Motore di ricerca datesheet componenti elettronici |
|
AD8316ARM-REEL7 Scheda tecnica(PDF) 9 Page - Analog Devices |
|
AD8316ARM-REEL7 Scheda tecnica(HTML) 9 Page - Analog Devices |
9 / 20 page REV. C AD8316 –9– 10mV PER VERTICAL DIVISION 2V PER VERTICAL DIVISION 2 s PER HORIZONTAL DIVISION VOUT AVERAGING = 16 SAMPLES VPOS INPUT 250ns RISE TIME 1 s RISE TIME TPC 31. Power-On and Power-Off Response with VSET and ENBL Grounded RFOUT H-P 8648B SIGNAL GENERATOR 0.1GHz –60dBm 52.3 AD8316 OUT2 FLT2 VPOS OUT1 COMM FLT1 BSEL* RFIN ENBL VSET CFLT CFLT H-P 8110A PULSE GENERATOR RL 1k TEK 1103 PWR SUPPLY TEK TDS3054 SCOPE PULSE OUT *BSEL HIGH OUT1; BSEL LOW OUT2 AD811 TEK P6204 FET PROBE 732 49.9 TEK P6204 FET PROBE TPC 32. Test Setup for Power-On and Power-Off Response with VSET and ENBL Grounded GENERAL DESCRIPTION AND THEORY The AD8316 is a wideband logarithmic amplifier (log amp) with two selectable outputs suitable for dual-band/dual-mode power amplifier control. It is strictly optimized for power control appli- cations rather than for use as a measurement device. Figure 1 shows its main features in block schematic form. The output pins, OUT1 and OUT2, are intended to be applied directly to the automatic power control (APC) pins of two distinct power amplifiers. When the band select pin, BSEL, directs one of the controller outputs to servo its amplifier toward the setpoint indicated by the power control pin VSET, the other output is forced to ground, disabling the second amplifier. Each output has a dedicated filter pin, FLT1 and FLT2, that allows the filtering and loop dynamics for each control loop to be opti- mized independently. Basic Theory Logarithmic amplifiers provide a type of compression in which a signal with a large range of amplitudes is converted to one of a smaller range. The use of the logarithmic function uniquely results in the output representing the decibel value of the input. The fundamental mathematical form is VV V V OUT SLP IN Z = log (1) Here VIN is the input voltage and VZ is called the intercept (volt- age) because when VIN = VZ the argument of the logarithm is unity, and thus the result is zero; VSLP is called the slope (volt- age), which is the amount by which the output changes for a certain change in the ratio (VIN/VZ). Because log amps do not respond to power, but only to voltages, and the calibration of the intercept is waveform dependent and only quoted for a sine wave signal, the equivalent power response can be written as VV P P OUT DB IN Z = (– ) (2) where the input power PIN and the equivalent intercept PZ are both expressed in dBm (thus, the quantity in the parentheses is simply a number of decibels), and VDB is the slope expressed as so many mV/dB. When base 10 logarithms are used, denoted by the function log10, VSLP represents V/dec, and since a decade corresponds to 20 dB, VSLP/20 represents the change in V/dB. For the AD8316, a nominal (low frequency) slope of 22 mV/dB (corresponding to a VSLP of 0.022 mV/dB × 20 dB = 440 mV) was chosen, and the intercept VZ was placed at the equivalent of –74 dBV, or 199 µV rms, for a sine wave input. This corre- sponds to a power level of –61 dBm when the net resistive part of the input impedance of the log amp is 50 Ω. However, both the slope and the intercept are dependent on frequency (see for example, TPC 13 and TPC 16). For a log amp with a slope VDB of +22 mV/dB and an inter- cept at –61 dBm, the output voltage for an input power of –30 dBm is 0.022 × (–30 – [–61]) = 0.682 V. OUT2 OUT1 FLT1 VSET 325mV TO 1.4V = 49dB FLT2 10dB COMM OFFSET COMPENSATION RFIN 10dB 10dB 10dB DET DET DET DET DET INTERCEPT POSITIONING LOW NOISE GAIN BIAS LOW NOISE BAND GAP REFERENCE OUTPUT ENABLE DELAY ENBL VPOS BSEL 1.35 HI-Z HI-Z V–I LOW NOISE RAIL-TO-RAIL BUFFERS 1.35 Figure 1. Block Schematic of the AD8316 |
Codice articolo simile - AD8316ARM-REEL7 |
|
Descrizione simile - AD8316ARM-REEL7 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEETIT.COM |
Lei ha avuto il aiuto da alldatasheet? [ DONATE ] |
Di alldatasheet | Richest di pubblicita | contatti | Privacy Policy | scambio Link | Ricerca produttore All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |