AD8372 41 dB RANGE, 1 dB Step Size, Programmable Dual VGA

For wide input dynamic range applications, the AD8372 provides a broad 41 dB gain range. The gain is programmed through a bidirectional 4-pin serial interface. The serial inter-face consists of a clock, latch, data input, and data output lines for each channel. The AD8372 provides the ability to set the transconductance of the output stage using a single external resistor. The RXT1 and RXT2 pins provide a band gap derived stable reference voltage of 1.56 V. Typically 2.0 kΩ shunt resistors to ground are used to set the maximum gain to a nominal value of 31 dB. The current setting resistors can be adjusted to manipulate the gain and distortion performance of each channel. This is a flexible feature in applications where it is desirable to trade off distortion performance for lower power consumption. The AD8372 is powered on by applying the appropriate logic level to the ENB1, ENB2 pins. When powered down, the AD8372 consumes less than 2.6 mA and offers excellent input-to-output isolation. The gain setting is preserved when powered down. Fabricated on an Analog Devices high frequency BiCMOS process, the AD8372 provides precise gain adjustment capabilities with good distortion performance. The quiescent current of the AD8372 is typically 106 mA per channel. The AD8372 amplifier comes in a compact, thermally enhanced 5 mm × 5 mm 32-lead LFCSP package and operates over the temperature range of −40°C to +85°C. Applications Differential ADC drivers CMTS upstream direct sampling receivers CATV modem signal scaling Generic RF/IF gain stages Single-ended-to-differential conversion Data Sheet, Rev. 0, 11/07

The AD8372 is a dual, digitally controlled, variable gain amplifier that provides precise gain control, high IP3, and low noise figure. The excellent distortion performance and moderate signal bandwidth make the AD8372 a suitable gain control device for a variety of multichannel receiver applications.

For wide input dynamic range applications, the AD8372 provides a broad 41 dB gain range. The gain is programmed through a bidirectional 4-pin serial interface. The serial inter-face consists of a clock, latch, data input, and data output lines for each channel.

The AD8372 provides the ability to set the transconductance of the output stage using a single external resistor. The RXT1 and RXT2 pins provide a band gap derived stable reference voltage of 1.56 V. Typically 2.0 kΩ shunt resistors to ground are used to set the maximum gain to a nominal value of 31 dB. The current setting resistors can be adjusted to manipulate the gain and distortion performance of each channel. This is a flexible feature in applications where it is desirable to trade off distortion performance for lower power consumption.

The AD8372 is powered on by applying the appropriate logic level to the ENB1, ENB2 pins. When powered down, the AD8372 consumes less than 2.6 mA and offers excellent input-to-output isolation. The gain setting is preserved when powered down.

Fabricated on an Analog Devices high frequency BiCMOS process, the AD8372 provides precise gain adjustment capabilities with good distortion performance. The quiescent current of the AD8372 is typically 106 mA per channel. The AD8372 amplifier comes in a compact, thermally enhanced 5 mm × 5 mm 32-lead LFCSP package and operates over the temperature range of −40°C to +85°C.

Applications

Data Sheet, Rev. 0, 11/07

Features and Benefits
  • Dual independent digitally controlled VGA
  • Differential input and output
    150 Ω differential input
    Open-collector differential output
  • 7.8 dB noise figure to 100 MHz @ maximum gain
  • HD2/HD3 better than 77 dBc for 1 V p-p differential output
  • −3 dB bandwidth of 150 MHz
  • 41 dB gain range
  • 1 dB step size ± 0.2 dB
  • Serial 8-bit bidirectional SPI control interface
  • Wide input dynamic range
  • Pin-programmable output stage
  • Power-down feature
  • Single 5 V supply: 106 mA per channel
RF & Microwave
Software & Systems Requirements
Data Sheets
Documentnote
AD8372: 41 dB Range, 1 dB Step Size, Programmable Dual VGA Data Sheet (Rev. B)PDF 715 kB
Frequently Asked Questions
Documentnote
Order Information
Part NumberPackagePacking QtyTemp RangePrice 100-499Price 1000+RoHS
AD8372ACPZ-R7 Production32 ld LFCSP (5x5mm)REEL 1500-40 to 85C06.58Y
AD8372ACPZ-WP Production32 ld LFCSP (5x5mm)REEL 36-40 to 85C9.119.11Y
Evaluation Boards
Part NumberDescriptionPriceRoHS
AD8372-EVALZEvaluation Board99Y
Reference Materials
AD8372: 41 dB Range, 1 dB Step Size, Programmable Dual VGA Data Sheet (Rev B, 06/2011) AD8372
AD8372 Evaluation Board Software ad8372
AD8372: 41 dB Range, 1 dB Step Size, Programmable Dual VGA Data Sheet (Rev. B) ad8372
RF Source Booklet adf9010