LM331ADQ3/TR-HG

The LM231/LM331 series voltage-to-frequency converters are ideal for use in simple, low-cost circuits, enabling a wide range of functions including analog-to-digital conversion, precision frequency-to-voltage conversion, long-term integration, linear frequency modulation, and demodulation. When used as a voltage-to-frequency converter, the output is a pulse train whose frequency is precisely proportional to the input voltage. As such, it offers all the inherent advantages of voltage-to-frequency conversion technology and is easily applicable to all standard V/F converter applications. Furthermore, the LM231A/LM331A achieves a new level of temperature accuracy that was previously only attainable with expensive V/F modules. In addition, the LM231/LM331 is well-suited for use in digital systems with low supply voltages and can provide low-cost analog-to-digital conversion in microprocessor-controlled systems. Moreover, the frequency generated by a battery-powered V/F converter can be easily transmitted through a simple optoisolator to provide isolation from high common-mode levels. The LM231/LM331 employs a new temperature-compensated bandgap reference circuit that delivers excellent accuracy over the entire operating temperature range at supply voltages as low as 4.0V. The precision timer circuit features low bias current without compromising the fast response required for 100kHz V/F conversion. The output is capable of driving 3 TTL loads, or sourcing high voltages up to 40V, with short-circuit protection against VCC.

Applications

• LM231/331 are monolithic circuits designed for precise and versatile operation in voltage-to-frequency (V-to-F) or frequency-to-voltage (F-to-V) converter applications.

Key features

• 0.01% maximum linearity
• Enhanced performance in existing V/F conversion applications
• Split or single-supply operation
• Single 5V supply compatible
• Pulse output compatible with all logic families
• Excellent temperature stability: ±50 ppm/°C maximum
• Low power: 15 mW typical at 5V
• Wide dynamic range: 100 dB minimum at 10 kHz full-scale frequency
• Wide full-scale frequency range: 1 Hz to 100 kHz
• Low cost
• Packages: DIP-8, SOP-8, DFN-8 (3×3)