RICOH PWM Step-Up DC DC Converter RH5RH XX1A XX2B XX3B Series Application Manual
Summary
Optimize your portable electronics with these ultra-low ripple PWM Step-up DC/DC Converter ICs. Designed for demanding battery-powered applications—such as professional audio gear, cameras, and PDAs—these converters provide high efficiency while maintaining an exceptionally low supply current (down to 2μA). The manual guides users through selecting the optimal model (1A, 2B, or 3B series) based on required output current and standby needs. Featuring integrated control circuits and options for external drivers, this solution is ideal for engineers who require dependable, quiet power sources without sacrificing longevity due to high quiescent draw.
Page 1 Text Content
PWM STEP-UP DC/DC CONVERTER RH5RH××1A/××2B/××3B SERIES
APPLICATION MANUAL
NO.EA-023-0006
Page Summary Contents For RICOH PWM Step-Up DC DC Converter RH5RH XX1A XX2B XX3B Series Application Manual
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PWM STEP-UP DC/DC CONVERTER RH5RH××1A/××2B/××3B SERIES APPLICATION MANUAL NO.EA-023-0006
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PWM STEP-UP DC/DC CONVERTER RH5RH××1A/××2B/××3B SERIES OUTLINE The RH5RH××1A/××2B/××3B Series are PWM Step-up DC/DC converter ICs by CMOS process. The RH5RH××1A IC consists of an oscillator, a PWM con...
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RH5RH BLOCK DIAGRAM VLX limiter Slow start Vref Buffer Phase Comp. Lx SW PWM control OSC Error Amp. Chip Enable Error Amp. (Error Amplifier) has a DC gain of 80d B, and Phase Comp. (Phase Compensation...
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RH5RH PIN CONFIGURATION SOT-89 SOT-89-5 (mark side) (mark side) PIN DESCRIPTION Pin No. Symbol Description VSS Ground Pin OUT Step-up Output Pin, Power Supply (for device itself) Lx Switching Pin (Nch...
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RH5RH ABSOLUTE MAXIMUM RATINGS Vss=0V Symbol Item Rating Unit Note VOUT Output Pin Voltage +12 VLX Lx Pin Voltage +12 Note1 VEXT EXT Pin Voltage 0.3 to VOUT+0.3 Note2 VCE CE Pin Voltage –0.3 to VOUT+0...
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RH5RH ELECTRICAL CHARACTERISTICS • RH5RH301A VOUT=3.0V Symbol Item Conditions MIN. TYP. MAX. Unit Note VOUT Output Voltage 2.925 3.000 3.075 VIN Input Voltage Vstart Start-up Voltage IOUT=1m A,VIN : 0...
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RH5RH • RH5RH501A VOUT=5.0V Symbol Item Conditions MIN. TYP. MAX. Unit Note VOUT Output Voltage 4.875 5.000 5.125 VIN Input Voltage Vstart Start-up Voltage Iout=1m A,Vin:0→2V 0.8 0.9 Vhold Hold-on Vol...
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RH5RH RH5RH302B VOUT=3.0V Symbol Item Conditions MIN. TYP. MAX. Unit Note VOUT Output Voltage 2.925 3.000 3.075 VIN Input Voltage Vstart Oscillator Start-up Voltage EXT no load,VOUT :0→2V 0.7 0.8 IDD1...
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RH5RH • RH5RH303B VOUT=3.0V Symbol Item Conditions MIN. TYP. MAX. Unit Note VOUT Output Voltage 2.925 3.000 3.075 VIN Input Voltage Vstart Start-up Voltage IOUT=1m A,VIN : 0→2V 0.8 0.9 Vhold Hold-on V...
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RH5RH • RH5RH503B VOUT=5.0V Symbol Item Conditions MIN. TYP. MAX. Unit Note VOUT Output Voltage 4.875 5.000 5.125 VIN Input Voltage Vstart Start-up Voltage IOUT=1m A,VIN : 0→2V 0.8 0.9 Vhold Hold-on V...
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RH5RH OPERATION OF STEP-UP DC/DC CONVERTER Step-up DC/DC Converter charges energy in the inductor when Lx Transistor (Lx Tr) is on, and discharges the energy with the addition of the energy from Input...
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RH5RH When the output current (IOUT) is relatively small, topen<toff as illustrated in the above diagram. In this case, the energy charged in the inductor during the time period of ton is discharge...
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RH5RH Therefore it is necessary that the setting of the input/output conditions and the selection of peripheral compo- nents should be made with ILmax taken into consideration. • Output Current in Con...
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RH5RH ut pu t V ol ta ge (V ut pu t V ol ta ge (V ut pu t V ol ta ge (V TYPICAL CHARACTERISTICS 1) Output Voltage vs. Output Current RH5RH301A RH5RH301A VIN =1.0V VIN=1.0V 2.0V Output Current IOUT(m A...
