TECHNICAL NOTE System Power Supply for TV Series FET Controller Type 3ch System Power Supply ICs BD8606FV ●Description BD8606FV has realized the high performance and reliability required as a power supply for thin-screen TV. Due to the high-speed load response, it is most suitable for TV-purpose processors with increasingly high performance, and due to the wide phase margin it leaves a good margin for board pattern & constant setting and so facilitates its application design. As a high-reliability design, it has various built-in protection circuits (overcurrent protection, output voltage abnormal protection, thermal protection, and off-latch function at the time of abnormality etc.), therefore as an advantage it does not easily damage in every possible abnormal condition such as all-pin short circuit test etc. and hence most suitable for thin-screen TV which requires the high reliability. ●Features 1) 2) 3) 4) 5) 6) 7) 8) 9) 10) 11) 3ch synchronous rectification step-down system DC/DC converter controller 3ch independent ON/OFF. controllable Soft start, soft off function Concentrated protection control with built-in sequencer Built-in low voltage protection function Built-in overvoltage protection function Built-in overcurrent protection function Built-in RT terminal open/short protection function Frequency setting by external resistance is available. Protection condition is output from PDET terminal. Built-in external reset output function Aug. 2008 ● Electric characteristic (Ta=25℃, VIN1, VIN2, VIN3=5.0V, VCC=5.0V, and GND=0V unless otherwise specified.) Parameter Symbol IQ1 IQ2 Circuit current 1 Circuit current 2 MIN - specification value TYP MAX 2.5 5 5.0 10 UNIT Condition mA mA CTL1,2,3=0V CTL1,2,3=VCC Terminal FB and FC terminal short < Error amplifier part Ch1,Ch2,Ch3 > Standard voltage （VREF） Terminal FB Input bias current Terminal FC Clamping voltage H Terminal FC Clamping voltage L Terminal FC Sink current Terminal FC Source current Open loop gain VREF IFBB VFCH VFCL 0.792 -1 1.8 0.5 - 0.8 0 100 0.808 1 0.2 -70 - V μA V V mA μA ｄB FOSC 100 - 600 kHz ISS VSSTH VSSCLM VSSSTB -4.0 1.0 1.44 0.11 -2.5 1.1 1.72 0.15 -1.0 1.2 2.0 0.19 μA V V V VSSSTB_HYS 5 50 100 mV RSS VSSPON 49 1.0 70 1.1 91 1.2 kΩ V VSS voltage (L→H) VSSPON_HYS 10 100 200 mV VSS voltage IFCSINK IFCSOURCE AVERR VFB=0.9V VFB=0.7V VFB=0.9V VFB=0.9V, VFC=0.4V VFB=0.7V, VFC=1.6V < OSC part > Oscillation frequency < Soft start part Ch1,Ch2,Ch3 > Charging current Terminal SS Threshold voltage Terminal SS Clamping voltage Terminal SS Standby voltage Terminal SS Standby voltage Maximum hysteresis error Terminal SS Discharge resistance Terminal SS Protection circuit start voltage Terminal SS Protection circuit start voltage Maximum hysteresis error VSS=1.0V VSS voltage, VFC=0.8V VSS voltage (L→H) < Low voltage, over voltage detection part Ch1,Ch2,Ch3 > VLVP 0.27 0.32 0.37 V VFB voltage VLVP_HYS 10 100 200 mV VFB voltage VOVP 1.08 1.2 1.32 V VFB voltage ILXB IOCPB -1 20 0 50 1 80 uA uA VRSTO IMONVCCB IRSTDLY VOL_RST 0.98 -1 -15 - 1.0 0 -10 - 1.02 1 -5 0.4 V uA uA V VMONVCC voltage (H→L) Terminal CTL input current VOL_RDET VIH_CTL VIL_CTL II_CTL 2.0 - 40 0.4 VCC 0.5 70 V V V uA Terminal DRV H output voltage VOH_DRV 4.5 - - V Terminal DRV L output voltage VOL_DRV - - 0.5 V IOL=100uA Terminal CTL1,2,3 Terminal CTL1,2,3 Terminal CTL1,2,3, CTL=VCC Terminal DRV1A,2A,3A,1B,2B,3B Terminal DRV1A,2A,3A,1B,2B,3B Terminal FB Low voltage detection voltage Terminal FB Low voltage detection Maximum hysteresis error Terminal FB Overvoltage detection voltage < Over current detection part Ch1,Ch2,Ch3 > Terminal LX input bias current Terminal OCP input bias current < Reset detection part > Terminal MONVCC reset detection voltage Terminal MONVCC input bias current Terminal RSTDLY charging current Terminal RESET L output voltage IOL=100uA < Others > Terminal PDET L output voltage Terminal CTL input voltage H level voltage Terminal CTL input voltage L level voltage VFB : FB terminal voltage, VFC : FC terminal voltage, VSS : SS terminal voltage, VMONVCC : MONVCC terminal voltage Not designed for radiation resistance. Current capability should not exceed Pd. 2 / 22 ● Block diagram 21 PGND3 22 DRV3B 23 LX3 24 DRV3A 25 VIN3 26 OCP3 27 FB3 12 28 FC3 29 SS3 30 RT 31 GND 32 TEST1 33 TEST2 34 CTL1 35 CTL2 36 CTL3 37 VCC 38 RESET RSTDLY 39 MONVCC PDET 40 VRSTO OVP1.5 LVP0.4 VREF Delay Driver Control SYSTEM CONTROL SEQUENCER SS1 SS2 SS3 Driver Control Driver Control VREF OVP1.5 LVP0.4 OVP1.5 LVP0.4 VREF OSC 20 PGND2 19 DRV2B 18 LX2 17 DRV2A 16 VIN2 15 OCP2 14 FB2 13 FC2 11 SS2 10 GND 9 SS1 8 FC1 7 FB1 6 OCP1 5 VIN1 4 DRV1A 3 LX1 2 DRV1B PGND1 1 Figure 1 Block char ● Terminal explanation Table 1 terminal explanation No. Symbol 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Description Ch1 power GND PGND1 (same potential as GND terminal) DRV1B Ch1 Nch drive output terminal LX1 Ch1 overcurrent detection terminal DRV1A Ch1 Pch drive output terminal VIN1 Ch1 power supply input terminal Ch1 overcurrent detection level OCP1 resistance connection terminal FB1 Ch1 voltage detection terminal FC1 Ch1 phase compensation terminal Ch1 soft start adjustment capacity SS1 connection terminal GND GND (0V connection) Frequency adjustment resistance RT connection terminal Ch2 soft start adjustment capacity SS2 connection terminal FC2 Ch2 phase compensation terminal FB2 Ch2 voltage detection terminal Ch2 overcurrent detection level resistance OCP2 connection terminal VIN2 Ch2 power supply input terminal DRV2A Ch2 Pch drive output terminal LX2 Ch2 overcurrent detection terminal DRV2B Ch2 Nch drive output terminal Ch2 power GND PGND2 (same potential as terminal GND) No. 21 22 Symbol Description Ch3 power GND PGND3 (same potential as terminal GND) DRV3B Ch3 Nch drive output terminal 23 LX3 24 25 DRV3A VIN3 26 OCP3 27 28 FB3 FC3 29 SS3 30 GND 31 TEST1 Test terminal (Connect to GND) 32 TEST2 Test terminal (connect to GND) 33 34 CTL1 CTL2 Ch1 control terminal Ch2 control terminal 35 CTL3 Ch3 control terminal 36 37 VCC RESET 38 39 40 Ch3 overcurrent detection terminal Ch3 Pch drive output terminal Ch3 power supply input terminal Ch3 overcurrent detection level resistance connection terminal Ch3 voltage detection terminal Ch3 phase compensation terminal Ch3 soft start adjustment capacity connection terminal GND (0V connection) Power supply input terminal Reset output terminal Reset delay adjustment capacity RSTDLY connection terminal MONVCC VCC monitor terminal PDET Off latch signal output ※Please give to VCC+0.3V as an operation condition in all input terminals. However, please do not exceed the absolute maximum rating as VCC=VIN1=VIN2=VIN3. 3 / 22 ● Terminal equivalent circuit chart Terminal No. Terminal name 1 PGND1 Ch1 Power GND (GND Terminal and this potential) 20 PGND2 Ch2 Power GND (GND Terminal and this potential) 21 PGND3 Ch3 Power GND (GND Terminal and this potential) 2 DRV1B Ch1 Nch Driving output terminal 19 DRV2B Ch2 Nch Driving output terminal 22 DRV3B Ch3 Nch Driving output terminal Explanation Terminal equivalent circuit chart VIN VIN ② ⑲ 22 PGND PGND VIN 3 LX1 Ch1 VIN Over current detection terminal VIN 18 LX2 Ch2 Over current detection terminal ③ ⑱ 23 23 LX3 Ch3 Over current detection terminal PGND VIN1 4 DRV1A Ch1 Pch Driving output terminal 17 DRV2A Ch2 Pch Driving output terminal VIN1 ④ ⑰ 24 24 DRV3A Ch3 Pch Driving output terminal PGND 5 