LT1810CMS8#PBF Linear Technology, LT1810CMS8#PBF Datasheet - Page 19

• Manufacturer Part Number: LT1810CMS8#PBF
• Description: IC OPAMP R-R I/O DUAL 8-MSOP
• Manufacturer: Linear Technology

Specifications of LT1810CMS8#PBF

• Amplifier Type: General Purpose
• Number Of Circuits: 2
• Output Type: Rail-to-Rail
• Slew Rate: 350 V/µs
• Gain Bandwidth Product: 180MHz
• -3db Bandwidth: 320MHz
• Current - Input Bias: 12.5µA
• Voltage - Input Offset: 800µV
• Current - Supply: 15mA
• Current - Output / Channel: 85mA
• Voltage - Supply, Single/dual (±): 2.5 V ~ 12.6 V, ±1.25 V ~ 6.3 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

TYPICAL APPLICATIONS
Driving A/D Converters
The LT1809/LT1810 have a 27ns settling time to 0.1% of
a 2V step signal and 20Ω output impedance at 100MHz
making it ideal for driving high speed A/D converters. With
the rail-to-rail input and output and low supply voltage
operation, the LT1809 is also desirable for single supply
applications. As shown in Figure 2, the LT1809 drives a
10Msps, 12-bit ADC, the LTC1420. The lowpass fi lter, R3
and C1, reduces the noise and distortion products that
might come from the input signal. High quality capacitors
2V
V
P-P
IN
1V
1k
V
P-P
IN
R1
1k
Figure 2. Noninverting A/D Driver
+
–
–
+
Figure 4. Inverting A/D Driver
LT1809
LT1809
–5V
–5V
5V
1k
5V
R2
1k
49.9Ω
49.9Ω
R3
C1
470pF
470pF –A
+A
+A
–A
IN
IN
IN
IN
PGA GAIN = 1
PGA GAIN = 1
REF = 2.048V
REF = 2.048V
LTC1420
LTC1420
–5V
–5V
5V
5V
1809 F04
1809 F02
•
•
•
•
•
•
and resistors, an NPO chip capacitor and metal-fi lm surface
mount resistors, should be used since these components
can add to distortion. The voltage glitch of the converter,
due to its sampling nature, is buffered by the LT1809 and
the ability of the amplifi er to settle it quickly will affect the
spurious-free dynamic range of the system. Figure 2 to
Figure 7 depict the LT1809 driving the LTC1420 at different
confi gurations and voltage supplies. The FFT responses
show better than 90dB of SFDR for a ± 5V supply, and 80dB
on a 5V single supply for the 1.394MHz signal.
12 BITS
10Msps
12 BITS
10Msps
–100
–120
–100
–120
–20
–40
–60
–80
–20
–40
–60
–80
0
0
Figure 5. 4096 Point FFT Response
Figure 3. 4096 Point FFT Response
0
0
1
1
LT1809/LT1810
FREQUENCY (MHz)
FREQUENCY (MHz)
2
2
3
V
A
f
f
SFDR = 90dB
3
V
A
f
f
SFDR = 90dB
SAMPLE
IN
SAMPLE
IN
S
V
S
V
= ±5V
= –1
= 1.394MHz
= ±5V
= +2
= 1.394MHz
= 10Msps
= 10Msps
4
4
1809 F05
1809 F03
5
5
19
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