Datasheet MAX866, MAX867 (Maxim) - 10
| Hersteller | Maxim |
| Beschreibung | 3.3V/5V or Adjustable Output, Single-Cell DC-DC Converters |
| Seiten / Seite | 12 / 10 — 3.3V/5V or Adjustable-Output, Single-Cell DC-DC Converters. Table 1. … |
| Dateiformat / Größe | PDF / 143 Kb |
| Dokumentensprache | Englisch |
3.3V/5V or Adjustable-Output, Single-Cell DC-DC Converters. Table 1. Component Suppliers. PRODUCTION. INDUCTORS. CAPACITORS
Modelllinie für dieses Datenblatt
Textversion des Dokuments
3.3V/5V or Adjustable-Output, Single-Cell DC-DC Converters Table 1. Component Suppliers PRODUCTION INDUCTORS CAPACITORS RECTIFIERS METHOD
Matsuo 267 series Motorola MBR 0530 Sprague 595D series Surface Mount See Table 2 Nihon EC15QS02L AVX TPS series Sanyo Miniature Sumida OS-CON series Motorola 1N5017 Through Hole RCH654-220 low-ESR organic semiconductor
MAX866/MAX867 COMPANY PHONE FAX
AVX USA: (803) 946-0690 (803) 626-3123 Coilcraft USA: (847) 639-6400 (847) 639-1469 Matsuo USA: (714) 969-2491 (714) 960-6492 Motorola USA: (602) 244-5303 (602) 244-4015 Murata-Erie USA: (800) 831-9172 (814) 238-0490 USA: (805) 867-2555 (805) 867-2698 Nihon Japan: 81-3-3494-7411 81-3-3494-7414 USA: (619) 661-6835 (619) 661-1055 Sanyo Japan: 81-7-2070-6306 81-7-2070-1174 USA: (847) 956-0666 (847) 956-0702 Sumida Japan: 81-3-3607-5111 81-3-3607-5144 TDK USA: (847) 390-4461 (847) 390-4405 J.W. Miller USA: (310) 515-1720 (310) 515-1962
Inductor Selection
which is well within the ratings of most surface-mount An inductor value of 330µH works well in most applica- coils. Higher efficiency and output current are achieved tions, supplying loads over 10mA and allowing typical with lower inductor resistance, but unfortunately this is start-up voltages of 0.8V. The inductor value is not inversely related to physical size. Table 2 indicates critical, and the MAX866/MAX867 can operate with val- resistance and height for each coil. Some of the small- ues from 22µH to 1mH. In general, smaller inductor val- est coils have resistances over 10Ω, and will not pro- ues supply more output current while larger values start vide the same output power or efficiency of a 1Ω coil. with lower input voltage. Several inductor suppliers and At light loads however (below 5mA), the efficiency dif- part numbers are listed in Tables 1 and 2. ferences between low- and high-resistance coils may The peak inductor current should not exceed the induc- be only a percent or two. The Typical Operating tor’s current rating. Since the MAX866/MAX867 current Characteristics graphs show efficiency and output cur- limit of 0.5A will not be reached in most applications, rent plots for 1.5Ω and 2.9Ω, 330µH coils. the peak coil current (IPK) is:
Capacitor Selection
IPK = (VIN(max) x 4.5µs) / L A 47µF, 6V, 0.85Ω, surface-mount tantalum (SMT) For a typical 1-cell alkaline design, V output filter capacitor typically provides 15mV output IN(max) is 1.55V, so: ripple when stepping up from 0.9V to 1.4V at 10mA. Smaller capacitors (down to 10µF with higher ESRs) are IPK = (1.55V x 4.5µs) / 330µH = 21.14mA acceptable for light loads or in applications that can
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Matsuo 267 series Motorola MBR 0530 Sprague 595D series Surface Mount See Table 2 Nihon EC15QS02L AVX TPS series Sanyo Miniature Sumida OS-CON series Motorola 1N5017 Through Hole RCH654-220 low-ESR organic semiconductor
MAX866/MAX867 COMPANY PHONE FAX
AVX USA: (803) 946-0690 (803) 626-3123 Coilcraft USA: (847) 639-6400 (847) 639-1469 Matsuo USA: (714) 969-2491 (714) 960-6492 Motorola USA: (602) 244-5303 (602) 244-4015 Murata-Erie USA: (800) 831-9172 (814) 238-0490 USA: (805) 867-2555 (805) 867-2698 Nihon Japan: 81-3-3494-7411 81-3-3494-7414 USA: (619) 661-6835 (619) 661-1055 Sanyo Japan: 81-7-2070-6306 81-7-2070-1174 USA: (847) 956-0666 (847) 956-0702 Sumida Japan: 81-3-3607-5111 81-3-3607-5144 TDK USA: (847) 390-4461 (847) 390-4405 J.W. Miller USA: (310) 515-1720 (310) 515-1962
Inductor Selection
which is well within the ratings of most surface-mount An inductor value of 330µH works well in most applica- coils. Higher efficiency and output current are achieved tions, supplying loads over 10mA and allowing typical with lower inductor resistance, but unfortunately this is start-up voltages of 0.8V. The inductor value is not inversely related to physical size. Table 2 indicates critical, and the MAX866/MAX867 can operate with val- resistance and height for each coil. Some of the small- ues from 22µH to 1mH. In general, smaller inductor val- est coils have resistances over 10Ω, and will not pro- ues supply more output current while larger values start vide the same output power or efficiency of a 1Ω coil. with lower input voltage. Several inductor suppliers and At light loads however (below 5mA), the efficiency dif- part numbers are listed in Tables 1 and 2. ferences between low- and high-resistance coils may The peak inductor current should not exceed the induc- be only a percent or two. The Typical Operating tor’s current rating. Since the MAX866/MAX867 current Characteristics graphs show efficiency and output cur- limit of 0.5A will not be reached in most applications, rent plots for 1.5Ω and 2.9Ω, 330µH coils. the peak coil current (IPK) is:
Capacitor Selection
IPK = (VIN(max) x 4.5µs) / L A 47µF, 6V, 0.85Ω, surface-mount tantalum (SMT) For a typical 1-cell alkaline design, V output filter capacitor typically provides 15mV output IN(max) is 1.55V, so: ripple when stepping up from 0.9V to 1.4V at 10mA. Smaller capacitors (down to 10µF with higher ESRs) are IPK = (1.55V x 4.5µs) / 330µH = 21.14mA acceptable for light loads or in applications that can
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