- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄371388 > 2495 (Linear Technology Corporation) 16-Bit 8-/16-Channel ツヒ ADC with PGA, Easy Drive and I2C Interface PDF資料下載
參數(shù)資料
| 型號： | 2495 |
| 廠商： | Linear Technology Corporation |
| 英文描述： | 16-Bit 8-/16-Channel ツヒ ADC with PGA, Easy Drive and I2C Interface |
| 中文描述： | 16位8-/16-ChannelツヒADC，帶PGA巡回賽，輕松驅(qū)動和I2C接口 |
| 文件頁數(shù)： | 25/32頁 |
| 文件大小： | 558K |
| 代理商： | 2495 |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁當(dāng)前第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁
LTC2495
25
2495f
every conversion cycle in order to remove the offset and
drift of the ADC. This calibration is performed through a
combination of front end switching and digital process-
ing. Since the external amplifier is placed between the
multiplexer and the ADC, it is inside this correction loop.
This results in automatic offset correction and offset drift
removal of the external amplifier.
The LTC6078 is an excellent amplifier for this function.
It operates with supply voltages as low as 2.7V and its
noise level is 18nV/√
H
z. The Easy Drive input technology
of the LTC2495 enables an RC network to be added directly
to the output of the LTC6078. The capacitor reduces the
magnitude of the current spikes seen at the input to the
ADC and the resistor isolates the capacitor load from the
op-amp output enabling stable operation. The LTC6078
can also be biased at supply rails beyond those used by
the LTC2495. This allows the external sensor to swing rail-
to-rail (–0.3V to V
CC
+ 0.3V) without the need of external
level shift circuitry.
Reference Current
Similar to the analog inputs, the LTC2495 samples the
differential reference pins (REF
+
and REF
–
) transferring
small amounts of charge to and from these pins, thus
producing a dynamic reference current. If incomplete set-
tling occurs (as a function the reference source resistance
and reference bypass capacitance) linearity and gain errors
are introduced.
For relatively small values of external reference capacitance
(C
REF
< 1nF), the voltage on the sampling capacitor settles
for reference impedances of many k
Ω
(
if C
REF
= 100pF up
to 10k
Ω
will not degrade the performance (see Figures
13 and 14)
)
.
In cases where large bypass capacitors are required on
the reference inputs (C
REF
> 0.01μF), full-scale and linear-
ity errors are proportional to the value of the reference
resistance. Every ohm of reference resistance produces
a full-scale error of approximately 0.5ppm
(
while operat-
ing in simultaneous 50Hz/60Hz mode (see Figures 15
and 16)
)
. If the input common mode voltage is equal to
the reference common mode voltage, a linearity error of
approximately 0.67ppm per 100
Ω
of reference resistance
results (see Figure 17). In applications where the input
and reference common mode voltages are different, the
errors increase. A 1V difference in between common mode
input and common mode reference results in a 6.7ppm
INL error for every 100
Ω
of reference resistance.
In addition to the reference sampling charge, the reference
ESD protection diodes have a temperature dependent leak-
age current. This leakage current, nominally 1nA (±10nA
max) results in a small gain error. A 100
Ω
reference
resistance will create a 0.5μV full-scale error.
Figure 13. +FS Error vs R
SOURCE
at V
REF
(Small C
REF
)
Figure 14. –FS Error vs R
SOURCE
at V
REF
(Small C
REF
)
APPLICATIONS INFORMATION
R
SOURCE
(
)
0
+
50
70
90
10k
2495 F13
30
10
40
60
80
20
0
–10
10
100
1k
100k
V
CC
= 5V
V
= 5V
V
REF
= 3.75V
V
IN–
= 1.25V
F
O
= GND
T
A
= 25
°
C
C
REF
= 0.01
μ
F
C
REF
= 0.001
μ
F
REF
= 100pF
C
REF
= 0pF
R
SOURCE
(
)
0
–
–30
–10
10
10k
2495 F14
–50
–70
–40
–20
0
–60
–80
–90
10
100
1k
100k
V
CC
= 5V
V
= 5V
V
REF
= 1.25V
V
IN–
= 3.75V
F
O
= GND
T
A
= 25
°
C
C
REF
= 0.01
μ
F
C
REF
= 0.001
μ
F
REF
= 100pF
C
REF
= 0pF
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| 249NQ | SCHOTTKY RECTIFIER |
| 249NQ135 | SCHOTTKY RECTIFIER |
| 249NQ135R | SCHOTTKY RECTIFIER |
| 249NQ150 | SCHOTTKY RECTIFIER |
| 249NQ150R | SCHOTTKY RECTIFIER |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| 24-9500 | 制造商:Distributed By MCM 功能描述:CAPACITOR 500V 220UF SNAPRADIAL HIGH-TEMP LOW ESR |
| 249-5005-002 | 制造商:ITT Interconnect Solutions 功能描述:DPA COAX - Bulk |
| 249-5008-000 | 制造商:ITT Interconnect Solutions 功能描述:RG58CU 制造商:ITT Interconnect Solutions 功能描述:RG-58 C/U - Bulk 制造商:ITT Interconnect Solutions 功能描述:RG-58 C/U / 249-5008-000 / Rack & Panel |
| 24-9501 | 制造商:STELLAR LABS 功能描述:3FT SINGLE CHANNEL AUDIO 1 RCARCA M-M |
| 249-5012-000 | 制造商:ITT Interconnect Solutions 功能描述:DPA C/AXIAL PLUG RG-58 / 249-5012-000 / Rack & Panel |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。