551600075-001 National Semiconductor, 551600075-001 Datasheet - Page 20

• Manufacturer Part Number: 551600075-001
• Description: BOARD FOR SOIC LMH6612/19
• Manufacturer: National Semiconductor
• Series: WEBENCH® Buildit Boardr

Specifications of 551600075-001

• Channels Per Ic: 2 - Dual
• Amplifier Type: General Purpose
• Board Type: Bare (Unpopulated)
• Utilized Ic / Part: LMH6612, LMH6619
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Operating Temperature: -
• Output Type: -
• Current - Output / Channel: -
• Voltage - Supply, Single/dual (±): -
• -3db Bandwidth: -
• Slew Rate: -
• Current - Supply (main Ic): -

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Application Information
The LMH6611 and LMH6612 are based on National
Semiconductor’s proprietary VIP10 dielectrically isolated
bipolar process. This device family architecture features the
following:
•
•
•
•
With 3V supplies and a common mode input voltage range
that extends beyond either supply rail, the LMH6611 is well
suited to many low voltage/low power applications. Even with
3V supplies, the −3 dB BW (at A
The LMH6611 and LMH6612 are designed to avoid output
phase reversal. With input overdrive, the output is kept near
the supply rail (or as close to it as mandated by the closed
loop gain setting and the input voltage).
input and output voltage when the input voltage significantly
exceeds the supply voltages.
FIGURE 1. Input and Output Shown with CMVR Exceeded
If the input voltage range is exceeded by more than a diode
drop beyond either rail, the internal ESD protection diodes will
start to conduct. The current flow in these ESD diodes should
be externally limited.
SHUTDOWN CAPABILITY AND TURN ON/OFF
BEHAVIOR
The LMH6611 can be shutdown by connecting the
DISABLE pin to a voltage 0.5V below the supply midpoint
which will reduce the supply current to typically 120 µA. The
DISABLE pin is “active low” and can be connected through a
resistor to V
is guaranteed when the DISABLE pin is 0.5V below the supply
midpoint at any operating supply voltage and temperature.
Typical turn on time is 20 ns and the turn off time is 60 ns.
In the shutdown mode, essentially all internal device biasing
is turned off in order to minimize supply current flow and the
output goes into high impedance mode. During shutdown, the
input stage has an equivalent circuit as shown in
Complimentary bipolar devices with exceptionally high f
(
bias current.
Common emitter push-push output stage. This
architecture allows the output to reach within millivolts of
either supply rail.
Consistent performance with little variation from any
supply voltage (2.7V - 11V) for the most important
specifications (e.g. BW, SR, I
Significant power saving compared to competitive devices
on the market with similar performance.
∼
8 GHz) even under low supply voltage (2.7V) and low
+
or left floating for normal operation. Shutdown
V
OUT
= +1) is typically 305 MHz.
.)
Figure 1
30033622
Figure
shows the
2.
t
20
When the LMH6611 is shutdown, there may be current flow
through the internal diodes shown, caused by input potential,
if present. This current may flow through the external feed-
back resistor and result in an apparent output signal. In most
shutdown applications the presence of this output is incon-
sequential. However, if the output is “forced” by another de-
vice, the other device will need to conduct the current
described in order to maintain the output potential.
To keep the output at or near ground during shutdown when
there is no other device to hold the output low, a switch using
a transistor can be used to shunt the output to ground.
SELECTION OF R
PEAKING
The peaking of the LMH6611 depends on the value of the
R
creases, the peaking increases.
For A
and peaking is about 0.6 dB whereas at R
dB bandwidth is about 110 MHz and peaking is 0 dB. R
the input capacitance form a pole in the amplifier’s response.
If the time constant is too big, it will cause peaking and ringing.
Except for A
settings it is recommended that R
1 kΩ to ensure optimum performance.
FIGURE 3. Closed Loop Gain vs. Frequency and R
F
FIGURE 2. Input Equivalent Circuit During Shutdown
. From the graph shown in
V
= 2, at R
V
= 1 when R
F
= 1 kΩ, the −3 dB bandwidth is 113 MHz
F
AND EFFECT ON STABILITY AND
F
should be 0Ω, across all other gain
Figure
F
remain between 500Ω and
3, as the R
F
= 665Ω, the −3
30033692
F
30033639
value in-
F
F
= R
and
G