RH5RI302B-T2

VFM STEP-UP DC/DC CONVERTER RH5RI××1B/××2B/××3B SERIES APPLICATION MANUAL NO.EA-025-0006 VFM STEP-UP DC/DC CONVERTER RH5RI ×× 1B/ ×× 2B/ ×× 3B SERIES OUTLINE The RH5RI ×× 1B/×× 2B/×× 3B Series are VFM (Chopper) Step-up DC/DC converter ICs with ultra low supply current by CMOS process. The RH5RI×× 1B IC consists of an oscillator, a VFM control circuit, a driver transistor (Lx switch), a reference voltage unit, an error amplifier, resistors for voltage detection, and an Lx switch protection circuit. A low ripple, high efficiency step-up DC/DC converter can be constructed of this RH5RI×× 1B IC with only three external components, that is, an inductor, a diode and a capacitor. The RH5RI×× 2B IC uses the same chip as that employed in the RH5RI×× 1B IC and is provided with a drive pin (EXT) for an external transistor instead of an Lx pin, so that a power transistor with a low saturation voltage can be externally provided, whereby a large current can be caused to flow through the inductor and accordingly a large current can be obtained. Therefore, the RH5RI×× 2B IC is recommendable to the user who need a current as large as several tens mA toseveral hundreds mA. The RH5RI×× 3B IC also includes an internal chip enable circuit so that it is possible to set the standby supply current at MAX. 0.5µA. These RH5RI×× 1B/×× 2B/×× 3B ICs are suitable for use with battery-powered instruments with low noise and ultra low supply current. FEATURES • Small Number of External Components ..........Only an inductor, a diode and a capacitor (RH5RI ×× 1B) • Ultra Low Input Current ...................................TYP. 4µA (RH5RI301B/303B at no load,with 1.5V input) • High Output Voltage Accuracy .........................±2.5% • Low Ripple and Low Noise • Low Start-up Voltage (When the output current is 1mA) ......................MAX. 0.9V • High Efficiency ...................................................TYP.80% • Low Temperature-Drift Coefficient of Output Voltage ..........................TYP. ±50 ppm/˚C • Small Packages ...................................................SOT-89 (RH5RI ×× 1B, RH5RI ×× 2B) SOT-89-5 (RH5RI ×× 3B) 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 appliances which require higher cell voltage than that of batteries used in the appliances. 1 RH5RI BLOCK DIAGRAM VLX limiter LxSW Buffer – Lx Vref OUT Vss VFM Control + OSC 100kHz EXT Chip Enable Error Amp. CE (Note) Lx Pin............only for RH5RI ×× 1B and RH5RI ×× 3B EXT Pin.........only for RH5RI ×× 2B and RH5RI×× 3B CE Pin...........only for RH5RI ×× 3B SELECTION GUIDE In RH5RI Series, the output voltage, the driver, and the taping type for the ICs can be selected at the user's request. The selection can be made by designating the part number as shown below : RH5RI ×××× – × × ← Part Number } } ↑↑ ab } ↑ c Code Contents a Setting Output Voltage (VOUT): Stepwise setting with a step of 0.1V in the range of 2.5V to 7.5V is possible. Designation of Driver: 1B: Internal Lx Tr. Driver (Oscillator Frequency 100kHz) 2B: External Tr. Driver (Oscillator Frequency 100kHz) 3B: Internal Tr./External Tr. (selectively available) (Oscillator Frequency 100kHz, with chip enable function) Designation of Taping type : Ex. SOT-89 : T1, T2 SOT-89-5 : T1, T2 (refer to Taping Specification) “T1” is prescribed as a standard. b c For example, the product with Output Voltage 5.0V, the External Driver (the Oscillator Frequency 100kHz) and Taping Type T1, is designated by Part Number RH5RI502B-T1. 2 RH5RI PIN CONFIGURATION • SOT-89 • SOT-89-5 5 4 (mark side) (mark side) 1 ×× 1A/×× 2B 2 3 1 2 3 PIN DESCRIPTION Pin No. ×× 1B 1 2 3 — — ×× 2B 1 2 — 3 — ×× 3B 5 2 4 3 1 Symbol Description VSS OUT Lx EXT CE Ground Pin Step-up Output Pin, Power Supply (for device itself) Switching Pin (Nch Open Drain) External Tr. Drive Pin (CMOS Output) Chip Enable Pin (Active Low) 3 RH5RI ABSOLUTE MAXIMUM RATINGS Symbol Item Rating Unit Vss=0V Note VOUT VLX VEXT VCE ILX IEXT PD Topt Tstg Tsolder Output Pin Voltage Lx Pin Voltage EXT Pin Voltage CE Pin Voltage Lx Pin Output Current EXT Pin Current Power Dissipation Operating Temperature Range Storage Temperature Range Lead Temperature (Soldering) +12 +12 –0.3 to VOUT+0.3 –0.3 to VOUT+0.3 250 ±50 500 –30 to +80 –55 to +125 260˚C,10s V V V V mA mA mW ˚C ˚C Note1 Note2 Note3 Note1 Note2 (Note 1) Applicable to RH5RI ×× 1A and RH5RI ×× 3B. (Note 2) Applicable to RH5RI ×× 2B and RH5RI ×× 3B. (Note 3) Applicable to RH5RI ×× 3B. ABSOLUTE MAXIMUM RATINGS Absolute Maximum ratings are threshold limit values that must not be exceeded even for an instant under any conditions. Moreover, such values for any two items must not be reached simultaneously. Operation above these absolute maximum ratings may cause degradation or permanent damage to the device. These are stress ratings only and do not necessarily imply functional operation below these limits. 