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RH5RH ffi ci en cy ffi ci en cy ffi ci en cy 2) Efficiency vs. Output Current RH5RH301A RH5RH301A VIN=1.0V VIN=1.0V Output Current IOUT(m A) Output Current IOUT(m A) ffi ci en cy ffi ci en cy RH5RH501...
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RH5RH ip pl ol ta ge (m -p up pl ur re nt II µA up pl ur re nt II µA 3) Supply Curret (No Load) vs. Input Voltage RH5RH301A RH5RH301A 1.0 1.2 1.4 1.6 1.8 2.0 1.0 1.2 1.4 1.6 1.8 2.0 Input Voltage VIN(...
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RH5RH ta rt -u p/ ol d- on ol ta ge st ar t/V ho ld ip pl ol ta ge (m -p ip pl ol ta ge (m -p RH5RH301A RH5RH501A VIN=0.9V VIN=0.9V Output Current IOUT(m A) Output Current IOUT(m A) RH5RH302B RH5RH502...
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RH5RH ut pu t V ol ta ge ut pu t V ol ta ge ta rt -u p/ ol d- on ol ta ge st ar t/V ho ld RH5RH302B RH5RH502B Vstart Vstart 1.0 1.0 0.6 0.6 Vhold Vhold Output Current IOUT(m A)S Output Current IOUT(m ...
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RH5RH Lx itc hi ng ur re nt IL up pl ur re nt ID 1( µA ta rt -u ol ta ge st ar t( 7) Start-up Voltage vs. Temperature 8) Hold-on Voltage vs. Temperature RH5RH501A RH5RH501A Temperature Topt(˚C) Temper...
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RH5RH sc ill at or ut yc le ax dt y( sc ill at or re qu en cy fo sc (k z) sc ill at or re qu en cy fo sc (k z) 13) Oscillator Frequency vs. Temperature RH5RH301A IOUT=10m A RH5RH501A IOUT=10m A VIN=2V...
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RH5RH ut pu t C ur re nt IE (m LX ol ta ge im it LX lim (V sc ill at or ut yc le ax dt y( IOUT=10m A IOUT=10m A RH5RH302B RH5RH502B VIN=2V VIN=3V L=28µH L=28µH Temperature Topt(˚C) Temperature Topt(˚C...
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RH5RH 18) Load Transient Response ut pu t V ol ta ge ut pu t V ol ta ge RH5RH301A IOUT=1m A-30m A RH5RH501A IOUT=1m A-30m A VIN=2V VIN=3V L=120µH L=120µH 3.5 Output Voltage 5.5 Output Voltage Output C...
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RH5RH 19) Distribution of Output Voltage ut pu t V ol ta ge sc ill at or re qu en cy fo sc k H z) RH5RH501A Distribution (%) 20) Distribution of Oscillator Frequency RH5RH501A Distribution (%)
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RH5RH TYPICAL APPLICATIONS • RH5RH××1A Diode Inductor Lx OUT Capacitor Components Inductor (L) : 120µH (Sumida Electric Co., Ltd.) Diode (D) : MA721 (Matsushita Electronics Corporation, Schottky Type)...
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RH5RH RH5RH××3B Diode Inductor Lx OUT NC EXT CE Vss Capacitor Components Inductor (L) : 120µH (Sumida Electric Co., Ltd.) Diode (D) : MA721 (Matsushita Electronics Corporation, Schottky Type) Capacito...
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RH5RH CE pin Drive Circuit Diode Inductor RH5RH××3B Lx OUT NC EXT CE Vss Pull-up resistor Capacitor FIG. 5
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RH5RH APPLICATION CIRCUITS 12V Step-up Circuit Inductor Diode ZD:6.8V RH5RH502B Cb OUT VIN Capacitor EXT Vss Starter Circuit (Note) When the Output Current is small or the Output Voltage is unstable,u...
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RH5RH Step-up/Step-down Circuit with Flyback Diode Trance1:1 RH5RH××1A Capacitor Starter Circuit (Note) Use a RH5RH××2B,depend on the Output Current. FIG. 8 *The Starter Circuit is necessary for all a...
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RH5RH APPLICATION HINTS When using these ICs, be sure to take care of the following points : Set external components as close as possible to the IC and minimize the connection between the components a...
Manual Details
| Brand | Ricoh |
|---|---|
| Pages | 29 |
| File Size | 199.59 KB |
| Published | May 27, 2026 |
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Frequently Asked Questions
Which RH5RH model is best for large output currents?
The RH5RH 2B or 3B series are recommended because they feature a drive pin (EXT) that allows using an external transistor to achieve high current outputs (tens to hundreds of mA).
What is the typical low-load supply current for this converter?
For the RH5RH 1A, the ultra-low supply current at no load is typically 15μA. It can be maintained down to 2μA when the input voltage is sufficiently high.
Does one model offer a specific standby operation feature?
Yes, the RH5RH 3B IC includes an internal chip enable circuit that allows setting the standby supply current as low as MAX. 0.5μA.
How many external components are required to build this converter?
Only three external components—an inductor, a diode, and a capacitor—are needed for the RH5RH 1A model.