Ricoh manuals, page 8
RICOH RP400xxx1A SERIES HIGH EFFICIENCY SMALL PACKAGES STEP-UP DC/DC CONVERTERS handbook
RP400xxx1A Series are high efficiency, step-up DC/DC converter ICs packaged in compact 5pin SOT23 or 6pin DFN(PLP). This converter starts up of low voltage (Typ.0.8V) operation from one to two alkaline or a nickel-metal-hydride (NiMH) or one-cell Lithium-ion (Li+) battery. This IC consists of 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. As a protection circuit, RP400xxx1A has a current limit circuit which limits the peak current of the inductor at each clock cycle. A low ripple high efficiency step up DC/DC converter can be composed of RP400xxx1A Series with only an inductor, a diode and capacitors. This converter is based on a fixed frequency current mode PWM control which goes to power save mode (VFM mode) at light load automatically. RP400xxx1A Series has built-in Anti-ringing switch to prevent switching node from ringing, when the converter enters the discontinuous current mode. The output voltage of RP400K001A can be set within 1.8~5.0V (recommended range of output voltage) by external divider resistors.
RICOH RP400x Series Current Mode PWM/VFM Step-up DC/DC Converter handbook
The RP400x series are CMOS-based automatic switch PWM- or VFM-controlled step-up DC/DC converters. RP400x includes a soft start circuit. By simply using an inductor, a capacitor, a diode, and (resistors) as external components, a high-efficiency step-up DC/DC converter can be easily configured. Due to current mode PWM control, the RP400x provides a fast response and high efficiency. Ceramic output capacitors can be used. The output voltage can be selected from the internally fixed or the externally adjustment. The RP400x has an anti-ringing switch that prevents inductor current from ringing in PWM discontinuous mode. RP400x switches automatically to VFM control in low output current, keeping high efficiency. In addition to SOT-23-5 package, a 1.8mm × 2.0mm square DFN(PLP)1820-6 package is also available.
RICOH R1213K SERIES PWM STEP-UP DC/DC CONVERTERS handbook
R1213K Series are CMOS-based, PWM control low consumption current step-up DC/DC converter ICs.
RICOH R1213K Series 2.5A PWM Step-up DC/DC Converter handbook
The R1213K Series are low supply current, CMOS-based PWM step-up DC/DC converters. R1213K includes a soft start circuit, an under-voltage lockout circuit (UVLO), a thermal shutdown circuit, and a latch protection circuit. By simply using an inductor, resisters and capacitors as external components, a high-efficiency step-up DC/DC converter can be easily configured. The soft start time as well as phase compensation can be set with external resistors and capacitors. Built-in a timer latch protection circuit. Built-in a shutdown control circuit. It turns off the external Pch MOSFET at the latch protection time, so it cut off the power line from VDD to VOUT. To release the latch protection, change to the stand-by mode by the CE pin, or change the VDD voltage lower than the UVLO detect voltage.
RICOH R1210Nxx2x SERIES PWM Step-up DC/DC Controller handbook
The R1210Nxx2C/xx2D Series are CMOS-based PWM step-up DC/DC Converter controllers, with high accuracy, low supply current.
RICOH R1210Nxx1x SERIES PWM STEP-UP DC/DC CONVERTER handbook
The R1210Nxx1x Series are CMOS-based PWM step-up DC/DC Converter, with high accuracy, low supply current.
RICOH R1210N Series 8V Input PWM Step-up DC/DC Converter handbook
The R1210N Series are low supply current, CMOS-based PWM step-up DC/DC converters. By simply using an inductor, a diode, and a capacitor as external components, a high-efficiency step-up DC/DC converter can be easily configured. The xx1 version with an internal output transistor and the xx2 version with an external transistor are available. The oscillator frequency can be selected from 100kHz or 180kHz. The xx1A version is also available, which contains a basic frequency changeover circuit that switches the oscillator frequency from 100kHz to 35kHz when output load is reduced. R1210N also has a function that detects drastic changes in output voltage and reduces the amount of overshoot/undershoot by switching control mode.
RICOH RN5RK SERIES VFM STEP-UP DC/DC CONVERTER handbook
The RN5RK series is a CMOS-based VFM (Chopper) Step-up DC/DC converter IC with ultra low supply current and high output voltage accuracy.
RICOH RN5RK Series 8V Input VFM Step-up DC/DC Converter handbook
The RN5RK Series are low supply current, CMOS-based VFM step-up DC/DC converters. By simply using an inductor, a diode, and a capacitor as external components, a high-efficiency step-up DC/DC converter can be easily configured. RN5RK comes in two versions: xx1 version with an internal output transistor and xx2 version with an external transistor.
RICOH R1201x SERIES STEP-UP DC/DC CONVERTER FOR WHITE LED BACK LIGHT handbook
The R1201x Series is a PWM control type step-up DC/DC converter IC with low supply current. It can drive white LEDs in constant current with high efficiency by using an inductor, a resistor and capacitors as external components.
RICOH R1201N Series PWM Step-up DC/DC Converter for White LED handbook
The R1201N Series are CMOS-based PWM step-up DC/DC converters, which are optimized to drive white LEDs with constant current. R1201N includes a forward diode, an under-voltage lockout circuit (UVLO), and over-voltage protection circuit (OVP). By simply using an inductor, a resistor, and capacitors as external components, white LEDs can be driven with constant current and high efficiently. A diode is built-in; therefore it is possible to drive up to 5 serial LEDs without an external diode. The oscillator frequency can be selected from 1MHz or 1.2MHz. The LED current can be determined by the value of current setting resistor. The brightness of the LEDs can be adjusted quickly by applying a PWM signal (200Hz to 300kHz) to the CE pin.
RICOH R1203x SERIES STEP-UP DC/DC CONVERTER FOR WHITE LED BACK LIGHT handbook
R1203x series step-up DC/DC converter is dedicated for driving white LEDs with constant current. It is characterized by low supply current, high efficiency, high reliability and good EMI performance.
RICOH R1203x Series PWM Step-up DC/DC Converter for White LED handbook
The R1203x Series are CMOS-based PWM step-up DC/DC converters, which are optimized to drive white LEDs with constant current
RICOH R1218x SERIES Step-up DC/DC converter for White LED Backlight handbook
The R1218x Series are PWM control type step-up DC/DC converter ICs with low supply current.
RICOH R1218x Series PWM Step-up DC/DC Converter for White LED handbook
The R1218x Series are CMOS-based PWM step-up DC/DC converters, which are optimized to drive white LEDs with constant current. R1218x includes an under-voltage lockout circuit (UVLO), over-voltage protection circuit (OVP). By simply using an inductor, (a diode), a resistor, and a capacitor as external components, white LEDs can be driven with constant current efficiently. R1218xxx1A for 2 to 4 lights contains an internal diode while R1218xxx2A for 5 to 7 lights requires an external diode. The LED current can be determined by the value of current setting resistor. The brightness of the LEDs can be adjusted by applying a PWM signal to the CE or VFB pin.