- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄1981 > AD7490BRU-REEL (Analog Devices Inc)IC ADC 12BIT 16CH 28-TSSOP T/R PDF資料下載
參數(shù)資料
| 型號(hào)： | AD7490BRU-REEL |
| 廠商： | Analog Devices Inc |
| 文件頁數(shù)： | 17/29頁 |
| 文件大?。?/td> | 0K |
| 描述： | IC ADC 12BIT 16CH 28-TSSOP T/R |
| 產(chǎn)品變化通告： | IDD Specification Change 17/Jun/2009 Product Discontinuance 27/Oct/2011 |
| 標(biāo)準(zhǔn)包裝： | 2,500 |
| 位數(shù)： | 12 |
| 采樣率（每秒）： | 1M |
| 數(shù)據(jù)接口： | DSP，MICROWIRE?，QSPI?，串行，SPI? |
| 轉(zhuǎn)換器數(shù)目： | 1 |
| 功率耗散（最大）： | 12.5mW |
| 電壓電源： | 單電源 |
| 工作溫度： | -40°C ~ 85°C |
| 安裝類型： | 表面貼裝 |
| 封裝/外殼： | 28-TSSOP（0.173"，4.40mm 寬） |
| 供應(yīng)商設(shè)備封裝： | 28-TSSOP |
| 包裝： | 帶卷 (TR) |
| 輸入數(shù)目和類型： | 16 個(gè)單端，單極 |
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頁當(dāng)前第17頁第18頁第19頁第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
Data Sheet
AD7490
Rev. D | Page 23 of 28
If the WEAK/TRI bit in the control register is set to 1, instead of
returning to true three-state on the 16th SCLK falling edge, the
DOUT line is pulled weakly to the logic level corresponding to
ADD3 of the next serial transfer. This is done to ensure that the
MSB of the next serial transfer is set up in time for the first
SCLK falling edge after the CS falling edge. If the WEAK/TRI bit
is set to 0 and the DOUT line has been in true three-state
between conversions, the ADD3 address bit may not be set up
in time for the DSP/microcontroller to clock it in successfully,
depending on the particular DSP or microcontroller interfacing
to the AD7490. In this case, ADD3 would only be driven from
the falling edge of CS and must then be clocked in by the DSP
on the following falling edge of SCLK. However, if the WEAK/
TRI bit is set to 1, although DOUT is driven with the ADD3
address bit since the last conversion, it is nevertheless so weakly
driven that another device may still take control of the bus. It
does not lead to a bus contention (for example, a 10 k pull-up
or pull-down resistor is sufficient to overdrive the logic level of
ADD3 between conversions), and all 16 channels may be
identified. If this does happen and another device takes control
of the bus, it is not guaranteed that DOUT will be fully driven
to ADD3 again in time for the read operation when control of
the bus is taken back.
This is especially useful if using an automatic sequence mode to
identify to which channel each result corresponds. If only the
first eight channels are in use, Address Bit ADD3 does not need
to be decoded, and whether it is successfully clocked in as a 1
or 0 does not matter as long as it is still counted by the DSP/
microcontroller as the MSB of the 16-bit serial transfer.
POWER vs. THROUGHPUT RATE
By operating the AD7490 in auto shutdown or auto standby
mode, the average power consumption of the ADC decreases at
lower throughput rates. Figure 29 shows that as the throughput
rate is reduced, the part remains in shutdown state longer and
the average power consumption drops accordingly over time.
For example, if the AD7490 is operated in a continuous
sampling mode with a throughput rate of 100 kSPS and an
SCLK of 20 MHz (VDD = 5 V), with PM1 = 0 and PM0 = 1 (that
is, the device is in auto shutdown mode), the power
consumption is calculated as shown in Equation 1.
The maximum power dissipation during normal operation is
12.5 mW (VDD = 5 V). If the power-up time from auto shut-
down is one dummy cycle, that is, 1 s, and the remaining
conversion time is another cycle, that is, 1 s, then the AD7490
can be said to dissipate 12.5 mW for 2 s during each conver-
sion cycle. For the remainder of the conversion cycle, 8 s, the
part remains in shutdown mode. The AD7490 can be said to
dissipate 2.5 W for the remaining 8 s of the conversion cycle.
If the throughput rate is 100 kSPS, the cycle time is 10 s and
the average power dissipated during each cycle is
mW
502
.
2
μW
5
.
2
10
8
mW
5
.
12
10
2
=
×
+
×
(1)
When operating the AD7490 in auto standby mode (PM1 =
PM0 = 0 at 5 V, 100 kSPS), the AD7490 power dissipation is
calculated as shown in Equation 2.
