1
FN4727.3
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2003. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
HFA1305
Triple, 560MHz, Low Power, Video
Operational Amplifier
The HFA1305 is a triple, high speed, low power current
feedback amplifier built with Intersil's proprietary
complementary bipolar UHF-1 process.
These amplifiers deliver up to 560MHz bandwidth and
2500V/
s slew rate, on only 58mW of quiescent power. They
are specifically designed to meet the performance, power,
and cost requirements of high volume video applications.
The excellent gain flatness and differential gain/phase
performance make these amplifiers well suited for
component or composite video applications. Video
performance is maintained even when driving a double
terminated cable (R
L
= 150
), and degrades only slightly
when driving two double terminated cables (R
L
= 75
). RGB
applications will benefit from the high slew rates, and high
full power bandwidth.
The HFA1305 is a pin compatible, low power, high
performance upgrade for the popular Intersil HA5013, and
for the AD8073 and CLC5623, in
5V applications.
Features
Low Supply Current . . . . . . . . . . . . . . . . . 5.8mA / Op Amp
High Input Impedance . . . . . . . . . . . . . . . . . . . . . . . 1M
Wide -3dB Bandwidth (A
V
= +2) . . . . . . . . . . . . . 560MHz
Very Fast Slew Rate . . . . . . . . . . . . . . . . . . . . . 2500V/
s
Gain Flatness (to 50MHz)
. . . . . . . . . . . . . . . . . . . . .
0.03dB
Differential Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.02%
Differential Phase. . . . . . . . . . . . . . . . . . . . . 0.03 Degrees
All Hostile Crosstalk (5MHz) . . . . . . . . . . . . . . . . . . -60dB
Pin Compatible Upgrade to HA5013, AD8073 and
CLC5623 in
5V Supply Applications.
Applications
Flash A/D Drivers
Professional Video Processing
Video Digitizing Boards / Systems
Computer Video Plug-In Boards
RGB Preamps
Medical Imaging
Hand Held and Miniaturized RF Equipment
Battery Powered Communications
High Speed Oscilloscopes and Analyzers
Related Literature
Technical Brief TB363 "Guidelines for Handling and
Processing Moisture Sensitive Surface Mount Devices
(SMDs)"
Pinout
HFA1305 (SOIC)
TOP VIEW
Ordering Information
PART NUMBER
TEMP.
RANGE (
o
C)
PACKAGE
PKG.
NO.
HFA1305IB
-40 to 85
14 Ld SOIC
M14.15
HA5025EVAL (Note)
High Speed Op Amp SOIC Evaluation
Board
NOTE: Requires a SOIC-to-DIP adapter. See "Evaluation Board"
section inside.
NC
NC
NC
V+
+IN 1
-IN 1
OUT 1
OUT 3
-IN 3
+IN 3
V-
+IN 2
-IN 2
OUT 2
1
2
3
4
5
6
7
14
13
12
11
10
9
8
+
+
+
-
-
-
Data Sheet
May 2003
2
Absolute Maximum Ratings
T
A
= 25
o
C
Thermal Information
Voltage Between V+ and V-. . . . . . . . . . . . . . . . . . . . . . . . . . . . 11V
DC Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V
SUPPLY
Differential Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5V
Output Current (Note 2) . . . . . . . . . . . . . . . . .Short Circuit Protected
30mA Continuous
60mA
50% Duty Cycle
ESD Rating
Human Body Model (Per MIL-STD-883 Method 3015.7) . . . 600V
Operating Conditions
Temperature Range. . . . . . . . . . . . . . . . . . . . . . . . . . -40
o
C to 85
o
C
Thermal Resistance (Typical, Note 1)
JA
(
o
C/W)
SOIC Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
120
Moisture Sensitivity (see Technical Brief TB363)
All Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Level 1
Maximum Junction Temperature (Plastic Package) . . . . . . . 150
o
C
Maximum Storage Temperature Range . . . . . . . . . -65
o
C to 150
o
C
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . 300
o
C
(Lead Tips Only)
CAUTION: Stresses above those listed in "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTE:
1.
JA
is measured with the component mounted on a low effective thermal conductivity test board in free air. See Tech Brief TB379 for details.
2. Output is short circuit protected to ground. Brief short circuits to ground will not degrade reliability, however continuous (100% duty cycle) output
current must not exceed 30mA for maximum reliability.
Electrical Specifications
V
SUPPLY
= 5V, A
V
= +1, R
F
= 510
, R
L
= 100
, Unless Otherwise Specified
PARAMETER
TEST CONDITIONS
(NOTE 4)
TEST
LEVEL
TEMP.