VIN1 Ch1 Power supply input terminal 16 VIN2 Ch2 Power supply input terminal 25 VIN3 Ch3 Power supply input terminal 4 / 22 PGND Terminal No. Terminal name Explanation Terminal equivalent circuit chart VCC 6 OCP1 VIN1 Ch1 Over current detection level Set resistance connection terminal ⑥ ⑮ 15 OCP2 26 Ch2 Over current detection level Set resistance connection terminal GND Ch3 Over current detection level Set resistance connection terminal 26 OCP3 7 FB1 Ch1 Voltage detection terminal 14 FB2 Ch2 Voltage detection terminal VCC ⑦ ⑭ 27 27 FB3 Ch3 Voltage detection terminal GND VCC 8 FC1 Ch1 Phase amends terminal ⑧ ⑬ 28 13 FC2 Ch2 Phase amends terminal 28 FC3 Ch3 Phase amends terminal GND 5 / 22 Terminal No.. Terminal name 9 SS1 Ch1 Soft start Adjustment capacity connection terminal 12 SS2 Ch2 Soft start Adjustment capacity connection terminal 29 SS3 Ch3 Soft start Adjustment capacity connection terminal 10 GND GND （0V Connection） 30 GND GND （0V Connection） Explanation Terminal equivalent circuit chart VCC ⑨ ⑫ 29 GND VCC 11 RT Frequency adjustment resistance connection terminal ⑪ GND 31 TEST1 Test terminal VCC 32 TEST2 Test terminal 33 CTL1 Ch1 Control terminal 34 CTL2 Ch2 Control terminal 35 CTL3 Ch3 Control terminal 31 32 33 34 35 GND 6 / 22 Terminal No. Terminal name 36 VCC Explanation Terminal equivalent circuit chart Power supply input terminal VCC 37 RESET 37 Reset output terminal GND VCC 38 RSTDLY Reset Delay Adjustment capacity connection terminal 38 GND VCC 39 MONVCC 39 VCC Monitor terminal GND VCC 40 PDET 40 Off latch output terminal GND 7 / 22 ● Circuit chart PGND2 21 20 PGND3 Driver Control 19 DRV2B 22 DRV3B Driver Control LX2 23 18 LX3 DRV2A 24 17 DRV3A VIN3 25 16 VIN2 OCP2 26 15 OCP3 VREF VREF FB2 27 14 FB3 FC3 28 13 FC2 OVP1.5 LVP0.4 29 SS2 12 OVP1.5 LVP0.4 SS3 GND TEST1 31 10 GND TEST2 FC1 36 VCC 7 6 OCP1 VIN1 DRV1A 4 37 RESET VREF 5 35 CTL3 FB1 SS1 SS2 SS3 SYSTEM CONTROL SEQUENCER 8 33 34 CTL2 RSTDLY PWM Counter 3 DRV1B PGND1 1 40 VRSTO Driver Control 2 38 Delay LX1 MONVCC 39 9 32 SS1 OVP1.5 LVP0.4 CTL1 PDET 11 30 OSC RT ※ It measures it by the static test mode. ※ The circuit chart of CH2 and CH3 is omitted. Figure 2 Circuit chart 8 / 22 PWM Counter 16 25 15 26 14 27 13 28 12 29 10 31 9 32 8 33 6 35 5 36 4 37 3 38 2 39 1 40 9 / 22 7 34 Figure 3 Application circuit chart 11 30 OSC 17 24 SS1 SS2 SS3 18 23 SYSTEM CONTROL SEQUENCER 19 22 Delay 20 21 VRSTO ● Application circuit chart ●. Each characteristic reference data 600 550 500 450 SWITCHING FREQUENCY : fosc[kHz] ERROR AMP REFERENCE VOLTAGE : VREF[V] 0.900 0.875 0.850 0.825 0.800 0.775 0.750 0.725 400 350 300 250 200 150 100 0.700 -40 -30 -20 -10 0 10 20 30 40 50 60 70 RT=27kΩ -40 -30 -20 -10 80 Figure 4 Standard voltage-temperature characteristic 135 GAIN [dB] 40 45 20 0 0 Gain -45 -40 Ph ase [de g] 90 -90 -60 -80 -135 -100 -180 1000 10000 100000 20 30 40 50 60 70 80 4.0 SS CHARGE CURRENT : Iss[μA] Phase 60 -20 10 Figure 5 Switching frequency-temperature characteristic 180 100 80 0 AMBIENT TEMPERATURE : Ta[℃] AMBIENT TEMPERATURE : Ta[℃] 1000000 3.5 3.0 2.5 2.0 1.5 1.0 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 AMBIENT TEMPERATURE : Ta[℃] 10000000 f [H z] Figure 7 Terminal SS charge current-temperature characteristic Figure 6 Open loop characteristic 15 RSTDLY CHARGE CURRENT : Irstdly[μA] OCP INPUT CURRENT : Iocp[μA] 80 70 60 50 40 30 20 -40 -30 -20 -10 0 10 20 30 40 50 60 70 14 13 12 11 10 9 8 7 6 5 -40 -30 -20 -10 80 AMBIENT TEMPERATURE : Ta[℃] Figure 8 Terminal OCP inflow current-temperature characteristic 10 20 30 40 50 60 70 80 Figure 9 Terminal RSTDLY charge current-temperature characteristic 1.10 PWM FREQUENCY [kHz] 1000 1.05 Vrsto[V] 0 AMBIENT TEMPERATURE : Ta[℃] 1.00 0.95 0.90 -40 -30 -20 -10 0 10 20 30 40 50 60 70 100 10 80 10 AMBIENT TEMPERATURE : Ta[℃] 100 1000 RT RESISTANCE [kΩ] Figure 10 MONVCC reset detection voltage-temperature characteristic Figure 11 Switching frequency-terminal RT resistance characteristic 5V 100 90 CTL POWER EFFICIENCY[%] 3.4ms 1.72V SS 3.3V 80 70 60 50 40 VIN=5.0V Vo=3.3V External FET：SP8M4 Drive 30 20 10 Vo 0 Css=6800pF 0.0 0.5 1.0 1.5 2.0 LOAD CURRENT[A] Figure 12 Soft start crimp Figure 13 Efficiency 10 / 22 2.5 3.0 Reference data of dead time Figure 14 Dead time (VCC=5.0V,VIN=5.0V,Ta=25℃) Parameter min 90 100 Symbol PchMOS OFF→NchMOS ON Dead time NchMOS OFF→PchMOS ON Dead time Trdeat Tfdeat 200 typ 120 140 max 160 190 UNIT ns ns 200 VCC=4.0V VCC=4.0V VCC=5.0V Tfdeat [nsec] 150 Trdeat [nsec] 150 VCC=5.0V VCC=7.0V 100 VCC=7.0V 100 50 50 -40 -20 0 20 40 60 80 -40 AMBIENT TEMPERATURE : Ta[℃] -20 0 20 40 60 80 AMBIENT TEMPERATURE : Ta[℃] Figure 15 Dead time Trdeat - Temperature characteristic (pcs) 7 Figure 16 Dead time Tfdeat - Temperature characteristic (pcs) 7 VCC=VIN=5.0V Ta=25℃ n=12(2lot) 6 6 5 5 5 4 4 VCC=VIN=5.0V Ta=25℃ n=12(2lot) 6 6 4 3 3 2 2 2 1 190 188 185 183 180 178 175 173 170 168 165 163 160 158 155 153 150 148 145 143 140 138 135 133 130 128 125 123 120 118 115 113 110 108 105 103 100 160 158 155 153 150 148 145 143 140 138 135 133 130 128 125 123 120 118 115 113 110 108 0 105 103 100 0 98 95 93 1 90 1 Trdeat[ns] Tfdeat[ns] Figure 17 Dead time Trdeat - Difference Figure 18 Dead time Tfdeat - Difference 11 / 22 Reset detection data Figure 19 Circuit chart Figure 20 Reset detection (VCC=5V,Ta=25℃) Parameter Terminal MONVCC reset detection voltage Terminal MONVCC reset detection voltage Maximum hysteresis error min 0.98 typ 1.0 max 1.02 UNIT VRSTO VRST_HYS 20 72 180 mV Symbol 12 / 22 V Permissible loss Tcmax θjc [℃/W] θja [℃/W] TSTGmin [℃ ] TSTGmax [℃ ] Ta min [ ℃] Ta max [ ℃] 28.0 111.1 -50.0 150.0 -45.0 85.0 Destruction Destruction temperature temperature [ ℃] [ ℃] 150.0 1.2 Permissible loss ： Pd [W] 1 ROHM standard substrate mounting θja=111.1℃/W 0.8 0.6 0.4 0.2 0 0 25 50 75 100 125 150 Ambient temperature ： Ta [℃] ROHM standard substrate specification Material The glass epoxy Size 70mm×70mm×1.6mmt Figure 2 Heat decrease curve ※These values are the example values, and no guarantee values. 13 / 22 Tj max 150.0 ● Operation description ON/OFF control DC/DC converter controller ON/OFF function DC/DC converter controller of each Ch can be independently controlled ON/OFF by CTL1, CTL2, and CTL3 terminal. Analog circuit of Ch interlocked to each CTL terminal starts operation at ON control (on mode), and goes down to setting output voltage. Analog circuit of Ch interlocked to each CTL terminal should be standby at OFF control (off mode), and output voltage becomes 0V. Table1 DC/DC converter controller ON/OFF function CTL1 terminal voltage Ch1 CTL2 terminal voltage Ch2 CTL3 terminal voltage Ch3 >VIHCTL1 ON control >VIHCTL2 ON control >VIHCTL3 ON control <VILCTL1 OFF control <VILCTL2 OFF control <VILCTL3 OFF control Soft start time set function DC/DC converter controller of each Ch can do soft start without overshoot by charging soft start capacity (Css) connected between ss terminal and GND in each Ch by charging current at ON control. The mute of the output is released when it reaches VSS=0.15V (VSSSTB), and the output voltage does the soft start operation from the point of VSS=0.3V (typ) in proportion to the voltage of the terminal SS. Also, soft start time (tss) can be set by setting soft start capacity arbitrarily. Soft start time (tss) should be set at 3msec < tss < 30msec. ※Please note that the overshoot is not caused in the output setting voltage when setting it to tss≦3msec. t SS = 400us ＋ 1.1V × C SS 2.5uA Discharge function DC/DC converter controller of each Ch can do soft off by discharging load discharged to soft start capacity connected between SS terminal to GND by discharging resistance at OFF control. Soft off operates in proportion to the voltage of the terminal SS the output voltage from the point of VSS=0.8V (typ). 