ICs for CD/CD-ROM Player AN8086S Low Voltage Operation IC for DC-DC Converter ■ Overview 15 3 14 4 13 5 12 6 11 7 10 8 9 1.5±0.2 0.4 0.4±0.25 16 2 0.3 0.15 0.65 0.1±0.1 1.27 ■ 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 1 10.1±0.3 Unit : mm 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. 4.2±0.3 6.5±0.3 16-lead SOP package (SOP016-P-0225A) ■ Block Diagram RESET VCC 15 EMP VSEN START CT VREF 13 14 10 7 12 16 2.2V VREF 0.85V 0.25V + – Triangular Wave Starter 9 CLK 8 PVCC 2.7V→ 2.5V Starter SW Early Value Set. 4.8V 2.0V – + + – 1.25V 0.7V + – Power Off – + + 30kΩ 11 POWER Switching Circuit 0.725V 0.9V 3.24V + – 6 63kΩ 1 2 3 4 5 IN FB SPRO DED OUT GND ICs for CD/CD-ROM Player AN8086S ■ Absolute Maximum Ratings (Ta=25˚C) Parameter Symbol Rating VCC 14.4 PVCC 14.4 Supply Voltage Unit V Power Dissipation PD 380 Operating Ambient Temperature Topr –20 ~ +75 ˚C Storage Temperature Tstg –55 ~ +125 ˚C mW ■ Recommended Operating Range (Ta=25˚C) Parameter Symbol Range VCC 3.6V ~ 12V PVCC 1.1V ~ 12V Operating Supply Voltage Range ■ Electrical Characteristics (Ta=25˚C) Parameter Symbol Power VCC Stand-by Mode Supply Current IPVCC VCC=0V, PVCC=3V Power VCC No Load Supply Current IPVCC VCC=3.1V, PVCC=3V Output Voltage Condition min. typ. 1.2 VO max. Unit 2 µA 3 mA 3.6 Reset Output Threshold Voltage VTH (RESET) VTH × 0.85 Decreased Voltage Detection Threshold Voltage VTH (VSEN) 2.1 Short-Circuit Protection Operating Voltage VO (SPRO) VIN=0V, VPOWER=2V Short-Circuit Protection Operating Voltage VO (SPRO) Triangular oscillation Frequency in Normal Operation fOSC1 Triangular oscillation Frequency at Start fOSC2 V VTH × 9 VTH × 0.95 V 1.35 2.1 V VIN=1V, VPOWER=0V 1.7 3.2 V RREF=33kΩ, CT=330pF RREF=33kΩ, CT=330pF VCC=1.9V, PVCC=3V 60 70 80 kHz 80 100 120 kHz 1.2 1.6 V 0.4 V VOH (OUT) IO=–20mA, VCT=0V Output Voltage VOL (OUT) IO=20mA, VCT=1V Note) Unless otherwise specified, VCC =4.8V, PVCC=3V ■ Application Circuit Example 3.6V RESET VCC EMP 15 16 CT START VSENSE 13 14 10 2.2V 7 VREF 330pF VREF 33kΩ 12 0.85V 0.25V – + Triangular Wave Starter CLK 9 2.7V→ 2.5V PVCC Starter SW Early Value Set. 4.8V 2.0V 8 POWER – + + 1.25V 0.7V Power OFF – –25µA – + + + – 30kΩ 0.725V 1 2 IN 33kΩ 0.01µF Swiching Circuit 6 0.01µF 63kΩ 3 FB + 11 GND 0.9V 3.24V + – 4 SPRO 47µF V 2.3 Output Voltage 2.2 100Ω 5 DED 0.01µF OUT ICs for CD/CD-ROM Player AN8086S ■ Pin Description Description Pin No. Symbol 1 IN • Input pin for error amplifier • Threshold voltage ; 0.7V 2 FB • Output pin for error amplifier 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 4 DED • Dead time control input Maximum duty ratio set to 85%. 5 OUT • Switching output pin Output current ; IO=20mA (max.) 6 GND • GND pin • Triangular oscillating capacitor pin T1 = 7 CT CV CV T2 = I (Discharged) I (Charged) V f= 1 T1 + T2 I (Discharged) =52µA I (Charged) =30µA V = 0.58V In normal operation T1 T2 PVCC • DC voltage input pin Operates with 1.1V or more. 9 CLK • 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. 10 START 11 POWER 8 • 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.”) 12 VREF • 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) 13 EMP • Decreased voltage detection output pin “H” when detected by open collector output form 14 VSEN • Decreased voltage detection input pin · Threshold voltage ; 2.2V 15 Reset • Reset output pin · “H” when VCC becomes VO × 0.9V or more · Open collector output form 16 VCC • DC voltage input pin Operates with 3.6V or more.