R1245 Series
1.2A 30V Input PWM Step-down DC/DC Converter
Download Datasheet
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Description
The R1245 Series are 30V input, CMOS-based PWM step-down DC/DC converters featuring 1.2A*output current. R1245 includes a soft start circuit and latch or fold-back protection circuit. By simply using an inductor, resistors, a diode, and capacitors as external components, a high-efficiency step-down DC/DC converter can be easily configured. Due to current mode PWM control, the R1245 provides a fast response and high efficiency. Ceramic output capacitors can be used.
Compared with R1240, R1245 has a lot of variation of oscillator frequency and can select 330kHz. In case of 330kHz, R1245 can set VOUT lower than R1240. The oscillator maximum duty cycle (Min.) of R1245 is larger than R1240, so it is suitable for low dropout voltage situation. The noise characteristic has been improved rather than R1240, and voltage accuracy is also improved. In addition to HSOP-8E package can be selected, so R1245S is suitable for high power dissipation case.
*) This is an approximate value, because output current depending on conditions and external parts.
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Spec
Consumer Automotive Input Voltage Range 4.5 V to 30.0 V (32.0 V) Operating Temperature Range -40°C to 105°C (125°C) -40°C to 105°C (150°C) Supply Current Typ. 500 µA Standby Current Typ. 0 µA Output Voltage Range Externally Adjustable: 0.8 V to 27.6 V Externally Adjustable
(Ver.A/B/C/D) 0.8 V to 27.3 V
(Ver.E/F) 0.8 V to 25.8 V
(Ver.G/H) 0.8 V to 21.3 VFeedback Voltage 0.8 V Feedback Voltage Accuracy ±8 mV Feedback Voltage Temperature Coefficient ±100 ppm/°C Output Current 1.2 A Driver ON-resistance Typ. 0.35 Ω Oscillator Frequency 330 kHz (Ver.A/B), 500 kHz (Ver.C/D), 1 MHz (Ver.E/F), 2.4 MHz (Ver.G/H) Package DFN(PL)2020-8B, SOT-23-6W, HSOP-8E DFN2020-8, HSOP-8E フォールドバック周波数 170 kHz (Ver.B), 170 kHz (Ver.D), 250 kHz (Ver.F), 400 kHz (Ver.H) 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 
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Technical
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R1245x00xA/B Typical Application
(VOUT=1.2V, VIN=24.0V)
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R1245x00xA/B Efficiency vs. Output Current
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Related Links
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Quality &
PackagesProduct Name Compatibility Package Marking Reliability R1245K003x-TR DFN(PL)2020-8 R1245K R1245K R1245N001x-TR-FE SOT-23-6W R1245N R1245N-FE R1245S003x-E2-FE HSOP-8E R1245S R1245S-FE R1245L003x-TR-AE DFN2020-8 R1245L R1245L-AE R1245S003x-E2-JE HSOP-8E R1245S R1245S-JE R1245S003x-E2-AE HSOP-8E R1245S R1245S-AE - 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.
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Sample / Buy
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Buy Online
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Buy, Request for Samples, Request for Information Materials
Authorized Distributors
Please contact your local distributors for any sales-related inquiry such as price, stock, delivery, etc.
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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 |