2.0V CTL terminal voltage 0.5V 1.9V 1.1V 0.8V SS terminal voltage 0.3V 0.15V Output voltage Mute release tss Figure 22 Wave form at ON/OFF control 14 / 22 OSC oscillation frequency setting function DRVA and DRVB output oscillation frequency of DC/DC converter controller of each Ch can be set by installing resistance between RT terminal and GND externally. スイッチング周波数[KHz Switching frequency[KHz] 10000 1000 100 10 1 10 100 RT terminal resistance[KΩ] RT端子抵抗[KΩ] 1000 *参考データ *reference data Figure 23 Terminal RT resistance-oscillation frequency Off latch signal output function PDET terminal outputs condition of off latch when protection operation of DC/DC converter controller of each Ch operates. Table 2 PDET terminal off latch signal output function Protection operation Terminal PDET ON LOW OFF Hi-Z 15 / 22 Reset output function Reset output function observes voltage value from MONVCC terminal and does reset operation compared to internal reference level. Set MONVCC terminal external resistance to make VCC voltage more than 5.0V at reset release. Table 3 DC/DC converter controller ON/OFF function MONVCC terminal voltage RESET terminal LOW ＜1.0V(typ) Hi-Z ＞1.072V(typ) Delay time until detecting reset release is settable by capacitor connected to RSTDLY terminal. Y L D T Y S L R D C T S V R 5 I 3 2 . 1 Y L D T S R T Figure 24 Reset operation ( TRSTDLY：Delay time until detecting reset release ) 16 / 22 Output Duty Output Duty of DRVA of the DC/DC converter controller of each Ch is decided depending on the voltage of the terminal FC of each Ch. Setting output Duty Output setting voltage 100 [%] VIN voltage Duty [%] 9% Setting output Duty 92% Figure 25 FC Voltage-Output Duty Linearity 17 / 22 ● Protection function Protection circuit is effective for destruction prevention due to accident so that avoid using by continuous protection operation. Low voltage protection function(LVP) Low voltage protection function detects output voltage VO set in each Ch from FB terminal of each Ch and off-latched all DC/DC converter controller compared to internal reference level. Low voltage protection function operates when FB terminal voltage falls below VLVP (=1.5 × VREF) and continues about more than 400μsec (typ). Table 4 Low voltage protection function CTL Low voltage Low voltage SS terminal FB terminal terminal protection function protection operation >VIHCTL >1.1V(typ) <VLVP ON Enable >VLVP+VLVP_HYS OFF <1.0V(typ) Disable OFF <VILCTL Disable OFF ※Constant voltage protection function is enabled when SS terminal voltage of each Ch becomes more than 1.1V (typ) in the transition to ON control (during soft start). Overvoltage protection function(OVP) Overvoltage protection function detects output voltage VO set in each Ch from FB terminal of each Ch and off-latched all DC/DC converter controller compared to internal reference level. Overvoltage protection function operates when FB terminal voltage exceeds VOVP (=1.5 × VREF) and continues about more than 400μsec (typ). Table 5 Overvoltage protection function CTL Overvoltage Overvoltage SS terminal FB terminal terminal protection function protection operation >VIHCTL >1.1V(typ) >VOVP ON Effective <VOVP OFF <1.0V(typ) Invalidity OFF <VILCTL Invalidity OFF ※Overvoltage protection function is enabled when SS terminal voltage of each Ch