For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824

Phone: 978-250-3343

Fax: 978-250-3373

Order On-line at www.hittite.com

Application Support: Phone: 978-250-3343 or apps@hittite.com

20

HMC992LP5E

v03.1013

IF AUTOMATIC GAIN CONTROLLER

(IF-AGC), 50 - 800 MHz

Similarly, the lower side of the dynamic range is limited by the noise floor of the VGA or the lowest power level detect-

able by the log detector. To eliminate any limitations on the lower side of the dynamic range, the coupler ratio should be

low enough to translate the minimum VGA output power level to a value higher than the lowest detectable log detector

power level.

Please also refer to the Log Detector section for more information.

Figure 7a shows the output power vs. input power transfer characteristic of the HMC992LP5E over different VSET

voltages for a closed AGC loop configuration. For low and high input power levels the HMC992LP5E attenuation rage

is saturated and the output is a linear function of the input. For input power levels within the dynamic range, the

HMC992LP5E automatically adjusts the attenuation level as shown in Figure 7c to maintain a constant output power

level. When Vset=0.6 V, the output power level is set to -13 dBm and the HMC992LP5E’s AGC amplifier provides a gain

control range of 46 dB from -51 dBm to -5 dBm with an excellent ripple within 0.06 dB.

Figure 7a: Output Power vs. input power over VSET,

2 attenuators @ 300 MHz.

-40

-30

-20

-10

0

10

-70

-60

-50

-40

-30

-20

-10

0

10

VSET=0.4V

VSET=0.6V

VSET=0.8V

INPUT POWER (dBm)

20 dB coupler is used

Figure 7c: DETOUT vs. input power over VSET, 2 attenuators @ 300 MHz.

0

1

2

3

4

5

-70

-60

-50

-40

-30

-20

-10

0

10

VSET= 0.4V

VSET= 0.6V

VSET= 0.8V

INPUT POWER (dBm)

20 dB coupler is used

Figure 7b: Output Power vs. input power, 2 attenua-

tors @ 400 MHz & VSET=0.6V

-20

-18

-16

-14

-12

-10

-8

-70

-60

-50

-40

-30

-20

-10

0

10

+25C

+85C

-40C

INPUT POWER (dBm)

20 dB coupler is used

Information furnished by Analog Devices is believed to be accurate and reliable. However, no

responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other

rights of third parties that may result from its use. Specifications subject to change without notice. No

license is granted by implication or otherwise under any patent or patent rights of Analog Devices.

Trademarks and registered trademarks are the property of their respective owners.

For price, delivery, and to place orders: Analog Devices, Inc.,

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106

Phone: 781-329-4700 • Order online at www.analog.com

Application Support: Phone: 1-800-ANALOG-D