XC9515 Series ETR0706-010 2 channel Synchronous Step-Down DC/DC Converter with Manual Reset ■GENERAL DESCRIPTION The XC9515 series consists of 2 channel synchronous step-down DC/DC converters and a voltage detector with delay circuit built-in. The DC/DC converter block incorporates a P-channel 0.35Ω (TYP.) driver transistor and a synchronous N-channel 0.35Ω (TYP.) switching transistor. By minimizing ON resistance of the built-in transistors, the XC9515 series can deliver highly efficient and a stable output current up to 800mA. With high switching frequencies of 1MHz, a choice of small inductor is possible. The series has a built-in UVLO (under-voltage lock-out) function, therefore, the internal P-channel driver transistor is forced OFF when input voltage becomes 1.8V or lower (for XC9515A, 2.7V or lower). The voltage detector block can be set delay time freely by connecting an external capacitor. With the manual reset function, the series can output a reset signal at any time. ■APPLICATIONS ■FEATURES DC/DC Block Input Voltage Range Output Voltage ●DVDs : 2.5V~5.5V : VOUT1=1.2V~4.0V VOUT2=1.2V~4.0V (Accuracy ±2%) Oscillation Frequency : 1MHz (Accuracy ±15%) High Efficiency : 95% (VIN=5V, VOUT=3.3V) Output Current : 800mA Control : PWM control Protection Circuits : Thermal Shutdown : Integral Latch (Over Current Limit) : Short Protection Circuit Ceramic Capacitor Compatible Voltage Detector (VD) Block Detect Voltage Range : 2.0~5.5V(Accuracy ±2%) Delay Time : 173 ms (When Cd=0.1μF is connected) Output Configuration : N-channel open drain Package : QFN-20 ●Blue-ray Disk ●LCD TVs, LCD modules ●Multifunctional printers ●Photo printers ●Set top boxes ■TYPICAL APPLICATION CIRCUIT ■ TYPICAL PERFORMANCE CHARACTERISTICS ● Efficiency vs. Output Current L1 VOUT1 VIN=5V,FOSC=1MHz VIN=5V, fOSC=1MHz, L=4.7μH (CDRH4D28C) EN1 VIN L=4.7uH(CDRH4D28C),CIN=10uF(ceramic),CL=10uF(ceramic) EN2 CIN=10μF (ceramic), CL=10μF (ceramic) 100 VOUT=3.3V PVSS 1 MR NC 70 MR AVSS PVSS 2 NC LX2 NC PVDD 2 VDOUT Cd NC VOUT 2 Cd Efficiency[%] VOUT 1 NC 80 CL1 EN2 EN1 NC PVDD 1 CIN1 LX1 90 60 VOUT=1.5V 50 40 30 20 RUP CIN2 CL2 VDOUT VOUT=1.8V 10 0 1 L2 VOUT2 10 100 Output Current : IOUT [mA] 1000 1/21 20 PVDD1 19 NC 18 LX1 17 EN1 ■PIN CONFIGURATION 16 EN2 XC9515 Series Vout1 15 1 NC MR 14 2 PVSS1 AVSS 13 NC 7 4 PVSS2 5 NC PVDD2 6 NC 9 VDOUT 10 QFN-20 (BOTTOM VIEW) LX2 8 CD 12 Vout2 11 3 NC ※1 ■ PIN ASSIGNMENT QFN-20 PIN NUMBER PIN NAME FUNCTION PIN NUMBER PIN NAME FUNCTION 1 NC No Connection 11 VOUT2 Output Voltage Sense 2 2 P_VSS1 Power Ground 1 12 Cd Delay Capacitor Connection Analog Ground 3 NC No Connection 13 A_VSS 4 P_VSS2 Power Ground 2 14 MR Manual Reset 5 NC No Connection 15 VOUT1 Output Voltage Sense1 6 P_VDD2 Power Supply 2 16 EN2 CH2 ON/OFF Control 7 NC No Connection 17 EN1 CH1 ON/OFF Control 8 LX2 Switching Output 2 18 LX1 Switching Output 1 9 NC No Connection 19 NC No Connection 10 VDOUT Voltage Detector output 20 P_VDD1 Power Supply 1 *1 Back metal pad voltage :VSS level (The back metal pad should be soldered to enhance mounting strength and heat release. If the pad needs to be connected to other circuit, care should be taken for the pad voltage level.) 