CR-F33T Preliminary Specification PFM STEP-UP DC/DC CONVERTER TM BLOCK DIAGRAM GENERAL DESCRIPTION The CR-F33T is a PFM step-up DC/DC converter IC and has a high efficiency. These devices consist of a bandgap, a comparator, an oscillator, a driver, and a high current output switch. The CR-F33T provides a higher fixed voltage from the smaller input voltage. The CR-F33T is used for single- or dual-cell battery operation. VDD LX Bandgap Digital Control FB VSSA Clock Select 150KHz OSC EN VSS FEATURES PIN CONFIGURATION z z z z Low Voltage Operation Possible Low Supply Current Small Number of External Components Internal Power Switch SOP-8 (Top View) APPLICATIONS z z z z 8 LX VDD 1 FB 2 7 VSSA EN 3 6 VSS NC 4 5 NC SOT-89-3 Battery-Powered Instruments Hand-Held Instruments Hand-Held Communication Instruments Cameras (Top View) 1 3 2 VSS VDD LX ORDERING INFORMATION CR-FXXX Step-up 1 Package P: SOP-8 T: SOT-89-3 Output Voltage 33 : 3.3V CR-F33T Preliminary Specification PFM STEP-UP DC/DC CONVERTER TM PIN DESCRIPTION Pin No. Pin Name Pin Function 1 VDD 2 FB The pin of feedback voltage 3 EN Chip enable pin 4 NC No internal connection to this pin 5 NC No internal connection to this pin 6 VSS Ground pin 7 VSSA Ground pin 8 LX Output voltage pin and also power supply pin for the device Switch pin, connected to inductor/diode STEP-UP CONVERTER APPLICATION 1N5819 1N5819 VDD FB EN 100uF 220uH 220uH VDD VIN 100uF CR-F33-P CR-F33-T LX LX VSSA VSS VSS Absolute Maximum Ratings Supply Voltage-------------------------------------------------------------- - 0.3V to 7V Input Voltage---------------------------------------------------------------- - 0.3V to VDD+0.3 Operating Temperature Range--------------------------------------------- 0 o C to 50 o C Storage Temperature Range----------------------------------------------- - 40 o C to 150 o C 2 VIN CR-F33T Preliminary Specification PFM STEP-UP DC/DC CONVERTER TM Electrical Characteristics Parameter Symbol Test Conditions Min. Start-Up Voltage VST Iload = 1mA Holding Voltage VHold Iload = 1mA 0.45 Input Voltage VIN No Load 1 Output Voltage VDD Typ. Max. Units 0.9 1 V V 3 3.5 V 3.3 3.6 V 8 14 μA 2 μA No-Load Input Current IIN No Load Standby Current ISB VEN = 0 Input Low Voltage VIL Enable/Disable Pin 0 0.4 V Input High Voltage VIH Enable/Disable Pin 1 VDD V Oscillator Frequency Fosc Efficiency η VIN = 1.5V, Iload = 10mA 150 KHz 83 % OPERATION OF STEP-UP CONVERTER A step-up converter diagram is illustrated below. In the diagram, the converter can generate a fixed, higher voltage from a lower one. When SW stays ON, IL1 flows through L, and the converter converts the electric energy into the magnetic one and stores it in L, in which Imax is proportional to ton; when SW lies OFF, Shottky diode is forced to be ON, while the energy stored in inductor L be discharged into capacitor, thereby