AN8086

ICs for CD/CD-ROM Player AN8086S Low Voltage Operation IC for DC-DC Converter s Overview The AN8086S is an IC for controlling a DC-DC converter suitable for the switching power supply of various portable equipment. It can operate with input voltage 1.1V or more. The AN8086S is based on AN8083S with the output voltage in the secondary side changed to 3.6V. 0.4 1 2 3 0.4±0.25 4 5 1.27 6 7 8 16 15 14 13 12 11 10 9 1.5±0.2 0.3 4.2±0.3 6.5±0.3 VREF 12 0.85V 0.25V +– 3.24V +– 2.7V→ 2.5V 4.8V Starter SW Early Value Set. 2.0V 0.7V 1.25V + – 30kΩ 0.725V 0.9V 6 63kΩ GND – + – + + Power Off Switching Circuit Starter Triangular Wave 9 8 CLK PVCC 11 POWER 0.15 0.65 10.1±0.3 Unit : mm s Features • Operatable with low voltage input (PVCC>1.1V) • Decreased voltage detection circuit built-in • Short-circuit protection feature built-in • Provided with reset output • Synchronizable with outside clock • Low consumption current in stand-by mode s Block Diagram RESET VCC 15 16 EMP 13 2.2V VSEN 14 VREF START 10 CT 7 + – 1 IN 2 FB 3 SPRO 4 DED 5 OUT 0.1±0.1 16-lead SOP package (SOP016-P-0225A) ICs for CD/CD-ROM Player s Absolute Maximum Ratings (Ta=25˚C) Parameter Supply Voltage Power Dissipation Operating Ambient Temperature Storage Temperature Symbol VCC PVCC PD Topr Tstg Rating 14.4 14.4 380 –20 ~ +75 –55 ~ +125 AN8086S Unit V mW ˚C ˚C s Recommended Operating Range (Ta=25˚C) Parameter Operating Supply Voltage Range Symbol VCC PVCC Range 3.6V ~ 12V 1.1V ~ 12V s Electrical Characteristics (Ta=25˚C) Parameter Power VCC Stand-by Mode Supply Current Power VCC No Load Supply Current Output Voltage Reset Output Threshold Voltage Decreased Voltage Detection Threshold Voltage Short-Circuit Protection Operating Voltage Short-Circuit Protection Operating Voltage Triangular oscillation Frequency in Normal Operation Triangular oscillation Frequency at Start Output Voltage Output Voltage Symbol IPVCC IPVCC VO VTH (RESET) VTH (VSEN) VO (SPRO) VO (SPRO) fOSC1 fOSC2 VOH (OUT) VOL (OUT) VIN=0V, VPOWER=2V VIN=1V, VPOWER=0V RREF=33kΩ, CT=330pF RREF=33kΩ, CT=330pF VCC=1.9V, PVCC=3V IO=–20mA, VCT=0V IO=20mA, VCT=1V VTH × 0.85 2.1 1.35 1.7 60 80 1.2 70 100 Condition VCC=0V, PVCC=3V VCC=3.1V, PVCC=3V 1.2 3.6 VTH × 9 VTH × 0.95 2.2 2.3 2.1 3.2 80 120 1.6 0.4 min. typ. max. 2 3 Unit µA mA V V V V V kHz kHz V V Note) Unless otherwise specified, VCC =4.8V, PVCC=3V s Application Circuit Example 3.6V 330pF VREF 33kΩ 12 RESET VCC EMP 15 16 13 VSENSE 2.2V START 14 VREF 10 CT 7 0.85V 0.25V +– –+ Starter 2.7V→ 2.5V 3.24V Triangular Wave CLK 9 PVCC 8 POWER 4.8V Starter SW Early Value Set. 2.0V 0.7V 1.25V + – – + – + + Power OFF Swiching Circuit 11 –25µA 30kΩ 0.9V 0.725V + – GND 63kΩ 6 0.01µF 1 IN 33kΩ 2 FB + 0.01µF 3 SPRO 47µF 4 DED 0.01µF 5 OUT 100Ω ICs for CD/CD-ROM Player s Pin Description Pin No. 1 2 Symbol IN FB • Input pin for error amplifier • Threshold voltage ; 0.7V • Output pin for error amplifier Description AN8086S 3 SPRO • Short-circuit protection input pin If output of error amplifier does not become “L” when t = CVth/ISPRO output of IC is not switched. ISPRO =25µA Vth = 0.9V • Dead time control input Maximum duty ratio set to 85%. • Switching output pin Output current ; IO=20mA (max.) • GND pin • Triangular oscillating capacitor pin CV CV T2 = I (Discharged) I (Charged) 4 5 6 DED OUT GND T1 = 7 CT V f= T1 T2 1 T1 + T2 I (Discharged) =52µA I (Charged) =30µA V = 0.58V In normal operation 8 PVCC • DC voltage input pin Operates with 1.1V or more. • Clock input · It is used to synchronize triangular oscillation with clock input and operates at rise edge of clock. · The threshold level is TTL level. · It is open when not used. • Start pin · Starts switching of starter (start at “L”) · Threshold voltage, PVCC – 0.9V • Power ON/OFF pin Output ON/OFF switching pin (Output is off at “L.”) • Reference voltage pin · 1.25V output · Charged and discharged current of triangular oscillation is determined by external R. V – 0.7 I (Charged) = REF RREF +1kΩ I (Discharged)=1.40 × I (Charged) • Decreased voltage detection output pin “H” when detected by open collector output form • Decreased voltage detection input pin · Threshold voltage ; 2.2V • Reset output pin · “H” when VCC becomes VO × 0.9V or more · Open collector output form • DC voltage input pin Operates with 3.6V or more. 9 CLK 10 START 11 POWER 12 VREF 13 14 EMP VSEN 15 Reset 16 VCC