2/21 XC9515 Series ■FUNCTION CHART ●EN1, EN2 and MR pins are internally pulled up. * PIN EN1 EN2 MR 2) LEVEL OPERATIONAL STATUS High , Open DC/DC_CH1 Operation Low DC/DC_CH1 Stop High , Open DC/DC_CH2 Operation Low DC/DC_CH2 Stop High , Open VD_OUT Detect RESET Signal Output Low VD_OUT Force RESET Signal Output EN1, EN2 and MR pins are internally pulled up so that the levels of High and Open are same function. ●EN1, EN2 and MR pins are left open internally. * PIN EN1 EN2 MR 2) LEVEL OPERATIONAL STATUS High DC/DC_CH1 Operation Low DC/DC_CH1 Stop High DC/DC_CH2 Operation Low DC/DC_CH2 Stop High VD_OUT Detect RESET Signal Output Low VD_OUT Force RESET Signal Output EN1, EN2 and MR pins are floated inside so that these pins shall not be left open outside. 2) * Please refer to the PRODUCTION CLASSIFICATION to see the combination of pull-up status regarding the EN1, EN2, and MR pins. ■PRODUCT CLASSIFICATION ●Ordering Information (Standard products) XC9515①②③④⑤⑥-⑦(*1) DESIGNATOR DESCRIPTION ① Input Voltage & UVLO ② EN & MR logic control conditions SYMBOL A Input Voltage Range 5V±10%, UVLO Voltage 2.7V (TYP.) B A Input Voltage Range 2.5V~5.5V, UVLO Voltage 1.8V (TYP.) EN1, EN2, MR pins are not pulled up internally EN1, EN2 pins have built-in pull-up resistors, MR pin has a built-in pull-up resistor EN1, EN2 Pins are not pulled up internally, MR pin has a built-in pull-up resistor EN1, EN2 pins have built-in pull-up resistors, MR pin are not pulled up internally B C D (*1) (*2) DESCRIPTION ③④ Set Voltage Combinations 01~ Based on Torex Standard Product Number ⑤⑥-⑦ Packages (*2) Taping Type ZR-G QFN-20 (Halogen & Antimony free) The “-G” suffix indicates that the products are Halogen and Antimony free as well as being fully RoHS compliant. The device orientation is fixed in its embossed tape pocket. For reverse orientation, please contact your local Torex sales office or representative. (Standard orientation: ⑤R-⑦, Reverse orientation: ⑤L-⑦) 3/21 XC9515 Series ■BLOCK DIAGRAM ●EN1 Pin, EN2 Pin, MR Pin, Pull-up Inside ●EN1 Pin, EN2 Pin, MR Pin, internally floating PVDD1 VOUT1 Current Limit PVDD1 VOUT1 Current Limit Error Amp Error Amp Current Feedback Current Feedback PVDD1 LX1 LX1 EN1 EN2 PWM Comparator Soft Start ON/OF F Control Logic EN1 Ramp Wave Vref PVSS1 Thermal Shutdown OSC Current Limit Ramp Wave Soft Start EN2 ON/OF F Control Soft Start Error Amp PVSS1 OSC PVDD2 VOUT2 Current Limit Ramp Wave Soft Start Current Feedback LX2 PWM Comparator Logic Buffer Drive Thermal Shutdown Current Feedback PVDD1 Logic Ramp Wave Vref PVDD2 VOUT2 PWM Comparator Buffer Drive Error Amp Buffer Drive PVDD1 LX2 PWM Comparator Logic Buffer Drive PVSS2 PVSS2 MR MR VDOUT VDOUT Rdelay Rdelay Vref Vref AVSS AVSS Cd Cd ■ABSOLUTE MAXIMUM RATINGS Ta=25℃ PARAMETER SYMBOL P_VDD1・P_VDD2 Pin Voltage P_VDD1, P_VDD2 -0.3~6.5 V VOUT1・VOUT2 Pin Voltage VOUT1, VOUT2 -0.3~6.5 V UNITS Cd