AD8002AR-EBZ(2015) Просмотр технического описания (PDF) - Analog Devices
Номер в каталоге
Компоненты Описание
производитель
AD8002AR-EBZ Datasheet PDF : 21 Pages
| |||
AD8002
Data Sheet
APPLICATIONS INFORMATION
LAYOUT CONSIDERATIONS
The specified high speed performance of the AD8002 requires
careful attention to board layout and component selection.
Proper RF design techniques and low parasitic component
selection are mandatory.
Use a ground plane to cover all unused portions of the
component side of the board to provide a low impedance
ground path. Remove the ground plane from the area near
the input pins to reduce stray capacitance.
Use chip capacitors for supply bypassing (see Figure 58). Connect
one end to the ground plane and the other within ⅛ inch of
each power pin. Connect an additional large tantalum
electrolytic capacitor (4.7 µF to 10 µF) in parallel, but not
necessarily so close, to supply current for fast, large signal
changes at the output.
Locate the feedback resistor close to the inverting input pin
to keep the stray capacitance at this node to a minimum.
Capacitance variations of less than 1 pF at the inverting input
significantly affects high speed performance.
Use stripline design techniques for long signal traces (greater than
about 1 inch). Design these with a characteristic impedance of
50 Ω or 75 Ω and ensure they are properly terminated at each
end.
Table 4 and Table 5 show the recommended component values.
Table 4. AD8002AR (SOIC) Recommended Component Values1
Component
RF
RG
RBT (Nominal)
RC2
RS
RT (Nominal)
Small Signal Bandwidth
0.1 dB Flatness
−10
−2
−1
499
499
549
49.9
249
549
49.9
49.9
49.9
N/A
N/A
N/A
49.9
49.9
49.9
N/A
61.9
54.9
250
410
410
50
100
100
RF
+VS
RG
IN
RT
RS
–VS
RBT
OUT
Figure 57. Inverting Configuration
+VS
C1
0.1µF
C3
10µF
C2
0.1µF
C4
10µF
–VS
Figure 58. Supply Bypassing
RF
+VS
RG
RC
IN
RBT
OUT
RT
–VS
Figure 59. Noninverting Configuration
Gain
+1
+2
+10
+100
Unit
953
681
499
1000
Ω
N/A
681
54.9
10
Ω
49.9
49.9
49.9
49.9
Ω
75
75
0
0
Ω
N/A
N/A
N/A
N/A
Ω
49.9
49.9
49.9
49.9
Ω
600
500
170
17
MHz
35
90
24
3
MHz
1 N/A means not applicable
2 RC is recommended to reduce peaking, and minimizes input reflections at frequencies above 300 MHz. However, RC is not required.
Table 5. AD8002ARM (MSOP) Recommended Component Values1
Gain
Component
−10
−2
−1
+1
+2
+10
+100
Unit
RF
499
499
590
1000
681
499
1000
Ω
RG
49.9
249
590
N/A
681
54.9
10
Ω
RBT (Nominal)
RC2
RS
49.9
49.9
49.9
49.9
49.9
49.9
49.9
Ω
N/A
N/A
N/A
75
75
0
0
Ω
49.9
49.9
49.9
N/A
N/A
N/A
N/A
Ω
RT (Nominal)
Small Signal Bandwidth
N/A
61.9
49.9
49.9
49.9
49.9
49.9
Ω
270
400
410
600
450
170
19
MHz
0.1 dB Flatness
60
100
100
35
70
35
3
MHz
1 N/A means not applicable
2 RC is recommended to reduce peaking, and minimizes input reflections at frequencies above 300 MHz. However, RC is not required.
Rev. E | Page 18 of 21
Share Link: 