HMC714LP5 Datasheet, PDF (34/40 Pages) Hittite Microwave Corporation – DUAL RMS POWER DETECTOR 0.1 - 3.9 GHz

v05.0309
HMC714LP5 / 714LP5E
DUAL RMS POWER DETECTOR
0.1 - 3.9 GHz
LOG-Slope and Intercept (Continued)
Example: The logarithmic slope can be simply increased by choosing appropriate RFBK and RSHUNT values while
not populating the R_SET resistor on the evaluation board to keep the intercept at nominal value. Setting RFBK =
820Ω and RSHUNT = 2200Ω results in an optimized slope of:
Optimized Slope = ß * log_slope = 1.42 * 36.5 mV / dB
Optimized Slope = 52 mV / dB
Slope Adjustment
4.5
4
High Slope
3.5
Nominal
3
2.5 Slope=51mV/dB
Rset=open
2 Rfbk=820ohm
Rshunt=2200ohm
1.5
1
Slope=36.2mV/dB
Rset=open
0.5
Rfbk=0ohm
Rshunt=open
0
-70 -60 -50 -40 -30 -20 -10 0 10
INPUT POWER (dBm)
Example: The logarithmic intercept can also be adjusted by choosing appropriate R_FBK, R_SHUNT, and R_SET values
while keeping the logarithmic slope at about 50mV/dB. Setting R_FBK = 820 Ohm and R_SHUNT = R_SET = 4700Ω
results in an optimized slope of:
Optimized Slope = ß * log_slope = 1.4 * 36.5 mV / dB
Optimized Slope = 51 mV / dB
Optimized Intercept = log_intercept -
R *V
FBK ZC
R_SET
Optimized Intercept = log_intercept - 0.174 * V
ZC
12
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
-60
Intercept Adjustment
Rset=4700ohm
Rfbk=820ohm
Rshunt=4700ohm
Vzc=0
Vzc=0.8
Vzc=1.6
Vzc=3.2
Vzc=-0.8
Vzc=-1.6
Vzc=-3.2
-50 -40 -30 -20 -10
0
10
INPUT POWER (dBm)
Intercept Adjustment (with Temp)
4.5
4
+25C
VSET=-1.6V
+85C
3.5
-40C
3
VSET=0V
2.5
2
VSET=1.6V
1.5
1
0.5
0
-60 -50 -40 -30 -20 -10
0
10
INPUT POWER (dBm)
For price, delivery, and to place orders, please contact Hittite Microwave Corporation:
20 Alpha Road, Chelmsford, MA 01824 Phone: [phone] Fax: [phone]
Order On-line at www.hittite.com
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