AD8372ACPZ-R7 Variable Gain Amplifier IC CATV 32-LFCSP-WQ (5x5) integrated circuits

General Description
The AD8372 is a dual, digitally controlld, variable gain
amplifier (VGA) 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 mutichannel 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 kQ 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
perfor mance 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, Inc., 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 x 5 mm 32 -lead
LFCSP package and operates over the temperature range of
- 40*C to +85*C.

FEATURES
Dual independent digitally controlledVGA
Differential input and output
150 A 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 130 MHz
41 dB gain range
1dBstepsize土0.2dB
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
32-lead LFCSP, 5 mm x 5 mm package
APPLICATIONS
Differential ADC drivers
CMTS upstream direct sampling receivers
CATV modem signal scaling
Generic RF/IF gain stages
Single-ended-to-differential conversion

1. Variable Gain Amplifier: The AD8372 is a digitally controlled VGA that allows for precise gain adjustment in RF and IF signal chains. It provides a wide dynamic range to accommodate different input signal levels.

2. Frequency Range: The AD8372 is designed to operate in a wide frequency range, typically from a few megahertz (MHz) up to several gigahertz (GHz). The specific range may vary depending on the configuration and settings.

3. Gain Control: The amplifier offers digital gain control, allowing for accurate and rapid gain adjustment. It typically provides a high gain range with fine gain resolution.

4. High Linearity: The AD8372 is designed for high linearity performance, which is crucial in applications where signal integrity and dynamic range are critical.

5. Low Noise Figure: The VGA features a low noise figure, which ensures minimal degradation of the input signal-to-noise ratio.

6. Power Supply: The AD8372 is typically powered by a single power supply voltage, making it suitable for a variety of system designs.

7. Gain Control Range: The AD8372 offers a wide gain control range, typically from -12 dB to +36 dB. This range allows for both attenuation and amplification of the input signal.

8. Control Interface: The amplifier utilizes a serial peripheral interface (SPI) for digital gain control. This interface enables easy integration with microcontrollers or other digital control systems.

9. Gain Accuracy: The AD8372 provides high gain accuracy, typically with a gain error of less than ±0.2 dB. This ensures precise gain control and consistency in the amplifier's performance.

10. Operating Modes: The AD8372 includes different operating modes to optimize its performance for different applications. These modes include variable gain mode, bypass mode, and power-down mode.

11. Output Power: The amplifier can drive a variety of loads, typically up to +16 dBm. This allows for direct connection to other components in the signal chain, such as mixers, filters, or ADCs (analog-to-digital converters).

12. Supply Voltage Range: The AD8372 is designed to operate with a supply voltage range of +5 V to +3.3 V, making it compatible with common power supply configurations.

13. Package: The AD8372ACPZ-R7 comes in a compact 24-lead LFCSP (lead-frame chip-scale package), which offers small footprint and ease of integration in space-constrained designs.

14. Applications: The AD8372 is commonly used in wireless communication systems, including cellular base stations, wireless infrastructure, point-to-point radio links, and software-defined radios (SDRs). It is also suitable for other RF and IF signal processing applications that require variable gain control.