1
March 1997
HFA1109
450MHz, Low Power, Current Feedback
Video Operational Amplifier
Features
Wide - 3dB Bandwidth (A
V
= +2) . . . . . . . . . . . . 450MHz
Gain Flatness (To 250MHz) . . . . . . . . . . . . . . . . . . 0.8dB
Very Fast Slew Rate (A
V
= +2) . . . . . . . . . . . . . 1100V/
s
High Input Impedance . . . . . . . . . . . . . . . . . . . . . 1.7M
Differential Gain/Phase . . . . . . . . . 0.02%/0.02 Degrees
Low Supply Current . . . . . . . . . . . . . . . . . . . . . . . 10mA
Applications
Professional Video Processing
Video Switchers and Routers
Medical Imaging
PC Multimedia Systems
Video Distribution Amplifiers
Flash Converter Drivers
Radar/IF Processing
Description
The HFA1109 is a high speed, low power, current feedback
amplifier built with Intersil's proprietary complementary bipo-
lar UHF-1 process. This amplifier features a unique combi-
nation of power and performance specifically tailored for
video applications.
The HFA1109 is a standard pinout op amp. It is a higher
performance, drop-in replacement (no feedback resistor
change required) for the CLC409.
If a comparably performing op amp with an output disable
function (useful for video multiplexing) is required, please
refer to the HFA1149 data sheet.
Pinout
HFA1109
(PDIP, SOIC)
TOP VIEW
Ordering Information
PART NUMBER
(BRAND)
TEMP.
RANGE (
o
C)
PACKAGE
PKG.
NO.
HFA1109IP
-40 to 85
8 Ld PDIP
E8.3
HFA1109IB (H1109)
-40 to 85
8 Ld SOIC
M8.15
HFA11XXEVAL
DIP Evaluation Board for High Speed
Op Amps
NC
-IN
+IN
V-
1
2
3
4
8
7
6
5
NC
V+
OUT
NC
+
-
File Number
4019.3
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143 | Copyright Intersil Corporation 1999
2
Absolute Maximum Ratings
Thermal Information
Voltage Between V+ and V- . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12V
DC Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V
SUPPLY
Differential Input Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8V
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) . . 1400V
Charged Device Model (Per EOS/ESD DS5.3, 4/14/93). . . 2000V
Machine Model (Per EIAJ ED-4701Method C-111) . . . . . . . . 50V
Operating Conditions
Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . -40
o
C to 85
o
C
Thermal Resistance (Typical, Note 1)
JA
(
o
C/W)
PDIP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
130
SOIC Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
170
Maximum Junction Temperature (Die). . . . . . . . . . . . . . . . . . . . 175
o
C
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
(SOIC - 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.
NOTES:
1.
JA
is measured with the component mounted on an evaluation PC board in free air.
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
= +2, R
F
= 250
, R
L
= 100
, Unless Otherwise Specified
PARAMETER
TEST CONDITIONS
(NOTE 3)
TEST
LEVEL
TEMP.
(
o
C)
MIN
TYP
MAX
UNITS
INPUT CHARACTERISTICS
