Datasheet

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LPC3152_3154 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2010. All rights reserved.
Preliminary data sheet Rev. 0.12 — 27 May 2010 45 of 88
NXP Semiconductors
LPC3152/3154
• The nominal charge current is programmed with an external program-resistor. This
allows the charge current to be adapted to the USB enumeration.
• Uses a widespread method to charge a Li-ion battery with the following stages:
– Trickle charging with a small current for an (almost) empty battery.
– Fast charging in Constant Current mode (CC mode) to the maximum battery
voltage of 4.2 V ± 1%.
– Switch from CC mode to Constant Voltage charging (CV mode) keeping the battery
voltage at 4.2 V and monitoring the current for ending the charge process.
• Short circuit resistant.
• Charger state can be observed through a register.
7.4 USB charge pump (host mode)
The USB charge pump uses the Li-ion battery to provide a low-power USB VBUS signal
for the USB controller in host mode.
7.5 Power Supply Unit (PSU)
The integrated PSU allows the system to run directly from the battery voltage or the USB
power supply voltage USB_VBUS. It converts the battery voltage or the USB_VBUS
voltage into the supply voltages required for both the digital and analog blocks in the rest
of the system.