R1270 Series
3A 34V Input PWM/VFM Step-down DC/DC Converter with PLL Synchronization
Description
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.
Spec
| Standard | 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 | ||
Protections / Functions
| TSD | OCP | OVP | UVLO | OVLO | Reverse | Shutdown | Soft Start | SSCG | PGOOD | Auto Discharge | Anti-ringing | Sequencing | Max Duty | Ext. Phase | LED Adjust |
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Functional Description
| TSD | Thermal Shutdown Function |
|---|---|
| OCP | Overcurrent Protection Note: The function previously labeled as "ILX (LX Current Limit Function)" is now shown as "OCP." |
| 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 |
Technical Documents
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Typical Application
* PLLREF pin must not be “OPEN”. When using the Nisshinbo Micro Devices' evaluation board, a pull-down resistor (RPLLREF2: 100 kΩ) is contained on the evaluation board.
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Efficiency vs. Output Current
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Related Links
Quality & Packages
- 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.
FAQ
Buy / Contact
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Purchase, Request for samples and documentsSales are made through distributors. Please contact your local distributors for any sales-related inquiry such as price.
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Available from 1 piece!Our electronic device products are available through our authorized online distributors.
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Technical Support