The maximum power dissipation is 12.5 mW at 5 V during nor-
mal operation. Again the power-up time from auto standby is
one dummy cycle, 1 s, and the remaining conversion time is
another dummy cycle, 1 s. The AD7490 dissipates 12.5 mW
for 2 s during each conversion cycle. For the remainder of the
conversion cycle, 8 s, the part remains in standby mode,
dissipating 460 W for 8 s. If the throughput rate is 100 kSPS,
the cycle time is 10 s and the average power dissipated during
each conversion cycle is
mW
868
.
2
μW
460
10
8
mW
5
.
12
10
2
=
×
+
×
(2)
Figure 29 shows the power vs. throughput rate when using both
the auto shutdown mode and auto standby mode with 5 V
supplies. At the lower throughput rates, power consumption for
the auto shutdown mode is lower than that for the auto standby
mode, with the AD7490 dissipating less power when in shut-
down compared to standby. As the throughput rate is increased,
however, the part spends less time in power-down states; hence,
the difference in power dissipated is negligible between modes.
For 3 V supplies, the power consumption of the AD7490
decreases. Similar power calculations can be done at 3 V.
10
0.01
0.1
1
0
50
100
150
200
250
300
350
02691-
028
THROUGHPUT (kSPS)
PO
W
ER
(m
V)
VDD = 5V
AUTO STANDBY
AUTO SHUTDOWN
Figure 29. Power vs. Throughput Rate in Auto Shutdown
and Auto Standby Mode
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| AD7492ARZ-5 | IC ADC 12BIT REF/CLOCK 24SOIC |
| AD7495BRM | IC ADC 12BIT SRL LP W/REF 8MSOP |
| AD75004KP | IC DAC 12BIT QUAD W/BUFF 28-PLCC |
| AD7521LN | CONV D/A 12BIT 1MHZ 2LSB 18-DIP |
| AD7524LNZ | IC DAC 8BIT MULTIPLYING 16DIP |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| AD7490BRU-REEL7 | 制造商:Analog Devices 功能描述:ADC Single SAR 1Msps 12-bit Serial 28-Pin TSSOP T/R 制造商:Analog Devices 功能描述:ADC SGL SAR 1MSPS 12-BIT SERL 28TSSOP - Tape and Reel 制造商:Rochester Electronics LLC 功能描述:12 BIT 16 CHANNEL ADC IC - Tape and Reel |
| AD7490BRUZ | 功能描述:IC ADC 12BIT 16CH 1MSPS 28TSSOP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 模數(shù)轉(zhuǎn)換器 系列:- 標(biāo)準(zhǔn)包裝:1 系列:microPOWER™ 位數(shù):8 采樣率（每秒）:1M 數(shù)據(jù)接口:串行，SPI? 轉(zhuǎn)換器數(shù)目:1 功率耗散（最大）:- 電壓電源:模擬和數(shù)字 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:24-VFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:24-VQFN 裸露焊盤（4x4） 包裝:Digi-Reel® 輸入數(shù)目和類型:8 個(gè)單端，單極 產(chǎn)品目錄頁面:892 (CN2011-ZH PDF) 其它名稱:296-25851-6 |
| AD7490BRUZ-REEL | 功能描述:IC ADC 12BIT 16CHAN 28TSSOP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 模數(shù)轉(zhuǎn)換器 系列:- 標(biāo)準(zhǔn)包裝:1,000 系列:- 位數(shù):16 采樣率（每秒）:45k 數(shù)據(jù)接口:串行 轉(zhuǎn)換器數(shù)目:2 功率耗散（最大）:315mW 電壓電源:模擬和數(shù)字 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:28-SOIC（0.295"，7.50mm 寬） 供應(yīng)商設(shè)備封裝:28-SOIC W 包裝:帶卷 (TR) 輸入數(shù)目和類型:2 個(gè)單端，單極 |
| AD7490BRUZ-REEL7 | 功能描述:IC ADC 12BIT 16CHAN 28TSSOP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 模數(shù)轉(zhuǎn)換器 系列:- 標(biāo)準(zhǔn)包裝:1,000 系列:- 位數(shù):16 采樣率（每秒）:45k 數(shù)據(jù)接口:串行 轉(zhuǎn)換器數(shù)目:2 功率耗散（最大）:315mW 電壓電源:模擬和數(shù)字 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:28-SOIC（0.295"，7.50mm 寬） 供應(yīng)商設(shè)備封裝:28-SOIC W 包裝:帶卷 (TR) 輸入數(shù)目和類型:2 個(gè)單端，單極 |
| AD7490SRU-EP-RL7 | 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 12-BIT 16CH IC w/ Sequencer RoHS:否 制造商:Analog Devices 通道數(shù)量: 結(jié)構(gòu): 轉(zhuǎn)換速率: 分辨率: 輸入類型: 信噪比: 接口類型: 工作電源電壓: 最大工作溫度: 安裝風(fēng)格: 封裝 / 箱體: |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。