- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄17070 > DC1011A-A (Linear Technology)BOARD DELTA SIGMA ADC LTC2498 PDF資料下載
參數(shù)資料
| 型號(hào)： | DC1011A-A |
| 廠商： | Linear Technology |
| 文件頁數(shù)： | 20/38頁 |
| 文件大?。?/td> | 0K |
| 描述： | BOARD DELTA SIGMA ADC LTC2498 |
| 軟件下載： | QuikEval System |
| 設(shè)計(jì)資源： | DC1011A Schematic DC1011A Design Files |
| 標(biāo)準(zhǔn)包裝： | 1 |
| 系列： | Easy Drive™, 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? |
| 已用 IC / 零件： | LTC2498 |
| 已供物品： | 板 |
| 相關(guān)產(chǎn)品： | LTC2498HUHF#TRPBF-ND - IC ADC 24BIT 16CH DELTA 38-QFN LTC2498HUHF#PBF-ND - IC ADC 24BIT 16CH DELTA 38-QFN LTC2498IUHF#TRPBF-ND - IC ADC 24BIT 16CH 38-QFN LTC2498CUHF#TRPBF-ND - IC ADC 24BIT 16CH 38-QFN LTC2498IUHF#PBF-ND - IC ADC 24BIT 16CH 38-QFN LTC2498CUHF#PBF-ND - IC ADC 24BIT 16CH 38-QFN |
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頁當(dāng)前第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁
LTC2498
27
2498ff
The input data is shifted through the SDI pin on the ris-
ing edge of SCK (including the first rising edge) and the
output data is shifted out the SDO pin on the falling edge
of SCK. The data input/output cycle is concluded and a
new conversion automatically begins after the 32nd rising
edge of SCK. During the next conversion, SCK and SDO
remain HIGH until the conversion is complete.
The Use of a 10k Pull-Up on SCK for Internal SCK
Selection
If CS is pulled HIGH while the converter is driving SCK
LOW, the internal pull-up is not available to restore SCK
to a logic HIGH state if SCK is floating. This will cause the
device to exit the internal SCK mode on the next falling
edge of CS. This can be avoided by adding an external 10k
pull-up resistor to the SCK pin.
Whenever SCK is LOW, the LTC2498’s internal pull-up at
SCK is disabled. Normally, SCK is not externally driven if
the device is operating in the internal SCK timing mode.
However, certain applications may require an external
driver on SCK. If the driver goes Hi-Z after outputting a
LOW signal, the internal pull-up is disabled. An external
10k pull-up resistor prevents the device from exiting the
internal SCK mode under this condition.
AsimilarsituationmayoccurduringthesleepstatewhenCS
is pulsed HIGH-LOW-HIGH in order to test the conversion
status. If the device is in the sleep state (EOC = 0), SCK
will go LOW. If CS goes HIGH before the time tEOCTEST,
the internal pull-up is activated. If SCK is heavily loaded,
the internal pull-up may not restore SCK to a HIGH state
before the next falling edge of CS. The external 10k pull-up
resistor prevents the device from exiting the internal SCK
mode under this condition.
PRESERVING THE CONVERTER ACCURACY
The LTC2498 is designed to reduce as much as possible
sensitivity to device decoupling, PCB layout, anti-aliasing
circuits, line frequency perturbations, and temperature
sensitivity. In order to achieve maximum performance a
few simple precautions should be observed.
Digital Signal Levels
The LTC2498’s digital interface is easy to use. Its digital
inputs (SDI, fO, CS, and SCK in external serial clock mode)
accept standard CMOS logic levels. Internal hysteresis
circuitscantolerateedgetransitiontimesasslowas100s.
The digital input signal range is 0.5V to VCC – 0.5V. During
transitions, the CMOS input circuits draw dynamic cur-
rent. For optimal performance, application of signals to
the serial data interface should be reserved for the sleep
and data output periods.
During the conversion period, overshoot and undershoot
of fast digital signals applied to both the serial digital
interface and the external oscillator pin (fO) may degrade
the converter performance. Undershoot and overshoot
occur due to impedance mismatch of the circuit board
trace at the converter pin when the transition time of an
external control signal is less than twice the propagation
delay from the driver to the input pin. For reference, on a
regularFR-4board,thepropagationdelayisapproximately
183ps/inch. In order to prevent overshoot, a driver with
a 1ns transition time must be connected to the converter
through a trace shorter than 2.5 inches. This becomes
difficult when shared control lines are used and multiple
reflections occur.
Parallel termination near the input pin of the LTC2498 will
eliminate this problem, but will increase the driver power
dissipation. A series resistor from 27 to 54 (depend-
ing on the trace impedance and connection) placed near
the driver will also eliminate over/undershoot without
additional driver power dissipation.
For many applications, the serial interface pins (SCK, SDI,
CS, fO) remain static during the conversion cycle and no
degradation occurs. On the other hand, if an external
oscillator is used (fO driven externally) it is active during
the conversion cycle. Moreover, the digital filter rejection
is minimal at the clock rate applied to fO. Care must be
taken to ensure external inputs and reference lines do not
cross this signal or run near it. These issues are avoided
when using the internal oscillator.
applications inForMation
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| NR5040T100M | INDUCTOR 10UH 2.1A 20% SMD |
| EVAL-AD5405EBZ | BOARD EVAL FOR AD5405 |
| EVAL-AD5062EBZ | BOARD EVAL FOR AD5062 |
| V48C2E50BL2 | CONVERTER MOD DC/DC 2V 50W |
| DC1010A-C | BOARD DELTA SIGMA ADC LTC2487 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| DC1011A-B | 功能描述:BOARD DELTA SIGMA ADC LTC2496 RoHS:是 類別:編程器，開發(fā)系統(tǒng) >> 評(píng)估板 - 模數(shù)轉(zhuǎn)換器 (ADC) 系列:Easy Drive™, QuikEval™ 產(chǎn)品培訓(xùn)模塊:Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:1 系列:- ADC 的數(shù)量:1 位數(shù):12 采樣率（每秒）:94.4k 數(shù)據(jù)接口:USB 輸入范圍:±VREF/2 在以下條件下的電源（標(biāo)準(zhǔn)）:- 工作溫度:-40°C ~ 85°C 已用 IC / 零件:MAX11645 已供物品:板，軟件 |
| DC1011A-C | 功能描述:BOARD DELTA SIGMA ADC LTC2494 RoHS:是 類別:編程器，開發(fā)系統(tǒng) >> 評(píng)估板 - 模數(shù)轉(zhuǎn)換器 (ADC) 系列:Easy Drive™, QuikEval™ 產(chǎn)品培訓(xùn)模塊:Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:1 系列:- ADC 的數(shù)量:1 位數(shù):12 采樣率（每秒）:94.4k 數(shù)據(jù)接口:USB 輸入范圍:±VREF/2 在以下條件下的電源（標(biāo)準(zhǔn)）:- 工作溫度:-40°C ~ 85°C 已用 IC / 零件:MAX11645 已供物品:板，軟件 |
| DC-1012 | 制造商:BCM Advanced Research 功能描述:BCM NANO-ITX POWER BOARD - Bulk |
| DC1012080 WAF | 制造商:ON Semiconductor 功能描述: |
| DC1012-103L | 制造商:Coilcraft Inc 功能描述:Power inductor, 10% tol, RoHS |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。