Packaging information
| Package | Pins VQFN (RGV) | 16 |
| Operating temperature range (°C) 0 to 70 |
| Package qty | Carrier 2,500 | LARGE T&R |
Features for the LOG114
- 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
- Stable over temperature
- Low quiescent current: 10mA
- Dual or single supply: ±5V, 5V
- Package: Small QFN-16 (4mm × 4mm)
- Specified temperature range: −5°C to 75°C
Description for the LOG114
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 verified 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 can 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/decade of input current, which limits the output so that the output fits within a 5V or 10V range. The output can be scaled and offset with one of the available additional amplifiers, so the output 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.