Key facts
- Brand
- Ricoh
- Model
- R1225N
- Industry
- Industrial
- Documents
- 2
- Languages
- EN
- Last added
- 2012-07-10
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Ricoh R1225N Series PWM/VFM Step-Down DC/DC Controller Datasheet
The R1225N Series are CMOS-based PWM step-down DC/DC Converter controllers designed for low supply current applications. Each IC integrates an oscillator, PWM control circuit, reference voltage unit, error amplifier, soft-start circuit, latch-type protection circuit, and a PWM/VFM alternative circuit to improve efficiency at small load currents. The series is available with various oscillator frequencies (180kHz, 300kHz, 500kHz) and includes options without the PWM/VFM alternative circuit.
The document provides detailed electrical characteristics, absolute maximum ratings, and application hints for designing power source circuits for hand-held communication equipment, cameras, and battery-powered devices. It specifies the pin configuration for the SOT-23-6W package and includes equations for calculating the protection circuit delay time using an external capacitor.
Ricoh R1225N specifications
| Operating Input Voltage | 2.3V ~ 18.5V |
|---|---|
| Output Voltage Range | 1.2V ~ 6.0V |
| Output Voltage Accuracy | Typ. 2.0% |
| Standby Current | Typ. 0.0uA |
| Operating Temperature Range | -40 ~ +85 °C |
| Package Type | SOT-23-6W |
Source: Ricoh R1225N Series PWM/VFM Step-Down DC/DC Controller Datasheet
All Ricoh R1225N documents by type
Ratings, dimensions and ordering codes, for selection and design work.
Questions answered in these manuals
What is the function of the PWM/VFM alternative circuit?
When the load current is small, the operation automatically switches from the PWM oscillator to the VFM oscillator to improve efficiency at small load currents.
From: Ricoh R1225N Series PWM/VFM Step-Down DC/DC Controller Datasheet
How is the protection circuit delay time adjusted?
The delay time for the protection circuit is adjustable with an external capacitor connected to the DLY pin.
From: Ricoh R1225N Series PWM/VFM Step-Down DC/DC Controller Datasheet
What external components are required to configure the R1225N Series?
The device requires a power transistor, an inductor, a diode, and a capacitor as external components.
From: RICOH R1225N Series 18.5V Input PWM/VFM Step-down DC/DC Controller with Ext. Tr Manual
How does the PWM/VFM alternative circuit function?
It automatically switches to VFM control when operating in the smaller output current range to provide high efficiency.
From: RICOH R1225N Series 18.5V Input PWM/VFM Step-down DC/DC Controller with Ext. Tr Manual