(
o
C)
MIN
TYP
MAX
UNITS
INPUT CHARACTERISTICS
Input Offset Voltage
A
25
-
2
5
mV
A
Full
-
3
8
mV
Average Input Offset Voltage Drift
B
Full
-
1
10
V/
o
C
Input Offset Voltage
Common-Mode Rejection Ratio
V
CM
=
1.8V
A
25
45
48
-
dB
V
CM
=
1.8V
A
85
43
46
-
dB
V
CM
=
1.2V
A
-40
43
46
-
dB
Input Offset Voltage
Power Supply Rejection Ratio
V
PS
=
1.8V
A
25
48
52
-
dB
V
PS
=
1.8V
A
85
46
48
-
dB
V
PS
=
1.2V
A
-40
46
48
-
dB
Non-Inverting Input Bias Current
A
25
-
6
15
A
A
Full
-
10
25
A
Non-Inverting Input Bias Current Drift
B
Full
-
5
60
nA/
o
C
Non-Inverting Input Bias Current
Power Supply Sensitivity
V
PS
=
1.8V
A
25
-
0.5
1
A/V
V
PS
=
1.8V
A
85
-
0.8
3
A/V
V
PS
=
1.2V
A
-40
-
0.8
3
A/V
Non-Inverting Input Resistance
V
CM
=
1.8V
A
25
0.8
1.2
-
M
V
CM
=
1.8V
A
85
0.5
0.8
-
M
V
CM
=
1.2V
A
-40
0.5
0.8
-
M
Inverting Input Bias Current
A
25
-
2
7.5
A
A
Full
-
5
15
A
Inverting Input Bias Current Drift
B
Full
-
60
200
nA/
o
C
Inverting Input Bias Current
Common-Mode Sensitivity
V
CM
=
1.8V
A
25
-
3
6
A/V
V
CM
=
1.8V
A
85
-
4
8
A/V
V
CM
=
1.2V
A
-40
-
4
8
A/V
HFA1305
3
Inverting Input Bias Current
Power Supply Sensitivity
V
PS
=
1.8V
A
25
-
2
5
A/V
V
PS
=
1.8V
A
85
-
4
8
A/V
V
PS
=
1.2V
A
-40
-
4
8
A/V
Inverting Input Resistance
C
25
-
60
-
Input Capacitance
B
25
-
1.4
-
pF
Input Voltage Common Mode Range
(Implied by V
IO
CMRR, +R
IN
, and -I
BIAS
CMS Tests)
A
25, 85
1.8
2.4
-
V
A
-40
1.2
1.7
-
V
Input Noise Voltage Density
f = 100kHz
B
25
-
3.5
-
nV/
Hz
Non-Inverting Input Noise Current Density
f = 100kHz
B
25
-
2.5
-
pA/
Hz
Inverting Input Noise Current Density
f = 100kHz
B
25
-
20
-
pA/
Hz
TRANSFER CHARACTERISTICS
Open Loop Transimpedance Gain
C
25
-
500
-
k
AC CHARACTERISTICS (Note 3)
-3dB Bandwidth
(V
OUT
= 0.2V
P-P
, Notes 3, 5)
A
V
= +1
B
25
-
375
-
MHz
A
V
= -1
B
25
-
420
-
MHz
A
V
= +2
B
25
-
560
-
MHz
Full Power Bandwidth
(V
OUT
= 5V
P-P
, Notes 3, 5)
A
V
= +1
B
25
-
160
-
MHz
A
V
= -1
B
25
-
260
-
MHz
A
V
= +2
B
25
-
165
-
MHz
Gain Flatness
(V
OUT
= 0.2V
P-P
, Notes 3, 5)
A
V
= +1, To 25MHz
B
25
-
0.03
-
dB
A
V
= +1, To 50MHz
B
25
-
0.03
-
dB
A
V
= +1, To 100MHz
B
25
-
0.07
-
dB
A
V
= -1, To 25MHz
B
25
-
0.03
-
dB
A
V
= -1, To 50MHz
B
25
-
0.04
-
dB
A
V
= -1, To 100MHz
B
25
-
0.09
-
dB
A
V
= +2, To 25MHz
B
25
-
0.03
-
dB
A
V
= +2, To 50MHz
B
25
-
0.03
-
dB
A
V
= +2, To 100MHz
B
25
-
0.07
-
dB
Minimum Stable Gain
A
Full
-
1
-
V/V
Crosstalk
(A
V
= +1, All Channels Hostile,
Note 5)
5MHz
B
25
-
-60
-
dB
10MHz
B
25
-
-56
-
dB
OUTPUT CHARACTERISTICS A
V
= +2 (Note 3), Unless Otherwise Specified
Output Voltage Swing
(Note 5)
A
V
= -1, R
L
= 100
A
25
3
3.4
-
V
A
Full
2.8
3
-
V
Output Current
(Note 5)
A
V
= -1, R
L
= 50
A
25, 85
50
60
-
mA
A
-40
28
42
-
mA
Output Short Circuit Current
B
25
-
90
-
mA
Closed Loop Output Impedance
B
25
-
0.2
-
Electrical Specifications
V
SUPPLY
= 5V, A
V
= +1, R
F
= 510
, R
L
= 100
, Unless Otherwise Specified (Continued)
PARAMETER
TEST CONDITIONS
(NOTE 4)
TEST
LEVEL
TEMP.
