Electronics News
Archive : 17 January 2008 год
Both devices integrate a reverse blocking diode, current sensing, programmable current limit and single control pin switching functions. The AAT4674 and AAT4674-1 connect the supply voltage on IN1 and IN2 to the output through very low RDS(ON) power MOSFETs that minimise voltage drops and power dissipation. The enable (EN) and select (SEL) pin voltages control the operational state of the internal power MOSFET switches. A break-before-make switchover feature minimises output voltage droop during the transition between the input supplies on IN1 and IN2 to the output (OUT). To power the output, both input supplies must be above the under-voltage lockout (UVLO) threshold.
If both supplies are above the threshold and the device is enabled, both devices will connect the supply from IN1 to OUT when the SEL pin voltage is logic low and connect the supply from IN2 to OUT when the SEL pin voltage is logic high. If either input voltage is below the UVLO threshold on the AAT4674, then the output floats. When only one of the input voltages is above the UVLO threshold on the AAT4674-1, the device passes through the input that is above the UVLO threshold to the output. Qualified across the -40 to +85C temperature range, the AAT4674 and AAT4674-1 are available in a Pb-free, 12-pin TSOPJW packages.
From Schurter robust metal switches are available with a push-on, push-off latching function. The switch position (ON / OFF) is easy to recognize from the resting position of the actuator. In the OFF state, the actuator position protrudes from the housing; in the ON state, it is depressed into the housing. This provides a user-friendly actuating function and also prevents inadvertent switching, e.g. caused by objects leaning on the switch. The switch is designed with two isolated contacts and may thus be used for single- and two-pole switching solutions. The MSM LA can be used at an operating voltage of 30 VDC up to 250 VAC at a maximum switching current of 12 A.
Due to the IP 67 rating the switch is suitable for different fields of application. The switch is available with a mounting diameter of 19 and 22 mm and may be used within a temperature range of -25°C to +85°C. The design of the new MSM LA is the same as that of the existing MSM product line. In addition, the switch is also available with ring illumination. The illumination can be used to display the switch position or may be activated to provide visibility during night-time use. Typical application areas for the switch include industrial automation, the food-processing industry, passenger transportation, medical equipment, measuring devices, info terminals, vending machines and operating units.