LT1630 Linear Technology, LT1630 Datasheet - Page 16

• Manufacturer Part Number: LT1630
• Description: 30MHz/ 10V/us/ Dual/Quad Rail-to-Rail Input and Output Precision Op Amps
• Manufacturer: Linear Technology

RELATED PARTS
LT1630/LT1631
TYPICAL APPLICATIONS
RF Amplifier Control Biasing and DC Restoration
Taking advantage of the rail-to-rail input and output, and
the large output current capability of the LT1630, the
circuit, shown in Figure 6, provides precise bias currents
for the RF amplifiers and restores DC output level. To
ensure optimum performance of an RF amplifier, its bias
point must be accurate and stable over the operating
temperature range. The op amp A1 combined with Q1, Q2,
R1, R2 and R3 establishes two current sources of 21.5mA
to bias RF1 and RF2 amplifiers. The current of Q1 is
determined by the voltage across R2 over R1, which is
replicated in Q2. These current sources are stable and
precise over temperature and have a low dissipated power
due to a low voltage drop between their terminals. The
amplifier A2 is used to restore the DC level at the output.
With a large output current of the LT1630, the output can
be set at 1.5VDC on 5V supply and 50 load. This circuit
has a 3dB bandwidth from 2MHz to 2GHz and a power gain
of 25dB.
PART NUMBER
LT1211/LT1212
LT1213/LT1214
LT1215/LT1216
LT1498/LT1499
LT1632/LT1633
C-Load is a trademark of Linear Technology Corporation.
16
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] FAX: [phone] www.linear-tech.com
DESCRIPTON
Dual/Quad 14MHz, 7V/ s, Single Supply Precision Op Amps
Dual/Quad 28MHz, 12V/ s, Single Supply Precision Op Amps
Dual/Quad 23MHz, 50V/ s, Single Supply Precision Op Amps
Dual/Quad 10MHz, 6V/ s Rail-to-Rail Input and Output
C-Load
Dual/Quad 45MHz, 45V/ s Rail-to-Rail Input and Output Op Amps
TM
Op Amps
U
0.01 F
C1
V
Figure 6. RF Amplifier Control Biasing and DC Restoration
IN
+
COMMENTS
Input Common Mode Includes Ground, 275 V V
6 V/ C Max Drift, Max Supply Current 1.8mA per Op Amp
Input Common Mode Includes Ground, 275 V V
6 V/ C Max Drift, Max Supply Current 3.5mA per Op Amp
Input Common Mode Includes Ground, 450 V V
6 V/ C Max Drift, Max Supply Current 6.6mA per Op Amp
High DC Accuracy, 475 V V
Max Supply Current 2.2mA per Amp
High DC Accuracy, 1.35mV V
Max Supply Current 5.2mA per Amp
L3
3.9 H
R2
453
R5
50
R3
10k
1500pF
C2
HP-MSA0785
–
+
1/2 LT1630
A1
RF1
5V
+
–
1/2 LT1630
5V
A2
OS(MAX)
L1
220 H
Q1
2N3906
R1
10
OS(MAX)
LINEAR TECHNOLOGY CORPORATION 1998
1500pF
C3
16301f LT/TP 0998 4K • PRINTED IN USA
+
, 4 V/ C Max Drift,
HP-MSA0785
, 70mA Output Current,
C5
0.01 F
RF2
OS(MAX)
OS(MAX)
OS(MAX)
Q2
2N3906
L2
220 H
R4
10
1500pF
C4
,
,
,
+
L4
3.9 H
1630/31 F06
C6
0.01 F
V
OUT