becomes more than 1.1V (typ) in the transition to ON control (during soft start). Figure 26 Low voltage and over voltage protection 18 / 22 Overcurrent protection function(OCP) Overcurrent protection function compared drain voltage (LX terminal voltage) with OCP terminal voltage when external Pch POWER MOS is ON. When LX terminal voltage becomes lower than OCP terminal voltage, external MOS would be OFF. Up to 50uA (typ) of constant current from OCP terminal is synchronized. Overcurrent detection level (OCP terminal voltage) can be set arbitrarily by external resistance value. Off latch by overcurrent protection function operates when LX terminal voltage falls below OCP terminal voltage and continues about more than 400μsec (typ). Table 6 overcurrent protection function CTL LX terminal Overcurrent SS terminal terminal voltage protection function >VIHCTL >1.1V(typ) <VOCP Enable >VOCP <1.0V(typ) Disable <VILCTL Disable ※Set OCP terminal voltage to be more than VIN-2.5V (typ). Overcurrent protection operation ON OFF OFF OFF LX terminal Voltage OCP terminal Voltage Immediately off Immediately off Immediately off DRVA DRVB Output current Rocp LX Protection ON OFF 400usec (typ) to an off latch in continuance 400usec OCP Immediately off operation Off latch Figure 27 Overcurrent protection 19 / 22 Output current Terminal FC abnormality protection function FCHP=1.95V(typ) 1.5V(typ) Internal triangular wave FC 0.9V(typ) FCLP=0.62V(typ) About 400usec(typ) continuance and an off latch. About 400usec(typ) Off latch The terminal FC abnormality protection function Ofrattis it all DC/DC converter controller detecting the continuance of the state that FC which is the difference input of PWMCOMP does not intersect with an internal triangular wave. The terminal FC abnormality protection function is exceeded 1.95V(typ) by the voltage of the terminal FC or operates when it falls below 0.62V(typ), and about 400usec(typ) or more continues. CTL terminal > VIHCTL < VIHCTL > 1.1V(typ) Protection operation Enable < 1.0V(typ) Disable SS terminal FC terminal Terminal FC abnormality protection operation > 1.95V(typ) 0.62V(typ) < , < 1.95V(typ) < 0.62V(typ) - ON OFF ON OFF ※Terminal FC abnormality protection function is enabled when SS terminal voltage of each Ch becomes more than 1.1V (typ) in the transition to ON control (during soft start). RT terminal open/short protection function RT terminal open/shot protection function off-latches all DC/DC converter controller by detecting open/short condition internally from RT terminal to prevent from output voltage error caused by abnormal oscillation of internal triangular wave at RT terminal open/short. RT terminal open/short protection function is regularly enabled after boot-up. RT terminal open/short protection function operates when error detection condition continues about more than 400μsec (typ). 20 / 22 Soft start time-out function Each Ch DC/DC converter controller off-latch-controls when VSS does not exceed VSSPON from VSS > VSSSTB+VSSSTB_HYS after 50msec (typ) passed from soft start. Figure 28 At soft start time-out Error detection (off latch) release method Each Ch DC/DC converter controller comes into off latch condition when protection function operates. Off latch can be released by the following method. Each Ch DC/DC converter controller becomes able to do ON control transition by releasing off latch. 1. Set all Ch CTL terminal voltage as < VILCTL and continue that condition about more than 200usec (typ). 