Overview
The AD8338ACPZ-R7, produced by Analog Devices Inc., is a low-power, 18 MHz variable gain amplifier (VGA) designed for applications requiring a fully differential signal path, low noise, and a well-defined gain over frequency. This device is particularly suited for scenarios where high dynamic range and precision gain control are essential. The AD8338 operates on a single-supply voltage of 3.0 V to 5.0 V and consumes as little as 3 mA of quiescent current at mid-gain settings. It is available in a 3 mm × 3 mm, RoHS-compliant, 16-lead LFCSP package and is specified over the industrial temperature range of −40°C to +85°C.
Key Specifications
| Parameter | Value | Conditions |
|---|---|---|
| Gain Range | 0 dB to 80 dB (standard), 20 dB to 100 dB (with external resistors) | VGAIN = 0.1 V to 1.1 V, VBAT = 3.0 V, TA = 25°C |
| Gain Slope | 12.5 mV/dB | |
| Bandwidth | 18 MHz | VBAT = 3.0 V, TA = 25°C |
| Supply Voltage | 3.0 V to 5.0 V | |
| Quiescent Current | 3 mA (typical at mid-gain) | VBAT = 3.0 V, TA = 25°C |
| Input Voltage Range | 3 V p-p | VBAT = 3.0 V, TA = 25°C |
| Peak Slew Rate | 50 V/μs | VGAIN = 0.6 V |
| Noise | 4.5 nV/√Hz at 80 dB gain | |
| Output Current | 5 mA (typical) | VBAT = 3.0 V, TA = 25°C |
| Output Voltage | 1.5 V (typical) | TA = 25°C |
| Temperature Range | −40°C to +85°C | |
| Package | 16-lead LFCSP (3 mm × 3 mm) |
Key Features
- Fully differential signal path for high signal integrity.
- Low power consumption with a quiescent current of 3 mA at mid-gain.
- Wide gain range of 0 dB to 80 dB, extendable to 20 dB to 100 dB with external resistors.
- Low noise of 4.5 nV/√Hz at 80 dB gain.
- Automatic gain control (AGC) to maintain a constant rms output voltage.
- Offset correction circuit to remove DC offset voltages.
- Access to internal summing nodes and output amplifiers for customization.
- Internal 1.5 V reference voltage.
- High slew rate of 50 V/μs.
Applications
The AD8338ACPZ-R7 is suitable for various applications requiring precise gain control and low noise, such as:
- Audio and video signal processing.
- Medical imaging and diagnostic equipment.
- Industrial control and automation systems.
- Wireless communication systems.
- Test and measurement instruments.
Q & A
- What is the typical quiescent current of the AD8338ACPZ-R7?
The typical quiescent current is 3 mA at mid-gain settings.
- What is the gain range of the AD8338ACPZ-R7?
The gain range is 0 dB to 80 dB in standard configuration, and it can be extended to 20 dB to 100 dB with external resistors.
- What is the bandwidth of the AD8338ACPZ-R7?
The typical bandwidth is 18 MHz.
- What is the noise level of the AD8338ACPZ-R7 at 80 dB gain?
The noise level is 4.5 nV/√Hz at 80 dB gain.
- Does the AD8338ACPZ-R7 support automatic gain control?
Yes, it includes an automatic gain control (AGC) feature to maintain a constant rms output voltage.
- How can the gain slope of the AD8338ACPZ-R7 be inverted?
The gain slope can be inverted via the logic Pin MODE.
- What is the temperature range for the AD8338ACPZ-R7?
The device is specified over the industrial temperature range of −40°C to +85°C.
- What package type is the AD8338ACPZ-R7 available in?
The device is available in a 16-lead LFCSP (3 mm × 3 mm) package.
- Can the AD8338ACPZ-R7 be driven with a single-ended source?
Yes, although the inputs are differential, the device can also be driven with a single-ended source if required.
- How does the offset correction circuit work in the AD8338ACPZ-R7?
The offset correction circuit behaves like a high-pass filter whose corner frequency is set with an external capacitor, removing DC offset voltages.
