10MHz to 500MHz Dual Analog Voltage Variable Attenuator with On-Chip 10-Bit SPI-Controlled DAC

The MAX19794 dual general-purpose analog voltage variable attenuator (VVA) is designed to interface with 50Ω systems operating in the 10MHz to 500MHz frequency range. This device includes a patented control circuit that provides 22.4dB of attenuation range (per attenuator) with a typical linear control slope of 8dB/V.

Both attenuators share a common analog control. They can be cascaded together to yield 44.7dB of total attenuation range with a typical combined linear control slope of 16dB/V (5V operation). Alternatively, the on-chip, 4-wire SPI-controlled 10-bit DAC can be used to control both attenuators. In addition, a step-up/down feature allows user-programmable attenuator stepping through command pulses without re-programming the SPI interface.

The MAX19794 is a monolithic device designed using one of Maxim's proprietary SiGe BiCMOS processes. The part operates from a single +5V supply or alternatively operates from a single +3.3V supply. It is available in a compact 36-pin TQFN package (6mm x 6mm x 0.8mm) with an exposed pad. Electrical performance is guaranteed over the -40°C to +100°C extended temperature range.

Applications

* Automatic Level Control (ALC) * Broadband System Applications, Including Wireless Infrastructure Digital and Spread-Spectrum Communication Systems * General Test Equipment * Lineup Gain Trim * Microwave Point to Point Systems * Receiver Gain Control * Temperature Compensation Circuits * Transmitter Gain Control * VSAT/Satellite Modems * WCDMA/LTE, TD-SCDMA/TD-LTE, WiMAX®, cdma2000®, GSM/EDGE and MMDS Base Stations

* Wide Band Coverage

* RF Frequency Range from 10MHz to 500MHz

* High Linearity

* Greater than +34.4dBm IIP3 over the Full Attenuation Range

* +21.8dBm Input P1dB

* Integrates Two Analog Attenuators in One Monolithic Device

* Two Convenient Control Options

* Single Analog Voltage

* On-Chip, SPI-Controlled 10-Bit DAC

* Step-Up/Down Pulse Command Inputs

* Flexible Attenuation Control Ranges

* 22.4dB (per Attenuator)

* 44.7dB (Both Attenuators Cascaded)

* Linear dB/V Analog Control Response Curve Simplifies Automatic Leveling Control and Gain Trim Algorithms

* Excellent Attenuation Flatness over Wide Frequency Ranges and Attenuation Settings

* On-Chip Comparator (for Successive Approximation Measurement of Attenuator Control Voltage)

* Low 13mA Supply Current

* Single +5V or 3.3V Supply Voltage

* Pin Similar with MAX19791, MAX19792, and MAX19793

* Lead-Free Package