| DC Switching Regulators1 |
| | The LM2770SD-12157 is a precision, single digital-output, low-power thermostat comprised of an internal reference, DAC, temperature sensor and comparator. Utilizing factory programming, it can be manufactured with different trip points as well as different digital output functionality. The trip point (TOS) can be preset at the factory to any temperature in the range of +120°C to +150°C in 1°C increments. The LM2770SD-12157 has one digital output (OS/OS/US/US), one digital input (HYST) and one analog output (VTEMP). The digital output stage can be preset as either open-drain or push-pull. In addition, it can be factory programmed to be active HIGH or LOW. The digital output can be factory programmed to indicate an over temperature shutdown event (OS or OS) or an under temperature shutdown event (US or US). When preset as an overtemperature shutdown (OS) it will go LOW to indicate that the die temperature is over the internally preset TOS and go HIGH when the temperature goes below (TOS–THYST). Similarly, when preprogrammed as an undertemperature shutdown (US) it will go HIGH to indicate that the temperature is below TUS and go LOW when the temperature is above (TUS+THYST). The typical hysteresis, THYST, can be set to 2°C or 10°C and is controlled by the state of the HYST pin. A VTEMP analog output provides a voltage that is proportional to temperature and has a 10.7mV/°C output slope.Currently, there are several standard parts available, see . For other part options, contact a Texas Instruments Distributor or Sales Representative for information on minimum order qualification. The LM2770SD-12157 is currently available in a 5-lead SOT-23 package.Internal Comparator with Pin Selectable 2°Cor 10°C HysteresisNo External Components RequiredOpen-drain or Push-pull Digital Output;Supports CMOS Logic LevelsInternal Temperature Sensor with VTEMP Output PinVTEMP Output Allows After-assembly System TestingInternal Voltage Reference and DAC for Trip-point SettingCurrently Available in 5-pin SOT-23 Plastic PackageExcellent Power Supply Noise RejectionKey SpecificationsPower Supply Voltage 2.7V to 5.5VPower Supply Current 40μA (Max), 15μA (Typ)Hysteresis Temperature 2°C or 10°C (Typ)Temperature Trip Point Accuracy ±3°C (Max) | OTHER | In Stock | New Sealed Under Guarantee | | |
| | | OTHER | In Stock | New Sealed Under Guarantee | | |
| | 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. | OTHER | In Stock | New Sealed Under Guarantee | | |
