HGSEMI LM331AM/TR

The LM231/LM331 series voltage-to-frequency converters are ideally suited for use in simple, low-cost A/D conversion circuits, precision frequency-to-voltage conversion circuits, long-term integration circuits, linear frequency modulation or demodulation circuits, and many other functions. When used as a voltage-to-frequency converter, the output is a pulse train whose frequency is precisely proportional to the applied input voltage. Thus, it provides all the inherent advantages of V/F conversion technology and is easy to apply in all standard V/F converter applications. Furthermore, the LM231A/LM331A achieves a new high level of accuracy vs. temperature performance, previously attainable only with expensive V/F modules. In addition, the LM231/331 is well suited for use in digital systems operating from low supply voltages and can provide low-cost A/D conversion in microprocessor-controlled systems. Moreover, the output frequency from a battery-powered V/F converter can be easily transmitted through a simple optoisolator to provide isolation against high common-mode levels.

The LM231/LM331 incorporates a new temperature-compensated bandgap reference circuit that delivers excellent accuracy over the full 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 100 kHz V/F conversion. The output is capable of driving 3 TTL loads, or providing high-voltage outputs up to 40V, with built-in protection against short circuits to VCC.

• Guaranteed linearity max 0.01%
• Enhanced performance for existing voltage-to-frequency conversion applications
• Split or single supply operation
• Single 5V supply operation
• Pulse output compatible with all logic families
• Excellent temperature stability: max ±50 ppm/°C
• Low power consumption: typical 15 mW at 5V
• Wide dynamic range, min 100 dB at 10 kHz full-scale frequency
• Wide full-scale frequency range: 1 Hz to 100 kHz
• Low cost
• DIP-8
• SOP-8