plessey semiconductors ltd, tamerton road, roboroug h, plymouth, uk pl6 7bq data sheet 292204 issue 1 tel: +44 (0)1752 693000 fax: +44 (0)1752 693200 w eb: www.plesseysemiconductors.com email: sales@plesseysemi.com ; october 12, 2010 1 PS22922 12v, 1a fast transient response linear regulator preliminary data sheet 292204 issue 1 mar-13 typical application description the PS22922 is a high performance, precision linear regulator with very low dropout voltage and excellent transie nt response. it is designed to operate with wide input voltage r ange of 1.7 ? 12 volts making it ideal for two step conversion. the device is capable of supplying 1a of output current with a ty pical dropout voltage of 350mv. the output voltage is available i n either fixed or adjustable options. for fixed option, the inter nal resistor network can be set in 100mv increment ranging from 0.5 to 5.0 volts. the product includes an enable pin for electrical o n/off of the regulator. forcing the enable pin to logic low shu ts down the ldo and reduces the supply current below 1 a. the PS22922 features fast transient response and low self outpu t noise. connecting a capacitor form bypass to gnd further e nhances the psrr and the output noise. an open collector power good flag with 500s delay is available for systems requiring supply monitoring and sequenc ing of other supplies. the regulator features the full su ite of protection with a combination of current limit and thermal ove rload protection. the PS22922 is available in sot223 and it is rated for a -40c to +125c junction temperature range. features ? v in range 1.7 ? 12v ? fixed and adjustable output voltage ? 1a maximum output current ? 350mv typical dropout voltage ? bypass output for low psrr and output noise ? power good pin with 500s delay ? low self noise ? shutdown mode for longer battery life ? high psrr typically 60db at 100hz ? stable with a wide range of ceramic, tantalum or electrolytic capacitors ? current limit protection ? thermal shutdown ? -40c to 125c temperature range ? available in sot223 applications ? set top boxes ? digital audio systems ? dsp ? pol regulators ? smps post regulator vin = 1.7 ? 12v
PS22922 plessey semiconductors ltd, tamerton road, roboroug h, plymouth, uk pl6 7bq data sheet 292204 issue 1 tel: +44 (0)1752 693000 fax: +44 (0)1752 693200 w eb: www.plesseysemiconductors.com email: sales@plesseysemi.com; october 12, 2010 2 pin description symbol pin # sot223 description en n/a enable pin. it controls the electrical on/off of t he device. when connected to logic low, the device shuts off and consumes less t han 1 a of current. logic high will resume normal operation. bypass n/a bypass pin. connect an external capacitor from byp to ground to bypass the noise generated by the internal bandgap. this impr oves power supply rejection ratio and output noise. a minimum capacitor of 2 20pf is recommended. v in 1 input supply pin. connect a 10 f capacitor between this pin and ground. nc n/a no connect. fb n/a feedback voltage. a resistor network of two resisto rs is used to set-up the output voltage connected between v out and gnd. the center tap of the two resistors is connected to fb pin. for fixed voltag e options, the resistors are internally connected to v out . v out 3 regulated output voltage. connect a 10 f capacitor from this pin to ground. pg n/a power good. it is an open collector, active high o utput that indicates the status of the output voltage. when output voltage (v out ) exceeds the pg trip threshold, the pg pin goes in to a high impedance state. when the device is out of regulation or shutdown, the pg pin is pulled low. a 10k to 1m resistor should be connected from pg to v out . gnd 2 ground connection. tab expose pad. connected to pcb ground plane for good thermal dissipation. nb: n/a = not available in the shown package type pin configuration 2 1 gnd vin 3 vout sot223 (top view)
