The MAX4207ETE+T logarithmic amplifier computes the log ratio of an input current relative to a reference current (externally or internally generated) and provides a corresponding voltage output with a default -0.25V/decade scale factor. The device operates from dual ±2.7V to ±5.5V supplies and is capable of measuring five decades of input current across a 10nA to 1mA range. The MAX4207's uncommitted op amp can be used for a variety of functions, including filtering noise, adding offset, and adding additional gain. A 0.5V reference is also included to generate an optional precision current reference using an external resistor, which adjusts the log intercept of the MAX4207. The output-offset voltage and the adjustable scale factor are also set using external resistors. The MAX4207ETE+T is available in a space-saving 16-pin thin QFN package (4mm x 4mm x 0.8mm), and is specified for operation over the -40°C to +85°C extended temperature range.
Feature
- ±2.7V to ±5.5V Dual-Supply Operation
- 5 Decades of Dynamic Range (10nA to 1mA)
- Monotonic Over a 1nA to 1mA Range
- -0.25V/Decade Internally Trimmed Output Scale Factor
- Adjustable Output Scale Factor
- Adjustable Output Offset Voltage
- Internal 10nA to 10μA Reference Current Source
- Input Amplifiers Summing Nodes at Ground
- Small 16-Pin Thin QFN Package (4mm x 4mm x 0.8mm)
- -40°C to +85°C Operating Temperature Range
- Evaluation Kit Available (Order MAX4206EVKIT)
Applications
- Analog Signal Processing
- Medical Instrumentation
- Photodiode Current Monitoring
- Portable Instrumentation