Pin Voltage VCd -0.3~P_VDD1・2 + 0.3 V VDOUT Pin Voltage VDOUT -0.3~6.5 V VDOUT Pin Current IDOUT 10 mA EN1・EN2・MR Pin Voltage VEN1,VEN2,VMR -0.3~6.5 V LX1・LX2 Pin Voltage VLx1, VLx2 -0.3~P_VDD1・2+0.3 V LX1・LX2 Pin Current ILx1, ILx2 1500 mA Power Dissipation QFN-20 Operating Temperature Range Storage Temperature Range * P_VDD1・2 stands for P_VDD1=P_VDD2 A_VSS=P_VSS1=P_VSS2=0V 4/21 RATINGS Pd (Free air) 300 Pd (PCB mounted) 1000 Topr -40 ~ +85 o -55 ~ +125 o Tstg mW C C XC9515 Series ■ELECTRICAL CHARACTERISTICS XC9515AB04xx ● DC/DC CH1, CH2 (VOUT1=1.5V, VOUT2=3.3V, fOSC =1MHz, EN1・2 Pull-up inside) PARAMETER SYMBOL Input Voltage VIN Output Voltage 1 VOUT1 Output Voltage 2 VOUT2 Maximum Output Current 1・2 (*1) CONDITIONS Connected to the external components, P_VDD1・2=VEN1=VEN2=0V, IOUT1=30mA Connected to the external components, P_VDD1・2=VEN2=VEN1=0V, IOUT2=30mA IOUTMAX1 MIN. TYP. 4.5 5.0 MAX. UNITS CIRCUIT 5.5 V - 1.470 1.500 1.530 V ① 3.234 3.300 3.366 V ① 800 - - mA ① 1000 - - mA ② Connected to the external components, IOUT=10mA 0.85 1.00 1.15 MHz ① IOUTMAX2 ILIM1, Current Limit 1・2 Ta =25 oC ILIM 2 Oscillation Frequency fOSC Maximum Duty Cycle DMAX VOUT1=VOUT2=0V 100 - - % ② Minimum Duty Cycle DMIN VOUT1=VOUT2=VIN - - 0 % ② - 89 - % ① - 94 - % ① - 0.35 (*4) - Ω ③ - 0.35 (*4) - Ω - - 6 - ms ⑦ - 1.3 - ms ① (*6) 1.2 - 5 V ④ (*6) AVSS - 0.4 V ④ μA ④ μA ④ μA ④ μA ④ Connected to the external components, Efficiency 1 (*2) EFFI1 P_VDD1・2=VEN1=5.0V, VEN2=0V, VOUT1=1.5V, IOUT1=200mA Connected to the external components, Efficiency 2 (*2) EFFI2 P_VDD1・2=VEN2=5.0V, VEN1=0V, VOUT2=3.3V, IOUT2=200mA LX1・2 "H" ON Resistance RLX1H・RLX2H LX1・2 "L" ON Resistance RLX1L・RLX2L VOUT1=VOUT2=0V, ILx1=ILx2=100mA (*3) LX1 and LX2 are pulled down by a resistor of 200Ω tLAT1, tLAT2 Integral Latch Time 1・2 VOUT1=Setting Voltage×0.9, VOUT2= Setting Voltage ×0.9 tSS1, tSS2 Soft-Start Time 1・2 VEN1H, EN1・2 "H" Level Voltage VEN2H VEN1L, EN1・2 "L" Level Voltage VEN2L IEN1H, IEN2H EN1・2 "H" Level Current IEN1L, IEN2L EN1・2 "L" Level Current LX1・2 "H" Leakage Current (*7) LX1・2 "L" Leakage Current ILEAK1H, ILEAK2H ILEAK1L, ILEAK2L (*5) Time until EN1, EN2 or both pins changes from 0V to VIN and voltage becomes VOUT1・2×0.95, IOUT1・2=10mA VOUT1=VOUT2=0V Voltage which LX1 or LX2 becomes ”H” VOUT1=VOUT2=0V Voltage which LX1 or LX2 becomes ”L” P_VDD1・2=VEN1=VEN2=5.5V 0.1 - P_VDD1・2=5.5V, VEN1=VEN2=0V - P_VDD1・2=VLX1=VLX2=5.5V, VEN1=VEN2=0V - P_VDD1・2=5.5V, VLX1=VLX2=VEN1=VEN2=0V -3.0 (*9) -6 (*8) - - (*8) - 1.0 (*9) - Test Conditions: * P_VDD1・2 stands for P_VDD1=P_VDD2 **Unless otherwise stated, P_VDD1・2=5V, VEN1=VEN2= P_VDD1・2 *** A_VSS=P_VSS1=P_VSS2=0V NOTE : *1:When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes. If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance. *2:EFFI = { ( output voltage x output current ) / ( input voltage x input current) } x 100 *3:On resistance (Ω)= (VIN - Lx pin measurement voltage) / 100mA *4:Designed value. *5:Time until it short-circuits LX1 (LX2 in the side of 2CH) with GND via 1Ωof resistor from an operational state and is set to Low level from current limit pulse generating. *6:”H” is judged as “H”>VIN-0.1V, ”L” is judged as ”L”<0.1V. *7:When temperature is high, a current of approximately 20μA (maximum) may leak. *8:Current which EN1 and EN2 are measured separately. *9:Lead current which LX1 and LX2 are measured separately. 