(
o
C)
MIN
TYP
MAX
UNITS
HFA1305
4
Second Harmonic Distortion
(V
OUT
= 2V
P-P
, Note 5)
10MHz
B
25
-
-51
-
dBc
20MHz
B
25
-
-46
-
dBc
Third Harmonic Distortion
(V
OUT
= 2V
P-P
, Note 5)
10MHz
B
25
-
-63
-
dBc
20MHz
B
25
-
-56
-
dBc
TRANSIENT CHARACTERISTICS A
V
= +2 (Note 3), Unless Otherwise Specified
Rise and Fall Times
(V
OUT
= 0.5V
P-P
, Note 3)
A
V
= +1
B
25
-
1.0
-
ns
A
V
= -1
B
25
-
-
-
ns
A
V
= +2
B
25
-
0.8
-
ns
Overshoot
(V
OUT
= 0.5V
P-P
, V
IN
t
RISE
= 1ns, Notes 3,
6)
A
V
= +1, +OS
B
25
-
5
-
%
A
V
= +1, -OS
B
25
-
11
-
%
A
V
= -1, +OS
B
25
-
7
-
%
A
V
= -1, -OS
B
25
-
8
-
%
A
V
= +2, +OS
B
25
-
5
-
%
A
V
= +2, -OS
B
25
-
10
-
%
Slew Rate
(V
OUT
= 5V
P-P
at A
V
= +2, -1,
V
OUT
= 4V
P-P
, at A
V
= +1,
Notes 3, 5)
A
V
= +1, +SR
B
25
-
1230
-
V/
s
A
V
= +1, -SR
B
25
-
1350
-
V/
s
A
V
= -1, +SR
B
25
-
2500
-
V/
s
A
V
= -1, -SR
B
25
-
1900
-
V/
s
A
V
= +2, +SR
B
25
-
1700
-
V/
s
A
V
= +2, -SR
B
25
-
1700
-
V/
s
Settling Time
(V
OUT
= +2V to 0V Step, Note 5)
To 0.1%
B
25
-
23
-
ns
To 0.05%
B
25
-
30
-
ns
To 0.025%
B
25
-
37
-
ns
Overdrive Recovery Time
V
IN
=
2V
B
25
-
8.5
-
ns
VIDEO CHARACTERISTICS A
V
= +2 (Note 3), Unless Otherwise Specified
Differential Gain
(f = 3.58MHz)
R
L
= 150
B
25
-
0.02
-
%
R
L
= 75
B
25
-
0.03
-
%
Differential Phase
(f = 3.58MHz)
R
L
= 150
B
25
-
0.03
-
Degrees
R
L
= 75
B
25
-
0.06
-
Degrees
POWER SUPPLY CHARACTERISTICS
Power Supply Range
C
25
4.5
-
5.5
V
Power Supply Current (Note 5)
A
25
-
5.8
6.1
mA/Op Amp
A
Full
-
5.9
6.3
mA/Op Amp
NOTES:
3. The optimum feedback resistor depends on closed loop gain. See the "Optimum Feedback Resistor" table in the Application Information section
for details.
4. Test Level: A. Production Tested; B. Typical or Guaranteed Limit Based on Characterization; C. Design Typical for Information Only.
5. See Typical Performance Curves for more information.
6. Undershoot dominates for output signal swings below GND (e.g., 2V
P-P
), yielding a higher overshoot limit compared to the V
OUT
= 0V to 2V
condition. See the "Application Information" section for details.
Electrical Specifications
V
SUPPLY
= 5V, A
V
= +1, R
F
= 510
, R
L
= 100
, Unless Otherwise Specified (Continued)
PARAMETER
TEST CONDITIONS
(NOTE 4)
TEST
LEVEL
TEMP.
