DataSheet.es AD548 Hoja de datos PDF



PDF AD548 Datasheet ( Hoja de datos )

Low Power BiFET Op Amp - Analog Devices

Número de pieza AD548
Descripción Low Power BiFET Op Amp
Fabricantes Analog Devices 
Logotipo Analog Devices Logotipo
Vista previa
Total 13 Páginas
		
AD548 datasheet

1 Page

AD548 pdf
AD548
ABSOLUTE MAXIMUM RATINGSl
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 18 V
Internal Power Dissipation2 . . . . . . . . . . . . . . . . . . . . 500 mW
Input Voltage3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 18 V
Output Short Circuit Duration . . . . . . . . . . . . . . . . . Indefinite
Differential Input Voltage . . . . . . . . . . . . . . . . . . +VS and –VS
Storage Temperature Range (Q, H) . . . . . . . –65°C to +150°C
(N, R) . . . . . . . . –65°C to +125°C
Operating Temperature Range
AD548J/K . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C
AD548B . . . . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to +85°C
Lead Temperature Range (Soldering 60 sec) . . . . . . . . . 300°C
NOTES
1Stresses above those listed under Absolute Maximum Ratings may cause
permanent damage to the device. This is a stress rating only; functional operation
of the device at these or any other conditions above those indicated in the
operational sections of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
2Thermal Characteristics: 8-Pin SOIC Package: θJA = 160°C/W, θJC = 42°C/W;
8-Lead Plastic Package: θJA = 90°C/W.
3For supply voltages less than ± 18 V, the absolute maximum input voltage is equal
to the supply voltage.
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection.
Although the AD548 features proprietary ESD protection circuitry, permanent damage may
occur on devices subjected to high-energy electrostatic discharges. Therefore, proper ESD
precautions are recommended to avoid performance degradation or loss of functionality.
WARNING!
ESD SENSITIVE DEVICE
–4– REV. D

