Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . -40°C to +85°C
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:
3.
JA
is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. See
Tech Brief TB379.
4. 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.
(NOTE 5)
TEST
LEVEL
PARAMETER
INPUT CHARACTERISTICS
Input Offset Voltage
TEST CONDITIONS
TEMP. (°C)
MIN
TYP
MAX
UNITS
A
A
25
Full
Full
25
Full
25
Full
25
Full
Full
25
Full
25
Full
Full
25
Full
25
Full
25, 85
-40
25
-
-
-
47
45
50
47
-
-
-
-
-
-
-
-
-
-
-
-
0.8
0.5
-
1
2
10
50
48
53
51
4
5
30
0.5
0.5
2
3
40
3
3
1.6
1.6
1.7
1.4
60
5
8
-
-
-
-
-
10
15
-
1
3
10
15
-
6
8
5
8
-
-
-
mV
mV
V/°C
dB
dB
dB
dB
A
A
nA/°C
A/V
A/V
A
A
nA/°C
A/V
A/V
A/V
A/V
M
M
Average Input Offset Voltage Drift
Input Offset Voltage
Common-Mode Rejection Ratio
Input Offset Voltage
Power Supply Rejection Ratio
Non-Inverting Input Bias Current
DV
CM
= ±2V
B
A
A
DV
PS
= ±1.25V
A
A
A
A
Non-Inverting Input Bias Current Drift
Non-Inverting Input Bias Current
Power Supply Sensitivity
Inverting Input Bias Current
DV
PS
= ±1.25V
B
A
A
A
A
Inverting Input Bias Current Drift
Inverting Input Bias Current
Common-Mode Sensitivity
Inverting Input Bias Current
Power Supply Sensitivity
Non-Inverting Input Resistance
DV
CM
= ±2V
B
A
A
DV
PS
= ±1.25V
A
A
DV
CM
= ±2V
A
A
Inverting Input Resistance
B
FN4019 Rev.5.00
April 23, 2007
Page 2 of 12
HFA1109
Electrical Specifications
V
SUPPLY
=
5V,
A
V
= +2, R
F
= 250, R
L
= 100, Unless Otherwise Specified.
(Continued)
(NOTE 5)
TEST
LEVEL
B
A
PARAMETER
Input Capacitance
Input Voltage Common Mode Range
(Implied by V
IO
CMRR, +R
IN
, and -I
BIAS
CMS
tests)
Input Noise Voltage Density (Note 6)
Non-Inverting Input Noise Current Density
(Note 4)
Inverting Input Noise Current Density
(Note 4)
TRANSFER CHARACTERISTICS
Open Loop Transimpedance Gain (Note 6)
Minimum Stable Gain
AC CHARACTERISTICS
-3dB Bandwidth
(V
OUT
= 0.2V
P-P
, Note 6)
TEST CONDITIONS
TEMP. (°C)
25
Full
MIN
-
2
TYP
1.6
±2.5
MAX
-
-
UNITS
pF
V
f = 100kHz
B
B
25
25
25
-
-
-
4
2.4
40
-
-
-
nV/Hz
pA/Hz
pA/Hz
f = 100kHz
B
B
B
25
Full
-
-
500
1
-
-
k
V/V
A
V
= -1, R
F
= 200
B
B
25
Full
25
Full
25
Full
25
Full
25
Full
25
Full
25
Full
25
Full
25
Full
25
Full
300
290
280
260
390
350
-
-
-1.0
-1.1
-1.6
-1.7
-1.9
-2.2
0.3
0.4
0.8
0.9
1.3
1.4
375
360
330
320
450
410
0
0
-0.45
-0.45
-0.75
-0.75
-0.85
-0.85
±0.1
±0.1
±0.35
±0.35
±0.6
±0.6
-
-
-
-
-
-
0.2
0.5
-
-
-
-
-
-
-
-
-
-
-
-
MHz
MHz
MHz
MHz
MHz
MHz
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
A
V
= +1, +R
S
= 550 (PDIP),
+R
S
= 700 (SOIC)
A
V
= +2
B
B
B
B
Gain Peaking
A
V
= +2, V
OUT
= 0.2V
P-P
B
B
Gain Flatness
(A
V
= +2, V
OUT
= 0.2V
P-P
, Note 6)
To 125MHz
B
B
To 200MHz
B
B
To 250MHz
B
B
Gain Flatness
(A
V
= +1, +R
S
= 550 (PDIP),
+R
S
= 700 (SOIC), V
OUT
= 0.2V
P-P
,
(Note 6)
To 125MHz
B
B
To 200MHz
B
B
To 250MHz
B
B
OUTPUT CHARACTERISTICS
Output Voltage Swing, Unloaded
(Note 6)
Output Current
(Note 6)
Output Short Circuit Current
Closed Loop Output Resistance (Note 6)
A
V
= -1, R
L
= Infinity
A
A
A
V
= -1, R
L
= 75
A
A
A
V
= -1
DC, A
V
= +1
B
B
25
Full
25, 85
-40
25
25
3
2.8
33
30
-
-
±3.2
±3
±36
±33
120
0.05
-
-
-
-
-
-
V
V
mA
mA
mA
W
FN4019 Rev.5.00
April 23, 2007
Page 3 of 12
HFA1109
Electrical Specifications
V
SUPPLY
=
5V,
A
V
= +2, R
F
= 250, R
L
= 100, Unless Otherwise Specified.
