33730_10 Datasheet, PDF (19/26 Pages) Freescale Semiconductor, Inc – Switch Mode Power Supply with Multiple Linear Regulators

FUNCTIONAL DEVICE OPERATION
OPERATIONAL MODES
VDDH
out of
re gu latio n
B att ery
Vo lta ge
VDDH = 5. 0 V
V DD3,
V DDL
out of
regulat ion
10 0u s
V DDH
tu rn ed
o ff
VDDL = V _DD3 = 3. 3V
VDD3, V DDL
act ively
pulled low
43..05VV
VKA _M = 1.0V
RS TKA M
RS TL, RS T3
RSTH
Figure 7. Battery Voltage Ramp Down
OPERATIONAL MODES
The 33730 can operate in the two modes: Low quiescent
current Sleep mode and Normal mode of operation.
SLEEP MODE
The 33730 operates in the Sleep mode when both the
VIGN pin and the REGON pins are pulled low. Both of these
pins have internal pull-downs, which assures that the IC is in
this defined state when those pins are left open.
When the IC enters the Sleep mode, all major functions
are disabled except for the Standby regulators. The Keep-
Alive regulator VKAM stays always operational (see Table 6).
If this output stays unloaded, the IC in the Sleep mode
consumes very low quiescent current (I_Q).
If the VDD3 output was programmed as a VDD3 Standby
regulator (see Table 6), it too stays operational during the
Sleep mode, as well as the VKAM regulator. In this case, the
IC consumes about 100 μA of additional quiescent current
(assuming both VKAM and VDD3 Standby outputs are
unloaded).
NOTE: In the Sleep mode, the RSTKAM and RST3 are not
active and their outputs (as well as the outputs of RSTL and
RSTH) are in the high-impedance state.
NORMAL MODE
The 33730 enters the Normal mode of operation when
either the VIGN pin or the REGON pin is pulled high. In this
case the IC is fully operational with all regulator outputs ready
to supply power and all control, monitoring and protection
features activated.
Analog Integrated Circuit Device Data
Freescale Semiconductor
33730
19