L5962 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'L5962' PDF : 24 Pages View PDF
L5962
4
Device description
Device description
The IC includes one standby regulator, always active to guarantee the standby functions;
two switched linear regulators, managed by the I2C bus and a step-down switching voltage
regulator with selectable current limit.
4.1
4.1.1
Regulators
The VSTBY regulator is always active when the IC is supplied.
The other regulators can be enabled or disabled. Their outputs are automatically disabled
whenever the VBAT voltage exceeds the over-voltage shutdown threshold. Upon return from
over-voltage shutdown, the outputs recover without intervention from the system.
Linear regulators
VSTBY (3.3 V / 5.0 V standby)
VSTBY is a linearly regulated 3.3/5 V output. This output is enabled on battery connect. It is
supplied from the protected battery input (VBATP).
In order to select the 3.3 V output, the VSTBYSEL pin must be connected to ground.
In order to select the 5.0 V output, the VSTBYSEL pin must be connected to 5 V.
When the dropout voltage of the regulator cannot be maintained, the output shall track the
VBATP input voltage less the saturation voltage of the regulator pass element.
This regulator has a short circuit protection consisting of current limit, and thermal
shutdown. If the local die temperature exceeds the thermal shutdown detection threshold,
the output is disabled. The thermal shutdown circuitry has hysteresis such that the output is
enabled only after the die temperature falls below the thermal shutdown disable threshold.
Thermal shutdown on this output doesn't directly disable any other circuitry.
RST provides an indication that VSTBY is in regulation. It is an open drain output used to
indicate that VSTBY is in regulation (below the low-voltage threshold). RST remains low
until VSTBY achieves regulation and the RSTDLY input has charged to its threshold. For
instance, RST remains low during battery connect and disconnect and under low-voltage
battery lockout. The transition from standby mode to active mode (and vice versa) does not
cause the RST output to be triggered.
RSTDLY provides a means to delay the releasing of RST once VSTBY has achieved
regulation. It is used to delay the release of RST when VSTBY achieves regulation. This
input has a current source to charge an external capacitor and an internal pull-down to
discharge the external capacitor. The voltage on this capacitor is used to control the
operation of the RST output.
The RSTDLY pull-down is activated when a loss of regulation is detected. The input remains
low until VSTBY once again achieves regulation.
When the RSTDLY is released the current source charges the external capacitor. When the
voltage exceeds the pin's threshold, RST pin is also released, disabling its pull-down.
Doc ID 16819 Rev 2
15/24
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