参数资料
型号: AD7888ARUZ-REEL7
厂商: Analog Devices Inc
文件页数: 2/17页
文件大小: 0K
描述: IC ADC 12BIT SRL 125KSPS 16TSSOP
标准包装: 1
位数: 12
采样率(每秒): 125k
数据接口: DSP,MICROWIRE?,QSPI?,串行,SPI?
转换器数目: 1
功率耗散(最大): 3.5mW
电压电源: 单电源
工作温度: -40°C ~ 105°C
安装类型: 表面贴装
封装/外壳: 16-TSSOP(0.173",4.40mm 宽)
供应商设备封装: 16-TSSOP
包装: 标准包装
输入数目和类型: 8 个单端,单极
其它名称: AD7888ARUZ-REEL7DKR
AD7888
–10–
order to obtain optimum performance from the device it is
advised to disable the internal reference by setting the REF bit
in the Control Register when an external reference is applied.
When the internal reference is disabled, SW1 in Figure 11 will
open and the input impedance seen at the REF IN/REF OUT
pin is the input impedance of the reference buffer, which is in
the region of giga
. When the reference is enabled, the input
impedance seen at the pin is typically 5 k
.
SW1
5k
2.5V
REF IN/REF OUT
Figure 11. On-Chip Reference Circuitry
Table III. Power Management Options
PM1
PM0
Mode
00
Normal Operation. In this mode, the AD7888
remains in full power mode regardless of the
status of any of the logic inputs. This mode
allows the fastest possible throughput rate from
the AD7888.
01
Full Shutdown. In this mode, the AD7888 is
in full shutdown mode with all circuitry on the
AD7888, including the on-chip reference, enter-
ing its power-down mode. The AD7888 retains
the information in the control Register bits
while in full shutdown. The part remains in full
shutdown until these bits are changed.
10
Autoshutdown. In this mode, the AD7888
automatically enters full shutdown mode at the
end of each conversion. Wake-up time from full
shutdown is 5
s and the user should ensure that
5
s have elapsed before attempting to perform
a valid conversion on the part in this mode.
11
Autostandby. In this standby mode, portions
of the AD7888 are powered down but the on-
chip reference voltage remains powered up. The
REF bit should be 0 to ensure the on-chip refer-
ence is enabled. This mode is similar to auto-
shutdown but allows the part to power-up
much faster.
POWER-DOWN OPTIONS
The AD7888 provides flexible power management to allow the
user to achieve the best power performance for a given through-
put rate.
The power management options are selected by programming
the power management bits (i.e., PM1 and PM0) in the control
register. Table III summarizes the options available. When the
power management bits are programmed for either of the auto
power-down modes, the part will enter the power-down mode
on the 16th rising SCLK edge after the falling edge of
CS. The
first falling SCLK edge after the
CS falling edge will cause the
part to power up again. When the AD7888 is in full shutdown,
the only way to fully power it up again is to reprogram the
power management bits to PM1 = PM0 = 0, i.e., normal
mode. In this case the device will power up on the 16th SCLK
rising edge after the
CS falling edge as this is when the power
management bits become effective.
Power-Up Times
The AD7888 has an approximate 1
s power-up time when
powering up from standby or when using an external reference.
When VDD is first connected, the AD7888 will fully power up,
i.e., it powers up in normal mode. If the part is put into shut-
down, a subsequent power-up will take approximately 5
s. The
AD7888 wake-up time is very short in the autostandby mode so
it is possible to wake up the part and carry out a valid conver-
sion in the same read/write operation.
POWER vs. THROUGHPUT RATE
By operating the AD7888 in autoshutdown or autostandby
mode the average power consumption of the AD7888 decreases
at lower throughput rates. Figure 12 shows how as the through-
put rate is reduced, the device remains in its power-down state
longer and the average power consumption over time drops
accordingly.
