference pins. If large external
input and/or reference capacitors (CIN, CREF) are used, the
previous section provides formulae for evaluating the
effect of the source resistance upon the converter perfor-
mance for any value of fEOSC. If small external input and/
or reference capacitors (CIN, CREF) are used, the effect of
the external source resistance upon the LTC2412 typical
performance can be inferred from Figures 13, 14, 18 and
19 in which the horizontal axis is scaled by 153600/fEOSC.
Third, an increase in the frequency of the external oscilla-
tor above 460800Hz (a more than 3
× increaseintheoutput
data rate) will start to decrease the effectiveness of the
internal autocalibration circuits. This will result in a pro-
gressive degradation in the converter accuracy and linear-
ity. Typical measured performance curves for output data
rates up to 100 readings per second are shown in Fig-
ures 23, 24, 25, 26, 27, 28, 29 and 30. In order to obtain
the highest possible level of accuracy from this converter
at output data rates above 20 readings per second, the
user is advised to maximize the power supply voltage used
and to limit the maximum ambient operating temperature.
In certain circumstances, a reduction of the differential
reference voltage may be beneficial.
Figure 22. INL vs Differential Input Voltage (VIN = IN
+ – IN)
and Reference Source Resistance (RSOURCE at REF+ and REF
for Large CREF Values (CREF ≥ 1F)
VINDIF/VREFDIF
–0.5 –0.4–0.3–0.2–0.1 0
0.1 0.2 0.3 0.4 0.5
INL
(ppm
OF
V
REF
)
15
12
9
6
3
0
–3
–6
–9
–12
–15
VCC = 5V
REF+ = 5V
REF– = GND
VINCM = 0.5 (IN
+ + IN) = 2.5V
FO = GND
CREF = 10F
TA = 25°C
RSOURCE = 1000
RSOURCE = 500
RSOURCE = 100
2412 F22
相關(guān)PDF資料
PDF描述
SLPX222M100C7P3 CAP ALUM 2200UF 100V 20% SNAP
RS3-243.3DZ/H3 CONV DC/DC 3W 9-27VIN +/-3.3VOUT
AP2162MPG-13 IC PWR SW USB 2CH 1A 8-MSOP
RS3-2415DZ/H3 CONV DC/DC 3W 9-27VIN +/-15VOUT
SC75B-470 INDUCTOR SMD 47UH 1.10A 2.52MHZ
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DC74HC259 制造商:TI 制造商全稱:Texas Instruments 功能描述:High Speed CMOS Logic 8-Bit Addressable Latch
DC-750 制造商:Bivar 功能描述:CARD GUIDE DEEP 7.5" 0.08" BK
DC-750-102 制造商:Bivar 功能描述:CARD GUIDE DEEP 7.5" 0.102" BK
DC-750-102-CI 制造商:Bivar 功能描述:CARD GUIDE INSERT 7.5" 0.102" BK
DC750KA 制造商:Dewalt 功能描述:9.6V 3/8" Cordless Compact Drill/Driver Kit 制造商:DEWALT 功能描述:9.6V DRILL/DRIVER KIT 3/8 RATCHETING CHUCK