Electronic Components Datasheet Search |
|
RH5RH453B-T1 Datasheet(PDF) 2 Page - RICOH electronics devices division |
|
RH5RH453B-T1 Datasheet(HTML) 2 Page - RICOH electronics devices division |
2 / 29 page PWM STEP-UP DC/DC CONVERTER 1 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 control circuit, a driver transistor (Lx switch), a refer- ence voltage unit, an error amplifier, a phase compensation circuit, resistors for voltage detection, a soft-start cir- cuit, and an Lx switch protection circuit. A low ripple, high efficiency step-up DC/DC converter can be constructed of this RH5RH ××1A IC with only three external components, that is, an inductor, a diode and a capacitor. These RH5RH ××1A/××2B/××3B ICs can achieve ultra-low supply current (no load) –TYP. 15µA –by a new- ly developed PWM control circuit, equivalent to the low supply current of a VFM (chopper) Step-up DC/DC con- verter. Furthermore, these ICs can hold down the supply current to TYP. 2µA by stopping the operation of the oscil- lator when the input voltage > (the output voltage set value + the dropout voltage by the diode and the inductor). These RH5RH ××1A/××2B/××3B Series ICs are recommendable to the user who desires a low ripple PWM DC/DC converter, but cannot adopt a conventional PWM DC/DC converter because of its too large supply current. The RH5RH ××2B/××3B Series ICs use the same chip as that employed in the RH5RH××1A IC and are pro- vided with a drive pin (EXT) for an external transistor. Because of the use of the drive pin (EXT), an external transistor with a low saturation voltage can be used so that a large current can be caused to flow through the inductor and accordingly a large output current can be obtained. Therefore, these RH5RH ××2B/××3B Series ICs are recommendable to the user who need a current as large as several tens mA to several hundreds mA. The RH5RH ××3B IC also includes an internal chip enable circuit so that it is possible to set the standby sup- ply current at MAX. 0.5µA. These RH5RH ××1A/××2B/××3B ICs are suitable for use with battery-powered instruments with low noise and low supply current. • Small Number of External Components ..........Only an inductor, a diode and a capacitor (RH5RH ××1A) • Low Supply Current...........................................TYP. 15µA (RH5RH301A) • Low Ripple and Low Noise • Low Start-up Voltage (when the output current is 1mA) ..................MAX. 0.9V • High Output Voltage Accuracy..........................±2.5% • High Efficiency ...................................................TYP. 85% • Low Temperature-Drift Coefficient of Output Voltage ......................TYP. ±50 ppm/˚C • Soft-Start.............................................................MIN. 500µs • Small Packages...................................................SOT-89 (RH5RH ××1A, RH5RH××2B), SOT-89-5 (RH5RH ××3B) FEATURES APPLICATIONS • Power source for battery-powered equipment. • Power source for cameras, camcorders, VCRs, PDAs, electronic data banks,and hand-held communication equipment. • Power source for instruments which require low noise and low supply current, such as hand-held audio equip- ment. • Power source for appliances which require higher cell voltage than that of batteries used in the appliances. |
Similar Part No. - RH5RH453B-T1 |
|
Similar Description - RH5RH453B-T1 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |