The LT1085CT#PBF from Analog Devices is part of the LT1083 series, which are positive adjustable regulators designed to offer high efficiency with an output current of 3A. These regulators are capable of operating down to a 1V input-to-output differential, making them suitable for applications requiring a low dropout voltage. The dropout voltage is fully specified as a function of load current, with a maximum of 1.5V at full output current, decreasing at lower loads. The device includes on-chip trimming to adjust the reference voltage to 1%, and current limit trimming to minimize stress on the regulator and power source circuitry under overload conditions.
The LT1085CT#PBF is compatible with older 3-terminal regulators, requiring a 10µF output capacitor for stability. Unlike PNP regulators, which can waste up to 10% of the output current as quiescent current, the quiescent current of the LT1085CT#PBF flows into the load, thereby increasing efficiency. This feature, along with its low dropout performance, makes it an ideal choice for high-efficiency linear regulators, post regulators for switching supplies, constant current regulators, and battery chargers.
Voltage Regulators
Low dropout (LDO) regulators are a type of voltage regulator designed to maintain a constant output voltage while minimizing the voltage drop between the input and output. They are particularly useful in applications where the input voltage is only slightly higher than the desired output voltage, making efficiency a key concern.
When selecting an LDO regulator, engineers should consider the dropout voltage, output current, line and load regulation, package type, and thermal performance. The dropout voltage is especially important as it determines the minimum input voltage required to maintain the desired output voltage. High output current capability is crucial for applications requiring significant power, while line and load regulation ensure stable output under varying input conditions and loads.
The LT1085CT#PBF is a positive adjustable regulator with a focus on high efficiency and low dropout performance. It is suitable for a wide range of applications, including linear regulators, switching supply post-regulators, and battery charging systems. Its compatibility with older 3-terminal regulators and requirement for a minimal output capacitor make it an adaptable choice for upgrading existing designs or implementing new ones.
In summary, the LT1085CT#PBF offers a combination of low dropout voltage, high output current, and efficient operation, making it a versatile choice for engineers designing power supply circuits.