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R1278 Series

30 V, 2 A Synchronous PWM Step-down DC/DC Converter

  • Consumer
  • Industrial
  • Automotive
  • PLP
  • AEC-Q100
  • RoHS

The R1278 is a 36 V maximum rated synchronous step-down DC/DC converter with built-in drivers.

With the operating frequency at 2 MHz and a spread-spectrum clock generator, the interference effect on the AM band is small. When an input voltage drops, the switching frequency is automatically reduced to keep output voltage level constant.

  • Provides a high switching frequency at 2 MHz with the efficiency of 87%.
  • Maintains the output voltage constant when an input voltage drops by reducing a switching frequency to the minimum of 1/4.
  • Achieves the EMI noise reduction by using a spread spectrum clock generator. (Diffusion Rate: +10%).

Specs & Datasheets

  Consumer Industrial Automotive
Input Voltage Range 3.6 V to 30.0 V (36.0 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 Externally Adjustable: 3.3 V to 5.0 V
Feedback Voltage 0.64 V
Feedback Voltage Accuracy ±1.0%
Output Current 2 A
Driver ON-resistance High side: Typ. 0.145 Ω, Low side: Typ. 0.095 Ω
Oscillator Frequency Typ. 2 MHz
Package HSOP-18

Download Datasheet

Protections / Functions

Functional Description

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

Technical Documents

Typical Application

Efficiency (VOUT=5V)

Efficiency (VOUT=5V)

Quality & Packages

Product Name Compatibility Package Marking Reliability
  • gradeConsumerC
  • plpP
HSOP-18 R1278S R1278S-FE
  • gradeIndustrialI
  • plpP
HSOP-18 R1278S R1278S-YE
  • gradeAutomotiveA
  • aecQ1001
  • plpP
HSOP-18 R1278S R1278S-AE
  • gradeAutomotiveA
  • aecQ1001
  • plpP
HSOP-18 R1278S R1278S-KE

Refer to the datasheets for the details on the product.
The package file includes package dimensions, taping specifications, taping reels dimensions, power dissipations, and recommended land pattern.
Please contact us or our distributors for unpublished reliability information.

Sample / Buy

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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