LPV531MK/NOPB National Semiconductor, LPV531MK/NOPB Datasheet - Page 16

• Manufacturer Part Number: LPV531MK/NOPB
• Description: IC OPAMP PROG R-R OUT TSOT23-6
• Manufacturer: National Semiconductor
• Series: PowerWise®r

Specifications of LPV531MK/NOPB

• Amplifier Type: General Purpose
• Number Of Circuits: 1
• Output Type: Rail-to-Rail
• Slew Rate: 2.5 V/µs
• Gain Bandwidth Product: 4.6MHz
• Current - Input Bias: 0.05pA
• Voltage - Input Offset: 1000µV
• Current - Supply: 425µA
• Current - Output / Channel: 24mA
• Voltage - Supply, Single/dual (±): 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: TSOT-23-6, TSOT-6
• Number Of Channels: 1
• Voltage Gain Db: 128 dB
• Common Mode Rejection Ratio (min): 72 dB
• Input Offset Voltage: 4.5 mV at 5 V
• Operating Supply Voltage: 5 V
• Supply Current: 0.53 mA at 5 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• -3db Bandwidth: -
• Lead Free Status / Rohs Status: Details
• Other names: LPV531MK; LPV531MKTR

www.national.com
Typical Application
For simplicity, the op amp is modelled as an ideal integrator
with a unity gain frequency of A
(or gain) in the frequency domain is A
equations in the frequency domain, ignoring C
ment, results in the following equation for the gain:
It can be inferred from the denominator of the transfer func-
tion that it has two poles, whose expressions can be ob-
tained by solving for the roots of the denominator:
Equation (2) shows that as the values of R
increased, the magnitude of the poles is reduced, and hence
the bandwidth of the amplifier is decreased. Furthermore, R
and R
2
are related by the gain of the amplifier.
0
. Hence, its transfer function
(Continued)
0
/s. Solving the circuit
1
F
and R
for the mo-
2
are
(1)
(2)
1
16
A
R
It is the presence of pairs of poles in Equation (2) that causes
gain peaking. In order to eliminate this effect, the poles
should be placed in Butterworth position, since poles in
Butterworth position do not cause gain peaking. To achieve a
Butterworth pair, the quantity under the square root in Equa-
tion 2 should be set to equal −1. Using this fact and the
relation between R
found. This is shown in Equation (3). If R
larger than this optimum value, gain peaking will occur.
In Figure 9, C
and to increase stability. In addition, C
the gain peaking that can be caused by having a larger
feedback resistor.
V
2
= −R
= −A
V
2
/R
R
1
1
, or alternatively
F
is added to compensate for input capacitance
1
and R
2
, the optimum value for R
F
reduce or eliminates
1
is chosen to be
1
can be
(3)