AD780
5V
V SUPPLY
Data Sheet
2
+V IN
AD7884
2
0.1 ? F
1k ?
2N2907
3 +
2 –
1 ? F
V OUT
AD780
2.5V/3.0V
6
V REF + F
V REF + S
AD780
4
6
7
OP90
4
6
2.5k ?
10 ? F
V OUT
0.1 ? F
GND
4
SELECT
8
0.1 ? F
3.9 ?
Figure 21. Precision 3 V Reference for the AD7884 16-Bit, High Speed ADC
5k ?
0.01%
4k ?
0.01%
The AD780 is also ideal for use with higher resolution
converters, such as the AD7710/AD7711/AD7712 (see Figure
22. While these parts are specified with a 2.5 V internal
reference, the AD780 in 3 V mode can be used to improve the
absolute accuracy, temperature stability, and dynamic range. It
is shown in Figure 22 with the two optional noise reduction
capacitors.
5V
Figure 23. 4.5 V Reference from a Single 5 V Supply
NEGATIVE (–2.5 V) REFERENCE
The AD780 can produce a negative output voltage in shunt
mode by connecting the input and output to ground, and
connecting the AD780’s GND pin to a negative supply via a bias
resistor, as shown in Figure 25.
2
AD7710
2
+V IN
7
NC
+V IN
1
NC
V OUT 6
1 ? F
V OUT
AD780
6
REF IN+
1 ? F
AD780
TRIM 5
100nF
3
GND
2.5V/3.0V
O/P SELECT
100 ? F
3
TEMP
GND
O/P SELECT
2.5V – NC
3.0V – GND
4
8
4
8
REF IN–
Figure 22. Precision 2.5 V or 3.0 V Reference for the
AD7710 High Resolution, Σ-Δ ADC
R=
V OUT – (V–)
I L + I S MIN
V–
–2.5 V OUT
NOTES
1. I L = LOAD CURRENT
2. I S MIN = MINIMUM SHUNT CURRENT
3. NC = NO CONNECT
4.5 V REFERENCE FROM 5 V SUPPLY
Some 5 V high resolution ADCs can accommodate reference
voltages up to 4.5 V. The AD780 can be used to provide a
precision 4.5 V reference voltage from a 5 V supply using the
circuit shown in Figure 23. This circuit provides a regulated
4.5 V output from a supply voltage as low as 4.7 V. The high
quality tantalum 10 μF capacitor, in parallel with the ceramic
AD780 0.1 μF capacitor and the 3.9 Ω resistor, ensures a low
Figure 24. Negative (?2.5 V Shunt Mode Reference)
A precise –2.5 V reference capable of supplying up to 100 mA to
a load can be implemented with the AD780 in series mode,
using the bootstrap circuit shown in Figure 25.
+5V
+V IN
2
output impedance around 50 MHz.
1k ?
OUT
AD780
+5V
6
4
8
CONNECT IF
–3V OUTPUT
DESIRED
–2.5V (I L ? 100mA)
OP07
2N3906
+
–5V
–5V
1000pF
Figure 25. ?2.5 V High Load Current Reference
Rev. F | Page 10 of 12
相关PDF资料
GEM15DRXS CONN EDGECARD 30POS DIP .156 SLD
GMM03DRAN CONN EDGECARD 6POS R/A .156 SLD
TAAD336M035G CAP TANT 33UF 35V 20% AXIAL
SJP7402-3/4-50-BLACK HOOK BLACK 3/4" X 50YD X 0.11"
GCM08DCCN CONN EDGECARD 16POS R/A .156 SLD
TAAD336K035G CAP TANT 33UF 35V 10% AXIAL
GCM08DCCH CONN EDGECARD 16POS R/A .156 SLD
GCM08DCCD CONN EDGECARD 16POS R/A .156 SLD
相关代理商/技术参数
AD780CRZ-REEL7 功能描述:IC VREF SERIES SHUNT PREC 8-SOIC RoHS:是 类别:集成电路 (IC) >> PMIC - 电压基准 系列:- 标准包装:2,000 系列:- 基准类型:旁路,可调节,精度 输出电压:1.24 V ~ 16 V 容差:±0.5% 温度系数:- 输入电压:1.24 V ~ 16 V 通道数:1 电流 - 阴极:100µA 电流 - 静态:- 电流 - 输出:20mA 工作温度:-40°C ~ 85°C 安装类型:通孔 封装/外壳:TO-226-3、TO-92-3(TO-226AA)成形引线 供应商设备封装:TO-92-3 包装:带卷 (TR)
AD781 制造商:AD 制造商全称:Analog Devices 功能描述:Complete 700 ns Sample-and-Hold Amplifier
AD7810 制造商:AD 制造商全称:Analog Devices 功能描述:2.7 V to 5.5 V, 2 us, 10-Bit ADC in 8-Lead microSOIC/DIP
AD7810YN 制造商:Analog Devices 功能描述:ADC Single SAR 350ksps 10-bit Serial 8-Pin PDIP 制造商:Rochester Electronics LLC 功能描述:10-BIT SERIAL SINGLE ADC I.C. - Bulk 制造商:Analog Devices 功能描述:IC 10-BIT ADC
AD7810YNZ 功能描述:IC ADC 10BIT SRL HS LP 8DIP RoHS:是 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 其它有关文件:TSA1204 View All Specifications 标准包装:1 系列:- 位数:12 采样率(每秒):20M 数据接口:并联 转换器数目:2 功率耗散(最大):155mW 电压电源:模拟和数字 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-TQFP 供应商设备封装:48-TQFP(7x7) 包装:Digi-Reel® 输入数目和类型:4 个单端,单极;2 个差分,单极 产品目录页面:1156 (CN2011-ZH PDF) 其它名称:497-5435-6
AD7810YR 功能描述:IC ADC 10BIT 2.7V 8-SOIC RoHS:否 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:-
AD7810YRM 制造商:Analog Devices 功能描述:ADC Single SAR 350ksps 10-bit Serial 8-Pin MSOP 制造商:Rochester Electronics LLC 功能描述:10-BIT SERIAL SINGLE ADC I.C. - Bulk