参数资料
型号: DC746A
厂商: Linear Technology
文件页数: 16/36页
文件大小: 0K
描述: BOARD DELTA SIGMA ADC LTC2412
软件下载: QuikEval System
设计资源: DC746A Design File
DC746A Schematic
标准包装: 1
系列: QuikEval™
ADC 的数量: 1
位数: 24
采样率(每秒): 7.5
数据接口: MICROWIRE?,串行,SPI?
工作温度: 0°C ~ 70°C
已用 IC / 零件: LTC2412
已供物品:
相关产品: 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
23
2412f
APPLICATIO S I FOR ATIO
WU
U
Parallel termination near the LTC2412 pin will eliminate
this problem but will increase the driver power dissipation.
A series resistor between 27
and 56 placed near the
driver or near the LTC2412 pin will also eliminate this
problem without additional power dissipation. The actual
resistor value depends upon the trace impedance and
connection topology.
An alternate solution is to reduce the edge rate of the
control signals. It should be noted that using very slow
edges will increase the converter power supply current
during the transition time. The multiple ground pins used
in this package configuration, as well as the differential
input and reference architecture, reduce substantially the
converter’s sensitivity to ground currents.
Particular attention must be given to the connection of the
FO signal when the LTC2412 is used with an external
conversion clock. This clock is active during the conver-
sion time and the normal mode rejection provided by the
internal digital filter is not very high at this frequency. A
normal mode signal of this frequency at the converter
reference terminals may result into DC gain and INL
errors. A normal mode signal of this frequency at the
converter input terminals may result into a DC offset error.
Such perturbations may occur due to asymmetric capaci-
tive coupling between the FO signal trace and the converter
input and/or reference connection traces. An immediate
solution is to maintain maximum possible separation
between the FO signal trace and the input/reference sig-
nals. When the FO signal is parallel terminated near the
converter, substantial AC current is flowing in the loop
formed by the FO connection trace, the termination and the
ground return path. Thus, perturbation signals may be
inductively coupled into the converter input and/or refer-
ence. In this situation, the user must reduce to a minimum
the loop area for the FO signal as well as the loop area for
the differential input and reference connections.
Driving the Input and Reference
The input and reference pins of the LTC2412 converter are
directly connected to a network of sampling capacitors.
Depending upon the relation between the differential input
voltage and the differential reference voltage, these ca-
pacitors are switching between these four pins transfering
small amounts of charge in the process. A simplified
equivalent circuit is shown in Figure 11, where IN+ and IN
refer to the selected differential channel and the unselected
channel is omitted for simplicity.
VREF+
VIN+
VCC
RSW (TYP)
20k
ILEAK
VCC
ILEAK
VCC
RSW (TYP)
20k
CEQ
18pF
(TYP)
RSW (TYP)
20k
ILEAK
IIN+
VIN
IIN
IREF+
IREF
2412 F11
ILEAK
VCC
ILEAK
SWITCHING FREQUENCY
fSW = 76800Hz INTERNAL OSCILLATOR (FO = LOW OR HIGH)
fSW = 0.5 fEOSC EXTERNAL OSCILLATOR
VREF
RSW (TYP)
20k
IIN
VV
V
R
IIN
VV
V
R
I REF
VV
V
R
V
VR
I REF
VV
V
R
V
VR
where
AVG
IN
INCM
REFCM
EQ
AVG
IN
INCM
REFCM
EQ
AVG
REF
INCM
REFCM
EQ
IN
REF
EQ
AVG
REF
INCM
REFCM
EQ
IN
REF
EQ
+
+
() = +
() = +
() =
+
() =
+
+
05
15
05
15
05
2
.
::
.
./
V
REF
V
REF
VIN
IN
V
IN
R
M
INTERNAL OSCILLATOR
Hz Notch F
LOW
R
M
INTERNAL OSCILLATOR
Hz Notch F
HIGH
R
f
EXTERNAL OSCILLATOR
REF
REFCM
IN
INCM
EQ
O
EQ
O
EQ
EOSC
=
+
=
==
()
==
()
=
()
+
2
361
60
432
50
0 555 1012
Figure 11. LTC2412 Equivalent Analog Input Circuit
相关PDF资料
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
相关代理商/技术参数
参数描述
DC74HC259 制造商:TI 制造商全称: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