LMH6518SQEVK National Semiconductor, LMH6518SQEVK Datasheet - Page 4

• Manufacturer Part Number: LMH6518SQEVK
• Description: KIT EVAL FOR LMH6518 VGA
• Manufacturer: National Semiconductor
• Series: PowerWise®r

Specifications of LMH6518SQEVK

• Channels Per Ic: 1 - Single
• Amplifier Type: Variable Gain
• Output Type: Differential
• -3db Bandwidth: 900MHz
• Operating Temperature: -40°C ~ 85°C
• Current - Supply (main Ic): 210mA
• Voltage - Supply, Single/dual (±): 4.75 V ~ 5.25 V
• Board Type: Fully Populated
• Utilized Ic / Part: LMH6518
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output / Channel: -
• Slew Rate: -
• Lead Free Status / Rohs Status: Supplier Unconfirmed

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3. Default device turn-on state: Preamp Low Gain, 20 dB
4. When the Power Mode is switched, the change in +5V
ladder attenuation, Full power mode, Filter full. With the
USB Interface board connected, the LMH6518 evaluation
board will remain powered on through the interconnect to
the USB Interface board, even if the 5V supply to the board
is disconnected. Therefore, the device states will not reset
to default power-on even if the power is turned off.
supply current (
trace is enough to cause a noticeable difference in the
voltage at “−IN“ (voltage-divided from 5V supply). This
∼
60 mA) through the power supply wiring/
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could cause enough input offset difference to shift or rail
the output, especially at high gains (i.e. Preamp HG and
little or no ladder attenuation). If this occurs, readjust R
(bottom side of the board) as described in section 3.2.3 to
null the output offset which is caused by the way the un-
driven input is biased. This is merely a consequence of
how the undriven input is biased.
In an oscilloscope application, the driven input’s offset
needs to be servo’d to the undriven input potential, similar
to the JFET LNA shown in the LMH6518 datasheet; thus,
the cause is eliminated.
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