N900 Hardware Power management
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=Hardware=
=Hardware=
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The TWL4030 (to be precise the TWL5030B, see [http://people.openmoko.org/joerg/n900/images/n900_01.jpeg] aka TPS65950) has USB PHY, power managment and audio codec.
 
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The USB PHY isn't used and is handled by the nxp1707a [http://www.spinics.net/lists/linux-usb/msg25167.html] See [[N900_Hardware_USB|more information on USB]]
 
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It seems to be documented - not under this part number - at [http://focus.ti.com/docs/prod/folders/print/tps65950.html TIs website]
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There are four chips involved in the USB subsystem.
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A quick check indicates the I2C bus addresses match - see 13.3 in above datasheet.
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====SoC====
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If this is the correct part, the following description applies:
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The System-on-a-chip is the main processor on the n900.
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This is the [http://focus.ti.com/docs/prod/folders/print/omap3530.html  TI omap3430]
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====Gaia====
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The [[N900_Hardware_Chipset|TWL4030]] is a TI companion chip to the SoC.
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====USB battery charger====
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The [http://focus.ti.com/docs/prod/folders/print/bq24150.html bq24150] charger from TI is a flexible charger. It, along with the PHY chip - support charging without the intervention of the SoC when the system is charging from a completely dead battery. The PHY chip detects a charger (shorted D+ and D- pins) and the charger uses this information to charge more rapidly.
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It also features reverse boost mode - which enables power to be supplied to a USB device connected to the N900. (up to a limit of 200mA)
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For more information see [[N900 Hardware Battery Charger]]
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The TPS65950 contains;
 
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* Power management
 
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** Several regulators - switched mode and LDO.
 
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* Audio codec
 
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** Five DACs, two ADCs
 
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** Several power amplifiers.
 
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** Microphone amplifiers
 
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* USB tranciever
 
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** Highspeed OTG compatible with integrated charge pump, and carkit support, designed for direct connection to the SoC.
 
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* an ac/USB charger
 
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* LED drivers
 
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* ADC
 
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** ADC can measure both input voltages to device, or voltages connected externally.
 
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* RTC
 
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* GPIO
 
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** This can support switches, keypads, ...
 
=Software=
=Software=
[[Category:n900]] [[Category:n900_Hardware]]
[[Category:n900]] [[Category:n900_Hardware]]

Revision as of 10:43, 4 June 2010

The power managment on the n900 is very complex, and involves a large number of interacting systems.

Contents

Hardware

There are four chips involved in the USB subsystem.

SoC

The System-on-a-chip is the main processor on the n900. This is the TI omap3430

Gaia

The TWL4030 is a TI companion chip to the SoC.

USB battery charger

The bq24150 charger from TI is a flexible charger. It, along with the PHY chip - support charging without the intervention of the SoC when the system is charging from a completely dead battery. The PHY chip detects a charger (shorted D+ and D- pins) and the charger uses this information to charge more rapidly.

It also features reverse boost mode - which enables power to be supplied to a USB device connected to the N900. (up to a limit of 200mA)

For more information see N900 Hardware Battery Charger

Software

Retrieved from "http://wiki.maemo.org/N900_Hardware_Power_management"