Only For Training And Service Purposes - LG GB220 Service Manual

3. TECHNICAL BRIEF
3.2.6 Power Supply Start-up sequence
In order to avoid an excessive drop on the battery voltage caused by in-rush current during system power-
on, possibly leading to system instability and "hick-ups" a staggered turn-on approach for the regulators is
implemented. The regulators are turned on in a well defined sequence, thus spreading the in-rush current
transients over time.
The IO's of X-GOLD TM 213 are isolated in OFF mode (core supply is off). The isolation signal is controlled by
the PMU state machine. This ensures that the PADs are in a well defined state during core supply settling.
This allows to power up the LCORE core regulator and wait for the core to reach reset state before powering
up the I/O supply regulators.
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LGE Internal Use Only - 28 - Copyright © 2009 LG Electronics. Inc. All right reserved. Copyright © 2007 LG Electronics. Inc. All right reserved.

Only for training and service purposes

Only for training and service purposes