OP271EZ AD [Analog Devices], OP271EZ Datasheet - Page 9

• Manufacturer Part Number: OP271EZ
• Description: High-Speed, Dual Operational Amplifier
• Manufacturer: AD [Analog Devices]

Figure 5 compares the phase error performance of the low
phase error amplifier with a conventional single op amp
amplifier and a cascaded two-stage amplifier. The low phase
error amplifier shows a much lower phase error, particularly for
frequencies where
-0.1 occurs at 0.002
at 0.11
For more detailed information on the low phase error amplifier,
see Application Note AN-107.
REV. A
Figure 5. Phase Error Comparison
T
–1
–2
–3
–4
–5
–6
–7
0.001
for the low phase error amplifier.
0
SINGLE OP AMP,
CONVENTIONAL
LOW PHASE ERROR
REFERENCE
FREQUENCY RATIO – 1/
CONTROL
VOLTAGE
0.005
(TWO STAGES)
12-BIT DATABUS PINS 6–17
CASCADED
T
DAC
DESIGN
0.01
AMPLIFIER
<0.1. For example, phase error of
10V
T
for the single op amplifier, but
22
18
20
19
4
0.005
V
V
DAC A/DAC B
LDAC
WR
DAC-8222EW
REF
REF
0.1
A
B
/
DAC A
DAC B
Figure 6. Dual 12-Bit Voltage Output DAC
DGND
0.5
5V
V
DD
21
1.0
R
R
FB
FB
I
AGND
I
OUT
OUT
A
B
A
B
3
2
1
24
23
10pF
10pF
–9–
Dual 12-Bit Voltage Output DAC
The dual voltage output DAC shown in Figure 6 will settle to
12-bit accuracy from zero to full scale in 2 s typically. The
CMOS DAC-8222 utilizes a 12-bit, double-buffered input
structure allowing faster digital throughput and minimizing
digital feedback.
Fast Current Pump
Maximum output current of the fast current pump shown in
Figure 7 is 11 mA. Voltage compliance exceeds 10 V with
of over 3 M
output range.
15 V supplies. The current pump has an output resistance
2
3
6
5
V
IN
I
OUT
+
+
–
1/2
OP271EZ
–
1/2
OP271EZ
=
+15V
10k
10k
V
RS
R1
R2
8
IN
and maintains 12-bit linearity over its entire
0.1 F
10 F
=
100
Figure 7. Fast Current Pump
V
IN
=10mA/V
4
7
2
3
10k
R4
1/2
OP271FZ
10k
0.1 F
R3
7
1
OP271FZ
10 F
+15V
–15V
8
4
1/2
100
V
–15V
V
R5
OUT
OUT
5
6
A
B
OP271
I
OUT
11mA