this is information on a product in full production. february 2014 docid13496 rev 4 1/25 l9777 low power voltage regulator datasheet - production data features ? operating dc supply voltage range 5.6 v to 31 v ? low current consumption (110 a typ @ i out = 0) ? high precision output voltage (2 %) ? low dropout voltage ? vdd tracking regulator switchable on/off by vdd_en pin ? reset circuit sensing the output voltage down to 1 v. ? double reset function ? adjustable reset threshold ? external capacitor to set nmi/ reset power up delay and watchdog frequency ? over temperature protection ? wide temperature range (t j = -40 c to 150 c) ? short circuit proof ? suitable for use in automotive electronics description the l9777 is a monolithic integrated low drop regulator which can supply up to 200 ma, available in the powersso-12 package. it is designed to supply microprocessor systems under severe conditions of automotive applications and therefore equipped with additional protection functions against over load, short circuit and over temperature. of course the l9777 can also be used in other applications where a regulated voltage is required. powersso-12 (exposed die pad) ' ! 0 ' 0 3 table 1. device summary order code package packing l9777a powersso-12 tray l9777b powersso-12 tray L9777B13TR powersso-12 tape and reel l9777c powersso-12 tray l9777c13tr powersso-12 tape and reel www.st.com
contents l9777 2/25 docid13496 rev 4 contents 1 block diagrams and pins configuration . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.1 block diagram (option a) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.2 option b features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.3 option c features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2 absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3 functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.1 voltage regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.2 reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.3 nmi and reset driver delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.4 reset adjustable threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.5 watchdog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 4 vdd regulated voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 5 vdd_low (option c) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 6 device options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 6.1 option a . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 6.2 option b . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 6.3 option c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 7 electrical and thermal characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . 19 8 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 9 revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
docid13496 rev 4 3/25 l9777 list of tables 3 list of tables table 1. device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 table 2. pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 table 3. absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 table 4. electrical and thermal characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 table 5. revision history. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
list of figures l9777 4/25 docid13496 rev 4 list of figures figure 1. block diagram (option a). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 figure 2. package pin configuration (options a and b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 figure 3. block diagram (option b). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 figure 4. block diagram (option c) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 figure 5. package pin configuration (option c) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 figure 6. vcc versus output current ivcc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 figure 7. filter time between vcc and nmi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 figure 8. reset time diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 figure 9. filter time between nmi and reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 figure 10. reset and nmi drivers fall time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 figure 11. resistor divider to adjust the under voltage threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 figure 12. watchdog timing waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 figure 13. vdd_low filter time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 figure 14. powersso-12 mechanical data and package dimensions . . . . . . . . . . . . . . . . . . . . . . . . . 23
docid13496 rev 4 5/25 l9777 block diagrams and pins configuration 24 1 block diagrams and pins configuration 1.1 block diagram (option a) figure 1. block diagram (option a) 1.2 option b features ? vdd can sustain short to 40 v regardless of vi battery voltage ? current capability of vdd scaled down to 50 ma with dropout of 1.5 v (max.) ? in default condition, vdd and wd functions are disabled using 2 pull down current on vdd_en and wd_en pin ? standby current consumption reduced to 100 a (typ.) figure 2. package pin configuration (options a and b) w a t c h d o g 6 ) 6 b a t t 7 $ $ # $ 4 ) - ) . ' . - ) 7 $ ? % . ' . $ 6 # # # 6 # # ) 6 # # m ! 6 o l t a g e 2 e f e r e n c e , o w 6 o l t a g e 2 e s e t 3 t a r t u p 2 2 6 / & |