(
o
C)
MIN
TYP
MAX
UNITS
HFA1305
5
Application Information
Performance
The amplifiers comprising the HFA1305 are high frequency
current feedback amplifiers. As such, they are sensitive to
feedback capacitance which destabilizes the op amp and
causes overshoot and peaking. Unfortunately, the standard
triple op amp pinout places the amplifier's output next to its
inverting input, thus making the package capacitance an
unavoidable parasitic feedback capacitor.
Optimum Feedback Resistor
Although a current feedback amplifier's bandwidth
dependency on closed loop gain isn't as severe as that of a
voltage feedback amplifier, there can be an appreciable
decrease in bandwidth at higher gains. This decrease may
be minimized by taking advantage of the current feedback
amplifier's unique relationship between bandwidth and R
F
.
All current feedback amplifiers require a feedback resistor,
even for unity gain applications, and R
F
, in conjunction with
the internal compensation capacitor, sets the dominant
pole of the frequency response. Thus, the amplifier's
bandwidth is inversely proportional to R
F
. The HFA1305
design is optimized for R
F
= 510
(SOIC) at a gain of +2.
Decreasing R
F
decreases stability, resulting in excessive
peaking and overshoot (Note: Capacitive feedback causes
the same problems due to the feedback impedance
decrease at higher frequencies). However, at higher gains
the amplifier is more stable so R
F
can be decreased in a
trade-off of stability for bandwidth.
The table below lists recommended R
F
values for various
gains, and the expected bandwidth. For good channel-to-
channel gain matching, it is recommended that all resistors
(termination as well as gain setting) be
1% tolerance or better.
Non-inverting Input Source Impedance
For best operation, the DC source impedance seen by the
non-inverting input should be
50
.
This is especially
important in inverting gain configurations where the non-
inverting input would normally be connected directly to GND.
Pulse Undershoot
The HFA1305 utilizes a quasi-complementary output stage to
achieve high output current while minimizing quiescent supply
current. In this approach, a composite device replaces the
traditional PNP pulldown transistor. The composite device
switches modes after crossing 0V, resulting in added distortion
for signals swinging below ground, and an increased
undershoot on the negative portion of the output waveform (see
Figure 6). This undershoot isn't present for small bipolar
signals, or large positive signals (see Figure 4 and Figure 5).
PC Board Layout
The frequency response of this amplifier depends greatly on
the amount of care taken in designing the PC board. The
use of low inductance components such as chip
resistors and chip capacitors is strongly recommended,
while a solid ground plane is a must!
Attention should be given to decoupling the power supplies.
A large value (10
F) tantalum in parallel with a small value
(0.1
F) chip capacitor works well in most cases.
Terminated microstrip signal lines are recommended at the
input and output of the device. Capacitance, parasitic or
planned, connected to the output must be minimized, or
isolated as discussed in the next section.
Care must also be taken to minimize the capacitance to
ground at the amplifier's inverting input (-IN). The larger this
capacitance, the worse the gain peaking, resulting in pulse
overshoot and eventual instability. To reduce this
capacitance the designer should remove the ground plane
under traces connected to -IN, and keep connections to -IN
as short as possible.
An example of a good high frequency layout is the
Evaluation Board shown in Figure 3.
Driving Capacitive Loads
Capacitive loads, such as an A/D input, or an improperly
terminated transmission line will degrade the amplifier's
phase margin resulting in frequency response peaking and
possible oscillations. In most cases, the oscillation can be
avoided by placing a resistor (R
S
) in series with the output
prior to the capacitance.
Figure 1 details starting points for the selection of this
resistor. The points on the curve indicate the R
S
and C
L
combinations for the optimum bandwidth, stability, and
settling time, but experimental fine tuning is recommended.
Picking a point above or to the right of the curve yields an
overdamped response, while points below or left of the curve
indicate areas of underdamped performance.
R
S
and C
L
form a low pass network at the output, thus limiting
system bandwidth well below the amplifier bandwidth of
560MHz. By decreasing R
S
as C
L
increases (as illustrated in
the curve), the maximum bandwidth is obtained without
sacrificing stability. In spite of this, bandwidth still decreases
as the load capacitance increases.
OPTIMUM FEEDBACK RESISTOR
GAIN
(A
CL
)
R
F
(
)
SOIC
BANDWIDTH (MHz)
SOIC
-1
360
420
+1
464 (+R
S
= 649)
375
+2
510
560
+5
200
330
+10
180
140
HFA1305
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