RICOH Manuals

R5220x SERIES PWM Step-down DC/DC Converter with switch function

The R5220x Series 400mA ∗PWM Step-down DC/DC Converter with Switch Function is a CMOS-based PWM step-down DC/DC converter with synchronous rectifier. R5220x also has the function of switching to the LDO regulator. By switching with the MODE pin, the device can be used as an LDO regulator (Output Current 50mA) in the smaller output current range, while it can be used as a DC/DC converter (Output Current 400mA∗) under high load conditions. (The polarity of the MODE pin is selectable.) The DC/DC converter contains an under-voltage lockout circuit (UVLO), a soft start circuit, and a latch type protection circuit. By simply using an inductor and a capacitor, a high-efficiency DC/DC converter can be easily configured.

The RP901K Series are CMOS-based PWM/VFM step-down DC/DC converters equipped with voltage regulator and voltage detector. The DC/DC converter can be selected from two control types - fixed PWM control or PWM/VFM auto switching control in which mode automatically switches to high-efficiency VFM mode in low output current. RP901K was developed for applications that require multiple power supplies such as storage devices. It integrates an 800mA output current step-down DC/DC converter, a 600mA output current LDO regulator, and a voltage detector with a built-in delay circuit into a small package. The regulator can be started after soft start of the DC/DC converter by sequence control.

The document is about the technical manual of RP901K. It introduces the features and characteristics of the product, including the working principle, usage method, precautions, etc.

The RP904 series are CMOS-based PWM/PFM step-down DC/DC converters with synchronous rectifier, low supply current and through mode. The DC/DC converter of the RP904X consists of an oscillator, a PWM/PFM control circuit, a reference voltage unit, an error amplifier, a soft-start circuit, protection circuits, a protection against miss operation under low voltage (UVLO), PWM-DC to DC converter or bypass switch alternative circuit, a chip enable circuit, and a driver transistor. A high efficiency step-down DC/DC converter can be easily composed of this IC with only a few kinds of external components, or an inductor and capacitors. The output voltage of the DC/DC converter has two kinds of output voltage, and alternative with the VSEL pin. The RP904 series are PWM/PFM step-down DC/DC converter, thus, when the load current is small, the operation can be switching into the PFM operation from PWM control if the user chooses the VFM mode. As protection circuits, the current limit circuit which limits peak current of Lx at each clock cycle, and the latch type protection circuit which works if the term of the over-current condition keeps on a certain time in PWM mode. Latch-type protection circuit works to latch an internal driver with keeping it disable. To release the protection, after disable this IC with a chip enable circuit, enable it again, or restart this IC with p-MOSFET.

The RP904Z Series are CMOS-based step-down DC/DC converters with Synchronous Rectifier featuring 1A∗∗ output current and have through mode. RP904Z includes an under-voltage lockout circuit (UVLO), a soft start circuit and a timer latch protection circuit. By simply using an inductor and capacitors as external components, a high-efficiency step-down DC/DC converter can be easily configured. The output voltage of DC/DC converter can be selected from 2 voltage by inputting signal to VSEL pin. The DC/DC converter is PWM/VFM manual switching control. RP904Z is able to select DC/DC mode or through mode by inputting signal to BYPASS pin. WLCSP-11-P2 package is available.

The R5400N Series are high input voltage CMOS-based protection ICs for over-charge/discharge of rechargeable one-cell Lithium-ion (Li-ion) / Lithium polymer excess load current, further include a short circuit protector for preventing large external short circuit current and excess discharge-current. Each of these ICs is composed of three voltage detectors, reference units, a delay circuit, a short circuit detector, an oscillator, a counter, and a logic circuit. SOT-23-5 package is available.

The R5402Nx Series is a high input voltage CMOS-based protection ICs for over-charge/discharge of rechargeable one-cell Lithium-ion (Li-ion) / Lithium polymer excess load current, further include a short circuit protector for preventing large external short circuit current and excess charge/discharge-current. Each of these ICs is composed of four voltage detectors, reference units, a delay circuit, a short circuit protector, an oscillator, a counter, and a logic circuit. SOT-23-5 package is available.

R5403x/R5405x Series is a high input voltage CMOS-based protection IC for over-charge/discharge of rechargeable one-cell Lithium-ion (Li-ion) / Lithium polymer excess load current, further include a short circuit protector for preventing large external short circuit current and excess charge/discharge-current. Each of these ICs is composed of four voltage detectors, a reference unit, a delay circuit, a short circuit protector, an oscillator, a counter, and a logic circuit. In addition to SOT-23-5 and SOT-23-6 packages, DFN(PLP)1616-6, DFN(PLP)1820-6 are also available.

R5470x/R5471x series is a high input voltage CMOS-based protection IC for over-charge/discharge and over-current of rechargeable one-cell Lithium-ion/Lithium polymer battery. They can detect over-charge/discharge and excess-current of one-cell Li-ion, further include a short circuit protection. They consist of four voltage detectors, reference units, a delay circuit, a short circuit detector, an oscillator, a counter, and a logic circuit. Voltage accuracy is superior to previous items. DFN(PLP)2114-4B (for R5470K) and DFN(PLP)1616-6B (for R5471K) packages are available.

The R5463x series is a high-voltage CMOS-based protection IC for over-charge/discharge of rechargeable two-cell Li-ion/Lithium polymer, further include a short circuit protection circuit for preventing large external short circuit current and the protection circuits against the excess discharge-current and excess charge current. Each of these ICs is composed of six voltage detectors, reference units, a delay circuit, a short circuit protector, an oscillator, a counter, and logic circuits. DFN(PLP)1820-6B package is available.

The R5462x Series are high voltage CMOS-based protection ICs for over-charge/discharge of rechargeable two-cell Li-ion/Lithium polymer, further include a short circuit protection circuit for preventing large external short circuit current and the protection circuits against the excess discharge-current and excess charge current. Each of these ICs is composed of six voltage detectors, reference units, a delay circuit, a short circuit protector, an oscillator, a counter, and logic circuits. The over-charge detector threshold is high accuracy such as ±10mV(0°C∼50°C). DFN(PLP)1820-6B package is available.

R5461K series Li-ion/polymer 2Cell protector IC with alarm function

R5460x series Li-ION / POLYMER 2-cell PROTECTOR

The R5460x Series are high voltage CMOS-based protection ICs for over-charge/discharge of rechargeable two-cell Li-ion/Lithium polymer. They include a short circuit protection circuit for preventing large external short circuit current and protection circuits against excess discharge-current and excess charge current. Each IC consists of six voltage detectors, reference units, a delay circuit, a short circuit protector, an oscillator, a counter, and a logic circuit. In addition to SOT-23-6 package, DFN(PLP)1820-6 package is also available.