View LD2981ABU18TR_1445076.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

1/17 february 2003 n stable with low esr ceramic capacitors n ultra low dropout voltage (0.12v typ. at 50ma load, 7mv typ. at 1ma load) n very low quiescent current (80a typ. at no load in on mode; max 1a in off mode) n guaranteed output current up to 50ma n logic-controlled electronic shutdown n output voltage of 1.5; 1.8; 2.5; 2.85; 3.0; 3.2; 3.3; 3.6; 3.8; 4.0; 4.7; 4.85; 5.0v n internal current and thermal limit n 0.5% tolerance output voltage available (a version) n output low noise voltage 160vrms n temperature range: -40 to 125c n smallest package sot23-5l and sot-89 n fast dynamic response to line and load changes description the ld2981 series are 50ma fixed-output voltage regulator. the low drop-voltage and the ultra low quiescent current make them suitable for low noise, low power applications and in battery powered systems. the quiescent current in sleep mode is less than 1a when inhibit pin is pulled low. shutdown logic control function is available on pin n.3 (ttl compatible). this means that when the device is used as local regulator, it is possible to put a part of the board in standby, decreasing the total power consumption. the ld2981 is designed to work with low esr ceramic capacitor. typical applications are in cellular phone, palmtop/laptop computer, personal digital assistant (pda), personal stereo, camcorder and camera. ld2981 series ultra low drop voltage regulators with inhibit low esr output capacitors compatible schematic diagram sot23-5l sot-89
ld2981 series 2/17 absolute maximum ratings absolute maximum ratings are those values beyond which damage to the device may occur. functional operation under these condition is not implied. thermal data connection diagram (top view) pin description symbol parameter value unit v i dc input voltage -0.3 to 16 v v inh inhibit input voltage -0.3 to 16 v i o output current internally limited p d power dissipation internally limited t stg storage temperature range -55 to 150 c t op operating junction temperature range -40 to 125 c symbol parameter sot23-5l sot-89 unit r thj-case thermal resistance junction-case 81 15 c/w r thj-amb thermal resistance junction-ambient 255 110 c/w pin n sot23-5l pin n sot-89 symbol name and function 13 v in input port 2 2 gnd ground pin 3 inhibit control switch on/off. inhibit is not internally pulled-up; it cannot be left floating. disable the device when connected to gnd or to a positive voltage less than 0.18v 4 nc not connected 51v out output port sot23-5l sot-89
ld2981 series 3/17 ordering codes typical application circuit (*) inhibit pin is not internally pulled-up then it must not be left floating. disable the device when connected to gnd or to a positive voltage less than 0.18v. ab version c version output voltages sot23-5l sot-89 sot23-5l sot-89 ld2981abm15tr ld2981abu15tr ld2981cm15tr ld2981cu15tr 1.5 v ld2981abm18tr LD2981ABU18TR ld2981cm18tr ld2981cu18tr 1.8 v ld2981abm25tr ld2981abu25tr ld2981cm25tr ld2981cu25tr 2.5 v ld2981abm28tr ld2981abu28tr ld2981cm28tr ld2981cu28tr 2.85 v ld2981abm30tr ld2981abu30tr ld2981cm30tr ld2981cu30tr 3.0 v ld2981abm32tr ld2981abu32tr ld2981cm32tr ld2981cu32tr 3.2 v ld2981abm33tr ld2981abu33tr ld2981cm33tr ld2981cu33tr 3.3 v ld2981abm36tr ld2981abu36tr ld2981cm36tr ld2981cu36tr 3.6 v ld2981abm38tr ld2981abu38tr ld2981cm38tr ld2981cu38tr 3.8 v ld2981abm40tr ld2981abu40tr ld2981cm40tr ld2981cu40tr 4.0 v ld2981abm47tr ld2981abu47tr ld2981cm47tr ld2981cu47tr 4.7 v ld2981abm48tr ld2981abu48tr ld2981cm48tr ld2981cu48tr 4.85 v ld2981abm50tr ld2981abu50tr ld2981cm50tr ld2981cu50tr 5.0 v
