Datasheet

D1
D2
D3
D4
NON-INVERTING
INPUT
INVERTING
INPUT
R
S
200-400:
LMV116, LMV118
www.ti.com SNOSA87B –OCTOBER 2003–REVISED MAY 2013
APPLICATION NOTES
CIRCUIT DESCRIPTION
The LMV116 and LMV118 are based on TI’s proprietary VIP10 dielectrically isolated bipolar process.
The LMV116 and LMV118 architecture features the following:
• Complimentary bipolar devices with exceptionally high f
t
(∼8GHz) even under low supply voltage (2.7V) and
low Collector bias current.
• Common Emitter push-pull output stage capable of 20mA output current (at 0.5V from the supply rails) while
consuming only 600μA of total supply current. This architecture allows output to reach within milli-volts of
either supply rail at light loads.
• Consistent performance from any supply voltage (2.7V-10V) with little variation with supply voltage for the
most important specifications (e.g. BW, SR, I
OUT
, etc.)
APPLICATION HINTS
When the output swing approaches either supply rail, the output transistor will enter a Quasi-saturated state. A
subtle effect of this operational region is that there is an increase in supply current in this state (up to 1 mA). The
onset of Quasi-saturation region is a function of output loading (current) and varies from 100 mV at no load to
about 1V when output is delivering 20 mA, as measured from supplies. Both input common mode voltage and
output voltage level effect the supply current (see typical performance characteristics for plot).
MICRO-POWER SHUTDOWN
The LMV118 can be shutdown to save power and reduce its supply current to less than 50μA specified, by
applying a voltage to the SD pin. The SD pin is “active high” and needs to be tied to V
−
for normal operation. This
input is low current (<20μA, 4pF equivalent capacitance) and a resistor to V
−
(≤20kΩ) will result in normal
operation. Shutdown is specified when SD pin is 0.4V or less from V
+
at any operating supply voltage and
temperature.
In the shutdown mode, essentially all internal device biasing is turned off in order to minimize supply current flow
and the output goes into Hi-Z (high impedance) mode. Complete device Turn-on and Turn-off times vary
considerably relative to the output loading conditions, output voltage, and input impedance, but is generally
limited to less than 1μs (see tables for actual data).
During shutdown, the input stage has an equivalent circuit as shown below in Figure 23.
Figure 23.
As can be seen above, in shutdown, there may be current flow through the internal diodes shown, caused by
input potential, if present. This current may flow through the external feedback resistor and result in an apparent
output signal. In most shutdown applications the presence of this output is inconsequential. However, if the
output is “forced” by another device such as in a multiplexer, the other device will need to conduct the current
described in order to maintain the output potential.
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Product Folder Links: LMV116 LMV118