VFM STEP-UP DC/DC CONVERTER
The RN5RKxx1A/xx1B/xx2A Series are CMOS-based VFM (Chopper) Step-up DC/DC converter
ICs with ultra
low supply current and high output voltage accuracy.
Each of the RN5RKxx1A/xx1B consists of an oscillator, a VFM control circuit, a driver transistor to have low
ON resistance (Lx switch), a reference voltage unit, a high speed comparator, resistors for voltage detection,
an
Lx switch protection circuit and an internal chip enable circuit. A low ripple, high efficiency step-up DC/DC
converter can be composed of this RN5RKxx1A/xx1B with only three external components: an inductor, a diode
and a capacitor.
The RN5RKxx2A uses the same chip as what is employed in the RN5RKxx1A/1B IC and has a drive pin (EXT)
for an external transistor instead of an Lx pin. As it is possible to load a large output current with a power
transistor which has a low saturation voltage, RN5RKxx2A IC is recommendable to users who need an output
current as large as between several tens mA and several hundreds mA.
Using the chip enable function, it is possible to make the supply current on standby minimized.
Since the package for these ICs is SOT-23-5 ,
high density mounting of the ICs on board is
possible. |
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Small
Number of External Components |
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Only an inductor, a diode and a capacitor (RN5RKxx1A/xx1B) |
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| Standby
Current |
Typ. 0µA |
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Low Temperature-Drift Coefficient of Output Voltage |
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Typ. ±100ppm/°C |
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| Output Voltage Range |
2.0V to 5.5V |
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| Two Kinds of Duty Ratio |
77% (xx1A, xx2A)/ 55% (xx1B) |
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| High Output Voltage Accuracy |
±2.5% |
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| Small Packages |
SOT-23-5 |
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| High Efficiency |
Typ. 85% (RN5RK301B, VIN=2V, IOUT=10mA) |
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| Low Ripple and Low Noise |
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Including a Driver Transistor with Low ON Resistance |
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Only RN5RKxx1A/xx1B |
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| Low Start-up Voltage |
Max.0.9V |
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Power source for battery-powered equipment. |
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Power source for cameras, camcorders, VCRs, and hand-held communication
equipment. |
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Power source for those appliances which require higher cell voltage
than that of batteries. |
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| * All PDF files are less than 1MB unless otherwise stated. |
| * If you don't have Adobe Reader, you can download free. |
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Technical Info.
Technical Information on Ricoh Power Management ICs.
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Product Catalog
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| Selection guide is available for download in PDF format. |
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Non-promotion / Discontinued Products
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RN5RK Series