5/21 XC9515 Series ■ELECTRICAL CHARACTERISTICS (Continued) XC9515AB04xx Ta=25oC ●Voltage Detector (VD) (MR pin Pull-up Inside) Block PARAMETER Detect Voltage SYMBOL VDF(E) CONDITIONS MIN. (*1) Hysteresis Width VHYS VD Output Current IDOUT TYP. VDF(T) ×0.98 VHYS=(VDR(E) (*3) - VDF(E) ) / VDF(E) ×100 P_VDD1・2=VDF-0.01V, Apply 0.5V to VDOUT (*2) VDF(T) MAX. VDF(T) ×1.02 UNITS CIRCUIT V ⑤ - 5.0 - % - 5.0 6.6 8.0 mA ④ Delay Resistance RDLY - 2.5 - MΩ - MR "H" Level Voltage VMRH VDOUT=”H” Level Voltage (*3) 1.2 - 5.5 V ④ MR "L" Level Voltage VMRL VDOUT=”L” Level Voltage (*3) AVSS - 0.4 V ④ MR "H" Level Current IMRH P_VDD1・2=VMR=5.5V - - 0.1 μA ④ MR "L" Level Current IMRL P_VDD1・2=5.5V, VMR=0V - -6.0 - μA ④ Test Conditions: * P_VDD1・2 stands for P_VDD1=P_VDD2 **Unless otherwise stated, P_VDD1・2=5V, VEN1=VEN2= P_VDD1・2 *** A_VSS=P_VSS1=P_VSS2=0V NOTE : *1:VDF(E)=Detect Voltage *2:VDR(E)=Release Voltage *3:”H” is judged as “H”>VIN-0.1V, ”L” is judged as “L”<0.1V XC9515AB04xx Ta=25oC ●Whole Circuit (VOUT1=1.5V, VOUT2=3.3V, fOSC=1MHz, EN1・2 Pull-up Inside) PARAMETER SYMBOL CONDITIONS MIN. TYP. MAX. UNITS CIRCUIT Supply Current 1 Supply Current 2 IDD1 VOUT1=VOUT2=Setting Voltage x 0.9 - 950 1500 μA ⑥ IDD2 VOUT1=VOUT2=Setting Voltage x 1.1 (Oscillation stops) - 75 145 μA ⑥ Stand-by Current ISTB UVLO Detect Voltage VUVLOF UVLO Release Voltage Thermal Shutdown Temperature Thermal Shutdown Hysteresis Width - 18 33 μA ⑥ VIN voltage which VOUT1=0V and LX pin becomes ”L” (*1) 2.4 2.7 3.0 V ② VIN voltage which VOUT1=0V and LX pin becomes ”H” (*1) - - 3.5 V ② TTSD - 150 - o - THYS - 20 - o - VUVLOR VEN1=VEN2=0V Test Conditions: * P_VDD1・2 stands for P_VDD1=P_VDD2 **Unless otherwise stated, P_VDD1・2=5V, VEN1=VEN2= P_VDD1・2 *** A_VSS=P_VSS1=P_VSS2=0V NOTE : *1:”H” is judged “H”>VIN-0.1V, ”L” is judged “L”<0.1V 6/21 C C XC9515 Series ■ELECTRICAL CHARACTERISTICS (Continued) XC9515BA06xx ●DC/DC CH1, CH2 (VOUT1=1.5V, VOUT2=3.3V, fOSC=1MHz, EN1 and EN2 pins are internally floating) PARAMETER SYMBOL Input Voltage VIN CONDITIONS MIN. TYP. 2.5 Ta=25 oC MAX. UNITS CIRCUIT 5.5 V Connected to the external components, Output Voltage1 VOUT1 P_VDD1・2=VEN1, VEN2=0V 1.470 1.500 1.530 V ① 3.234 3.300 3.366 V ① mA ① IOUT1=30mA Connected to the external components, Output Voltage2 VOUT2 P_VDD1・2=VEN2, VEN1=0V IOUT2=30mA Maximum Output Current 1・2 (*1) IOUTMAX1 800 IOUTMAX2 Current Limit 1・2 ILIM1, ILIM 2 Oscillation Frequency fOSC Maximum Duty Cycle Minimum Duty Cycle 1000 Connected to the external components, IOUT=10mA 0.85 DMAX VOUT1=VOUT2=0V 100 DMIN VOUT1=VOUT2=VIN 1.00 1.15 mA ② MHz ① % ② % ② 89 % ① 94 % ① 0 Connected to the external components, Efficiency 1 (*2) EFFI1 