AT1452 Preliminary Product Information Photoflash Capacitor Charger for DSC Features General Description • 2.5 to 5.5V supply voltage operating range. • Low current consumption: 1mA in operation, • 50 kHz or 100kHz operation frequency . • Built-in maximum duty control. • Push-pull output. • Built-in soft start circuit. • Built-in auto-discharge function. • Built-in auto-refresh function. The AT1452 is a charger control IC for Photoflash capacitor with soft start function, adjustable maximum duty cycle, auto-refresh and autodischarge (soft start capacitor) circuit. Adjustable soft start is programmed with an external capacitor on SS pin. The control technique allows for the use of external resistor to change the switching duty and use of transformer to control the input current. Automatic refresh allows the capacitor to remain charged while output voltage dropped 10%. A logic high on the CHARGE pin initiates charging, while the READY pin signals that the capacitor is fully charged. It is ideal for DSC flash unit. Applications •Digital Still Cameras flash unit * Protected by U.S. Patent #6,724,989 Block Diagram Aimtron reserves the right without notice to change this circuitry and specifications. 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: [email protected] 1 AT1452 Preliminary Product Information Photoflash Capacitor Charger for DSC Pin Configuration Ordering Information Part number AT1452AP AT1452AP_GRE AT1452BP AT1452BP_GRE Package TSSOP8 TSSOP8,Green TSSOP8 TSSOP8,Green Marking AT1452AP AT1452AP, date code with one bottom line AT1452BP AT1452BP, date code with one bottom line A:50kHz B:100kHz Pin Description Pin No. Symbol I/O 1 2 3 4 5 6 7 8 CHARGE FB DUTY GND OUT VCC READY SS I I I O O I Description Charge enable input Error amplifier input Duty control input Ground Push-pull output Power supply Charge ready open drain output Soft-start setting 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: [email protected] 2 AT1452 Preliminary Product Information Photoflash Capacitor Charger for DSC Absolute Maximum Ratings Parameter Power Supply Voltage Source Average Current of OUT Sink Average Current of OUT Input Voltage to Error Amplifier Continuous power dissipation Operating temperature Junction temperature Storage temperature Lead temperature Condition — — — — TSSOP8（Ta=+25℃） SOP8（Ta=+25℃） — — — — Rated Value Min. Max. +6.5 -50 50 6.5 450 500 -30 +85 +125 -40 +150 +300 Unit V mA mA V mW mW 0 C 0 C 0 C 0 C Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Recommended Operating Conditions (Ta=+250C) Parameter Power supply voltage Operating temperature Symbol VCC TOP Values Min. 2.5 -30 Typ. -+25 Unit Max. 5.5 +85 Ｖ °C 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: [email protected] 3 AT1452 Preliminary Product Information Photoflash Capacitor Charger for DSC Electrical Characteristics (VCC = 3.3V,Ta =+25℃, unless otherwise noted.) Parameter Symbol Condition Values Unit Min. Typ. Max. Input Supply Range VCC Feedback Voltage VFB Reference Variation with Temperature Entire device Auto-Refresh Level Feedback Voltage line-regulation Oscillator Soft-Start and Duty Section Output Section Charge ON/OFF Section VFB1 VFB-Line Standby current ICCS Operating Current ICC Frequency fosc Threshold voltage of SS VSS_0 Threshold voltage of SS VSS Charging current 2.5 TDUTY Output source current ISOURCE Output sink current ISINK Output ON resistor ROH Output OFF resistor ROL Active mode Threshold VONH Disable mode Threshold VONL V 1.080 1.100 1.120 V Ta =-30℃ to +85℃ -2% - 2% % - 90 - % -5 1 5 mV - - 400 μA - 1.0 - mA 40 50 60 kHZ 90 100 110 kHZ - 0.3 - V - 1.1 - V 0.7 1.0 1.5 μA 80 83 90 % - -130 -80 mA 65 100 - mA - 18 30 Ω - 16 25 Ω VFB1 / VFB VCC=2.5V to 5.5V CHRGE=GND Duty=50%, fOSC=50KHz A B Duty Cycle=0% Duty Cycle=90% Maximum duty cycle 5.5 Ta =+25℃ 100 ISS -- VSS=0V Duty≧95%, OUT=0V Duty≦5%, OUT=5V OUT = -15mA OUT = 15mA 2.0 V 0.8 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: [email protected] 4 V AT1452 Preliminary Product Information Photoflash Capacitor Charger for DSC Timing Chart