charging the output voltage to a value expected. IL ILmax IL2 L Iout D + + IL1 VIN -- SW CL Vout -- 3 ILmin t ton toff T=1/fosc CR-F33T Preliminary Specification PFM STEP-UP DC/DC CONVERTER TM TYPICAL PERFORMANCE CHARACTERISTICS L=47uH; C=100uF 4 90 Vin=3V 80 Vin=3V 70 Vin=2.5V Vin=2.5V 3 Vin=1.2V Vin=1.2V Vin=2V E fficiency (% ) Efficiency (% ) Vin=1.5V 50 40 Vin=2V Vin=1.5V 60 2 30 1 20 10 0 0 0 10 20 30 40 50 60 70 80 90 0 100 10 20 30 40 50 70 80 90 100 L=100uH; C=100uF 4 90 80 Vin=3V 70 Vin=3V Vin=2.5V Vin=1.2V Vin=2.5V 3 Vin=2V Vin=2V Vin=1.5V 60 Vin=1.2V Efficiency (%) Efficiency (%) 60 Iload (mA) Iload (mA) Vin=1.5v 50 40 2 30 1 20 10 0 0 0 10 20 30 40 50 60 70 80 90 100 Iload (mA) 0 10 20 30 40 50 Iload (mA) 4 60 70 80 90 100 CR-F33T Preliminary Specification PFM STEP-UP DC/DC CONVERTER TM L=150uH; C=100uF 100 4 90 Vin=3V 80 Vin=1.2V Vin=3V 60 Vin=2.5V Vin=2V Efficiency (%) Efficiency (%) 3 Vin=1.2V 70 Vin=1.5V 50 40 Vin=2V Vin=1.5V Vin=2.5V 2 30 1 20 10 0 0 0 10 20 30 40 50 60 70 80 90 0 100 10 20 30 40 50 60 70 80 90 100 90 100 Iload (mA) Iload(mA) L=220uH; C=100uF 4 90 80 Vin=3V Vin=3V 70 Vin=1.2V 3 Vin=1.5V Vin=1.5V Vin=2V 50 Vin=2V Vin=2.5V Vin=1.2V Vin=2.5V E fficiency (% ) E fficiency (% ) 60 40 2 30 1 20 10 0 0 0 10 20 30 40 50 60 70 80 90 100 Iload (mA) 0 10 20 30 40 50 Iload (mA) 5 60 70 80 Preliminary Specification CR-F33T PFM STEP-UP DC/DC CONVERTER TM LX Pin Waveform & VDD LX Pin Waveform & VDD VDD VDD Vin=1.2V@Iload=15mA Vin=1.5V@Iload=15mA LX LX 5us/Div 5us/Div LX Pin Waveform & VDD LX Pin Waveform & VDD VDD VDD Vin=2V@Iload=15mA Vin=2.5V@Iload=15mA LX LX 5us/Div LX Pin Waveform & VDD 5us/Div VDD Vin=3V@Iload=15mA LX 5us/Div 6 CR-F33T Preliminary Specification PFM STEP-UP DC/DC CONVERTER TM The magnitude of inductor will influence the performance of DC/DC converter. The following table guides users to select the suitable magnitude of inductor for single- or dual-cell battery operation when the output terminal connects to different current load. Consequently, users can obtain a cell battery with longer life. Current Load (mA) 1-cell battery 2-cell battery Iload < 10 220uH 220uH 10 < Iload < 20 150uH 220uH 20 < Iload < 30 47uH 220uH 30 < Iload < 40 47uH 150uH 40 < Iload < 50 47uH 150uH 50 < Iload < 60 / 100uH 70 < Iload < 80 / 47uH 80 < Iload < 90 / 47uH 90 < Iload < 100 / 47uH 7 Preliminary Specification CR-F33T PFM STEP-UP DC/DC CONVERTER TM PACKAGE INFORMATION 8 Preliminary Specification CR-F33T PFM STEP-UP DC/DC CONVERTER TM 9 ˅ ˘ˡ ˞˦ˈˋˈˉ˔ˢʳʳˣ˴̇̇˸̅́ʳ˗˼˴˺̅˴̀ ˩˦˦ ˆ ˩˗˗ ˈ ˄ ˩˦˦˔ ˇ ˉ ˙˕ ˈˋˈˉˢ ˟ˢ˚ˢ ˠ˴˼́ʳʳˣ˴̇̇˸̅́ʳʳ˦˼̍˸ʳʳˍʳʳʳˉ˃˅ˁ˃˃˃ʳͪʳʳˉ˄˃ˁ˃˃˃ʳӴ̀ ˗˴̇˸ʳʳˍʳʳ˅˃˃ˇˁ˃˄ˁ˄ˈ ˥˸̀˴̅˾ʳʳˍʳʳ ˜˖ʳ̆̈˵̆̇̅˴̇˸ʳ˶̂́́˸˶̇ʳ̇̂ʳʳʳϭʳ˩˦˦˂˚ˡ˗ʳʳʳϭʳ˩˗˗ʳʳʳ̂̅ʳʳʳϭʳ˙˿̂˴̇˼́˺ ˟˫ ˄ˁʳ˦̇˸̃ˀ̈̃ʳ˶̂́̉˸̅̇˸̅ʳ˴̃̃˿˼˶˴̇˼̂́ 1N5819 220uH VDD FB EN 100uF ˅ˁʳ˕̂́˷˼́˺ʳ˗˼˴˺̅˴̀ VIN CR-F33-P LX VSSA VSS ˆˁʳˣ˖˕ʳ˿˴̌̂̈̇ʳ˹̂̅ʳ̅˸˹˸̅˸́˶˸ʳ̂́˿̌