ltc6910-2 Linear Technology Corporation, ltc6910-2 Datasheet - Page 22

• Manufacturer Part Number: ltc6910-2
• Description: Digitally Controlled Programmable Gain Amplifiers In Sot-23
• Manufacturer: Linear Technology Corporation

Measured frequency responses in Figure 8 with
LTC6910-1 PGAs demonstrate bandwidth settings of 10Hz,
100Hz and 1kHz, with digital codes at the BW inputs of
respectively 001, 100 and 111, and unity gain in each case.
By scaling C2, this circuit can serve other bandwidths,
LTC6910-1
LTC6910-2/LTC6910-3
TYPICAL APPLICATIO S
22
V
IN
CONTROL
3
GAIN
0.1 F
LTC6910-1
–20
–30
–40
–50
–60
–70
–80
–10
2
Figure 8. Low Noise AC Amplifier with Programmable Gain and Bandwidth
GN2 GN1 GN0
10
V
0
0
0
0
1
1
1
1
+
8
7
1
GN2 GN1 GN0 = 001
V
0
1
1
0
0
1
1
–
4
6
0.1 F
U
1
0
1
0
1
0
1
5
1
10 F R1
C1
GAIN = 1
GAIN = 2
GAIN = 5
GAIN = 10
GAIN = 20
GAIN = 50
GAIN = 100
15.8k
15.8k
10
R2
BW2
1 F
0.1 F
0
C2
BW1
V
0
–
1
2
3
4
Gain vs Frequency
BW0
V
1
100
–
+
–
FREQUENCY (Hz)
BW2
LT1884
1
BW1
0
such as a maximum of 10kHz with 0.1 F using LT1884
(gain-bandwidth product around 1MHz). Noise floor from
internal sources yields an output SNR of 76dB with 10mV
P
input, gain of 10 and 1000Hz bandwidth it is 64dB.
input, gain of 100 and 100Hz bandwidth; for 100mV
BW0
–
+
0
V
1k
+
8
7
6
5
R4 15.8k
BANDWIDTH 1Hz TO 10Hz
BANDWIDTH 1Hz TO 20Hz
BANDWIDTH 1Hz TO 50Hz
BANDWIDTH 1Hz TO 100Hz
BANDWIDTH 1Hz TO 200Hz
BANDWIDTH 1Hz TO 500Hz
BANDWIDTH 1Hz TO 1000Hz
15.8k
R3
V
OUT
V
BW2
+
10k
1
0.1 F
BW1
BANDWIDTH
1
CONTROL
BW0
1
6910 F06b
3
0.1 F
100k
LTC6910-1
2
BW2 BW1BW0
V
0
0
0
1
1
1
1
+
8
7
V
0
1
1
0
0
1
1
–
0.1 F
4
6
1
0
1
0
1
0
1
5
1
6910123fa
P-P
P-