ld2981 series 4/17 electrical characteristics for ld2981ab (t j = 25c, v i =v o(nom) +1v, c i =1 m f(x7r), c o =2.2 m f(x7r), i o =1ma,v inh = 2v, unless otherwise specified) symbol parameter test conditions min. typ. max. unit v op operating input voltage 2.5 16 v v o output voltage i o = 1 ma 1.488 1.5 1.511 v i o = 1 to 50 ma 1.485 1.515 i o =1to50ma t j = -40 to 125 c 1.462 1.537 v o output voltage i o = 1 ma 1.786 1.8 1.813 v i o = 1 to 50 ma 1.782 1.818 i o =1to50ma t j = -40 to 125 c 1.755 1.845 v o output voltage i o = 1 ma 2.481 2.5 2.518 v i o = 1 to 50 ma 2.475 2.525 i o =1to50ma t j = -40 to 125 c 2.437 2.562 v o output voltage i o = 1 ma 2.828 2.85 2.872 v i o = 1 to 50 ma 2.822 2.878 i o =1to50ma t j = -40 to 125 c 2.779 2.921 v o output voltage i o = 1 ma 2.977 3 3.023 v i o = 1 to 50 ma 2.970 3.030 i o =1to50ma t j = -40 to 125 c 2.925 3.075 v o output voltage i o = 1 ma 3.176 3.2 3.224 v i o = 1 to 50 ma 3.168 3.232 i o =1to50ma t j = -40 to 125 c 3.12 3.28 v o output voltage i o = 1 ma 3.275 3.3 3.325 v i o = 1 to 50 ma 3.267 3.333 i o =1to50ma t j = -40 to 125 c 3.217 3.383 v o output voltage i o = 1 ma 3.573 3.6 3.627 v i o = 1 to 50 ma 3.564 3.636 i o =1to50ma t j = -40 to 125 c 3.510 3.690 v o output voltage i o = 1 ma 3.771 3.8 3.829 v i o = 1 to 50 ma 3.762 3.838 i o =1to50ma t j = -40 to 125 c 3.705 3.895 v o output voltage i o = 1 ma 3.97 4 4.03 v i o = 1 to 50 ma 3.96 4.04 i o =1to50ma t j = -40 to 125 c 3.9 4.1 v o output voltage i o = 1 ma 4.664 4.7 4.735 v i o = 1 to 50 ma 4.653 4.747 i o =1to50ma t j = -40 to 125 c 4.582 4.817 v o output voltage i o = 1 ma 4.813 4.85 4.887 v i o = 1 to 50 ma 4.801 4.899 i o =1to50ma t j = -40 to 125 c 4.729 4.971 v o output voltage i o = 1 ma 4.962 5 5.038 v i o = 1 to 50 ma 4.950 5.050 i o =1to50ma t j = -40 to 125 c 4.875 5.125
ld2981 series 5/17 (note 1): for vo < 2.5v dropout voltage can be calculated according to the minimum input voltage in full temperature range. d v o line regulation v o(nom) +1 ld2981 series 6/17 electrical characteristics for ld2981c (t j = 25c, v i =v o(nom) +1v, c i =1 m f(x7r), c o =2.2 m f(x7r), i o =1ma,v inh = 2v, unless otherwise specified) symbol parameter test conditions min. typ. max. unit v op operating input voltage 2.5 16 v v o output voltage i o = 1 ma 1.481 1.5 1.519 v i o = 1 to 50 ma 1.470 1.530 i o =1to50ma t j = -40 to 125 c 1.447 1.552 v o output voltage i o = 1 ma 1.777 1.8 1.822 v i o = 1 to 50 ma 1.764 1.836 i o =1to50ma t j = -40 to 125 c 1.737 1.863 v o output voltage i o = 1 ma 2.468 2.5 2.531 v i o = 1 to 50 ma 2.45 2.55 i o =1to50ma t j = -40 to 125 c 2.412 2.587 v o output voltage i o = 1 ma 2.814 2.85 2.885 v i o = 1 to 50 ma 2.793 2.907 i o =1to50ma t j = -40 to 125 c 2.75 2.949 v o output voltage i o = 1 ma 2.962 3 3.037 v i o = 1 to 50 ma 2.94 3.06 i o =1to50ma t j = -40 to 125 c 2.895 3.105 v o output voltage i o = 1 ma 3.16 3.2 3.24 v i o = 1 to 50 ma 3.136 3.264 i o =1to50ma t j = -40 to 125 c 3.088 3.312 v o output voltage i o = 1 ma 3.258 3.3 3.341 v i o = 1 to 50 ma 3.234 3.366 i o =1to50ma t j = -40 to 125 c 3.184 3.415 v o output voltage i o = 1 ma 3.555 3.6 3.645 v i o = 1 to 50 ma 3.528 3.672 i o =1to50ma t j = -40 to 125 c 3.474 3.726 v o output voltage i o = 1 ma 3.752 3.8 3.847 v i o = 1 to 50 ma 3.724 3.876 i o =1to50ma t j = -40 to 125 c 3.667 3.933 v o output voltage i o = 1 ma 3.95 4 4.05 v i o = 1 to 50 ma 3.92 4.08 i o =1to50ma t j = -40 to 125 c 3.86 4.14 v o output voltage i o = 1 ma 4.641 4.7 4.758 v i o = 1 to 50 ma 4.606 4.794 i o =1to50ma t j = -40 to 125 c 4.535 4.864 v o output voltage i o = 1 ma 4.789 4.85 4.91 v i o = 1 to 50 ma 4.753 4.947 i o =1to50ma t j = -40 to 125 c 4.68 5.019 v o output voltage i o = 1 ma 4.937 5 5.062 v i o = 1 to 50 ma 4.9 5.1 i o =1to50ma t j = -40 to 125 c 4.825 5.175
ld2981 series 7/17 (note 1): for vo < 2.5v dropout voltage can be calculated according to the minimum input voltage in full temperature range. d v o line regulation v o(nom) +1 ld2981 series 8/17 typical performance characteristics (t j = 25c, v i =v o(nom) +1v, c i =1 m f(x7r), c o =2.2 m f(x7r), v inh = 2v, unless otherwise specified) figure 1 : output voltage vs temperature figure 2 : output voltage vs temperature figure 3 : line regulation vs temperature figure 4 : load regulation vs temperature figure 5 : dropout voltage vs temperature figure 6 : quiescent current vs temperature
