LPC661AIM National Semiconductor, LPC661AIM Datasheet - Page 11

• Manufacturer Part Number: LPC661AIM
• Description: IC OP AMP LOW PWR CMOS 8-SOIC
• Manufacturer: National Semiconductor

Specifications of LPC661AIM

• Amplifier Type: General Purpose
• Number Of Circuits: 1
• Output Type: Rail-to-Rail
• Slew Rate: 0.11 V/µs
• Gain Bandwidth Product: 350kHz
• Current - Input Bias: 0.002pA
• Voltage - Input Offset: 1000µV
• Current - Supply: 58µA
• Current - Output / Channel: 40mA
• Voltage - Supply, Single/dual (±): 4.75 V ~ 15.5 V, ±2.38 V ~ 7.75 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
• -3db Bandwidth: -
• Other names: *LPC661AIM

Application Hints
(Input pins are lifted out of PC board and soldered directly to components.
All other pins connected to PC board.)
BIAS CURRENT TESTING
The test method of Figure 10 is appropriate for bench-testing
bias current with reasonable accuracy. To understand its op-
eration, first close switch S2 momentarily. When S2 is
opened, then
Typical Single-Supply Applications
Note: A 5V bias on the photodiode can cut its capacitance by a factor of 2
or 3, leading to improved response and lower noise. However, this bias on
the photodiode will cause photodiode leakage (also known as its dark
current).
Photodiode Current-toVoltage Converter
FIGURE 9. Air Wiring
(Continued)
DS011227-15
DS011227-13
(V+ = 5.0 V
(Upper limit of output range dictated by input common-mode range; lower
limit dictated by minimum current requirement of LM385.)
11
A suitable capacitor for C2 would be a 5 pF or 10 pF silver
mica, NPO ceramic, or air-dielectric. When determining the
magnitude of I
must be taken into account. Switch S2 should be left shorted
most of the time, or else the dielectric absorption of the ca-
pacitor C2 could cause errors.
Similarly, if S1 is shorted momentarily (while leaving S2
shorted)
where C
FIGURE 10. Simple Input Bias Current Test Circuit
DC
x
)
Micropower Current Source
is the stray capacitance at the + input.
−
, the leakage of the capacitor and socket
DS011227-16
DS011227-14
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