Overview
The LOG114AIRGVR, produced by Texas Instruments, is a precision high-speed logarithmic amplifier designed for measuring low-level and wide dynamic range currents. This device is particularly useful in communications, lasers, medical, and industrial systems. It computes the logarithm or log-ratio of an input current or voltage relative to a reference current or voltage, ensuring high precision over a wide dynamic range of input signals on either bipolar (±5V) or single (+5V) supply. The LOG114 includes special temperature drift compensation circuitry and is specified over a temperature range of -5°C to +75°C, with operational capabilities from -40°C to +85°C.
Key Specifications
| Parameter | Value | Units | Conditions |
|---|---|---|---|
| Package | VQFN (RGV) | - | 16 pins |
| Operating Temperature Range | -5°C to +75°C | °C | Specified |
| Operating Temperature Range (Extended) | -40°C to +85°C | °C | Operational |
| Input Dynamic Range | 100pA to 10mA | A | Eight Decades |
| Voltage Reference | 2.5V | V | - |
| Quiescent Current | ±10mA | mA | IO = 0 |
| Supply Voltage Range | ±2.4V to ±5.5V | V | Dual Supply |
| Output Scale Factor | 0.375V per decade of input current | V/decade | - |
| Frequency Response (3dB Bandwidth) | Up to 2.3 MHz | Hz | Dependent on input current level |
| Thermal Resistance (JA) | 62°C/W | °C/W | - |
Key Features
- Tiny for High Density Systems: The LOG114 is packaged in a small QFN-16 (4mm x 4mm) package, making it ideal for high-density systems.
- Precision on One Supply: The device operates with high precision on either a single (+5V) or dual (±5V) supply.
- Fast Over Eight Decades: It has a wide input dynamic range of eight decades, from 100pA to 10mA, and fast response times.
- Two Scaling Amplifiers: Includes additional amplifiers for scaling and offsetting the output to match various ADC input ranges.
- Stable Over Temperature: Special temperature drift compensation circuitry ensures stable performance over a wide temperature range.
- Low Quiescent Current: The device has a low quiescent current of ±10mA, which is beneficial for power-sensitive applications.
Applications
- Optical Communications: Used in Erbium-Doped Fiber Optic Amplifiers (EDFA) and laser optical density measurements.
- Photodiode Signal Compression: Suitable for photodiode signal compression and log-ratio functions.
- Analog Signal Compression: Employed in front of analog-to-digital (ADC) converters for analog signal compression.
- Absorbance Measurement: Used in absorbance measurements and other applications requiring logarithmic signal processing.
Q & A
- What is the primary function of the LOG114AIRGVR?
The LOG114AIRGVR is a precision high-speed logarithmic amplifier that computes the logarithm or log-ratio of an input current or voltage relative to a reference current or voltage.
- What is the input dynamic range of the LOG114AIRGVR?
The input dynamic range is eight decades, from 100pA to 10mA).
- What is the output scale factor of the LOG114AIRGVR?
The output scale factor is 0.375V per decade of input current).
- Can the LOG114AIRGVR operate on a single supply?
Yes, the LOG114AIRGVR can operate on either a single (+5V) or dual (±5V) supply).
- What is the quiescent current of the LOG114AIRGVR?
The quiescent current is ±10mA).
- What are some common applications of the LOG114AIRGVR?
Common applications include Erbium-Doped Fiber Optic Amplifiers (EDFA), laser optical density measurements, photodiode signal compression, and analog signal compression in front of ADC converters).
- What is the specified temperature range for the LOG114AIRGVR?
The specified temperature range is -5°C to +75°C, with operational capabilities from -40°C to +85°C).
- What is the package type and size of the LOG114AIRGVR?
The LOG114AIRGVR is packaged in a small QFN-16 (4mm x 4mm) package).
- Does the LOG114AIRGVR include temperature drift compensation?
Yes, the device includes special temperature drift compensation circuitry).
- How can the output of the LOG114AIRGVR be scaled and offset?
The output can be scaled and offset using one of the available additional amplifiers to match various ADC input ranges).