5 Page

AD548 arduino
PHOTODIODE PREAMP
The performance of the photodiode preamp shown in Figure 7
is enhanced by the AD548’s low input current, input voltage
offset, and offset voltage drift. The photodiode sources a current
proportional to the incident light power on its surface. RF converts
the photodiode current to an output voltage equal to RF × IS.
Application Hints–AD548
Figure 7.
An error budget illustrating the importance of low amplifier
input current, voltage offset, and offset voltage drift to minimize
output voltage errors can be developed by considering the equi-
valent circuit for the small (0.2 mm2 area) photodiode shown in
Figure 7. The input current results in an error proportional to
the feedback resistance used. The amplifier’s offset will produce
an error proportional to the preamp’s noise gain (I + RF/RSH),
where RSH is the photodiode shunt resistance. The amplifier’s
input current will double with every 10°C rise in temperature,
and the photodiode’s shunt resistance halves with every 10°C
rise. The error budget in Figure 8 assumes a room temperature
photodiode RSH of 500 M, and the maximum input current
and input offset voltage specs of an AD548C.
TEMP
؇C RSH (M)
VOS (V) (1+ RF/RSH) VOS IB (pA) IBRF
TOTAL
25 15,970
0 2,830
25 500
50 88.5
75 15.6
85 7.8
150
200
250
300
350
370
151 µV
207 µV
300 µV
640 µV
2.6 mV
5.1 mV
0.30
2.26
10.00
56.6
320
640
30 µV 181 µV
262 µV 469 µV
1.0 mV 1.30 mV
5.6 mV 6.24 mV
32 mV 34.6 mV
64 mV 69.1 mV
Figure 8. Photodiode Preamp Errors Over Temperature
The capacitance at the amplifier’s negative input (the sum of the
photodiode’s shunt capacitance, the op amp’s differential input
capacitance, stray capacitance due to wiring, etc.) will cause a
rise in the preamp’s noise gain over frequency. This can result in
excess noise over the bandwidth of interest. CF reduces the
noise gain “peaking” at the expense of bandwidth.
INSTRUMENTATION AMPLIFIER
The AD548C’s maximum input current of 10 pA makes it an
excellent building block for the high input impedance instru-
mentation amplifier shown in Figure 9. Total current drain for
this circuit is under 600 µA. This configuration is optimal for
conditioning differential voltages from high impedance sources.
The overall gain of the circuit is controlled by RG, resulting in
the following transfer function:
VOUT = 1 + (R1 + R2 )
VIN RG
Figure 9. Low Power Instrumentation Amplifier
Gains of 1 to 100 can be accommodated with gain nonlinearities
of less than 0.01%. Input errors, which contribute an output
error proportional to in amp gain, include a maximum untrimmed
input offset voltage of 0.5 mV and an input offset voltage drift
over temperature of 4 µV/°C. Output errors, which are indepen-
dent of gain, will contribute an additional 0.5 mV offset and
4 µV/°C drift. The maximum input current is 15 pA over the
common-mode range, with a common-mode impedance of over
1 × 1012 . Resistor pairs R3/R5 and R4/R6 should be ratio
matched to 0.01% to take full advantage of the AD548’s high
common-mode rejection. Capacitors C1 and C1compensate for
peaking in the gain over frequency caused by input capacitance
when gains of 1 to 3 are used.
The –3 dB small signal bandwidth for this low power instrumenta-
tion amplifier is 700 kHz for a gain of 1 and 10 kHz for a gain of
100. The typical output slew rate is 1.8 V/µs.
LOG RATIO AMPLIFIER
Log ratio amplifiers are useful for a variety of signal conditioning
applications, such as linearizing exponential transducer outputs
and compressing analog signals having a wide dynamic range.
The AD548’s picoamp level input current and low input offset
voltage make it a good choice for the front-end amplifier of the
log ratio circuit shown in Figure 10. This circuit produces an
output voltage equal to the log base 10 of the ratio of the input
currents I1 and I2. Resistive inputs R1 and R2 are provided for
voltage inputs.
Input currents I1 and I2 set the collector currents of Q1 and Q2,
a matched pair of logging transistors. Voltages at points A and
B are developed according to the following familiar diode
equation:
VBE = (kT/q) ln (IC /IES )
In this equation, k is Boltzmann’s constant, T is absolute tem-
perature, q is an electron charge, and IES is the reverse saturation
current of the logging transistors. The difference of these two
voltages is taken by the subtractor section and scaled by a factor
of approximately 16 by resistors R9, R10, and R8. Temperature
REV. D
–9–

10 Page





PáginasTotal 13 Páginas
PDF Descargar[ AD548.PDF ]

Enlace url


Hoja de datos destacado

Número de piezaDescripciónFabricantes
AD5405Dual 12-Bit/ High Bandwidth/ Multiplying DAC with 4-Quadrant Resistors and Parallel InterfaceAnalog Devices
Analog Devices
AD5410Current Source DACAnalog Devices
Analog Devices
AD5412(AD5412 / AD5422) Current Source & Voltage Output DACAnalog Devices
Analog Devices
AD5415(AD5424 - AD5547) High Bandwidth Multiplying DACsAnalog Devices
Analog Devices
AD542High Performance/ BiFET Operational AmplifiersAnalog Devices
Analog Devices
AD5420Current Source DACAnalog Devices
Analog Devices
AD54214mA to 20mA DACAnalog Devices
Analog Devices


Número de piezaDescripciónFabricantes
SSM2604

Low Power Audio Codec.

Analog Devices
Analog Devices
SLG3NB3331

32.768 kHz and MHz GreenCLK.

Silego
Silego
SLA6805M

High Voltage 3 phase Motor Driver IC.

Sanken
Sanken
SDC1742

12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters.

Analog Devices
Analog Devices
SDC1741

12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters.

Analog Devices
Analog Devices


DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares,
permitiéndote verlos en linea o descargarlos en PDF.


Index : 0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z




www.DataSheet.es    |   2017   |  Contacto  |  Buscar