RT9470 datasheet(36/50 Pages) RICHTEK

36 / 50 page

RT9470/D

is a registered trademark of Richtek Technology Corporation.

www.richtek.com

DS9470/D-02

October 2023

ITRICKLE_CHG

IPRE_CHG[3:0]

IEOC_CHG[7:4]

VTRICKLE_CHG_RISE

VPRE_CHG_RISE[6:4]

ICHG_REG[5:0]

VBAT_REG[6:0]

Trickle Charge

Pre-Charge

Fast Charge

Constant Current

Back-Ground

Charge (optional)

Charge Current

Battery Voltage

VRE_CHG

Fast Charge

Constant Voltage

End of Charge

Figure 3. Charging Profile

⚫

End of Charge (EOC)

The charger enters end of charge status when

battery voltage is above recharge threshold, and the

charge current is below IEOC_CHG. IEOC_CHG setting

range is from 50mA to 800mA with 50mA resolution.

After EOC, the BATFET turns off with TE = 1 and

BG_CHG_TMR = 00, and the buck converter keeps

switching to supply power to the system. BATFET

will turn on again when battery voltage is under

recharge voltage threshold or device is in Battery

Supply Mode during EOC.

When EOC occurs, there are four conditions as

below :

Table 5. EOC Status Scenario

TE = 1

BG_CHG_TMR

(disable)

TE = 1

BG_CHG_TMR

(counting)

TE = 1

BG_CHG_TMR

(timeout)

TE = 0

BG_CHG_TMR

(disable)

ST_EOC

ST_CHG_DONE

ST_BG_CHG

STAT Pin

High

Low

IC_STAT

0111

0110

0111

0101

BATFET

OFF

If the device triggers AICR, MIVR, JEITA or

thermal regulation status during charging, the

actual charging current

will

less

than

programmed value. In this condition, EOC

function will be disabled and the safety timer’s

counter clock rate will be half.

The back-ground charge can be applied after

EOC is detected. The back-ground charge is

enabled by setting BG_CHG_TMR and TE = 1

only. When back-ground charge occurs, the

IC_STAT is set to 0110, and the BATFET will

turn off after back-ground charge timer expires.

RT9470 Datasheet(PDF) 36 Page - Richtek Technology Corporation

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