LMH6619MA National Semiconductor, LMH6619MA Datasheet - Page 23

• Manufacturer Part Number: LMH6619MA
• Description: OP AMP, DUAL, 130 MHZ, POWERWISE
• Manufacturer: National Semiconductor

Specifications of LMH6619MA

• Op Amp Type: High Speed
• No. Of Amplifiers: 2
• Bandwidth: 58MHz
• Slew Rate: 57V/µs
• Supply Voltage Range: 2.7V To 11V
• Amplifier Case Style: SOIC
• No. Of Pins: 8
• Operating Temperature Range: -40°C To
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

DC LEVEL SHIFTING
Often a signal must be both amplified and level shifted while
using a single supply for the op amp. The circuit in Figure 7
can do both of these tasks. The procedure for specifying the
resistor values is as follows.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10. Calculate R
11. Calculate R
12. Calculate R
Check that both the V
ranges of the LMH6618.
4
Figure 8 shows the LMH6619 used as the amplifier in a mul-
tiple feedback low pass filter. This filter is set up to have a gain
of +1 and a −3 dB point of 1 MHz. Values can be determined
th
ORDER MULTIPLE FEEDBACK LOW-PASS FILTER
Determine the input voltage.
Calculate the input voltage midpoint, V
(V
Determine the output voltage needed.
Calculate the output voltage midpoint, V
V
Calculate the gain needed, gain = (V
(V
Calculate the amount the voltage needs to be shifted
from input to output, ΔV
Set the supply voltage to be used.
Calculate the noise gain, noise gain = gain + ΔV
Set R
OUTMIN
INMAX
INMAX
F
.
– V
– V
+ (V
INMIN
INMIN
1
2
G
, R
, R
OUTMAX
, R
1
2
G
)/2.
)
= R
= R
= R
IN
– V
F
F
F
/gain.
/(noise gain-gain).
/(noise gain – 1).
and V
OUTMIN
OUT
= V
OUT
)/2.
FIGURE 8. 4
OUTMID
are within the voltage
OUTMAX
– gain x V
INMID
OUTMID
th
= V
– V
Order Multiple Feedback Low-Pass Filter
=
INMIN
OUTMIN
OUT
INMID
/V
+
.
S
)/
.
23
The following example is for a V
2V to 4V.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10. R
11. R
12. R
by using the WEBENCH
amplifiers.national.com.
V
V
V
V
Gain = (4V – 2V)/(1V – 0V) = 2
ΔV
For the example the supply voltage will be +5V.
Noise gain = 2 + 2/5V = 2.4
R
IN
INMID
OUT
OUTMID
F
1
2
G
OUT
= 2 kΩ
= 2 kΩ/2 = 1 kΩ
= 2 kΩ/(2.4-2) = 5 kΩ
= 2 kΩ/(2.4 – 1) = 1.43 kΩ
= 0V to 1V
= 2V to 4V
= 0V + (1V – 0V)/2 = 0.5V
= 3V – 2 x 0.5V = 2
= 2V + (4V – 2V)/2 = 3V
FIGURE 7. DC Level Shifting
®
Active Filter Designer found at
IN
of 0V to 1V with a V
20195828
20195848
www.national.com
OUT
of