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R1270 Series

3A 34V Input PWM/VFM Step-down DC/DC Converter with PLL Synchronization

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

The R1270 Series are 34V input (Absolute maximum rating: 36V), CMOS-based PWM/VFM step-down DC/DC converters capable of outputting the maximum 3A* current. The R1270 is selectable from two control types - PWM control or PWM/VFM auto switching control in which mode automatically switches to high-efficiency VFM mode in low output current. The R1270 includes a soft start circuit, a fold-back protection circuit and a latch protection circuit (only A Version). By simply using an inductor, resistors, and capacitors as external components, a high-efficiency step-down DC/DC converter can be easily configured. The R1270 can be synchronized externally by PLL.

*) This is an approximate value, because output current depending on conditions and external parts.

Specs & Datasheets

  Consumer Industrial Automotive
Input Voltage Range 3.6 V to 34.0 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. 18 µA
Standby Current Typ. 0 µA
Output Voltage Range Externally Adjustable: 0.8 V to 31.6 V
Feedback Voltage 0.8 V
Feedback Voltage Accuracy ±8 mV
Feedback Voltage Temperature Coefficient Typ. ±100 ppm/°C (−40°C ≤ Ta ≤ 125°C)
Output Current 3 A
Oscillator Frequency Externally Adjustable: 300 kHz to 2.4 MHz
Maximum Duty Cycle Min. 93% (fosc = 300 kHz), Min. 67% (fosc = 2.4 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

* PLLREF pin must not be “OPEN”. When using the Ricoh’s evaluation board, a pull-down resistor (RPLLREF2: 100 kΩ) is contained on the evaluation board.

Efficiency vs. Output Current

Efficiency vs. Output Current

Quality & Packages

Product Name Compatibility Package Marking Reliability
  • gradeConsumerC
  • plpP
HSOP-18 R1270S R1270S-FE
  • gradeIndustrialI
  • plpP
HSOP-18 R1270S R1270S-YE
  • gradeAutomotiveA
  • aecQ1001
  • plpP
HSOP-18 R1270S R1270S-KE
  • gradeAutomotiveA
  • aecQ1001
  • plpP
HSOP-18 R1270S R1270S-AE

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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