Rev 270 | Rev 390 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 88 | jelle | 1 | Manufacturer: STMICROELECTRONICS |
| 2 | Order Code: 1202824 |
||
| 3 | Manufacturer Part No: LD1117STR-E |
||
| 257 | jelle | 4 | Description: V REG ADJ +1.25/15V, SMD, 1117 |
| 270 | jelle | 5 | Supplier: http://nl.farnell.com/stmicroelectronics/ld1117str-e/v-reg-adj-1-25-15v-smd-1117/dp/1202824 |
| 257 | jelle | 6 | Datasheet: http://www.st.com/stonline/products/literature/ds/2572/ld1117xx.pdf |
| 7 | Catalogue Page: 436 / EBU |
||
| 270 | jelle | 8 | Price: € 1,14 |
| 88 | jelle | 9 | |
| 291 | agaran | 10 | ;------------------------------------------------------------------------ |
| 11 | ; |
||
| 12 | ;VOUT = VREF (1 + R2 / R1) |
||
| 13 | ; |
||
| 14 | ;VREF = 1.25V |
||
| 15 | ; |
||
| 16 | ;# notes |
||
| 17 | ; |
||
| 18 | ;The power dissipated by the device will be equal to: |
||
| 19 | ; IOUT(MAX)(VIN(MAX) – VOUT) + IGND(VIN(MAX)) |
||
| 20 | ;where, |
||
| 21 | ; IOUT(MAX) = 250mA |
||
| 22 | ; VIN(MAX) = 6V |
||
| 23 | ; IGND at (IOUT = 250mA, VIN = 6V) = 5mA |
||
| 24 | ;So, |
||
| 25 | ; P = 250mA(6V – 3.3V) + 5mA(6V) = 0.71W |
||
| 26 | ; |
||
| 27 | ;page 7: Thermal resistance junction-case: 14 C/W |
||
| 28 | ; |
||
| 29 | ; |
||
| 30 | ;=== 3.0 V ==== |
||
| 31 | ; |
||
| 32 | ;R1 = 220 |
||
| 33 | ;R2 = 330 |
||
| 34 | ; |
||
| 35 | ;VOUT = VREF (1 + R2 / R1) |
||
| 36 | ;3.000 = 1.25 * (1 + 280 / 200) |
||
| 37 | ;2.969 = 1.25 * (1 + 330 / 240) |
||
| 38 | ;3.125 = 1.25 * (1 + 330 / 220) |
||
| 39 | ; |
||
| 40 | ;( (VOUT / VREF) -1 ) = (R2 / R1) |
||
| 41 | ; |
||
| 42 | ;I = U / R |
||
| 43 | ;3 / 200 = 0.015 |
||
| 44 | ; |
||
| 45 | ;P = I * U |
||
| 46 | ; |
||
| 47 | ;0.015 * 3 = 0.045 W |
||
| 48 | ;0603 Case Size = 0.063 W |
||
| 49 | ; |
||
| 50 | ; |
||
| 51 | ;=== 3.3 V === |
||
| 52 | ; |
||
| 53 | ;R1 = 240 |
||
| 54 | ;R2 = 390 |
||
| 55 | ; |
||
| 56 | ;VOUT = VREF (1 + R2 / R1) |
||
| 57 | ;3.281 = 1.25 * (1 + 390 / 240) |
||
| 58 | ; |
||
| 59 | ;== +3.0V Limits == |
||
| 60 | ; |
||
| 61 | ;VOUT = VREF (1 + R2 / R1) |
||
| 62 | ;R1 = 240 |
||
| 63 | ;R2 = 330 |
||
| 64 | ;R1 = 99% = 237.6 |
||
| 65 | ;R1 = 101% = 242.4 |
||
| 66 | ;R2 = 99% = 326.7 |
||
| 67 | ;R2 = 101% = 333.3 |
||
| 68 | ; |
||
| 69 | ;MIN(2.940) = 1.238 * (1 + 326.7 / 237.6) |
||
| 70 | ;TYP(2.969) = 1.250 * (1 + 330.0 / 240.0) |
||
| 71 | ;MAX(3.004) = 1.262 * (1 + 333.3 / 242.4) |
||
| 72 | ; |
||
| 73 | ;== +3.125 V Limits == |
||
| 74 | ; |
||
| 75 | ;VOUT = VREF (1 + R2 / R1) |
||
| 76 | ;R1 = 220 |
||
| 77 | ;R2 = 330 |
||
| 78 | ;R1 = 99% = 217.8 |
||
| 79 | ;R1 = 101% = 222.2 |
||
| 80 | ;R2 = 99% = 326.7 |
||
| 81 | ;R2 = 101% = 333.3 |
||
| 82 | ; |
||
| 83 | ;MIN(3.095) = 1.238 * (1 + 326.7 / 217.8) |
||
| 84 | ;TYP(3.125) = 1.250 * (1 + 330.0 / 220.0) |
||
| 85 | ;MAX(3.115) = 1.262 * (1 + 333.3 / 222.2) |
||
| 86 | ; |
||
| 87 | ;3.125 = 1.25 * (1 + 330 / 220) |
||
| 88 | ; |
||
| 89 | ; |
||
| 90 | ;== +3.3V Limits == |
||
| 91 | ; |
||
| 92 | ;VOUT = VREF (1 + R2 / R1) |
||
| 93 | ;R1 = 240 |
||
| 94 | ;R2 = 390 |
||
| 95 | ;R1 = 99% = 237.6 |
||
| 96 | ;R1 = 101% = 242.4 |
||
| 97 | ;R2 = 99% = 386.1 |
||
| 98 | ;R2 = 101% = 393.9 |
||
| 99 | ;MIN(3.250) = 1.238 * (1 + 386.1 / 237.6) |
||
| 100 | ;TYP(3.281) = 1.238 * (1 + 386.1 / 237.6) |
||
| 101 | ;MAX(3.313) = 1.262 * (1 + 393.9 / 242.4) |