P_VDD1・2=VEN1=5.0V, VEN2=0V VOUT1=1.5V, IOUT1=200mA Connected to the external components, Efficiency 2 (*2) EFFI2 P_VDD1・2=VEN2=5.0V, VEN1=0V VOUT2=3.3V, IOUT2=200mA LX1・2 "H" ON Resistance LX1・2 "L" ON Resistance RLX1H, RLX2H tLAT1, tLAT2 Soft-Start Time 1・2 tSS1, tSS2 EN1・2 "H" Voltage VEN1H, VEN2H EN1・2 "L" Voltage VEN1L, VEN2L EN1・2 "H" Current IEN1H, IEN2H EN1・2 "L" Current (*7) LX1・2 "L" Leak Current (*3) RLX1L, RLX2L Integral Latch Time 1・2 LX1・2 "H" Leak Current VOUT1=VOUT2=0V, ILx1=ILx2=100mA LX1 and LX2 are pulled down by a resistor of 200Ω VOUT1= Setting Voltage×0.9, VOUT2= Setting Voltage×0.9 Time until EN1, EN2 or both pins changes from 0V to VIN and voltage becomes VOUT1・2×0.95, IOUT1・2=10mA VOUT1=VOUT2=0V Voltage which LX1 or LX2 becomes ”H” Ω ③ 0.35 (*4) Ω - 6 ms ⑦ 1.3 ms ① 1.2 5 V ④ (*6) AVSS 0.4 V ④ μA ④ μA ④ μA ④ μA ④ VOUT1=VOUT2=0V Voltage which LX1 or LX2 becomes ”L” (*4) (*6) P_VDD1・2=VEN1=VEN2=5.5V IEN1L, IEN2L P_VDD1・2=5.5V, VEN1=VEN2=0V Ileak1H, Ileak2H P_VDD1・2=VLX1=VLX2=5.5V, VEN1=VEN2=0V Ileak1L, Ileak2L (*5) 0.35 P_VDD1・2=5.5V, VLX1=VLX2=VEN1=VEN2=0V 0.1 (*8) 1.0 (*9) (*8) -0.1 (*9) -3.0 Test Conditions: * P_VDD1・2 stands for P_VDD1=P_VDD2 **Unless otherwise stated, P_VDD1・2=5V, VEN1=VEN2= P_VDD1・2 *** A_VSS=P_VSS1=P_VSS2=0V NOTE : *1:When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes. If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance. *2:EFFI = { ( output voltage x output current ) / ( input voltage x input current) } x 100 *3:On resistance (Ω)= (VIN - Lx pin measurement voltage) / 100mA *4:Designed value. *5:Time until it short-circuits LX1 (LX2 in the side of 2CH) with GND via 1Ωof resistor from an operational state and is set to Low level from current limit pulse generating. *6:”H” is judged as “H”>VIN-0.1V, ”L” is judged as ”L”<0.1V. *7:When temperature is high, a current of approximately 20μA (maximum) may leak. *8:Current which EN1 and EN2 are measured separately. *9:Lead current which LX1 and LX2 are measured separately. 7/21 XC9515 Series ■ELECTRICAL CHARACTERISTICS (Continued) XC9515BA06xx ●VD (MR pin is) internally floating PARAMETER Detect Voltage Ta=25 oC SYMBOL VDF(E) CONDITIONS (*1) (*2) MIN. TYP. MAX. UNITS CIRCUIT 2.94 3.00 3.06 -VDF(E) }/ VDF(E)×100 5.0 V ⑤ % - mA ④ Hysteresis Width VHYS VHYS={VDR(E) VD Output Current IDOUT P_VDD1・2=VDF-0.01V, Apply 0.5V to VDOUT Delay Resistance RDLY MR "H" Level Voltage VMR VDOUT=”H” Level Voltage (*3) 1.2 5.5 MR "L" Level Voltage VMR VDOUT=”L” Level Voltage (*3) AVSS 0.4 V ④ MR "H" Level Current IMR P_VDD1・2=MR=5.5V 0.1 μA ④ MR "L" Level Current IMR P_VDD1・2=5.5V,MR=0V μA ④ 5.0 6.6 8.0 2.5 (*8) -0.1 MΩ - V ④ Test Conditions: * P_VDD1・2 stands for P_VDD1=P_VDD2 **Unless otherwise stated, P_VDD1・2=5V, VEN1=VEN2= P_VDD1・2 *** A_VSS=P_VSS1=P_VSS2=0V NOTE : *1:VDF(E)=Detect Voltage *2:VDR(E)=Release Voltage *3:”H” is judged as “H”>VIN-0.1V, ”L” is judged as “L”<0.1V XC9515BA01xx ●Whole Circuit (VOUT1=1.5V, VOUT2=3.3V, fOSC=1MHz, EN1 and EN2 pins are internally floating) PARAMETER SYMBOL