ld2981 series 9/17 figure 7 : quiescent current vs output current figure 8 : off mode quiescent current vs temperature figure 9 : quiescent current vs input voltage figure 10 : dropout voltage vs output current figure 11 : inhibit input current vs temperature figure 12 : inhibit voltage vs temperature
ld2981 series 10/17 figure 13 : supply voltage rejection vs frequency figure 14 : noise voltage vs frequency figure 15 : best case: highest output version figure 16 : worst case: lowest output version figure 17 : load transient response figure 18 : line transient response v o = 4 .7 v , i o = 1 to 100 m a , c o = 4 .7 m fx 7 r v i = (v o(nom) + 1v) , v o = 4 .7 v , i o = 100 m a , c o = 4 .7 m fx 7 r
ld2981 series 11/17 application notes external capacitors like any low-dropout regulator, the ld2981 requires external capacitors for regulator stability. this capacitor must be selected to meet the requirements of minimum capacitance and equivalent series resistance. we suggest to solder input and output capacitors as close as possible to the relative pins. input capacitor an input capacitor whose value is 1f is required with the ld2981 (amount of capacitance can be increased without limit). this capacitor must be located a distance of not more than 0.5" from the input pin of the device and returned to a clean analog ground. any good quality ceramic, tantalum or film capacitors can be used for this capacitor. output capacitor the ld2981 is designed specifically to work with ceramic output capacitors. it may also be possible to use tantalum capacitors, but these are not as attractive for reasons of size and cost. by the way, the output capacitor must meet both the requirement for minimum amount of capacitance and esr (equivalent series resistance) value. the figures 1 and 2 show the allowable esr range as a function of the output capacitance. these curves represent the stability region over the full temperature and i o range. due to the different loop gain, the stability improves for higher output versions and so the suggested minimum output capacitor value, if low esr ceramic type is used, is 1f for output voltages equal or major than 3.8v, 2.2f for output voltages from 2.85 to 3.3v, and 3.3f for the other versions. however, if an output capacitor lower than the suggested one is used, its possible to make stable the regulator adding a resistor in series to the capacitor (see figure1 & figure2 to choose the right value according to the used version and keeping in account that the esr of ceramic capacitors has been measured @ 100khz). important the output capacitor must maintain its esr in the stable region over the full operating temperature to assure stability. also, capacitor tolerance and variation with temperature must be considered to assure the minimum amount of capacitance is provided at all times. this capacitor should be located not more than 0.5" from the output pin of the device and returned to a clean analog ground. inhibit input operation the inhibit pin can be used to turn off the regulator when pulled low, so drastically reducing the current consumption down to less than 1a. when the inhibit feature is not used, this pin must be tied to v i to keep the regulator output on at all times. to assure proper operation, the signal source used to drive the inhibit pin must be able to swing above and below the specified thresholds listed in the electrical characteristics section under v ih v il .anyslewratecanbeusedtodrivetheinhibit. reverse current the power transistor used in the ld2981 has not an inherent diode connected between the regulator input and output. if the output is forced above the input, no current will flow from the output to the input across the series pass transistor. when a v rev voltage is applied on the output, the reverse current measured, according to the test circuit in figure 19, flows to the gnd across the two feedback resistors. this current typical value is 160a. r 1 and r 2 resistors are implanted type; typical values are, respectively, 42.6 k w and 51.150 k w .
