AD8309 Analog Devices, AD8309 Datasheet
AD8309
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AD8309 Summary of contents
Page 1
... A CMOS-compatible control interface can enable the AD8309 within about 500 ns and disable standby current of under 1 A. The six cascaded amplifier/limiter cells in the main path have a small signal gain of 12. 4), with a –3 dB bandwidth of 850 MHz, providing a total gain ...
Page 2
... V rms. A power level of 0 dBm (1 mW offset of +13 dBm in the special case Due to the extremely high Gain Bandwidth Product of the AD8309, the output of either LMHI or LMLO will be unstable for levels below –78 dBV (–65 dBm Specifications subject to change without notice. (V ...
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... 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 AD8309 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 ...
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... AD8309–Typical Performance Characteristics 100 10 1 +25 C 0.1 +85 C 0.01 0.001 0.0001 0.00001 0.5 0.7 0.9 1.1 1.3 1.5 1.7 ENABLE VOLTAGE – V Figure 1. Supply Current vs. Enable Voltage @ T = –40 C, +25 C and + –13dBV VLOG –33dBV 500mV PER –53dBV VERTICAL –73dBV DIVISION –93dBV GROUND REFERENCE ENBL 5V PER VERTICAL DIVISION 500ns PER HORIZONTAL DIVISION Figure 2 ...
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... C, for Figure 12. Log Linearity of RSSI Output vs. Input Level +25 C, for Frequencies of 300 MHz, 400 MHz and A 500 MHz –5– AD8309 – –80 –60 – ...
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... AD8309 100 1 FREQUENCY – MHz Figure 13. RSSI Slope vs. Frequency Using Termination of 52.3 in Series with 4.7 nH 2ns PER HORIZONTAL DIVISION LIMITER OUTPUTS 100mV PER VERTICAL DIVISION 2mV PER VERTICAL DIVISION Figure 14. Limiter Output at 300 MHz for a Sine Wave Input of – ...
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... V For example 400 mV/decade (that is, 20 mV/dB, as for Y the AD8309), an offset of 120 mV added to the output will appear to lower the intercept by two tenths of a decade dB. Adding an offset to the output is thus indistinguishable from applying an input level that higher. ...
Page 8
... In this connection, note that the input impedance of the AD8309 is much higher that 50 , allowing the use of an im- pedance transformer at the input to raise the sensitivity dB. ...
Page 9
... X , while voltage is log ( ) An A/0 cell can be very simple. In the AD8309 it is based on a bipolar-transistor differential pair, having resistive loads R an emitter current source I an equivalent knee-voltage of E gain hyperbolic tangent (see dotted line in Figure 23). This function (5) is very precise, and the deviation from an ideal A/0 form is not detrimental. In fact, the “ ...
Page 10
... K biased with currents (not shown in the Figure) which can be derived from a band-gap reference and thus be stable with tem- perature. This is the architecture used in the AD8309. It affords complete control over the magnitude and temperature behavior of the logarithmic slope. A further step is yet needed to achieve the demodulation response, required in a log-limiter amp is to convert an alternating input into a quasi- dc baseband output ...
Page 11
... Input Matching Monolithic log amps present a nominal input impedance much higher than 50 . For the AD8309, this can be modeled shunted by 2.5 pF, at frequencies up to 300 MHz. Thus, a simple input matching network can considerably improve the basic sensitivity , when driving from a low-impedance source, by increasing the voltage applied to the input ...
Page 12
... A when Pin 8 is taken Left unconnected any voltage below 1 V, the AD8309 will be disabled, when it consumes a sleep current of much less than 1 A (leakage currents only); when tied to the supply, or any voltage above will be fully en- abled ...
Page 13
... ZERO-TC reduced by adding a grounded load resistance. COM1 USING THE AD8309 The AD8309 exhibits very high gain from 1 MHz to over 1 GHz, LMDR at which frequency the gain of the main path is still over 65 dB. Consequently susceptible to all signals within this very broad frequency range which find their way to the input termi- nals important to remember that these are quite indistin- guishable from the “ ...
Page 14
... AD8309 has a very high capacity for large input voltages. Figure 31 shows the output versus the input level, with the axis marked in dBm (correct only when terminated for sine inputs at 5 MHz, 50 MHz, 100 MHz and 200 MHz ...
Page 15
... The response is down one-tenth the center frequency, falling per decade below this. The very high frequency attenuation is relatively small, however, since in the limiting case it is determined simply by the ratio of the AD8309’s input capacitance to the coupling capacitors. Table I provides solu- tions for a variety of center frequencies f ...
Page 16
... Figure 37 may used. Note that at 50 mV/dB, the full 100 dB dynamic range of the AD8309 requires swing. This can be provided by a single supply operational amplifier having a rail-to-rail output stage and operating from supply. Where a lower range is 8.87k ...
Page 17
... Even higher output powers can be ob- 4.08 tained using emitter-followers. In Figure 38, the supply voltage 5.10 to the AD8309 is dropped from about 4 the diode. This increases the available swing at each output to about 2 V. Taking both outputs differentially, a square wave output p-p can be generated. ...
Page 18
... AD8309. When the input signal is above the limiting threshold, the output will then be a square- wave whose amplitude is proportional to the control bias. ...
Page 19
... Device Enable. When in position A, the ENBL pin is connected to +V AD8309 is in normal operating mode. In position B, the ENBL pin is connected to an SMA connector labeled Ext Enable. An applied signal can be applied to this connector to enable/disable the AD8309. If left open, the ENBL pin will float to ground putting the device in power-down mode. R1 This pad is used to ac-couple to ground for single-ended input drive ...
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... AD8309 Figure 43. Signal Layer Silkscreen OUTLINE DIMENSIONS Dimensions shown in inches and (mm). 16-Lead TSSOP (RU-16) 0.201 (5.10) 0.193 (4.90 PIN 1 0.006 (0.15) 0.0433 0.002 (0.05) (1.10) MAX 8° 0.0256 0.0118 (0.30) 0° SEATING 0.0079 (0.20) (0.65) 0.0075 (0.19) PLANE BSC 0.0035 (0.090) –20– Figure 44. Power Layer Silkscreen 0.028 (0.70) 0.020 (0.50) ...