Input Offset Voltage
A
25
-
1
5
mV
A
Full
-
2
8
mV
Average Input Offset Voltage Drift
B
Full
-
10
-
V/
o
C
Input Offset Voltage
Common-Mode Rejection Ratio
V
CM
=
2V
A
25
47
50
-
dB
V
CM
=
2V
A
Full
45
48
-
dB
Input Offset Voltage
Power Supply Rejection Ratio
V
PS
=
1.25V
A
25
50
53
-
dB
V
PS
=
1.25V
A
Full
47
51
-
dB
Non-Inverting Input Bias Current
A
25
-
4
10
A
A
Full
-
5
15
A
Non-Inverting Input Bias Current Drift
B
Full
-
30
-
nA/
o
C
Non-Inverting Input Bias Current
Power Supply Sensitivity
V
PS
=
1.25V
A
25
-
0.5
1
A/V
V
PS
=
1.25V
A
Full
-
0.5
3
A/V
Inverting Input Bias Current
A
25
-
2
10
A
A
Full
-
3
15
A
Inverting Input Bias Current Drift
B
Full
-
40
-
nA/
o
C
Inverting Input Bias Current
Common-Mode Sensitivity
V
CM
=
2V
A
25
-
3
6
A/V
V
CM
=
2V
A
Full
-
3
8
A/V
Inverting Input Bias Current
Power Supply Sensitivity
V
PS
=
1.25V
A
25
-
1.6
5
A/V
V
PS
=
1.25V
A
Full
-
1.6
8
A/V
Non-Inverting Input Resistance
V
CM
=
2V
A
25, 85
0.8
1.7
-
M
V
CM
=
2V
A
-40
0.5
1.4
-
M
Inverting Input Resistance
B
25
-
60
-
Input Capacitance
B
25
-
1.6
-
pF
HFA1109
3
Input Voltage Common Mode Range
(Implied by V
IO
CMRR, +R
IN
, and -I
BIAS
CMS tests)
A
Full
2
2.5
-
V
Input Noise Voltage Density (Note 4)
f = 100kHz
B
25
-
4
-
nV/
Hz
Non-Inverting Input Noise Current Density
(Note 4)
f = 100kHz
B
25
-
2.4
-
pA/
Hz
Inverting Input Noise Current Density
(Note 4)
f = 100kHz
B
25
-
40
-
pA/
Hz
TRANSFER CHARACTERISTICS
Open Loop Transimpedance Gain (Note 4)
B
25
-
500
-
k
Minimum Stable Gain
B
Full
-
1
-
V/V
AC CHARACTERISTICS
-3dB Bandwidth
(V
OUT
= 0.2V
P-P
, Note 4)
A
V
= -1, R
F
= 200
B
25
300
375
-
MHz
B
Full
290
360
-
MHz
A
V
= +1, +R
S
= 550
(PDIP),
+R
S
= 700
(SOIC)
B
25
280
330
-
MHz
B
Full
260
320
-
MHz
A
V
= +2
B
25
390
450
-
MHz
B
Full
350
410
-
MHz
Gain Peaking
A
V
= +2, V
OUT
= 0.2V
P-P
B
25
-
0
0.2
dB
B
Full
-
0
0.5
dB
Gain Flatness
(A
V
= +2, V
OUT
= 0.2V
P-P
, Note 4)
To 125MHz
B
25
-1.0
-0.45
-
dB
B
Full
-1.1
-0.45
-
dB
To 200MHz
B
25
-1.6
-0.75
-
dB
B
Full
-1.7
-0.75
-
dB
To 250MHz
B
25
-1.9
-0.85
-
dB
B
Full
-2.2
-0.85
-
dB
Gain Flatness
(A
V
= +1, +R
S
= 550
(PDIP),
+R
S
= 700
(SOIC), V
OUT
= 0.2V
P-P
,
Note 4)
To 125MHz
B
25
0.3
0.1
-
dB
B
Full
0.4
0.1
-
dB
To 200MHz
B
25
0.8
0.35
-
dB
B
Full
0.9
0.35
-
dB
To 250MHz
B
25
1.3
0.6
-
dB
B
Full
1.4
0.6
-
dB
OUTPUT CHARACTERISTICS
Output Voltage Swing, Unloaded
(Note 4)
A
V
= -1, R
L
=
A
25
3
3.2
-
V
A
Full
2.8
3
-
V
Output Current
(Note 4)
A
V
= -1, R
L
= 75
A
25, 85
33
36
-
mA
A
-40
30
33
-
mA
Output Short Circuit Current
A
V
= -1
B
25
-
120
-
mA
Closed Loop Output Resistance (Note 4)
DC, A
V
= +1
B
25
-
0.05
-
Second Harmonic Distortion
(V
OUT
= 2V
P-P
, Note 4)
20MHz
B
25
-
-55
-
dBc
60MHz
B
25
-
-57
-
dBc
Electrical Specifications
V
SUPPLY
=
5V, A
V
= +2, R
F
= 250
, R
L
= 100
, Unless Otherwise Specified (Continued)
PARAMETER
TEST CONDITIONS
(NOTE 3)
TEST
LEVEL
TEMP.