ld2981 series 12/17 figure 19 : reverse current test circuit
ld2981 series 13/17 dim. mm. mils min. typ max. min. typ. max. a 0.90 1.45 35.4 57.1 a1 0.00 0.15 0.0 5.9 a2 0.90 1.30 35.4 51.2 b 0.35 0.50 13.7 19.7 c 0.09 0.20 3.5 7.8 d 2.80 3.00 110.2 118.1 e 2.60 3.00 102.3 118.1 e1 1.50 1.75 59.0 68.8 e.95 37.4 e1 1.9 74.8 l 0.35 0.55 13.7 21.6 sot23-5l mechanical data 0
ld2981 series 14/17 dim. mm. mils min. typ max. min. typ. max. a 1.4 1.6 55.1 63.0 b 0.44 0.56 17.3 22.0 b1 0.36 0.48 14.2 18.9 c 0.35 0.44 13.8 17.3 c1 0.35 0.44 13.8 17.3 d 4.4 4.6 173.2 181.1 d1 1.62 1.83 63.8 72.0 e 2.29 2.6 90.2 102.4 e 1.42 1.57 55.9 61.8 e1 2.92 3.07 115.0 120.9 h 3.94 4.25 155.1 167.3 l 0.89 1.2 35.0 47.2 sot-89 mechanical data p025h
ld2981 series 15/17 dim. mm. inch min. typ max. min. typ. max. a 180 7.086 c 12.8 13.0 13.2 0.504 0.512 0.519 d 20.2 0.795 n 60 2.362 t 14.4 0.567 ao 3.13 3.23 3.33 0.123 0.127 0.131 bo 3.07 3.17 3.27 0.120 0.124 0.128 ko 1.27 1.37 1.47 0.050 0.054 0.0.58 po 3.9 4.0 4.1 0.153 0.157 0.161 p 3.9 4.0 4.1 0.153 0.157 0.161 tape & reel sot23-xl mechanical data
ld2981 series 16/17 dim. mm. inch min. typ max. min. typ. max. a 180 7.086 c 12.8 13.0 13.2 0.504 0.512 0.519 d 20.2 0.795 n 60 2.362 t 14.4 0.567 ao 4.70 4.80 4.90 0.185 0.189 0.193 bo 4.30 4.40 4.50 0.169 0.173 0.177 ko 1.70 1.80 1.90 0.067 0.071 0.075 po 3.9 4.0 4.1 0.153 0.157 0.161 p 7.9 8.0 8.1 0.311 0.315 0.319 tape & reel sot89 mechanical data
ld2981 series 17/17 information furnished is believed to be accurate and reliable. however, stmicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result f rom its use. no license is granted by implication or otherwise under any patent or patent rights of stmicroelectronics. specificati ons mentioned in this publication are subject to change without notice. this publication supersedes and replaces all information previously supplied. stmicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of stmicroelectronics. ? the st logo is a registered trademark of stmicroelectronics ? 2003 stmicroelectronics - printed in italy - all rights reserved stmicroelectronics group of companies australia - brazil - canada - china - finland - france - germany - hong kong - india - israel - italy - japan - malaysia - malt a - morocco singapore - spain - sweden - switzerland - united kingdom - united states. ? http://www.st.com

▲Up To Search▲

Price & Availability of LD2981ABU18TR

	To Download LD2981ABU18TR Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .