SLVSBC7E October 2013 – September 2018 LMZ31530
PRODUCTION DATA.
Refer to the PDF data sheet for device specific package drawings
The VADJ control sets the output voltage of the LMZ31530. The output voltage adjustment range is from 0.6V to 3.6V. The adjustment method requires the addition of RSET, which sets the output voltage, and the connection of SENSE+ to VOUT. The RSET resistor must be connected directly between the VADJ (pin 13) and AGND (pin 9). The SENSE+ pin (pin 14) must be connected to VOUT either at the load for improved regulation or at VOUT of the device.
The LMZ31530 relies on a precision trimmed 0.6 V reference for the feedback voltage regulation and operates by regulating the valley of the voltage ripple appearing at the VADJ pin. The voltage ripple is a function of the input voltage and the output voltage, therefore the RSET resistor will change based on the input voltage. Table 1 gives the calculated external RSET resistor for a number of common bus voltages for PVIN of 12 V, 5 V, and 3.3 V. The recommended switching frequency is 500 kHz which can be configured by leaving the FREQ_SEL pin open. To adjust the frequency, see Table 2.
RSET (Ω) | RSET (Ω) | |||||||
---|---|---|---|---|---|---|---|---|
VOUT (V) | PVIN = 12 V | PVIN = 5 V | PVIN = 3.3 V | VOUT (V) | PVIN = 12 V | PVIN = 5 V | PVIN = 3.3 V | |
0.60 | open | open | open | 2.15 | 566 | 563 | 560 | |
0.65 | 18787 | 18681 | 18588 | 2.20 | 548 | 545 | 542 | |
0.70 | 9024 | 8993 | 8966 | 2.25 | 532 | 528 | 525 | |
0.75 | 5939 | 5923 | 5908 | 2.30 | 516 | 513 | 510 | |
0.80 | 4427 | 4416 | 4406 | 2.35 | 502 | 498 | 495 | |
0.85 | 3529 | 3521 | 3513 | 2.40 | 488 | 484 | 481 | |
0.90 | 2934 | 2927 | 2921 | 2.45 | 475 | 471 | 468 | |
0.95 | 2511 | 2505 | 2500 | 2.50 | 462 | 459 | 456 | |
1.00 | 2195 | 2190 | 2185 | 2.55 | 451 | 447 | 444 | |
1.05 | 1950 | 1945 | 1941 | 2.60 | 439 | 436 | 433 | |
1.10 | 1754 | 1749 | 1745 | 2.65 | 429 | 425 | 422 | |
1.15 | 1594 | 1589 | 1586 | 2.70 | 419 | 415 | 412 | |
1.20 | 1460 | 1456 | 1453 | 2.75 | 409 | 405 | 402 | |
1.25 | 1348 | 1344 | 1341 | 2.80 | 400 | 396 | 393 | |
1.30 | 1251 | 1248 | 1244 | 2.85 | 391 | 387 | 384 | |
1.35 | 1168 | 1164 | 1161 | 2.90 | 382 | 379 | 375 | |
1.40 | 1095 | 1091 | 1088 | 2.95 | 374 | 370 | 367 | |
1.45 | 1031 | 1027 | 1024 | 3.00 | 367 | 363 | 359 | |
1.50 | 973 | 970 | 968 | 3.05 | 359 | 355 | 352 | |
1.55 | 922 | 919 | 916 | 3.10 | 352 | 348 | 345 | |
1.60 | 876 | 873 | 870 | 3.15 | 345 | 341 | 338 | |
1.65 | 834 | 831 | 828 | 3.20 | 339 | 335 | 331 | |
1.70 | 797 | 793 | 790 | 3.25 | 332 | 328 | 325 | |
1.75 | 762 | 759 | 756 | 3.30 | 326 | 322 | 318 | |
1.80 | 730 | 727 | 724 | 3.35 | 320 | 316 | 312 | |
1.85 | 701 | 698 | 695 | 3.40 | 315 | 310 | 307 | |
1.90 | 674 | 671 | 668 | 3.45 | 309 | 305 | 301 | |
1.95 | 650 | 646 | 643 | 3.50 | 304 | 300 | 296 | |
2.00 | 626 | 623 | 620 | 3.55 | 299 | 294 | 291 | |
2.05 | 605 | 602 | 599 | 3.60 | 294 | 289 | 286 | |
2.10 | 585 | 581 | 578 |