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HMC960LP4E

v00.0211

DC - 100 MHz DUAL DigitAL

VAriAbLe gAin AMpLifier with DriVer

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

978-250-3343 tel • 978-250-3373 fax • Order On-line at www.hittite.com

Application Support: apps@hittite.com

theory of Operation

The HMC960LP4E consists of the following functional blocks

1. Input Match & Gain Stage

2. Second Gain Stage

3. Output Driver & Gain Stage

4. Bias Circuit

5. Serial Port Interface

6. Parallel Port Interface

input Match & gain Stage

The HMC960LP4E input stage consists of a user selectable 100 Ω or 400 Ω differential input impedance and a

programmable gain of 0, 10 or 20 dB. A block diagram showing input impedance of the I channel is presented below,

Q channel is similar.

Figure 2. Input Stage Block Diagram

Second gain Stage

The HMC960LP4E second stage consists of a series of carefully scaled resistors to generate up to 10 dB of gain in 0.5

dB steps. The gain step is fully determined by resistor ratios and as such the gain precision is relatively independent

of both temperature and process variation.