Motore di ricerca datesheet componenti elettronici |
|
LM317LF Scheda tecnica(PDF) 4 Page - Tiger Electronic Co.,Ltd |
|
LM317LF Scheda tecnica(HTML) 4 Page - Tiger Electronic Co.,Ltd |
4 / 14 page LM317 4/14 APPLICATION INFORMATION 1. Basic circuit operation In operation, the LM 317 develops a nominal 1.25V reference voltage, Vref, between the output and adjustme nt terminal. The reference voltage is impressed across program resistor R1 and, since the voltage is constant, a constant current I1 then flows through the output set resistor R2, giving an output voltage of V o u t = V r e f ( 1 + R 2 / R 1 ) + I a d j * ( R 2 ) Since the 100 µA current from the adjustment terminal represents an error term, the LM 317 was designed to mi nimi ze Iadj and ma ke it very constant with line and load changes. To do this, all quiescent operating current is returned to the output establishing a mi nimu m load current requireme nt. If there is insufficient load on the output, the output will rise. Figure: Basic circuit configuration R1 R2 LL V V ADJ I V I V AD J 1 RE OU IN OU 2. Load Regulation The LM 31 7 is cap ab le of pro v i d in g extre m ely good load re gu latio n, b u t a few precaut i ons are nee d ed to obt a in ma xi m u m performance. For best performa nce, the programmi ng resistor (R1) shoul d be co nne cted as clos e to t h e regula t or as possi ble t o m i ni mi ze line drops which effecti v ely appear in series with the reference, t h ere b y degradi n g regulat io n. The gro und end of R2 ca n b e returned ne ar the loa d groun d to p r ovide rem o te groun d se n s ing an d i m prove loa d reg u la tio n Reg u lat o r with li ne resistance i n o u t p u t l e a d R1 R2 LM317L V V ADJ V OUT IN OUT Rs 240 VIN W317L W317L 3.External capacitors A 0 . 1 µF disc or 1.0µF tantalum input bypass capacitor (Cin) is recommended to reduce the sensitivity to input line impedance. T h e ad j u stme nt term inal ma y be by passe d to gro u n d to impro v e ripp le rejecti o n . This ca paci tor (Cadj) prevents ri pple from bein g amplified as t h e out pu t v o lta ge is increase d . A 10 µF capacitor should improve ripple rejection about 15dB at 120Hz in a |
Codice articolo simile - LM317LF |
|
Descrizione simile - LM317LF |
|
|
Link URL |
Privacy Policy |
ALLDATASHEETIT.COM |
Lei ha avuto il aiuto da alldatasheet? [ DONATE ] |
Di alldatasheet | Richest di pubblicita | contatti | Privacy Policy | scambio Link | Ricerca produttore All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |