LD59150PURY

Overview

The LD59150PURY is an automotive-grade, 1.5 A low-dropout linear regulator featuring NMOS topology for minimal voltage drop. It supports dual supply pins with VIN ranging from 0.8 V to 5.5 V and VBIAS from 2.7 V to 5.5 V. The output voltage is adjustable between 0.8 V and 3.6 V via an external resistor divider, maintaining high accuracy of 0.5% typical at ambient temperature. Key electrical characteristics include a dropout voltage of 65 mV typical (125 mV max) at full load and a current limit of approximately 3 A. The device operates within a junction temperature range of -40 °C to +150 °C.

Feature Summary

• AEC-Q100 qualified for automotive reliability standards
• Programmable soft-start circuit controls inrush current during power-up
• Power Good function monitors regulated output voltage status
• Integrated thermal shutdown and constant-current limit protection

Applications

• Automotive and industrial post-regulation
• Generic point-of-load (POL) conversion
• Supply for automotive and industrial ASICs and FPGAs
• Telecom infrastructure systems
• Advanced driver-assistance systems (ADAS)

Procurement Notes

Verify the specific ordering code matches the required qualification grade. The LD59150PURY suffix indicates the AEC-Q100 qualified automotive version, distinct from the industrial LD59150PUR variant. Confirm package details correspond to the DFN10 3x3 mm form factor with wettable flanks. Ensure application requirements align with the specified input and bias voltage ranges before finalizing procurement.

Selection Notes

Select this component when designing systems requiring high current capability with strict dropout voltage constraints. The dual supply architecture allows independent control of the pass element and internal circuitry, optimizing performance under varying load conditions. Consider the programmable soft-start feature for applications necessitating controlled power sequencing or limited inrush current. Verify that the output capacitor ESR remains above 2.2 µF to ensure stability across the operating temperature range.

Part Context

This device belongs to the LD59150 series of ultra-low-dropout linear regulators designed for demanding environments. The series includes both industrial and automotive grades, differentiated by qualification standards and marking codes. The LD59150 utilizes an NMOS pass element to achieve superior efficiency compared to PMOS alternatives, particularly at low input-to-output voltage differentials. It is engineered to provide stable power delivery for sensitive logic and mixed-signal circuits.

Replacement Considerations

The industrial version LD59150PUR serves as a direct functional substitute if automotive qualification is not required. Both variants share identical pinouts, electrical specifications, and package dimensions. Designers must verify that the replacement part meets all environmental and reliability requirements of the target application before substitution.

FAQ

How is the output voltage adjusted on the LD59150?

The output voltage is set between 0.8 V and 3.6 V using an external resistor divider connected to the feedback pin. The reference voltage is typically 0.8 V.

What determines the soft-start time duration?

The soft-start time is programmed by connecting an external capacitor to the SS pin. The duration depends on the capacitance value and the internal charging current.

How does the Power Good function operate?

The PG pin acts as an open-drain output that goes high-impedance when the output voltage is within the correct range and pulls low if the voltage falls below the threshold or if the device is disabled.