TIGER ELECTRONIC CO.,LTD AP1509 AP1509 APPLICATION: z Simp le High-efficiency step-down regulato r z On-card switching regu lato rs z Positive to negative converter PIN CONFIGURATION PIN DESCRIPTIONS Na me VIN Output AP1509 GND Description Op eratin g vo ltag e in put Switching output Ground FB Output voltage feedback control SD ON/OF F Sh utdown BLOCK DIAGRAM 2/6 AP1509 ABSOLUTE MAXIMUM RATINGS Characteristics Symbol VCC VSD VFB VOUT PD Tstg Topr VOP Supply Vo ltage ON/OFF pin input voltage Feedback pin vo ltage Output voltage to groun d Power dissipation Storage temperature Operating te mperature Operating voltage Valu e +40 -0.3~+18 -0.3~+18 -1 Internally li mited -65~+150 -40~+125* +4 .5 ~+22 Unit V V V V W °C °C V ELECTRICAL CHARACTERISTICS (Refer to the test circuit, V I N =12V for 3.3V,5V,adjustable version and V I N =18V for the 12 V version,I L O A D =0.5A) Characteristics Symbol Feedback bias current IFB Oscillator frequency Fosc Saturation voltage V S AT Max.duty cycle(ON) Min. duty cycle(OFF) DC Cu rren t li mit ICL Output leakage current (output=0) Output leakage current (output=-1) Quiescent cu rrent Standby quiescent current ON/OFF pin logic input threshold voltage ON/OFF pin logic input cu rrent ON/OF F pin input current Thermal resistance Thermal resistance with copper area of approximat ely 3 in 2 IL Test Conditions V F B =1.3V (Adjustable version only) Min -10 127 110 IOUT=2A No outside circuit V F B =0V force driver on V F B =0V force driver on V F B =12V force driver off Peak current No outside circuit V F B =0V force driver on No outside circuit V F B =12V force driver off Typ 150 1.25 nA KHz V A -200 5 VIL V F B =12V force driver off ON/OFF pin=5V V I N =36V Low(regulator ON) VIH High(regulator OFF) 70 2.0 Unit % 3 -5 ISTBY 1.5 100 0 V I N =36V IQ Max -50 -100 173 173 1.4 1.3 μA mA 10 150 200 0.6 IH V L O G I C =2.5V(OFF) 7 20 IL V L O G I C =0.5V(ON) 0.01 10 mA μA V μA ӨJC Junction to case 15 °C/W ӨJA J u n c t io n t o a mb i e n t 70 °C/W 3/6 AP1509 Continue: Characteristics AP1509-ADJ Output feedback Symbol VFB Efficiency AP1509-3.3V η Output voltage VOUT Efficiency AP1509-5V Output voltage Efficiency AP1509-12V Output voltage Efficiency η VOUT η VOUT η Test Conditions 4.5V≤V I N ≤36V 0.2A≤I L O A D ≤2A V O U T programmed for 3V V I N =12V,I L O A D =2A 4.75V≤V I N ≤36V 0.2A≤I L O A D ≤2A V I N =12V,I L O A D =2A 7V<V I N <22V 0.2A≤I L O A D ≤2A V I N =12V,I L O A D =2A 1 5 V≤V I N ≤36V 0.2A≤I L O A D ≤2A V I N =15V,I L O A D =2A Min Typ Max Unit 1.193 1.23 1.28 V 76 3.168 3.3 % 3.465 78 4.8 5 % 5.25 83 11.4 12 V V % 12.6 90 V % FUNCTION DESCRIPTION Pin Functi on +V I N This is th e positive input supply for the IC switching regulator. A suitable in pu t bypass capacitor mu st be presented at this pin to mi nimize voltage tran sien ts and to supply the switching currents needed by the regulator. Ground Circuit ground. Output Internal switch. The voltage at this pin switches between (+VIN – VSAT) and approximat ely – 0.5V, with a duty cycle of approxi mately VOUT / VIN. To mi ni mize coupling to sensitive circuitry, the PC board copper area connected to this pin should be mini mized. Feedback Senses the regulated output voltage to complete the feedback loop. SD Allows the switching regulator circuit to be shutdown using logic level signals thus dropping the total in put supp ly current to approximately150uA. Pulling this pin below a threshold vo ltage of approximately 1.3V turn s the regulator on , and pulling this pin above 1.3V (up to a maximu m of18V) shuts the regula to r down. If this shutdo wn feature is no t needed, the SD pin can be wired to the ground pin. 4/6 AP1509 Thermal Considerations The SOP8 package needs a heat sink under mo st conditions. Th e size of th e heatsink depends on the inpu t vo ltage, th e output voltage, th e load current and th e ambient te mp erature. The AP1509 junction te mp erature rises above ambient te mp erature for a2A lo ad and different input and output voltages. The data for these curves was taken with the AP1509 (SOP8 package) operating as a buck-switching regulator in an ambient temperature of 25oC (still air). These temp erature in cre ments are all approximate and are affected by man y factors. Higher ambient temp eratures requires mo re heat sinker. For the best thermal performance , wide copper traces and generous a mounts of printed circuit board copper should be used in the board layout. (One exception is the output (switch) pin, which should not have large areas of copper.) Large areas of copper provide the best tran sfer of heat(lower thermal resistance) to the surrounding air, and moving air lowers the th ermal resistance even further. Package thermal resist ance an d junction te mperature in cre ments are all approximate. The in cre ments are affected by a lo t of factors. So me of these factors include board size, shape, thickness, position, location, and even board temp erature. Other factors are, trace width, total printed circuit copp er area, copper thickness, single or double-sided, multi-layer board and the amount of solder on the board. The effectiv eness of th e PC board to dissipate heat also depends on the size, quantity and spacing of other components on the board, as well as whether the surrounding air is still or moving. Fu rthermo re, so me of these co mponents such as the catch diode will add heat to the PC board and the heat can vary as the input voltage ch anges. For the inducto r, depending on the physical size, type of core material and the DC resistance, it could either act as a heat sink taking heat away fro m the board, or it could add heat to the board. 5/6 AP1509 APPLICATION CIRCUIT Fixed Type Circuit AP1509 Adj ustable Type Circuit AP1509 Delay Start Circuit AP1509 6/6