Supply Current 1 IDD1 VOUT1=VOUT2= Setting Voltage×0.9 CONDITIONS MIN. Ta=25 oC TYP. MAX. UNITS CIRCUIT 950 1500 μA ⑥ Supply Current 2 IDD2 VOUT1=VOUT2= Setting Voltage×1.1 (Oscillation stops) 75 145 μA ⑥ Stand-by Current ISTB EN1=EN2=0V 5.5 11 μA ⑥ UVLO Detect Voltage VUVLOF VIN voltage which VOUT1=0V and LX pin becomes ”L” (*1) 2.1 V ② UVLO Release Voltage VUVLOR VIN voltage which VOUT1=0V and LX pin becomes ”H” (*1) 2.3 V ② Thermal Shutdown Temperature Thermal Shutdown Hysteresis Width 1.8 TTSD 150 o - THYS 20 o - Test Conditions: * P_VDD1・2 stands for P_VDD1=P_VDD2 **Unless otherwise stated, P_VDD1・2=5V, VEN1=VEN2= P_VDD1・2 *** A_VSS=P_VSS1=P_VSS2=0V NOTE : *1:”H” is judged “H”>VIN-0.1V, ”L” is judged “L”<0.1V 8/21 1.5 C C XC9515 Series ■TYPICAL APPRICATION CIRCUIT L1 VOUT1 EN1 VIN CL1 EN2 EN1 LX1 PVDD 1 CIN1 NC EN2 VOUT 1 NC PVSS 1 MR MR AVSS NC PVSS 2 NC LX2 NC PVDD 2 NC VDOUT Cd VOUT 2 Cd RUP CIN2 L2 CL2 VDOUT VOUT2 <Example of the External Components> L1 :4.7μH(CDRH4D28C, SUMIDA) L2 :4.7μH(CDRH4D28C, SUMIDA) CIN1 :10μF(ceramic) CIN2 :10μF(ceramic) CL1 :10μF(ceramic) CL2 :10μF(ceramic) RUP :100kΩ 9/21 XC9515 Series ■OPERATIONAL EXPLANATION XC9515 series consists of a reference voltage source, ramp wave circuit, error amplifier, PWM comparator, phase compensation circuit, output voltage adjustment resistors, P-channel driver transistor, N-channel synchronous switching transistor, current limit circuit, UVLO circuit and others. The series ICs compare, using the error amplifier, the voltage of the internal voltage reference source with the feedback voltage from VOUT pin through split resistors, RFB1 and RFB2. Phase compensation is performed on the resulting error amplifier output, to input a signal to the PWM comparator to determine the turn-on time during PWM operation. The PWM comparator compares, in terms of voltage level, the signal from the error amplifier with the ramp wave from the ramp wave circuit, and delivers the resulting output to the buffer driver circuit to cause the Lx pin to output a switching duty cycle. This process is continuously performed to ensure stable output voltage. The current feedback circuit monitors the P-channel driver transistor current for each switching operation, and modulates the error amplifier output signal to provide multiple feedback signals. This enables a stable feedback loop even when a low ESR capacitor, such as a ceramic capacitor, is used, ensuring stable output voltage. <Reference Voltage Source> The reference voltage source provides the reference voltage to ensure stable output voltage of the DC/DC converter. <Ramp Wave Circuit> The ramp wave circuit determines switching frequency. The frequency is fixed internally at 1MHz. Clock pulses generated in this circuit are used to produce ramp waveforms needed for PWM operation, and to synchronize all the internal circuits. <Error Amplifier> The error amplifier is designed to monitor output voltage. The amplifier compares the reference voltage with the feedback voltage divided by the internal