2. Drop down power supply VCC to below 3.7V. 21 / 22 SSOP-B40 <Dimension> <Tape and Reel information> 13.6 ± 0.2 21 1 20 2000pcs Direction of feed E2 0.3Min. (The direction is the 1pin of product is at the upper left when you hold reel on the left hand and you pull out the tape on the right hand) 0.15 ± 0.1 1234 （Unit:mm) 1234 1pin Reel 1234 0.08 M 1234 0.22 ± 0.1 1234 0.65 1234 0.1 1234 0.1 Embossed carrier tape Quantity 1234 1.8 ± 0.1 7.8 ± 0.3 5.4 ± 0.2 40 Tape Direction of feed ※When you order , please order in times the amount of package quantity. 22 / 22 Catalog No.08T273A '08.8 ROHM © Appendix Notes No technical content pages of this document may be reproduced in any form or transmitted by any means without prior permission of ROHM CO.,LTD. The contents described herein are subject to change without notice. The specifications for the product described in this document are for reference only. Upon actual use, therefore, please request that specifications to be separately delivered. Application circuit diagrams and circuit constants contained herein are shown as examples of standard use and operation. Please pay careful attention to the peripheral conditions when designing circuits and deciding upon circuit constants in the set. Any data, including, but not limited to application circuit diagrams information, described herein are intended only as illustrations of such devices and not as the specifications for such devices. ROHM CO.,LTD. disclaims any warranty that any use of such devices shall be free from infringement of any third party's intellectual property rights or other proprietary rights, and further, assumes no liability of whatsoever nature in the event of any such infringement, or arising from or connected with or related to the use of such devices. Upon the sale of any such devices, other than for buyer's right to use such devices itself, resell or otherwise dispose of the same, no express or implied right or license to practice or commercially exploit any intellectual property rights or other proprietary rights owned or controlled by ROHM CO., LTD. is granted to any such buyer. Products listed in this document are no antiradiation design. The products listed in this document are designed to be used with ordinary electronic equipment or devices (such as audio visual equipment, office-automation equipment, communications devices, electrical appliances and electronic toys). Should you intend to use these products with equipment or devices which require an extremely high level of reliability and the malfunction of which would directly endanger human life (such as medical instruments, transportation equipment, aerospace machinery, nuclear-reactor controllers, fuel controllers and other safety devices), please be sure to consult with our sales representative in advance. It is our top priority to supply products with the utmost quality and reliability. However, there is always a chance of failure due to unexpected factors. Therefore, please take into account the derating characteristics and allow for sufficient safety features, such as extra margin, anti-flammability, and fail-safe measures when designing in order to prevent possible accidents that may result in bodily harm or fire caused by component failure. ROHM cannot be held responsible for any damages arising from the use of the products under conditions out of the range of the specifications or due to non-compliance with the NOTES specified in this catalog. Thank you for your accessing to ROHM product informations. More detail product informations and catalogs are available, please contact your nearest sales office. ROHM Customer Support System www.rohm.com Copyright © 2008 ROHM CO.,LTD. THE AMERICAS / EUROPE / ASIA / JAPAN Contact us : webmaster@ rohm.co. jp 21 Saiin Mizosaki-cho, Ukyo-ku, Kyoto 615-8585, Japan TEL : +81-75-311-2121 FAX : +81-75-315-0172 Appendix1-Rev2.0