advanced power electronics corp. APE8875 1.6x linear regulator for dc fan driver features descriptioon low dropout voltage: 200mv@0.6a vo follows 1.6 times of vset enable/shutdown function stable with low esr ceramic capacitors current-limit and thermal shutdown protection tsot-26 & so-8 pb-free package halogen free product ordering / package information data and specifications subject to change without notice 1 20130108v2.1 typical application the APE8875 is a low dropout linear regulato r which is designed to power a dc fan and delivers up to 600ma output current. the output voltage follows the 1.6 times of vset voltage and typical dropout voltage is only 200mv (typical) at 600ma output current. the vset voltage can form 0.1v to 3.3v to guarantee vo 1.6 times of vset. an enable pin further reduces powe r dissipation while shut-down. the features of current limit (with fold back current) and over temperature protection protect the device against current over-loads and ove r temperature. the APE8875 is available in a tsot-26 & so-8 package. (top view) tsot-26 3 2 6 4 1 vin gnd vout 5 en vset gnd c1 2.2uf vout =1.6 x v set vin=5v u1 APE8875 vin gnd vset en vout c2 2.2uf vset fan ( top view ) 1 2 3 4 8 7 6 5 vout so-8 vin en gnd vset gnd gnd gnd package type ty : tsot-26 m : so-8 APE8875x
advanced power electronics corp. APE8875 absolute maximum ratings (at t a =25 o c) vin supply voltage (v in ) ------------------------- - -0.3 to 6.5v en voltage (v en ) ----------------------------------- - -0.3 to vin vset voltage (v set ) ------------------------------ - -0.3 to vin power dissipation (p d ) ---------------------------- - 0.4w storage temperature range (t st ) ------------- - -65 to +150c junction temperature range (t j ) -------------- -40 to +125c operating temperature range (t op ) ---------- - -40 to +85c tsot-26 50c/w so-8 25c/w tsot-26 100c/w so-8 70c/w note: rth ja is measured with the pcb copper area approximately 1.5 in 2 (multi-layer) that connect to gnd pins. (v set = 2v, v in = 5v, i out = 0.5a, c in =c out =2.2uf, t a =25 o c unless otherwise specified) parameter sym test condition min typ max units vin supply voltage range v in 4.5 - 6 v quiescent current i ccq no load - 50 80 ua standby current i stb v en =0v - 1 10 ua output voltage/v set voltage v o /v set v in =5.5v, v set =1v~3.3v 1.552 1.6 1.648 v/v line regulation v in =4.5v to 5.5v - 0.2 0.5 % load regulation i out =10ma ~ 0.6a - 30 60 mv dropout voltage v drop i out =0.6a, v set =3.3v - 200 320 mv current limit i limt 700 - - ma short circuit current i short vo<0.6v - 250 - ma vset voltage range v set 0.1 - 3.3 v vset pin current i set v set =5v - 80 200 na v en-h operating mode 2 - - v en-l shutdown mode - - 0.8 i enh v en =v in - 0.003 0.1 a i enl v in =5v, v en =0v - 1 5 a vout pull low resistance r o v en =0v - 60 - thermal shutdown temp t sd - 150 - c thermal shutdown hysteresis - 30 - c 2 electrical specifications thermal resistance from junction to ambient(rth ja ) en pin logic threshold voltage v enable pin current thermal resistance from junction to case(rth jc )
advanced power electronics corp. APE8875 pin descriptions pin symbol pin description vin ic power supply pin. en this pin is pulling high inside. if en input < 0.8v, the ic is into shutdown mode. this pin sets the output voltage. its voltage can form 0.1v to 3.3v to guarantee vout 1.6 times of vset gnd ground pin vout output pin. its voltage is 1.6 times of vset block diagram function descriptions output voltage regulation enable/shutdown 3 vset current limit and short protection - + vin vout gnd error amp thermal shutdown enable vset en the output voltage is set by vset voltage. vout output voltage follows the 1.6 times of vset voltage until it reaches vin voltage. driving the en high turns on the regulator, driving the en low puts the regulator into shutdown mode. a logic low also causes the output voltage to discharge to the gnd. the en is pulled hight by an internal resistor.
advanced power electronics corp. APE8875 function descriptions current-limit short current protection thermal shutdown application information capacitor selection thermal considerations 4 the APE8875 monitors the current via the output pmos and limits the maximum current to prevent load and APE8875 from damages during overload or short circuit conditions. when the output voltage drops below 0.6v (typical), which is caused by over load or short circuit, the fold back current limit circuitry limits the output current to 250ma. the fold back current limit is used to reduce the power dissipation during short circuit condition. a thermal shutdown circuit limits the junction temperature of APE8875. when the j unction temperature exceeds +150 c, a thermal sensor turns off the output pmos, allowing the device to cool down. the regulator regulates the output again through initiation of a new soft-start cycle after the junction temperature cools by 30 c, resulting in a pulsed output during continuous thermal overload conditions. normally, use a 2.2f capacitor on the input and a 2.2f capacitor on the output of the APE8875. in order to insure the circuit stability, the proper output capacitor value should be larger than 1uf. with x5r and x7r dielectrics, 2.2uf is sufficient at all operating temperatures. the APE8875 series can deliver a current of up to 600ma over the full operating j unction temperature range. however, the maximum output current must be dated at higher ambient temperature to ensure the junction temperature does not exceed 125 c. with all possible conditions, the junction temperature must be within the range specified under operating conditions. power dissipation can be calculated based on the output current and the voltage drop across regulator. p d = (v in - v out ) i o the final operating junction temperature for any set of conditions can be estimated by the following thermal equation: p d (max) = (t j (max) - t a ) / rth ja where t j(max) is the maximum junction temperature of the die (125c) and t a is the maximum ambient temperature. the junction to ambient thermal resistance (rth ja ) for tsot-26 package at recommended minimum footprint is 100c/w.
advanced power electronics corp. APE8875 function descriptions pcb layout pcb layout guide 5 1. please place the input capacitors close to the vin 2. ceramic capacitors for load must be placed near the load as close as possible 3. to place APE8875 and output capacitors near the load is good for performance. 4. large current paths that vin and output lines must have wide tracks. 5. gnd connect large copper area can reduced ic temperature. (top view) (bottom view)
advanced power electronics corp. APE8875 typical performance characteristics 6
advanced power electronics corp. APE8875 typical performance characteristics 7 en on/off line transient line transient
advanced power electronics corp. APE8875 typical performance characteristics 8 power on
advanced power electronics corp. APE8875 marking information tsot-26 so-8 9 hcyws part number : hc year : a = 2010 1 = 2011 week: a~z : 01~26 a~z : 27~52 id code : internal 8875m ywwsss part number date code (ywwsss) y last digit of the year ww week sss sequence package code
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