4 RH5RI ELECTRICAL CHARACTERISTICS • RH5RI301B Symbol Item Conditions MIN. TYP. MAX. Unit VOUT=3.0V Note VOUT VIN Vstart Vhold IIN1 Output Voltage Input Voltage Start-up Voltage Hold-on Voltage Input Current 1 IOUT=1mA,VIN:0→2V IOUT=1mA,VIN:2→0V To be measured at VIN at no load To be measured at VIN VIN=3.5V VLX=0.4V VLX=6V,VIN=3.5V 2.925 3.000 3.075 8 V V V V 0.8 0.7 4 0.9 8 µA IIN2 ILX ILXleak fosc Maxdty η VLXlim Input Current 2 Lx Switching Current Lx Leakage Current Maximum Oscillator Frequency Oscillator Duty Cycle Efficiency VLX Voltage Limit 2 60 5 µA mA 0.5 80 100 75 80 0.8 1.0 120 85 µA kHz % % V Note on (VLX “L” ) side 65 70 Lx Switch On 0.65 Unless otherwise provided, VIN=1.8V, Vss=0V, IOUT=10mA, Topt=25˚C, and use External Circuit of Typical Application (FIG. 1). (Note) ILX is gradually increased by the external inductor after Lx Switch is turned ON. In accordance with the increase of ILX, VLX is also increased. When VLX reaches VLXlim, Lx Switch is turned OFF by Lx Switch Protection Circuit. The time period from the time at which VLX reaches VLXlim to the time at which Lx Switch is turned OFF is about 3µs. 5 RH5RI • RH5RI501B Symbol Item Conditions MIN. TYP. MAX. Unit VOUT=5.0V Note VOUT VIN Vstart Vhold IIN1 Output Voltage Input Voltage Start-up Voltage Hold-on Voltage Input Current 1 IOUT=1mA,VIN:0 →2V IOUT=1mA,VIN:2→0V To be measured at VIN at no load 4.875 5.000 5.125 8 V V V V 0.8 0.7 6 0.9 12 µA IIN2 ILX ILXleak fosc Maxdty η VLXlim Input Current 2 Lx Switching Current Lx Leakage Current Maximum Oscillator Frequency Oscillator Duty Cycle Efficiency VLX Voltage Limit To be measured at VIN VIN=5.5V VLX=0.4V VLX=6V,VIN=5.5V 80 on (VLX “L” ) side 65 70 Lx Switch On 0.65 80 2 5 µA mA 0.5 100 75 80 0.8 1.0 120 85 µA kHz % % V Note2 Unless otherwise provided, VIN=3V, Vss=0V, IOUT=10mA, Topt=25˚C, and use External Circuit of Typical Application (FIG. 1). (Note) ILX is gradually increased by the external inductor after Lx Switch is turned ON. In accordance with the increase of ILX, VLX is also increased. When VLX reaches VLXlim, Lx Switch is turned OFF by Lx Switch Protection Circuit. The time period from the time at which VLX reaches VLXlim to the time at which Lx Switch is turned OFF is about 3µs. 6 RH5RI • RH5RI302B Symbol Item Conditions MIN. TYP. MAX. Unit VOUT=3.0V Note VOUT VIN Vstart IDD1 IDD2 IEXTH IEXTL fosc Output Voltage Input Voltage Oscillator Start-up Voltage Supply Current 1 Supply Current 2 EXT “H” Output Current EXT “L” Output Current Maximum Oscillator Frequency EXT at no load,VOUT:0 →2V EXT at no load,VOUT=2.88V EXT at no load,VOUT=3.5V VEXT=VOUT–0.4V VEXT=0.4V 2.925 3.000 3.075 8 V V V µA µA mA mA 0.7 30 2 0.8 50 5 –1.5 1.5 80 100 75 120 85 kHz % Maxdty Oscillator Duty Cycle VEXT “H” side 65 Unless otherwise provided, VIN=1.8V, Vss=0V, IOUT=10mA, Topt=25˚C, and use External Circuit of Typical Application (FIG. 2). • RH5RI502B Symbol Item Conditions MIN. TYP. MAX. Unit VOUT=5.0V Note VOUT VIN Vstart IDD1 IDD2 IEXTH IEXTL fosc Output Voltage Input Voltage Oscillator Start-up Voltage Supply Current 1 Supply Current 2 EXT “H” Output Current EXT “L” Output Current Maximum Oscillator Frequency EXT at no load,VOUT:0→2V EXT at no load,VOUT=4.8V EXT at no load,VOUT=5.5V VEXT=VOUT–0.4V VEXT=0.4V 4.875 5.000 5.125 8 V V V µA µA mA mA 0.7 60 2 0.8 90 5 –2 2 80 100 75 120 85 kHz % Maxdty Oscillator Duty Cycle VEXT “H” side 65 Unless otherwise provided, VIN=3V, Vss=0V, IOUT=10mA, Topt=25˚C, and use External Circuit of Typical Application (FIG. 2). 7 RH5RI • RH5RI303B Symbol Item Conditions MIN. TYP. MAX. Unit VOUT=3.0V Note VOUT VIN Vstart Vhold η IIN1 Output Voltage Input Voltage Start-up Voltage Hold-on Voltage Efficiency Input Current 1 To be measured at VIN at no load To be measured at VIN VIN=3.5V VLX=0.4V VLX=6V,VIN=3.5V VEXT=VOUT –0.4V VEXT=0.4V VOUT≥1.5V VOUT≥1.5V 0.8V≤VOUT