RT8223P View Datasheet(PDF) - Richtek Technology

Part Name

Description

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RT8223P

High Efficiency, Main Power Supply Controller for Notebook Computer

Richtek Technology 

RT8223P

ENTRIPx or cycle VIN to reset the UVP fault latch and

restart the controller.

Thermal Protection

The RT8223P features thermal shutdown protection to

prevent overheat damage to the device. Thermal shutdown

occurs when the die temperature exceeds 150°C. All

internal circuitry is inactive during thermal shutdown. The

RT8223P triggers thermal shutdown if VREGx is not

supplied from VOUTx, while the input voltage on VIN and

the drawing current from VREGx are too high. Even if

VREGx is supplied from VOUTx, large power dissipation

on automatic switches caused by overloading VREGx,

may also result in thermal shutdown.

Shutdown Mode

The RT8223P SMPS1, SMPS2, VREG3 and VREG5 have

independent enabling controls. Drive EN, ENTRIP1 and

ENTRIP2 below the precise input falling-edge trip level to

place the RT8223P in its low power shutdown state. The

RT8223P consumes only 20μA of input current while in

shutdown. When shutdown mode is activated, the

reference turns off. The accurate 0.4V falling-edge threshold

on the EN pin can be used to detect a specific analog

voltage level as well as to shutdown the device. Once in

shutdown, the 2.4V rising-edge threshold activates,

providing sufficient hysteresis for most applications.

Power Up Sequencing and On/Off Controls (ENC)

Discharge Mode (Soft-Discharge)

When ENTRIPx is low and a transition to standby or

shutdown mode occurs, or the output under voltage fault

latch is set, the output discharge mode will be triggered.

During discharge mode, the output capacitors' residual

charge will be discharged to GND through an internal

switch.

ENTRIP1 and ENTRIP2 control the SMPS power up

sequencing. When the RT8223P is in single channel mode,

ENTRIP1 or ENTRIP2 enables the respective output when

ENTRIPx voltage descends below 3V. Furthermore, the

RT8223P can also be in dual channel mode. In this mode,

outputs are enabled when ENC voltage rises above 2V.

Table 2. Operation Mode Truth Table

MODE

Condition

Power UP VREGx < UVLO threshold

RUN

EN = high, VOUT1 or VOUT2

enabled

Over Voltage Either output > 111% of the nominal

Protection level.

Under Either output < 52% of the nominal

Voltage level after 3ms time-out expires and

Protection output is enabled

Discharge

Standby

Either SMPS output is still high in

either standby mode or shutdown

mode

ENTRIPX < startup threshold,

EN = high.

Shutdown EN = low

Thermal

Shutdown

TJ > 150°C

Comment

Transitions to discharge mode after a VIN POR and after

REF becomes valid. VREG5, VREG3, and REF remain

active.

Normal Operation.

LGATEx is forced high. VREG3, VREG5 and REF active.

Exited by VIN POR or by toggling EN, ENTRIPx, ENC

Both UGATEx and LGATEx are forced low and enter

discharge mode. VREG3, VREG5 and REF are active.

Exited by VIN POR or by toggling EN, ENTRIPx, ENC

During discharge mode, there is one path to discharge the

outputs capacitor residual charge. That is output capacitor

discharge to GND through an internal switch.

VREG3, VREG5 and REF are active.

All circuitry off.

All circuitry off. Exit by VIN POR or by toggling EN, ENTRIPx,

ENC

www.richtek.com

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DS8223P-01 June 2011

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