(
o
C)
MIN
TYP
MAX
UNITS
HFA1109
4
Third Harmonic Distortion
(V
OUT
= 2V
P-P
, Note 4)
20MHz
B
25
-
-68
-
dBc
60MHz
B
25
-
-60
-
dBc
Reverse Isolation (S
12
)
30MHz
B
25
-
-65
-
dB
TRANSIENT CHARACTERISTICS
Rise and Fall Times
V
OUT
= 0.5V
P-P
B
25
-
1.1
1.3
ns
B
Full
-
1.1
1.4
ns
Overshoot
V
OUT
= 0.5V
P-P
B
25
-
0
2
%
B
Full
-
0.5
5
%
Slew Rate
A
V
= -1, R
F
= 200
V
OUT
= 5V
P-P
B
25
2300
2600
-
V/
s
B
Full
2200
2500
-
V/
s
A
V
= +1, V
OUT
= 4V
P-P
,
+R
S
= 550
(PDIP)
,
+R
S
= 700
(SOIC)
B
25
475
550
-
V/
s
B
Full
430
500
-
V/
s
A
V
= +2, V
OUT
= 5V
P-P
B
25
940
1100
-
V/
s
B
Full
800
950
-
V/
s
Settling Time
(V
OUT
= +2V to 0V step, Note 4)
To 0.1%
B
25
-
19
-
ns
To 0.05%
B
25
-
23
-
ns
To 0.01%
B
25
-
36
-
ns
Overdrive Recovery Time
V
IN
=
2V
B
25
-
5
-
ns
VIDEO CHARACTERISTICS
Differential Gain
(f = 3.58MHz)
R
L
= 150
B
25
-
0.02
0.06
%
B
Full
-
0.03
0.09
%
R
L
= 75
B
25
-
0.04
0.09
%
B
Full
-
0.05
0.12
%
Differential Phase
(f = 3.58MHz)
R
L
= 150
B
25
-
0.02
0.06
Degrees
B
Full
-
0.02
0.06
Degrees
R
L
= 75
B
25
-
0.05
0.09
Degrees
B
Full
-
0.06
0.13
Degrees
POWER SUPPLY CHARACTERISTICS
Power Supply Range
C
25
4.5
-
5.5
V
Power Supply Current (Note 4)
A
25
-
9.6
10
mA
A
Full
-
10
11
mA
NOTES:
3. Test Level: A. Production Tested; B. Typical or Guaranteed Limit Based on Characterization; C. Design Typical for Information Only.
4. See Typical Performance Curves for more information.
Electrical Specifications
V
SUPPLY
=
5V, A
V
= +2, R
F
= 250
, R
L
= 100
, Unless Otherwise Specified (Continued)
PARAMETER
TEST CONDITIONS
(NOTE 3)
TEST
LEVEL
TEMP.
(
o
C)
MIN
TYP
MAX
UNITS
HFA1109
5
Application Information
Optimum Feedback Resistor
Although a current feedback amplifier's bandwidth depen-
dency 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 inter-
nal compensation capacitor, sets the dominant pole of the
frequency response. Thus, the amplifier's bandwidth is
inversely proportional to R
F
. The HFA1109 design is opti-
mized for a 250
R
F
at a gain of +2. Decreasing R
F
decreases stability, resulting in excessive peaking and over-
shoot (Note: Capacitive feedback will cause the same prob-
lems due to the feedback impedance decrease at higher
frequencies). At higher gains the amplifier is more stable, so
R
F
can be decreased in a trade-off of stability for bandwidth.
Table 1 lists recommended R
F
values, and the expected
bandwidth, for various closed loop gains. For a gain of +1, a
resistor (
+
R
S
) in series with +IN is required to reduce gain
peaking and increase stability
PC Board Layout
The frequency response of this amplifier depends greatly on
the 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 directly on the
output must be minimized, or isolated as discussed in the
next section.
Care must also be taken to minimize the capacitance to ground
seen by the amplifier's inverting input (-IN). The larger this
capacitance, the worse the gain peaking, resulting in pulse
overshoot and possible instability. Thus it is recommended that
the ground plane be removed under traces connected to -IN,
and connections to -IN should be kept as short as possible.
Driving Capacitive Loads
Capacitive loads, such as an A/D input, or an improperly ter-
minated transmission line will degrade the amplifier's phase
margin resulting in frequency response peaking and possi-
ble oscillations. In most cases, the oscillation can be avoided
by placing a resistor (R
S
) in series with the output prior to
the capacitance.
R
S
and C
L
form a low pass network at the output, thus limit-
ing system bandwidth well below the amplifier bandwidth. By
decreasing R
S
as C
L
increases, the maximum bandwidth is
obtained without sacrificing stability. In spite of this, band-
width still decreases as the load capacitance increases.
Evaluation Board
The performance of the HFA1109 may be evaluated using
the HFA11XX evaluation board (part number
HFA11XXEVAL). Please contact your local sales office for
information. When evaluating this amplifier, the two 510
gain setting resistors on the evaluation board should be
changed to 250
.
The layout and schematic of the board are shown in Figure 1.
.
TABLE 1. OPTIMUM FEEDBACK RESISTOR
GAIN (A
CL
)
R
F
(
)
BANDWIDTH (MHz)
-1
200
400
+1
250 (+
R
S = 550
) PDIP
250 (+
R
S = 700
) SOIC
350
+2
250
450
+5
100
160
+10
90
70
BOARD SCHEMATIC
TOP LAYOUT
BOTTOM LAYOUT
FIGURE 1. EVALUATION BOARD SCHEMATIC AND LAYOUT
1
2
3
4
8
7
6
5
+5V
10
F
0.1
F
V
H
50
GND
GND
510
510
-5V
0.1
F
10
F
50
IN
OUT
V
L
V
H
+IN
V
L
V+
GND
1
V-
OUT
HFA1109
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