LMH6643MAX NSC [National Semiconductor], LMH6643MAX Datasheet - Page 16

• Manufacturer Part Number: LMH6643MAX
• Description: 3V, Low Power, 130MHz, 75mA Rail-to-Rail Output Amplifiers
• Manufacturer: NSC [National Semiconductor]

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Application Notes
CIRCUIT DESCRIPTION:
The LMH664X family is based on National Semiconductor’s
proprietary VIP10 dielectrically isolated bipolar process.
This device family architecture features the following:
Application Hints:
This Op Amp family is a drop-in replacement for the AD805X
family of high speed Op Amps in most applications. In addi-
tion, the LMH664X will typically save about 40% on power
dissipation, due to lower supply current, when compared to
competition. All AD805X family’s guaranteed parameters are
included in the list of LMH664X guaranteed specifications in
order to ensure equal or better level of performance. How-
ever, as in most high performance parts, due to subtleties of
applications, it is strongly recommended that the perfor-
mance of the part to be evaluated is tested under actual
operating conditions to ensure full compliance to all specifi-
cations.
With 3V supplies and a common mode input voltage range
that extends 0.5V below V
in low voltage/low power applications. Even with 3V sup-
plies, the −3dB BW (
tested limit of 80MHz. Production testing guarantees that
process variations with not compromise speed. High fre-
quency response is exceptionally stable confining the typical
-3dB BW over the industrial temperature range to
As can be seen from the typical performance plots, the
LMH664X output current capability (∼75mA) is enhanced
compared to AD805X. This enhancement, increases the
output load range, adding to the LMH664X’s versatility.
Because of the LMH664X’s high output current capability
attention should be given to device junction temperature in
order not to exceed the Absolute Maximum Rating.
• Complimentary bipolar devices with exceptionally high f
• A class A-B “turn-around” stage with improved noise,
• Common Emitter push-push output stage capable of
• Consistent performance from any supply voltage (3V-
• Significant power saving (∼40%) compared to competi-
(∼8GHz) even under low supply voltage (2.7V) and low
bias current.
offset, and reduced power dissipation compared to simi-
lar speed devices (patent pending).
75mA output current (at 0.5V from the supply rails) while
consuming only 2.7mA of total supply current per chan-
nel. This architecture allows output to reach within milli-
volts of either supply rail.
10V) with little variation with supply voltage for the most
important specifications (e.g. BW, SR, I
tive devices on the market with similar performance.
@
A
V
−
= +1) is typically 115MHz with a
, the LMH664X find applications
OUT
, etc.)
±
2.5%.
t
16
This device family was designed to avoid output phase
reversal. With input overdrive, the output is kept near supply
rail (or as closed to it as mandated by the closed loop gain
setting and the input voltage). See Figure 1:
However, if the input voltage range of −0.5V to 1V from V
exceeded by more than a diode drop, the internal ESD
protection diodes will start to conduct.The current in the
diodes should be kept at or below 10mA.
Output overdrive recovery time is less than 100ns as can be
seen from Figure 2 plot:
FIGURE 1. Input and Output Shown with CMVR
FIGURE 2. Overload Recovery Waveform
Exceeded
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is