Overview

This document is a datasheet or technical reference guide for the AMS (Advanced Micro Systems) family of voltage regulator chips, specifically the AMS 1117 series. It provides detailed specifications, operating characteristics, application guidelines, and typical performance data. The focus is on providing engineers with the information needed to design circuits using these regulators. The series provides a simple, inexpensive method to obtain a regulated voltage output.

Key Technical Information

️· Function: The AMS 1117 series provides a fixed voltage output (typically 1.2V to 15V, although specific voltage options vary within the series – see the specific part number documentation). It acts as a *linear* voltage regulator, meaning it dissipates excess power as heat.
️· Input Voltage: The input voltage range varies depending on the specific regulator, but it's designed to accept a wider voltage than the desired output.
️· Output Voltage: Fixed output voltages are available in various standard values.
️· Output Current: The maximum output current is typically 1 Ampere.
️· Protection Features:
- Thermal Shutdown: Protects the regulator from overheating.
- Current Limiting: Prevents excessive current draw, protecting both the regulator and the load.
- Reverse Polarity Protection: Offers some protection against incorrect voltage connection.
️· Package: TO-220 and similar packages are used for ease of heat dissipation.

Design Considerations

️· Heat Dissipation: Because these are linear regulators, they generate heat. The document emphasizes the importance of adequate heat sinking, especially at higher output currents. The datasheet provides equations and guidance on calculating heat dissipation and selecting appropriate heat sinks.
️· Input and Output Capacitors: Using appropriate input and output capacitors is critical for stability and transient response. The datasheet specifies minimum values and types of capacitors.
️· Transient Response: The datasheet includes charts demonstrating the regulator's transient response (how quickly it recovers from load changes).
️· Stability: Proper capacitor selection is crucial for stability. The datasheet has specific recommendations.
️· Reverse Voltage Protection: This can be achieved using diodes.
️· Short Circuit Conditions: The regulators are protected, but careful circuit design can minimize stress during short-circuit conditions.
️· Thermal Considerations: The documents has a section devoted to calculating power dissipation and provides calculations to guide the selection of heat sinks.

Important Notes

️· Read the Entire Datasheet: This is a common phrase in technical documents, emphasizing that all sections are important for proper application.
️· Specific Part Numbers: The datasheet covers the *series*. Always consult the specific datasheet for the exact part number you are using, as voltage and current limits may vary.
️· Application-Specific Testing: The datasheet provides general guidance. Actual circuit performance should be verified through testing in the intended application.
️· Temperature Range: Be mindful of the operating temperature range specified for the regulator.
️· Thermal Shutdown: The documentation explains how to implement a method to detect thermal shutdown and reset the circuit.



Abbreviations Used in the Document

️· AMS: Advanced Micro Systems
️· TO-220: A common electronic component package
️· µs: Microsecond (1 millionth of a second)
️· V: Volt (unit of electrical potential)
️· A: Ampere (unit of electrical current)
️· µF: Microfarad (unit of capacitance)
️· VIN: Input Voltage
️· VOUT: Output Voltage
️· VP-P: Peak-to-Peak voltage
️· C: Capacitance