iru1011-33 1 rev. 1.1 03/21/03 www.irf.com typical application description the iru1011-33 is a fixed linear regulator and it is ca- pable of supplying 1.3a of continuous current over line and temperature range. the iru1011-33 is stable with low value ceramic capacitors, allowing designers flex- ibility in external component selection. the output is pro- tected by both current limit and thermal shutdown. 1.3a low dropout positive fixed regulator figure 1 - typical application of iru1011-33. t a (c) 6-pin mlpm 3x3 (h) mlpm marking 0 to 150 IRU1011-33CH cm33 data sheet no.pd94544 package order information stable with ceramic capacitor guaranteed < 1.3v dropout at full load current fast transient response output current limiting built-in thermal shutdown features applications high efficiency linear regulator hard disk drivers, cd-roms, dvds adsl and cable modems preliminary data sheet v in gnd v out 5v 3.3v c2 4.7uf x5r c1 4.7uf x5r iru1011-33 nc nc nc 1 2 3 5 4 6
iru1011-33 2 rev. 1.1 03/21/03 www.irf.com absolute maximum ratings input voltage (v in ) .................................................... 10v operating junction temperature range ..................... 0c to 150c operating ambient temperature range ..................... -40c to 125c storage temperature range ...................................... -65c to 150c caution: stresses above those listed in "absolute maximum ratings" may cause permanent damage to the device. parameter sym test condition min typ max units v mv mv v a ma % %vo db 8 c ma % % % output voltage 3.3v line regulation load regulation dropout voltage d v out = -1% current limit minimum output current temperature stability rms output noise ripple rejection (v in to output) thermal shutdown quiescent current transient response change of v out with step load change transient response change of v out with application of v in transient response short circuit removal response 3.366 3.3825 15 12 1.3 2 5.4 6 10 6 10 6 10 6 20 3.3 3.3 5 8 1.1 1.9 0 1.5 0.003 65 155 4.3 <4.2 5 5 1 1 4.75v iru1011-33 3 rev. 1.1 03/21/03 www.irf.com pin # pin symbol pin description pin descriptions no connection. the power input pin of the regulator. a minimum of input capacitance must be connected from this pin to ground to insure that the input voltage does not sag below the minimum dropout voltage during the load transient response. this pin must always be higher than the v out pin by the amount of dropout voltage (see electrical specification) in order for the device to regulate properly. the output of the regulator. a minimum of output capacitance must be connected from this pin to ground to insure stability. this pin is connected with ground. it is also the tab of the package. 1,2,5 3 4 6 nc v in v out gnd note 1: low duty cycle pulse testing with kelvin con- nections is required in order to maintain accurate data. note 2: dropout voltage is defined as the minimum dif- ferential voltage between v in and v out required to main- tain regulation at v out . it is measured when the output voltage drops 1% below its nominal value. note 3: minimum load current is defined as the mini- mum current required at the output in order for the out- put voltage to maintain regulation. note 4: temperature stability is the change in output from nominal over the operating temperature range. note 5: guaranteed by design, but not tested in produc- tion. figure 2 - simplified block diagram of the iru1011-33. block diagram v in gnd 3 6 4 v out thermal shutdown 1.25v + + current limit
iru1011-33 4 rev. 1.1 03/21/03 www.irf.com v out = 3.3v v in = 5v i out = 1a (dc avg) application information introduction the iru1011-33 regulator is a 3-terminal device offered in a fixed output of 3.3v and it is designed specifically to provide an extremely low dropout voltage. the iru1011-33 is designed to meet the fast current transient needs as well as providing an accurate initial voltage, reducing the overall system cost with the need for fewer number of output capacitors. thermal protection when the junction temperature exceeds 150 8 c, the in- ternal thermal protection shuts the iru1011-33 down. current limit protection the iru1011-33 provides over current protection when the output current exceeds typically 2a. the output de- creases to limit the power dissipation. stability the iru1011-33 requires the use of an output capacitor as part of the frequency compensation in order to make the regulator stable. a minimum input capacitance of 4.7 m f and a minimum output capacitance 4.7 m f ce- ramic capacitor is needed for regulator stage as well as the specified minimum loads to guarantee stability. transient response and psrr the input and output capacitors are critical in order to ensure good transient response and psrr. the most important aspects of this are capacitor selection, place- ment and trace routing. place each capacitor as close as physically possible to its corresponding regulator pin. use wide traces for a low inductance path. couple di- rectly to the ground and power planes as possible. the use of low esr capacitors is crucial to achieving good results. larger capacitance and lower esr will improve both psrr and transient response. thermal design the iru1011-33 incorporates an internal thermal shut- down that protects the device when the junction tem- perature exceeds the allowable maximum junction tem- perature. although this device can operate with junction temperatures in the range of 150 8 c, it is recommended that the selected heat sink be chosen such that during maximum continuous load operation the junction tem- perature is kept below this number. the example below shows the steps in selecting the proper surface mount package. assuming, the following conditions: calculate the maximum power dissipation using the fol- lowing equation: for mlpm package, we have: layout consideration the iru1011-33, like many other high-speed regulators, requires that the output capacitors be close to the de- vice for stability. for power consideration, a ground plane pad of approximately one-inch square on the compo- nent side must be dedicated to the device where all gnd pins are connected to dissipate the power. if a multilayer board is used, it is recommended that the inner layers of the board are also dedicated to the size of the pad for better thermal characteristics. p d = 1 3 (5 - 3.3) = 1.7w p d = i out 3 (v in - v out ) ir world headquarters: 233 kansas st., el segundo, california 90245, usa tel: (310) 252-7105 tac fax: (310) 252-7903 visit us at www.irf.com for sales contact information data and specifications subject to change without notice. 02/01 r thja = 32 8 c/w t a = 45 8 c d t = p d 3 r thja = 1.7 3 32 = 54.4 tj = t a + d t = 99.4 8 c
iru1011-33 5 rev. 1.1 03/21/03 www.irf.com symbol desig a a1 a2 a3 b d d2 e e2 e l l1 l2 l3 l4 r s (h) mlpm package 6-pin note 1: details of pin #1 are optional, but must be located within the zone indicated. the identifier may be molded, marked or metalized features. note 2: if l1 max is not called out, the met- alized feature will extend to the exposed pad. thus l4 does not apply. min 0.80 0.00 0.65 0.15 0.33 1.92 1.11 0.20 0.16 --- 0.17 0.17 0 8 nom 0.90 0.025 0.70 0.20 0.35 2.02 1.21 0.29 0.24 --- --- --- 10 8 3.00 bsc max 1.00 0.05 0.75 0.25 0.43 2.12 1.31 0.45 0.40 0.125 0.30 --- 12 8 3.00 bsc 0.95 0.127 ref 6-pin 3x3 note: all measurements are in millimeters. a3 a1 a e d bottom view top view pin no. 1 side view l2 l2 a2 e2 d2 l e b pin no. 1 pin 1 mark area (see note 1) exposed pad (optional) l1 note 2 l3 l4 r s d/2 e/2
iru1011-33 6 rev. 1.1 03/21/03 www.irf.com ir world headquarters: 233 kansas st., el segundo, california 90245, usa tel: (310) 252-7105 tac fax: (310) 252-7903 visit us at www.irf.com for sales contact information data and specifications subject to change without notice. 02/01 pkg desig h package description mlpm 3x3 parts per tube --- parts per reel 3000 package shipment method pin count 6 t & r orientation fig a feed direction figure a - live bug 1 1 1
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