IC SMD Type PFM Step-up DC/DC Converter RCR2821 Features The RCR2821 IC consists of an oscillator, a PFM control • Minimal Number of External Components ( Only an Inductor, a Diode, and a Capacitor ) circuit, a driver transistor ( LX switch ), a reference voltage unit, an error amplifier, resistors for voltage detection, and a • Ultra Low Input Current ( 5μA at Switch Off ) LX switch protection circuit. A low ripple and high efficiency • ±2% High Output Voltage Accuracy step-up DC/DC converter can be constructed of this • Low Ripple and Low Noise RCR2821 IC with only three external components. • Low Start-up Voltage, 0.85V at 1mA • 85% Efficiency with Low Cost Inductor Applications • Power source for battery-powered equipment • SOT89 andSOT23-5L Small Packages • Power source for cameras, camcorders, VCRs, PDAs, General Description pagers, electronic data banks, and hand-held The RCR2821 Series are PFM Step-up DC/DC ICs with ultra communication equipment low supply current by CMOS process and suitable for use with battery-powered instruments. • Power source for applications, which require higher voltage than that of batteries used in the appliances Package Information ③ ① ② ③ SOT89 ④ Units:mm ② ① ⑤ SOT23-5L Pin Configurations Pin Port SOT89 SOT23-5L ① GND EN ② VOUT VOUT ③ LX NC ④ GND ⑤ LX www.kexin.com.cn 1 IC SMD Type RCR2821 Functional Block Diagram z Ordering Information RCR2821 - □ □ □ □ Package Type SK: SOT23-5L；SM: SOT89 Output Voltage … 20 = 2.0V; 25 = 2.5V; 30 = 3.0V; 33 = 3.3V; 36 = 3.6V; 50 = 5.0V… Indicate the product number Absolute Maximum Ratings Parameter Symbol Ratings Unit Output Voltage VOUT -0.3 to +10 V LX Pin Voltage VLX -0.3 to +10 V EN Pin Voltage EN -0.3 to +10 V LX Pin Output Current ILX 1 A Power Dissipation ( TA = 25℃) PD SOT23-5L 250 SOT89 500 mW Operating Temperature Range TOPR -40 to 125 ℃ Storage Temperature Range TSTG -65 to 150 ℃ 2 www.kexin.com.cn IC SMD Type RCR2821 Electrical Characteristics TA = 25 Parameter , unless otherwise specified Min Typ Max Unit ΔVOUT -2 -- +2 % Input Voltage VIN -- -- 10 V Start-up Voltage VST IOUT = 1mA, VIN : 0 to 2V -- 0.85 1.0 V Hold-on Voltage VHO IOUT = 1mA, VIN : 2 to 0V 0.7 -- -- V Efficiency EFFI -- 75 85 % -- 30 40 -- 50 60 -- 5 8 -- 6 10 VLX = 0.4V 100 200 -- mA Output Voltage Accuracy Input Current1 Input Current 2 VOUT ≤ 3.5V 3.5V ＜VOUT ≤ 5V VOUT ≤ 3.5V 3.5V＜VOUT ≤5V LX Switch_ ing Current Symbol Test Conditions ISS1 To be measured at VIN at no load ISS2 To be measured at VOUT in switch off condition ISWITCHING μA μA EN “H” Level VSH VOUT = VOUT（T）× 0.9 0.75 -- -- V EN “L” Level VSL VOUT= VOUT（T）× 0.9 -- -- 0.3 V EN “H” Input Current ISH VEN = 10V -- -- 0.1 μA EN “L” Input Current ISL VEN = 0V -0.5 -- 0.1 μA Maximum Oscillator FMAX 80 120 160 KHz Oscillator Duty Cycle DOSC 70 78 85 % On ( VLX ”L” ) side Note1. VOUT（T）= Specified output Voltage. Note2. Unless otherwise provided, VIN = 1.8V, VSS = 0V, IOUT = 10mA, TOPT = 25℃ Note3. Unless otherwise provided, VIN = 3V, VSS= 0V, IOUT = 10mA, TOPT = 25℃ Typical Application Circuit NO EN www.kexin.com.cn 3 IC SMD Type RCR2821 With EN Components: Inductor: 47uH, Diode: 1N5818 Output Capacitor:47uF/16V (Tantalum ) Typical Performance Characteristics 1、 RCR2821-30： Figure1. Output Voltage VS Output Current Figure2. Efficiency VS Output Current 2、 RCR2821-33： Figure3. Output Voltage VS Output Current 4 www.kexin.com.cn Figure4. Efficiency VS Output Current IC SMD Type RCR2821 Figure5. Output Voltage VS Output Current Figure6. Efficiency VS Output Current www.kexin.com.cn 5