DESCRIPTION

The LTM8024 is 40VIN, dual 3.5A or single 7A step-down Silent Switcher µModule® regulator. The Silent Switcher architecture minimizes EMI while delivering high efficiency at frequencies up to 3MHz. Included in the package are the controllers, power switches, inductors, and support components. Operating over a wide input voltage range, the LTM8024 supports output voltages from 0.8V to 8V, and a switching frequency range of 200kHz to 3MHz, each set by a single resistor. Only the bulk input and output filter capacitors are needed to finish the design. The LTM8024 product video is available on website.

The LTM8024 is packaged in a thermally enhanced, compact (9mm × 11.25mm × 3.32mm) over-molded ball grid array (BGA) package suitable for automated assembly by standard surface mount equipment. The LTM8024 is RoHS compliant.

 

CARACTÉRISTIQUES

Deux alimentations à découpage abaisseur de tension complètes

Architecture Silent Switcher® à faible bruit

Conforme à la norme CISPR22 Classe B

Large plage de tension d'entrée : 3V à 40V

Wide Output Voltage Range: 0.8V to 8V

3.5A Continuous Output Current Per Channel at 12VIN, 3.3VOUT, TA = 80°C

Fonctionnement en parallèle multiphase pour augmenter le courant

Selectable Switching Frequency: 200kHz to 3MHz

Compact Package (9mm × 11.25mm × 3.32mm) Surface Mount BGA

 

CANDIDATURES

Régulation des batteries automobiles

Puissance pour les produits portables

Régulation de l'approvisionnement distribué

Fournitures industrielles

 

INFORMATIONS SUR LES APPLICATIONS

For most applications, the design process is straightforward, summarized as follows:

  1. Look at Table 1 and find the row that has the desired input range and output voltage.
  2. Apply the recommended CIN, COUT, RFB and RT values.
  3. Connect BIAS as indicated.When using the LTM8024 with two different output volt

ages, the higher frequency recommended by Table 1 will usually result in the best operation. While these component combinations have been tested for proper operation, it is incumbent upon the user to verify proper operation over the intended system’s line, load and environmental conditions. Bear in mind that the maximum output current is limited by junction temperature, the relationship between the input and output voltage and other factors.

Please refer to the graphs in the Typical Performance Characteristics section for guidance.

The maximum frequency (and attendant RT value) at which the LTM8024 should be allowed to switch is given in Table 1 in the Maximum fSW column, while the recommended frequency (and RT value) for optimal efficiency over the given input condition is given in the fSW column.

There are additional conditions that must be satisfied if the synchronization function is used. Please refer to the Synchronization section for details.

Capacitor Selection Considerations

The CIN and COUT capacitor values in Table 1 are the minimum recommended values for the associated operating conditions. Applying capacitor values below those indicated in Table 1 is notrecommended and may result in undesirable operation. Using larger values is generally acceptable, and can yield improved dynamic response, if it is necessary. Again, it is incumbent upon the user to verify proper operation over the intended system’s line, load and environmental conditions.

Ceramic capacitors are small, robust and have very low ESR. However, not all ceramic capacitors are suitable. X5R and X7R types are stable over temperature and applied voltage and give dependable service. Other types, including Y5V and Z5U have very large temperature and voltage coefficients of capacitance. In an application circuit they may have only a small fraction of their nominal capacitance resulting in much higher output voltage ripple than expected.

Ceramic capacitors are also piezoelectric. In Burst Mode operation, the LTM8024’s switching frequency depends on the load current, and can excite a ceramic capacitor at audio frequencies, generating audible noise. Since the LTM8024 operates at a lower current limit during Burst Mode operation, the noise is typically very quiet to a casual ear