AT1452 Auto Refresh Mode AT1452 Charge Toggling Refresh Mode 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: [email protected] 5 AT1452 Preliminary Product Information Photoflash Capacitor Charger for DSC DUTY Setting The DUTY resistor selection depends on Duty Cycle , choose the component using the following equation: V DUTY (V ) = 0.3 + RDUTY ( KΩ) = DUTY 1.15 15 1.1 ( ) − 1.073 VDUTY Example: Set duty cycle is 50% VDUTY = 0.3 + RDUTY = 0.5 = 0.734 1.15 15 1.1 ( ) − 1.073 0.734 ≈ 35.2 KΩ Output Voltage Setting VOUT = R1 + R 2 × V FB R2 V FB = 1.1V 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: [email protected] 6 AT1452 Preliminary Product Information Photoflash Capacitor Charger for DSC Soft-Start Setting The soft start operation is determined by the capacitor connected to the SS terminal. It can calculate the soft start time Ts(s). C× − 0 .3 V ∆V = I → C × DUTY = 1µA ∆t ∆t Ts( s ) = (V DUTY − 0.3) × C ( µF ) Example: (Fig C) R5=47K Æ VDUTY=0.790V Æ Ts(s)=(0.790-0.3)*1=0.49(sec) CH1:VOUT CH2:SS CH3:DUTY CH4:IBAT 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: [email protected] 7 AT1452 Preliminary Product Information Photoflash Capacitor Charger for DSC Typical Curve 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: [email protected] 8 AT1452 Preliminary Product Information Photoflash Capacitor Charger for DSC 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: [email protected] 9 AT1452 Preliminary Product Information Photoflash Capacitor Charger for DSC Typical Application Schematic (A) IGBT Trigger 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: [email protected] 10 AT1452 Preliminary Product Information Photoflash Capacitor Charger for DSC (B) SCR Trigger 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: [email protected] 11 AT1452 Preliminary Product Information Photoflash Capacitor Charger for DSC (C) Li-Ion Application 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: [email protected] 12 AT1452 Preliminary Product Information Photoflash Capacitor Charger for DSC CH1:CHARGE CH2:READY CH3:VOUT(300V) CH4:IBAT Fig 3. VBAT=4.2V Fig 1. VBAT=3.0V VBAT 3.0V 3.6V 4.2V * RDUTY Charge Time 6.79s 4.62s 3.36s Charge Input Current 500mA 600mA 800mA can be change the Input Current. Fig 2. VBAT=3.6V 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: [email protected] 13 AT1452 Preliminary Product Information Photoflash Capacitor Charger for DSC (D) 2-Cell Battery Application 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: [email protected] 14 AT1452 Preliminary Product Information Photoflash Capacitor Charger for DSC CH1:READY CH2:SS CH3:VOUT(300V) CH4:IBAT VBAT 3.0V 2.0V * RDUTY Charge Time 4.79s 13.6s Charge Input Current 800mA 500mA can be change the Input Current. Fig 4. VBAT=2.0V Fig 5. VBAT=3.0V 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: [email protected] 15 AT1452 Preliminary Product Information Photoflash Capacitor Charger for DSC Application Information Photoflash Capacitor Charger Charge Time: The energy stored in the output capacitor is: C ×V 2 E= 2 The output power required by the flyback converter to charge the capacitor in a period of time is: E C ×V 2 = = V IN × I AVG × D × η t 2×t The approximate charge time for the converter circuit is: PCAP = 2 C OUT × VOUT t= 2 × V IN × I AVG × D × η Where: fs= Switching frequency D= Maximum Duty Cycle LPRI= Primary Inductance η= Efficiency I AVG = I BAT = I PK = I PK × D 2 V IN × D LPRI × f s 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: [email protected] 16 AT1452 Preliminary Product Information Photoflash Capacitor Charger for DSC Small Outline SYMBOL A B C D E F H K M α 8-pin TSSOP INCHES MIN MAX 0.114 0.122 0.169 0.177 0.244 0.260 0.026 BSC 0.010 0.012 0.002 0.006 0.041 0.047 0.005 BSC 0.020 0.028 80 00 MILLIMETERS MIN MAX 2.90 3.10 4.30 4.50 6.20 6.60 0.65 BSC 0.25 0.30 0.05 0.15 1.05 1.20 0.127 BSC 0.50 0.70 00 80 NOTES - 2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C. Tel: 886-3-563-0878 WWW: http://www.aimtron.com.tw Fax: 886-3-563-0879 Email: [email protected] 17