LT1800 Linear Technology, LT1800 Datasheet - Page 14

• Manufacturer Part Number: LT1800
• Description: 80MHz/ 25V/ms Low Power Rail-to-Rail Input and Output Precision Op Amp
• Manufacturer: Linear Technology

LT1800
TYPICAL APPLICATIO S
14
500mV/DIV
Figure 3. Current Sense Amplifier Large-Signal Response
0V
V
S
= 3V
V
V
S
IN
/2
50ns/DIV
909
U
909
2.67k
220pF
Figure 4. 3V, 1MHz, 4th Order Butterworth Filter
–100
–120
–20
–40
–60
–80
Figure 5. Frequency Response of Filter
0
1800 F03
47pF
1k
–
+
LT1800
10k
FREQUENCY (Hz)
100k
1.1k
Single 3V Supply, 1MHz, 4th Order Butterworth Filter
The circuit shown in Figure 4 makes use of the low voltage
operation and the wide bandwidth of the LT1800 to create
a DC accurate 1MHz 4th order lowpass filter powered from
a 3V supply. The amplifiers are configured in the inverting
mode for the lowest distortion and the output can swing
rail-to-rail for maximum dynamic range. Figure 5 displays
the frequency response of the filter. Stopband attenuation
is greater than 100dB at 50MHz. With a 2.25V
input signal, the filter has harmonic distortion products of
less than –85dBc. Worst case output offset voltage is less
than 6mV.
1M
1.1k
2.21k
470pF
10M
1800 F05
100M
22pF
–
+
LT1800
3V
1800 F04
V
OUT
P-P
, 250kHz
1800f