(Continued)
(NOTE 5)
TEST
LEVEL
B
B
B
B
B
PARAMETER
Second Harmonic Distortion
(V
OUT
= 2V
P-P
, Note 6)
Third Harmonic Distortion
(V
OUT
= 2V
P-P
, Note 6)
Reverse Isolation (S
12
)
TRANSIENT CHARACTERISTICS
Rise and Fall Times
TEST CONDITIONS
20MHz
60MHz
20MHz
60MHz
30MHz
TEMP. (°C)
25
25
25
25
25
MIN
-
-
-
-
-
TYP
-55
-57
-68
-60
-65
MAX
-
-
-
-
-
UNITS
dBc
dBc
dBc
dBc
dB
V
OUT
= 0.5V
P-P
B
B
25
Full
25
Full
25
Full
25
Full
25
Full
25
25
25
25
-
-
-
-
2300
2200
475
430
940
800
-
-
-
-
1.1
1.1
0
0.5
2600
2500
550
500
1100
950
19
23
36
5
1.3
1.4
2
5
-
-
-
-
-
-
-
-
-
-
ns
ns
%
%
V/s
V/s
V/s
V/s
V/s
V/s
ns
ns
ns
ns
Overshoot
V
OUT
= 0.5V
P-P
B
B
Slew Rate
A
V
= -1, R
F
= 200
V
OUT
= 5V
P-P
A
V
= +1, V
OUT
= 4V
P-P
,
+R
S
= 550 (PDIP),
+R
S
= 700 (SOIC)
A
V
= +2, V
OUT
= 5V
P-P
B
B
B
B
B
B
Settling Time
(V
OUT
= +2V to 0V step, Note 6)
To 0.1%
To 0.05%
To 0.01%
B
B
B
B
Overdrive Recovery Time
VIDEO CHARACTERISTICS
Differential Gain
(f = 3.58MHz)
V
IN
= ±2V
R
L
= 150
B
B
25
Full
25
Full
25
Full
25
Full
-
-
-
-
-
-
-
-
0.02
0.03
0.04
0.05
0.02
0.02
0.05
0.06
0.06
0.09
0.09
0.12
0.06
0.06
0.09
0.13
%
%
%
%
°
°
°
°
R
L
= 75
B
B
Differential Phase
(f = 3.58MHz)
R
L
= 150
B
B
R
L
= 75
B
B
POWER SUPPLY CHARACTERISTICS
Power Supply Range
Power Supply Current (Note 6)
C
A
A
NOTES:
5. Test Level: A. Production Tested; B. Typical or Guaranteed Limit Based on Characterization; C. Design Typical for Information Only.
6. See Typical Performance Curves for more information.
25
25
Full
4.5
-
-
-
9.6
10
5.5
10
11
V
mA
mA
FN4019 Rev.5.00
April 23, 2007
Page 4 of 12
HFA1109
Application Information
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 HFA1109 design is optimized
for a 250 R
F
at a gain of +2. Decreasing R
F
decreases
stability, resulting in excessive peaking and overshoot (Note:
Capacitive feedback will cause the same problems 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. OPTIMUM FEEDBACK RESISTOR
GAIN (A
CL
)
-1
+1
+2
+5
+10
R
F
(W)
200
250 (+
R
S
= 550W) PDIP
250 (+
R
S
= 700W) SOIC
250
100
90
BANDWIDTH (MHz)
400
350
450
160
70
capacitors is strongly recommended, while a solid ground
plane is a must!
Attention should be given to decoupling the
power supplies. A large value (10F) tantalum in parallel with a
small value (0.1F) 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
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.
R
S
and C
L
form a low pass network at the output, thus limiting
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, bandwidth
still decreases as the load capacitance increases.
Evaluation Board
The performance of the HFA1105 may be evaluated using the
HFA11XX Evaluation Board and a SOIC to DIP adaptor like the
Aries Electronics Part Number 14-350000-10. The layout and
schematic of the board are shown in Figure 1.
Please contact your local sales office for information. When
evaluating this amplifier, the two 510gain setting resistors on
the evaluation board should be changed to 250.
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