PS22922 plessey semiconductors ltd, tamerton road, roboroug h, plymouth, uk pl6 7bq data sheet 292204 issue 1 tel: +44 (0)1752 693000 fax: +44 (0)1752 693200 w eb: www.plesseysemiconductors.com email: sales@plesseysemi.com; october 12, 2010 3 absolute maximum ratings (1) maximum input supply voltage??????........?.? -0.8 to 15v enable voltage????????????????.... -0.8 to 15v power good?????????????????.... -0.8 to 15v feedback voltage???????????????...... -0.8 to 5v bypass voltage?????????????????. -0.8 to 5v recommended operating conditions input voltage?????????????.????.. 1.7 to 12v enable input voltage?????????.?????.. 0v to v in junction operating temperature??????..?? -40 ? c to 125 ? c thermal information (2) sot223 1 ja ................................................... ........................ 60 ? c/w storage temperature range?????..................... .... -65 to 150 ? c lead temperature???????..???? .?????? 260 ? c junction temperature? ???????? .???? ... -40 to 125 ? c electrical characteristics unless otherwise noted: v in =5.0v; v o =3.3v; c in =c out =22f; typical values are t a = 25 c parameter symbol conditions min. typ. max. units fixed option; 100mv increment 0.5 5.0 v output voltage range v o adjustable 0.5 v o +v do output voltage tolerance tbd feedback voltage v fb 0.494 0.50 0.506 v maximum output current i o 1.0 a shutdown current i shd v en =gnd 0.01 1.0 a current limit i lim 1.1 2.0 a supply current i q i out = 1a tbd ma load regulation 3 i out = 0.1ma ? 150ma -1.0 1.0 % line regulation v in = vo+1v to 12v; i out =10ma -0.5 0.5 % i out = 500ma 300 tbd i out = 750ma tbd dropout voltage v do i out = 1a tbd mv enable threshold low v en(l) 0.8 v enable threshold high v en(h) 1.4 v input enable low current i en(l) v en = 0v 0.01 2.0 a input enable high current i en(h) v en =2v 5.0 8.0 a freq=100hz 62 ripple rejection ratio psrr i o =50ma freq=10khz 60 db c byp = open tbd output noise e n bw; 10hz ? 100khz io=100ma c out = 10f c byp =100nf tbd nv/ hz power good low threshold v ol_pg i pg =200 a 400 mv power good delay v pg_delay 500 s thermal shutdown t sd 140 ?c thermal shutdown hys. t sd_hys 15 ?c notes: 1. stresses above those listed in absolute maximum rat ings may cause permanent damage to the device. meas ured on approximately 1? square of 1oz copper. 2. the PS22922 is guaranteed to meet performance speci fications over the -40c to +125c operating juncti on temperature range and is assured by design, characterization, and correla tion with statistical process control. 3. load regulation is measured using pulse techniques with duty cycle <5%.
PS22922 plessey semiconductors ltd, tamerton road, roboroug h, plymouth, uk pl6 7bq data sheet 292204 issue 1 tel: +44 (0)1752 693000 fax: +44 (0)1752 693200 w eb: www.plesseysemiconductors.com email: sales@plesseysemi.com; october 12, 2010 4 typical vdrop vs iout (a) typical line regulation vs vin (v)
PS22922 plessey semiconductors ltd, tamerton road, roboroug h, plymouth, uk pl6 7bq data sheet 292204 issue 1 tel: +44 (0)1752 693000 fax: +44 (0)1752 693200 w eb: www.plesseysemiconductors.com email: sales@plesseysemi.com; october 12, 2010 5 functional block diagram application hint input capacitor (c in ) input capacitor may be required when the device is not near the source power supply or when supplied by a batte ry. this capacitor will reduce the circuit?s sensitivit y when powered from complex source impedance and significa ntly enhance the output transient response. the input b ypass should be mounted with the short possible track dir ectly across the regulator?s input and ground terminals. a 10 f ceramic capacitor should be adequate for most appli cations. output capacitor (c out ) the output capacitor provides not only stability to the regulator, but also, enhances the load transient re sponse. a minimum capacitance of 10 f is required. when selecting a ceramic capacitor, only x5r and x7r dielectric ty pes should be used. other types such as z5u and y5f hav e such severe loss of capacitance due to effects of temperature variation and applied voltage, they may provide as little as 20% of rated capacitance in ma ny typical applications. always consult capacitor manufacturer?s data curves before selecting a capacitor. high-quality ceramic capacit ors can be obtained from taiyo-yuden, avx, and murata. hig her values of the output capacitance can be used to enh ance loop stability and transient response. the adjustable output voltage option allows the use r to select an output voltage by using an external resis tor divider. PS22922 uses a 0.5v reference voltage at t he positive terminal of the error amplifier. to set th e output voltage a programming resistor from the feedback pi n (fb) to ground must be selected. a 10k resistor is a good selection for a programming resistor r2. a higher v alue may result in an excessively sensitive feedback nod e while a lower value will draw more current and degrade th e light load efficiency. the equation for selecting the vol tage specific resistor is: fb o v r r v * 2 1 1 ?? ? ?? ? + = for the fixed output devices, r1 and r2 are include d within the device.
