参数资料
型号: AD8132AR
厂商: Analog Devices Inc
文件页数: 15/33页
文件大小: 0K
描述: IC AMP DIFF LDIST LP 70MA 8SOIC
标准包装: 98
放大器类型: 差分
电路数: 1
输出类型: 差分
转换速率: 1200 V/µs
-3db带宽: 360MHz
电流 - 输入偏压: 3µA
电压 - 输入偏移: 1000µV
电流 - 电源: 12mA
电流 - 输出 / 通道: 70mA
电压 - 电源,单路/双路(±): 2.7 V ~ 11 V,±1.35 V ~ 5.5 V
工作温度: -40°C ~ 125°C
安装类型: 表面贴装
封装/外壳: 8-SOIC(0.154",3.90mm 宽)
供应商设备封装: 8-SO
包装: 管件
AD8132
Rev. I | Page 21 of 32
OPERATIONAL DESCRIPTION
DEFINITION OF TERMS
Differential Voltage
It is the difference between two node voltages. For example, the
output differential voltage (or equivalently output differential
mode voltage) is defined as
VOUT, dm = (V+OUT VOUT)
where V+OUT and VOUT refer to the voltages at the +OUT and
OUT terminals with respect to a common reference.
Common-Mode Voltage
It is the average of two node voltages. The output common-
mode voltage is defined as
VOUT, cm = (V+OUT + VOUT)/2
AD8132
CF
+IN
–IN
RF
CF
RF
RG
+DIN
VOCM
–DIN
RL, dm
+OUT
VOUT, dm
–OUT
0
10
35
-0
64
Figure 64. Circuit Definitions
BASIC CIRCUIT OPERATION
One of the more useful and easy to understand ways to use the
AD8132 is to provide two equal ratio feedback networks. To
match the effect of parasitics, comprise these networks of two
equal value feedback resistors (RF) and two equal value gain
resistors (RG). This circuit is shown in Figure 64.
Like a conventional op amp, the AD8132 has two differential
inputs that can be driven with both differential mode input
voltage (VIN, dm) and common-mode input voltage (VIN, cm).
There is another input to consider (VOCM) on the AD8132 that
is not present on conventional op amps. VOCM is completely
separate from the previous inputs.
There are two complementary outputs whose response can be
defined by a differential mode output (VOUT, dm) and a common-
mode output (VOUT, cm).
Table 10 shows the gain from any type of input to either type
of output.
Table 10. Differential and Common-Mode Gains
Input
VOUT, dm
VOUT, cm
VIN, dm
RF/RG
0 (by design)
VIN, cm
0
0 (by design)
VOCM
0
1 (by design)
As listed in Table 10, the differential output (VOUT, dm) is equal to
the differential input voltage (VIN, dm) times RF/RG. In this case, it
does not matter if both differential inputs are driven, or only one
output is driven and the other is tied to a reference voltage, such
as ground. As seen from the two zero entries in the VOUT,dm column,
neither of the common-mode inputs has any effect on this gain.
The gain from VIN, dm to VOUT, cm is 0, and first-order, does not
depend on the ratio matching of the feedback networks. The
common-mode feedback loop within the AD8132 provides a
corrective action to keep this gain term minimized. The term
balance error describes the degree that this gain term differs
from 0.
The gain from VIN,cm to VOUT,dm directly depends on the matching
of the feedback networks. The analogous term for this transfer
function (used in conventional op amps) is common-mode
rejection ratio (CMRR). Therefore, if it has a high CMRR, the
feedback ratios must be well matched.
The gain from VIN, cm to VOUT, cm is ideally 0 and is first-order
independent of the feedback ratio matching. As in the case of
VIN, dm to VOUT, cm, the common-mode feedback loop keeps this
term minimized.
The gain from VOCM to VOUT,dm is ideally 0 when the feedback ratios
are matched only. The amount of differential output signal that is
created by varying VOCM is related to the degree of mismatch in the
feedback networks.
VOCM controls the output common-mode voltage VOUT, cm with a
unity-gain transfer function. With equal ratio feedback networks
(as previously assumed), its effect on each output is the same,
that is the gain from VOCM to VOUT, dm is 0. If not driven, the
output common-mode voltage is set with an internal voltage
divider to a level that is nominally midsupply. It is recommended
that a 0.1 μF bypass capacitor be connected to VOCM.
When unequal feedback ratios are used, the two gains associated
with VOUT, dm become nonzero. This significantly complicates the
mathematical analysis along with any intuitive understanding of
how the part operates.
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相关代理商/技术参数
参数描述
AD8132AR 制造商:Analog Devices 功能描述:SEMICONDUCTORS ((NW))
AD8132AR-EBZ 功能描述:BOARD EVAL FOR AD8132AR RoHS:是 类别:编程器,开发系统 >> 评估板 - 运算放大器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:1 系列:-
AD8132ARM 功能描述:IC AMP DIFF LDIST LP 70MA 8MSOP RoHS:否 类别:集成电路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 标准包装:1 系列:- 放大器类型:通用 电路数:4 输出类型:满摆幅 转换速率:0.028 V/µs 增益带宽积:105kHz -3db带宽:- 电流 - 输入偏压:3nA 电压 - 输入偏移:100µV 电流 - 电源:3.3µA 电流 - 输出 / 通道:12mA 电压 - 电源,单路/双路(±):2.7 V ~ 12 V,±1.35 V ~ 6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:14-TSSOP(0.173",4.40mm 宽) 供应商设备封装:14-TSSOP 包装:剪切带 (CT) 其它名称:OP481GRUZ-REELCT
AD8132ARM-EBZ 功能描述:BOARD EVAL FOR AD8132ARM RoHS:是 类别:编程器,开发系统 >> 评估板 - 运算放大器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:1 系列:-
AD8132ARM-REEL 制造商:Analog Devices 功能描述:SP Amp DIFF AMP Single ±5.5V/11V 8-Pin MSOP T/R