R1245 Series
1.2A 30V Input PWM Step-down DC/DC Converter
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.
Spec
| Standard | 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 V |
| Feedback 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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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 |
Technical Documents
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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
Quality & Packages
| Product 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.
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