PS22922 plessey semiconductors ltd, tamerton road, roboroug h, plymouth, uk pl6 7bq data sheet 292204 issue 1 tel: +44 (0)1752 693000 fax: +44 (0)1752 693200 w eb: www.plesseysemiconductors.com email: sales@plesseysemi.com; october 12, 2010 6 bypass capacitor connecting a capacitor between the byp pin and grou nd can significantly reduce output noise. values can r ange from 0pf to 100nf, depending on the sensitivity to output noise in the application. the start up speed of the ps22291 is inversely proportional to the size of the bypass capacitor. applications requiring a slow ramp-up of output vol tage should consider larger values of bypass capacitance . likewise, if rapid turn on is necessary, consider o mitting c byp . enable/shutdown the enable (en) pin is active high and is compatibl e with standard digital signalling levels. when v en below 0.8v, it turns the regulator off while v en above 1.4v turns the regulator on. if not used, en can be connected to the input voltage. if en is connected to v in , it should be connected as close as possible to the largest capacitance on the input to prevent voltage droops on that line from trigger ing the enable circuit. thermal consideration the ps22292 is designed to provide 1a of continuous current in a very small package. maximum power dissipation can be calculated based on the output c urrent and the voltage drop across the part. to determine the maximum power dissipation of the package, use the junction-to-ambient thermal resistance of the devic e and the following basic equation: ? ?? ? ? ?? ? ? = ja a j d t t p (max) (max) where t j(max) is the maximum junction temperature of the die, t a is the ambient operating temperature, and ja is layout dependent. the actual power dissipation of the regulator circuit can be determined using the equat ion: p d = (v in ? v out )*i out + v in *i sup substituting pd(max) for pd and solving for the ope rating conditions that are critical to the application wil l give the maximum operating conditions for the regulator.
plessey semiconductors ltd, tamerton road, roboroug h, plymouth, uk pl6 7bq data sheet 292204 issue 1 tel: +44 (0)1752 693000 fax: +44 (0)1752 693200 w eb: www.plesseysemiconductors.com email: sales@plesseysemi.com ; october 12, 2010 7 PS22922 ordering information device operating junction temp. package comments PS22922t8t2a5 -40c to +125c sot223 vo = 1.2v PS22922tet2a5 -40c to +125c sot223 vo = 1.8v PS22922tut2a5 -40c to +125c sot223 vo = 3.3v n.b for other values of output voltage please conta ct your local plessey semiconductors sales represen tative
PS22922 plessey semiconductors ltd, tamerton road, roboroug h, plymouth, uk pl6 7bq data sheet 292204 issue 1 tel: +44 (0)1752 693000 fax: +44 (0)1752 693200 w eb: www.plesseysemiconductors.com email: sales@plesseysemi.com; october 12, 2010 8 outline drawing and landing pattern (sot223) for further information about this and other produc ts, please visit: www.plesseysemiconductors.com legal notice product information provided by plessey semiconduct ors limited (?plessey?) in this document is believe d to be correct and accurate. plessey reserves the right to change/ correct the specifica tions and other data or information relating to pro ducts without notice but plessey accepts no liability for errors that may appear in this docume nt, howsoever occurring, or liability arising from the use or application of any information or data provided herein. neither the supply of such in formation, nor the purchase or use of products conv eys any licence or permission under patent, copyright, trademark or other intellectual property right of plessey or third parties. products sold by plessey are subject to its standar d terms and conditions of sale that are available o n request. no warranty is given that products do not infringe the intellectual property rights of third parties, and furthermore, the use o f products in certain ways or in combination with plessey, or non-plessey furnished equipments/c omponents may infringe intellectual property rights of plessey. the purpose of this document is to provide informat ion only and it may not be used, applied or reprodu ced (in whole or in part) for any purpose nor be taken as a representation relating to the pr oducts in question. no warranty or guarantee expres s or implied is made concerning the capability, performance or suitability of any produ ct, and information concerning possible application s or methods of use is provided for guidance only and not as a recommendation. the use r is solely responsible for determining the perform ance and suitability of the product in any application and checking that any specification or data it seeks to rely on has not been supersede d. products are intended for normal commercial applica tions. for applications requiring unusual environme ntal requirements, extended temperature range, or high reliability capability ( e.g. military, or medical applications), special pr ocessing/testing/conditions of sale may be available on application to plessey.
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