CLC425AJE National Semiconductor, CLC425AJE Datasheet - Page 12

• Manufacturer Part Number: CLC425AJE
• Description: IC OP AMP LO NOISE WIDE 8-SOIC
• Manufacturer: National Semiconductor

Specifications of CLC425AJE

• Amplifier Type: Voltage Feedback
• Number Of Circuits: 1
• Slew Rate: 350 V/µs
• Gain Bandwidth Product: 1.9GHz
• -3db Bandwidth: 95MHz
• Current - Input Bias: 12µA
• Voltage - Input Offset: 100µV
• Current - Supply: 15mA
• Current - Output / Channel: 90mA
• Voltage - Supply, Single/dual (±): 5 V ~ 12 V, ±2.5 V ~ 6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Output Type: -
• Other names: *CLC425AJE

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response is shown in Figure 12 and shows the influence C
has over gain flatness. Equation 4 provides the total input
current noise density (i
simpedance configuration and is plotted against feedback
resistance (R
ure 13. This plot indicates the expected total equivalent input
current noise density (i
(R
i
ni
*R
FIGURE 11. Transimpedance Amplifier Configuration
f
). The total equivalent output voltage noise density (e
FIGURE 12. Transimpedance Amplifier Frequency
f
FIGURE 13. Current Noise Density vs. Feedback
.
f
) showing all contributing noise sources in Fig-
ni
Resistance
Response
) for a given feedback resistance
ni
) equation for the basic tran-
12708 Version 11 Revision 3
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no
) is
f
Print Date/Time: 2009/07/15 16:53:30
12
Very Low Figure Amplifier
The circuit of Figure 14 implements a very low Noise Figure
amplifier using a step-up transformer combined with a
CLC425 and a CLC404. The circuit is configured with a gain
of 35.6dB. The circuit achieves measured Noise Figures of
less than 2.5dB in the 10-40MHz region, 3
exceed +30dB for frequencies less than 40MHz and gain flat-
ness of 0.5dB is measured in the 1-50MHz passbands. Ap-
plication Note OA-14 provides greater detail on these low
Noise Figure techniques.
Low Noise Integrator
The CLC425 implements a deBoo integrator shown in Figure
15. Integration linearity is maintained through positive feed-
back. The CLC425's low input offset voltage and matched
inputs allowing bias current cancellation provide for very pre-
cise integration. Stability is maintained through the constraint
on the circuit elements.
High-Gain Sallen-Key Active Filters
The CLC425 is well suited for high gain Sallen-Key type of
active filters. Figure 16 shows the 2
pass filter topology. Using component predistortion methods
as discussed in OA-21 enables the proper selection of com-
ponents for these high-frequency filters.
FIGURE 14. Very Noise Figure Amplifier
FIGURE 15. Low Noise Integrator
nd
order Sallen-Key low
rd
order intercepts
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