描述 Description

The LMx31 family of voltage-to-frequency converters are ideally suited for use in simple low-cost circuits for analog-to-digital conversion, precision frequency-to-voltage conversion, long-term integration, linear frequency modulation or demodulation, and many other functions. The output when used as a voltage-to-frequency converter is a pulse train at a frequency precisely proportional to the applied input voltage. Thus, it provides all the inherent advantages of the voltage-to-frequency conversion techniques, and is easy to apply in all standard voltage-to-frequency converter applications.Further, the LMx31A attain a new high level of accuracy versus temperature which could only be attained with expensive voltage-to-frequency modules. Additionally the LMx31 are ideally suited for use in digital systems at low power supply voltages and can provide low-cost analog-to-digital conversion in microprocessor-controlled systems. And, the frequency from a battery-powered voltage-to-frequency converter can be easily channeled through a simple photo isolator to provide isolation against high common-mode levels.The LMx31 uses a new temperature-compensated band-gap reference circuit, to provide excellent accuracy over the full operating temperature range, at power supplies as low as 4 V. The precision timer circuit has low bias currents without degrading the quick response necessary for 100-kHz voltage-to-frequency conversion. And the output are capable of driving 3 TTL loads, or a high-voltage output up to 40 V, yet is short-circuit-proof against VCC.

特性 Features

? Ensured Linearity 0.01% Maximum
? Improved Performance in Existing Voltage-to- Frequency Conversion Applications
? Split or Single-Supply Operation
? Operates on Single 5-V Supply
? Pulse Output Compatible With All Logic Forms
? Excellent Temperature Stability: ±50 ppm/°C Maximum
? Low Power Consumption: 15 mW Typical at 5 V
? Wide Dynamic Range, 100 dB Minimum at 10-kHz Full Scale Frequency
? Wide Range of Full Scale Frequency: 1 Hz to 100 kHz
? Low-Cost