For example, if the AD7888 were operated in a continuous
sampling mode, with a throughput rate of 10 kSPS and a SCLK
of 2 MHz (VDD = 5 V), and if PM1 = 1 and PM0 = 0, i.e., the
device is in autoshutdown mode and the on-chip reference is
used, the power consumption is calculated as follows. The
power dissipation during normal operation is 3.5 mW (VDD =
5 V). If the power-up time is 5
s and the remaining conversion-
plus-acquisition time is 15.5 tSCLK, i.e., approximately 7.75
s,
(see Figure 14a), the AD7888 can be said to dissipate 3.5 mW
for 12.75
s during each conversion cycle. If the throughput rate
is 10 kSPS, the cycle time is 100
s and the average power dissi-
pated during each cycle is (12.75/100)
× (3.5 mW) = 446.25 W.
If VDD = 3 V SCLK = 2 MHz, and the device is again in auto-
shutdown mode using the on-chip reference, the power dissipa-
tion during normal operation is 2.1 mW. The AD7888 can now
be said to dissipate 2.1 mW for 12.75
s during each conversion
cycle. With a throughput rate of 10 kSPS, the average power
dissipated during each cycle is (12.75/100)
× (2.1 mW) =
267.75
W. Figure 12 shows the power vs. throughput rate for
automatic shutdown with both 5 V and 3 V supplies.
THROUGHPUT – kSPS
10
0
POWER
mW
1
10
0.1
0.01
VDD = 5V
SCLK = 2MHz
VDD = 3V
SCLK = 2MHz
20
30
40
50
Figure 12. Power vs. Throughput
REV. C
相关PDF资料
PDF描述
MC10H115PG IC RECEIVER QUAD LINE ECL 16DIP
ADCMP562BRQ IC COMPARATOR PECL DUAL 20QSOP
ADCMP551BRQ IC COMPARATOR PECL/LVPECL 16QSOP
AD790JR-REEL IC COMPARATOR PREC W/LATCH 8SOIC
LT1016IS8 IC COMPARATOR 10NS HI-SPD 8-SOIC
相关代理商/技术参数
参数描述
AD7888ARZ 功能描述:IC ADC 12BIT 8CH SRL 16-SOIC RoHS:是 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 标准包装:1 系列:microPOWER™ 位数:8 采样率(每秒):1M 数据接口:串行,SPI? 转换器数目:1 功率耗散(最大):- 电压电源:模拟和数字 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:24-VFQFN 裸露焊盘 供应商设备封装:24-VQFN 裸露焊盘(4x4) 包装:Digi-Reel® 输入数目和类型:8 个单端,单极 产品目录页面:892 (CN2011-ZH PDF) 其它名称:296-25851-6
AD7888ARZ-REEL 功能描述:IC ADC 12BIT 8CH SRL 16-SOIC RoHS:是 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- 位数:12 采样率(每秒):3M 数据接口:- 转换器数目:- 功率耗散(最大):- 电压电源:- 工作温度:- 安装类型:表面贴装 封装/外壳:SOT-23-6 供应商设备封装:SOT-23-6 包装:带卷 (TR) 输入数目和类型:-
AD7888ARZ-REEL7 功能描述:IC ADC 12BIT 8CH SRL 16-SOIC RoHS:是 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 标准包装:1,000 系列:- 位数:16 采样率(每秒):45k 数据接口:串行 转换器数目:2 功率耗散(最大):315mW 电压电源:模拟和数字 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:28-SOIC(0.295",7.50mm 宽) 供应商设备封装:28-SOIC W 包装:带卷 (TR) 输入数目和类型:2 个单端,单极
AD7888BR 制造商:Analog Devices 功能描述:ADC Single SAR 125ksps 12-bit Serial 16-Pin SOIC N
AD7888BR-REEL 功能描述:IC ADC 12BIT 8CHAN SRL 16SOIC RoHS:否 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 标准包装:1,000 系列:- 位数:16 采样率(每秒):45k 数据接口:串行 转换器数目:2 功率耗散(最大):315mW 电压电源:模拟和数字 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:28-SOIC(0.295",7.50mm 宽) 供应商设备封装:28-SOIC W 包装:带卷 (TR) 输入数目和类型:2 个单端,单极