參數(shù)資料
型號(hào): ADR391
廠商: Analog Devices, Inc.
英文描述: Precision Low Drift 2.048 V/2.5 V/4.096 V/ 5.0 V SOT-23 Reference with Shutdown
中文描述: 精密低漂移2.048 V/2.5 V/4.096第V / 5.0V的SOT - 23封裝,帶有關(guān)斷參考
文件頁(yè)數(shù): 17/20頁(yè)
文件大?。?/td> 269K
代理商: ADR391
ADR390/ADR391/ADR392/ADR395
APPLICATIONS
BASIC VOLTAGE REFERENCE CONNECTION
The circuit shown in Figure 41 illustrates the basic configuration
for the ADR39x family. Decoupling capacitors are not required
for circuit stability. The ADR39x family is capable of driving
capacitive loads from 0 μF to 10 μF. However, a 0.1 μF ceramic
output capacitor is recommended to absorb and deliver the
charge, as required by a dynamic load.
Rev. F | Page 17 of 20
SHUTDOWN
INPUT
C
B
0.1
μ
F
C
B
0.1
μ
F
*
*
OUTPUT
*NOT REQUIRED
ADR39x
V
IN
SHDN
V
OUT(S)
GND
V
OUT(F)
0
Figure 41. Basic Configuration for the ADR39x Family
Stacking Reference ICs for Arbitrary Outputs
Some applications may require two reference voltage sources,
which are a combined sum of standard outputs. Figure 42 shows
how this stacked output reference can be implemented.
V
OUT(F)
V
OUT(S)
GND
5
V
IN
V
OUT2
V
OUT1
U2
1
2
3
4
U1
C2
0.1
μ
F
V
IN
3
4
1
2
V
IN
C2
0.1
μ
F
V
OUT(F)
V
OUT(S)
GND
5
OUTPUTTABLE
U1/U2
ADR390/ADR390
ADR391/ADR391
ADR392/ADR392
ADR395/ADR395
V
OUT1
(V)
2.048
2.5
4.096
5
V
OUT2
(V)
4.096
5.0
8.192
10
0
SHDN
SHDN
Figure 42. Stacking Voltage References with the
ADR390/ADR391/ADR392/ADR395
Two reference ICs are used, fed from an unregulated input, V
IN
.
The outputs of the individual ICs are simply connected in
series, which provides two output voltages, V
OUT1
and V
OUT2
.
V
OUT1
is the terminal voltage of U1, while V
OUT2
is the sum of
this voltage and the terminal voltage of U2. U1 and U2 are
simply chosen for the two voltages that supply the required
outputs (see the Output Table in Figure 42). For example, if
both U1 and U2 are ADR391s, V
OUT1
is 2.5 V and V
OUT2
is 5.0 V.
While this concept is simple, a precaution is required. Since the
lower reference circuit must sink a small bias current from U2
plus the base current from the series PNP output transistor in
U2, either the external load of U1 or R1 must provide a path for
this current. If the U1 minimum load is not well defined, the R1
resistor should be used and set to a value that will conservatively
pass 600 μA of current with the applicable V
OUT1
across it. Note
that the two U1 and U2 reference circuits are treated locally as
macrocells; each has its own bypasses at input and output for
best stability. Both U1 and U2 in this circuit can source dc
currents up to their full rating. The minimum input voltage,
V
IN
, is determined by the sum of the outputs, V
OUT2
, plus the
dropout voltage of U2.
A Negative Precision Reference without Precision
Resistors
A negative reference can be easily generated by adding an A1 op
amp and is configured as shown in Figure 43. V
OUTF
and V
OUTS
are at virtual ground and, therefore, the negative reference can
be taken directly from the output of the op amp. The op amp
must be dual-supply, low offset, and rail-to-rail if the negative
supply voltage is close to the reference output.
+V
DD
–V
DD
–V
REF
V
OUT(S)
V
OUT(F)
V
IN
GND
5
A1
2
4
3
1
0
SHDN
Figure 43. Negative Reference
相關(guān)PDF資料
PDF描述
ADR392 Precision Low Drift 2.048 V/2.5 V/4.096 V/ 5.0 V SOT-23 Reference with Shutdown
ADR392ART-RL Precision Low Drift 2.048 V/2.5 V/4.096 V/ 5.0 V SOT-23 Reference with Shutdown
ADR392ART-RL7 Precision Low Drift 2.048 V/2.5 V/4.096 V/ 5.0 V SOT-23 Reference with Shutdown
ADR395 Precision Low Drift 2.048 V/2.5 V/4.096 V/ 5.0 V SOT-23 Reference with Shutdown
ADR395ART-RL7 Precision Low Drift 2.048 V/2.5 V/4.096 V/ 5.0 V SOT-23 Reference with Shutdown
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
ADR391A 制造商:AD 制造商全稱:Analog Devices 功能描述:Micropower, Low Noise Precision Voltage References with Shutdown
ADR391ART-R2 制造商:Analog Devices 功能描述:
ADR391ART-REEL7 制造商:Analog Devices 功能描述: 制造商:Rochester Electronics LLC 功能描述:SOT23-5 VOLTAGE REFERENCE - Tape and Reel
ADR391ART-RL 制造商:AD 制造商全稱:Analog Devices 功能描述:Precision Low Drift 2.048 V/2.5 V/4.096 V/ 5.0 V SOT-23 Reference with Shutdown
ADR391ART-RL7 制造商:AD 制造商全稱:Analog Devices 功能描述:Precision Low Drift 2.048 V/2.5 V/4.096 V/ 5.0 V SOT-23 Reference with Shutdown