R1271 Series
30 V, 1 A Synchronous PWM Step-down DC/DC Converter

  • Description

    The R1271 is a synchronous step-down DC/DC converter with a maximum input voltage rating of 42 V. This device is suitable for small inductors with the switching frequency of 2 MHz. The external components are only an inductor and several capacitors and a resistance. The tiny DFN package option makes the power circuit compact.

    Key Benefits

    • High efficiency 85% is realized with switching frequency of 2 MHz
    • The output voltage is maintained at cranking by reducing a switching frequency to minimum 1/4 of normal frequency.
    • EMI noise reduction by using a spread spectrum clock generator. (Diffusion Rate: +10%).

  • Spec
    Consumer Industrial Automotive
    Input Voltage Range 3.6 V to 30.0 V (42.0 V)
    Operating Temperature Range -40°C to 105°C (125°C) -40°C to 125°C (150°C) -40°C to 125°C (150°C)
    Supply Current Typ. 1 mA
    Standby Current Typ. 4 µA
    Start-up Voltage 4.5 V
    Output Voltage Range 3.3 V, 3.6 V, 4.0 V, 5.0 V
    Output Voltage Accuracy ±1.0% (Ta = 25°C)
    Output Current 1 A
    Driver ON-resistance High side: Typ. 0.4 Ω, Low side: Typ. 0.2 Ω
    Oscillator Frequency Typ. 2 MHz
    Package DFN3030-12B, HSOP-18

    Protections / Functions

    TSD ILX OCP OVP UVLO OVLO Reverse Shutdown Soft Start SSCG PGOOD Auto Discharge Anti-ringing Sequencing Max Duty Ext. Phase LED Adjust
  • Technical
    • Typical Application

      Typical Application

    • DFN3030-12B PCB Example

      DFN3030-12B PCB Example

    • Related Links

      • Prime Designer

        Online Design Tool

        Registration to myNISD is required to use some of the functions, such as simulations.

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  • Quality &
    • Refer to the datasheets for the details on the product.
    • The package file or the datasheet includes package dimensions, taping specifications, taping reels dimensions, power dissipations, and recommended land pattern.

Download Datasheet

Functional Description

TSD Thermal Shutdown Function
ILX LX Current Limit Function
OCP Overcurrent Protection
OVP Overvoltage Protection
UVLO Undervoltage Lockout Protection
OVLO Overvoltage Lockout Protection
Reverse Reverse Current Protection Circuit
Shutdown Shutdown Function
Soft Start Soft Start Function
SSCG Spread Spectrum Clock Generator Function
PGOOD Power Good Output
Auto Discharge Auto Discharge Function
Anti-ringing Anti-ringing Switch Function
Sequencing Start-up Sequencing Control
Max Duty Maximum Duty Cycle
Ext. Phase Externally Adjustable Phase Compensation
LED Adjust LED High-speed Dimming Control

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