Precision High-Speed Logarithmic Amplifier with 2.5V Reference and Uncommitted Output Op Amps
Product details
Parameters
Package | Pins | Size
Features
- ADVANTAGES:
- - Tiny for High Density Systems
- - Precision on One Supply
- - Fast Over Eight Decades
- - Fully-Tested Function
- TWO SCALING AMPLIFIERS
- WIDE INPUT DYNAMIC RANGE: Eight Decades, 100pA to 10mA
- 2.5V REFERENCE
- STABILE OVER TEMPERATURE
- LOW QUIESCENT CURRENT: 10mA
- DUAL OR SINGLE SUPPLY: ±5V, +5V
- PACKAGE: Small QFN-16 (4mm x 4mm)
- SPECIFIED TEMPERATURE RANGE: –5°C to +75°C
- APPLICATIONS
- ONET ERBIUM-DOPED FIBER OPTIC AMPLIFIER (EDFA)
- LASER OPTICAL DENSITY MEASUREMENT
- PHOTODIODE SIGNAL COMPRESSION AMP
- LOG, LOG-RATIO FUNCTION
- ANALOG SIGNAL COMPRESSION IN FRONT OF ANALOG-TO-DIGITAL (ADC) CONVERTER
- ABSORBANCE MEASUREMENT
All trademarks are the property of their respective owners.
Description
The LOG114 is specifically designed for measuring low-level and wide dynamic range currents in communications, lasers, medical, and industrial systems. The device computes the logarithm or log-ratio of an input current or voltage relative to a reference current or voltage (logarithmic transimpedance amplifier).
High precision is ensured over a wide dynamic range of input signals on either bipolar (±5V) or single (+5V) supply. Special temperature drift compensation circuitry is included on-chip. In log-ratio applications, the signal current may be from a high impedance source such as a photodiode or resistor in series with a low impedance voltage source. The reference current is provided by a resistor in series with a precision internal voltage reference, photo diode, or active current source.
The output signal at VLOGOUT has a scale factor of 0.375V out per decade of input current, which limits the output so that it fits within a 5V or 10V range. The output can be scaled and offset with one of the available additional amplifiers, so it matches a wide variety of ADC input ranges. Stable dc performance allows accurate measurement of low-level signals over a wide temperature range. The LOG114 is specified over a -5°C to +75°C temperature range and can operate from -40°C to +85°C.
Technical documentation
| Type | Title | Date | |
|---|---|---|---|
| * | Datasheet | Single-Supply, High-Speed, Precision Logarithmic Amplifier datasheet (Rev. A) | Mar. 19, 2007 |
| User guide | LOG114EVM User Guide | Sep. 29, 2011 |
Design & development
For additional terms or required resources, click any title below to view the detail page where available.Hardware development
Description
The LOG114EVM is a ready-to-use platform for evaluating the performance of the LOG114 in various configurations.The LOG114EVM comes configured to operate on a single 5-V power supply. The circuit used in the LOG114EVM is designed to operate over a wide range of input currents (10 nA to 10 mA) and (...)
Features
- Easy to use
- High Speed + Precision
- Wide Input Dynamic Range
- Operates on a single 5V supply
- PCB footprint provided for photo diode or resistor input
Design tools & simulation
Features
- Leverages Cadence PSpice Technology
- Preinstalled library with a suite of digital models to enable worst-case timing analysis
- Dynamic updates ensure you have access to most current device models
- Optimized for simulation speed without loss of accuracy
- Supports simultaneous analysis of multiple products
- (...)
CAD/CAE symbols
| Package | Pins | Download |
|---|---|---|
| VQFN (RGV) | 16 | View options |
Ordering & quality
- RoHS
- REACH
- Device marking
- Lead finish/Ball material
- MSL rating/Peak reflow
- MTBF/FIT estimates
- Material content
- Qualification summary
- Ongoing reliability monitoring
Support & training
TI E2E™ forums with technical support from TI engineers
Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.
If you have questions about quality, packaging or ordering TI products, see TI support.