1.8V

0V

FET OF LILO (SMALL NMOS)

LARGE NMOS

(SMALL NMOS TO LARGE NMOS TRANSITION)

0V

1.2V

LM3686

SNVS520D – AUGUST 2008 – REVISED MARCH 2011

www.ti.com

Table 1. Enable Combinations (continued)

EN_DCDC

EN_LILO

EN_LDO

Function

1

0

0

DC-DC converter enabled only

1

1

0

Linear Regulator & DCDC enabled

High is 250 mA (Note A & B)

1

1

1

DC-DC converter and linear regulator active.

Linear regulator starts after DC-DC converter.

when this small NMOS is ON. If higher current > 50 mA is desired the following condition must be done: EN_DC

= HIGH .

Note B: When the switcher is enabled, a transition occurs from the small NMOS to a larger NMOS. The

small NMOS (Switcher EN = low).

Figure 4. Mode Transition

These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam

during storage or handling to prevent electrostatic damage to the MOS gates.

4

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