BD9489F Datasheet, PDF (27/39 Pages) Rohm – DCDC converter with current mode

BD9489F
3.5.3 Turn Off
Datasheet
STB
PWM
REG58
2.3V
REG58UVLO
DIMOUT
GATE
Vout
SS
RT 2.0V
STATE
ON
Dischange
OFF
(*1)
(*2)
Figure 38. Turn Off
(*1)…As STB=H→L, boost operation stops and REG58 starts to discharge.
(*2)…While STB=L, REG58UVLO=H, DIMOUT becomes same as PWM. REG58=5.8V is discharged by -5μA until REG58=2.3V,
and then IC becomes OFF state. REG58 is discharged rapidly and RT becomes 0V at the same time. V_OUT is discharged
completely until this time. It should be set to avoid a sudden brightness.
About capacitance value setting of REG58, please refer to the section 3.2.2.
www.rohm.com
© 2013 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
27/36
TSZ02201-0F1F0C100250-1-2
29.Oct 2014 Rev.002