Okay, here's a summary of the provided AMS1085 datasheet extract, broken down into key sections and points. I've aimed for clarity and conciseness.

1. Overview & General Information

️· Device: AMS1085 Adjustable/Fixed Voltage Regulator
️· Family: Part of the AMS1085 series – designed as an improvement over older regulators with lower dropout voltage, tighter tolerance, and better stability.
️· Pin Compatibility: Pin-compatible with older, adjustable three-terminal regulators.
️· Features: Short-circuit protection, thermal shutdown.

2. Electrical Characteristics (Key Points)

️· Adjustable Output Voltage: Defined by external resistors (R1 and R2) - *V OUT = V REF (1 + R2/R1) + I ADJ * R2*.
️· Reference Voltage (V REF): 1.25V
️· Minimum Load Current: 10mA (required for regulation)

3. Application Hints & Design Considerations

️· Stability: Requires an output capacitor (150µF electrolytic or 22µF tantalum) for stability. Larger capacitors improve transient response.
️· Ripple Rejection: Optimal ripple rejection requires bypassing the adjustment pin.
️· Protection Diodes: Not typically required (internal limiting resistors). However, a diode from input to output *is* recommended when using a crowbar circuit at the input and *may* be needed with high-value output capacitance and an instant grounding of the input pin.

️· Overload Recovery: In some cases, the power supply may need to be cycled (turned off and back on) to recover from an overload condition.
️· Load Regulation: Best load regulation is achieved by connecting R1 to the device case and R2 to the load, minimizing parasitic line resistance.
️· Thermal Considerations:
- Junction-to-case thermal resistance is critical for heat dissipation.
- Use thermal compound for optimal case-to-heat sink contact.
- Separate thermal resistance specifications are provided for the Control Section and the Power Transistor.

Key Formulas/Equations

️· Output Voltage Calculation: V OUT = V REF (1 + R2/R1) + I ADJ * R2
️· Ripple Rejection optimization: R1 value should be greater than the impedance of the adjust pin capacitor.



Let me know if you'd like me to elaborate on any of these points or focus on a specific aspect of the AMS1085!