ADL5507ACBZ-R7 datasheet(31/34 Pages) AD

31 / 34 page

Data Sheet

ADL5507

APPLICATIONS INFORMATION

analog.com

Rev. 0 | 31 of 34

Table 4. Input Impedance with 51 Ω Shunt for Select Frequency (Continued)

Frequency

S11

Impedance Ω

(GHz)

Real

Imaginary

(Series)

-0.731

-0.353

5.47 - j11.32

-0.545

-0.439

9.91 - j17.02

-0.609

-0.452

7.59 - j16.19

Table 5. Raw Input Impedance for Select Frequency

Frequency

S11

Impedance Ω

(GHz)

Real

Imaginary

(Series)

0.01

+0.925

-0.036

1024.75 - j518.10

0.1

+0.908

-0.028

941.18 - j301.57

0.5

+0.901

-0.114

384.78 - j498.60

+0.876

-0.222

141.67 - j343.22

+0.785

-0.415

48.43 - j189.73

+0.666

-0.566

27.38 - j131.03

+0.545

-0.672

19.07 - j101.97

+0.421

-0.750

14.47 - j83.55

+0.252

-0.788

13.33 - j66.74

+0.070

-0.810

11.13 - j53.25

-0.165

-0.761

10.18 - j39.28

-0.336

-0.671

9.75 - j30.03

-0.564

-0.524

7.50 - j19.27

-0.548

-0.356

11.37 - j14.11

-0.752

-0.262

5.84 - j8.34

-0.697

-0.375

6.18 - j12.43

-0.498

-0.365

13.01 - j15.34

-0.673

-0.344

7.35 - j11.81

FILTER CAPACITOR

The video bandwidth of VLOG is approximately 3.5 MHz. In CW

applications where the input frequency is much higher than this, no

further filtering of the demodulated signal is required. Where there

is a low frequency modulation of the carrier amplitude, however,

reduce the low-pass corner by the addition of an external filter

capacitor, CFLT. The video bandwidth is related to CFLT by

V ideo Bandwidtℎ =

2π × 12 kΩ × 3.65 pF + CFLT

(6)

VLOG PULSE RESPONSE TIME

The ADL5507 VLOG output response for rise and fall times to a

given RF input pulse is quickest for CFLT = open; that is, the only

capacitance on the CFLT node is the internal capacitor. Adding

off-chip capacitance from the CFLT pin to the VLOG pin decreases

the video bandwidth and slows the output response to an RF input

pulse. See the Filter Capacitor section for an approximate closed

form equation for the VLOG video bandwidth.

VLOG OUTPUT NOISE

The ADL5507 VLOG output noise for Positive Slope mode is shown

in Figure 37 and for Negative Slope mode is shown in Figure 72 in

the Typical Performance Characteristics section for Capacitor CFLT

= open. Placing capacitance from CFLT to VLOG decreases the

noise spectral density and the integrated noise. The choice of the

CFLT value depends on the requirements pertaining to integrated

noise and noise spectral density at a given frequency. Also, the

value of CFLT directly controls the video bandwidth of the output,

and thus controls the output response time to an RF pulse (see the

VLOG Pulse Response Time section).

EFFECT OF WAVEFORM TYPE ON INTERCEPT

Although, specified for input levels in decibels relative to 1 mW

(dBm), the ADL5507 fundamentally responds to voltage and not

to power. A direct consequence of this characteristic is that input

signals of equal RMS power but differing crest factors, produce

different results at the output of the log amplifier.

The effect of differing signal waveforms is to shift the effective

value of the intercept upwards or downwards. Graphically, this looks

like a vertical shift in the transfer function of the log amplifier. The

logarithmic slope, however, is not affected. For example, consider

the case of the ADL5507 being alternately fed by an unmodulated

sine wave and by a 64 QAM signal of the same RMS power. The

output voltage of the ADL5507 differs by the equivalent of 1.6 dB

(31 mV) over the complete dynamic range of the device (with the

output for a 64 QAM input being lower).

DEVICE HANDLING

The WLCSP package consists of solder bumps connected to the

active side of the die. The device is lead-free with 95.5% tin, 4.0%

silver, and 0.5% copper solder bump composition. The WLCSP

package can be mounted on printed circuit boards using standard

surface-mount assembly techniques; however, take caution to avoid

damaging the die. See the AN-617 Application Note for additional

information. WLCSP devices are bumped die, and exposed die can

be sensitive to light conditions, which can influence specified limits.

ADL5507ACBZ-R7 Folha de dados(PDF) 31 Page - Analog Devices

ADL5507ACBZ-R7 Folha de dados(HTML) 31 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34

Folha de dados Download

Ligação URL