RP401x Series are high efficiency, step-up DC/DC converter ICs packaged in compact 5pin SOT23-5， or 6pin DFN(PLP)1820-6. This IC can start up from low voltage (Typ.0.6V), therefore, it is suitable for using with single or 2 serial alkaline batteries, or a nickel-metal-hydride (NiMH) battery, or one-cell Lithium-ion (Li+) battery. This IC consists of an oscillator, a reference voltage unit with soft start, a chip enable circuit, an error amplifier, phase compensation circuits, a slope circuit, a PWM control circuit, a start-up circuit, a PWM/VFM mode control circuit, internal switches and a protection circuit. A low ripple high efficiency step-up DC/DC converter can be composed of the RP401x with only an inductor, a diode, (resisters for adjustable type), and capacitors. The output voltage of the RP401K001s is adjustable, and others are fixed internally. The output voltage range is from 1.8V to 5.5V. RP401Kxx1A/B series have a MODE pin to alternate between PWM fix and PWM/VFM automatic shift to improve the efficiency at light load. If MODE pin is set 'H', the mode is PWM fix, and when the MODE pin is set 'L', PWM/VFM automatic shift. The RP401xxx1C and D do not have MODE pin. The RP401xxx1C is PWM/PFM alternative type, and the RP401xxx1D is PWM fixed type.
The RP401x Series consists of high efficiency, step-up DC/DC converter ICs available in compact Spin SOT23-5 or 6pin DFN(PLP)1820-6 packages. These devices can start up from a low voltage (Typ. 0.6V), making them suitable for use with single or two serial alkaline batteries, NiMH batteries, or one-cell Lithium-ion batteries.
The series includes fixed output types (RP401Kxx1A/B and RP401Nxx1C/D) and adjustable output types (RP401K001C/D). Key features include a built-in Lx switch with an NMOS on-resistance of 0.4Ω, PWM oscillator frequency up to 1.2MHz, and output voltage ranges from 1.8V to 5.5V.
| Start-up Voltage (Typ.) | 0.6V |
|---|---|
| Input Voltage Range | 0.6V to 5.5V |
| Output Current (Typ.) | 500mA @ 3.3V output, Vin=1.5V |
| Built-in Lx Switch On-Resistance | 0.4Ω @ Vout = 3.3V, 25°C |
| PWM Oscillator Frequency | ~1.2MHz |
| Output Voltage Range (Fixed) | 1.8V to 5.5V |
| Peak Current Limit | ~Typ. 1.0A |
| Latch Protection Delay Time (Version A) | 3.3ms |
| Ambient Temperature Range | -40°C to +85°C |
The typical start-up voltage is 0.6V, allowing operation with low-voltage sources like single alkaline batteries.
The ICs are packaged in compact Spin SOT23-5 or 6pin DFN(PLP)1820-6.
The output voltage range for fixed types is from 1.8V to 5.5V.
Yes, RP401Kxx1A/B series have a MODE pin to alternate between PWM fix and PWM/VFM automatic shift.