split resistor, RFB1 and RFB2. When a voltage lower than the reference is fed back, the output voltage of the error amplifier increases. The gain and frequency characteristics of the error amplifier output are fixed internally to deliver an optimized signal to the mixer. <Current Limit> The current limiter circuit of the XC9515 series monitors the current flowing through the P-channel MOS driver transistor connected to the Lx pin, and features a combination of the current limit mode and the latch mode. ①When the driver current is greater than a specific level (peak value of coil current), the current limit function operates to off the pulses from the Lx pin at any giving timing. ②When the driver transistor is turned off, the limiter circuit is then released from the current limit detection state. ③At the next pulse, the driver transistor is turned on. However, the transistor is immediately turned off in the case of an over current state. ④When the over current is eliminated, the IC resumes its normal operation. The IC waits for the over current state to end by repeating the steps ① to ③. If an over current state continues for a few ms and the above three steps are repeatedly performed, the IC performs the function of latching the OFF state of the driver transistor. Both two DC/DC blocks stop operations when either CH1 or CH2 of protection circuit is activated. At this time, both Lx1 and Lx2 become high impedance. Once the IC is in latch mode, operations can be resumed by either turning the IC off after letting EN1 and EN2 pins down to low level, or by restoring power. For restoring power, the IC should be turned off after P_VDD1 and P_VDD2 voltages drop below the low level of EN1 and EN2 pin.)The latch operation can be released from the current limit detection state because of the circuit’s noise. Also, depending on the state of the PC Board, latch time may become longer and latch operation may not work. In order to avoid the effect of noise, the board should be laid out so that capacitors are placed as close to the chip as possible. Limit < # ms 10/21 Limit < # ms XC9515 Series ■OPERATIONAL EXPLANATION (Continued) <Thermal Shutdown> For protecting the IC from heat damage, the thermal shutdown circuit monitors the chip temperature. When the chip temperature reaches 150℃, the thermal shutdown circuit operates and the driver transistor will be set to OFF. As the chip temperature drops to 130℃ by stopping current flow, the soft-start function operates to turn the output on. <Short-Circuit Protection> The short-circuit protection circuit monitors the FB voltage. If the output is shorted incorrectly with the ground, the short-circuit protection circuit operates and turns the driver transistor off to latch when the FB voltage becomes less than half of the setting voltage. Both two DC/DC blocks stop operations when either CH1 or CH2 of protection circuit is activated. At this time, both Lx1 and Lx2 become high impedance. Once the IC is in latch mode, operations can be resumed by either turning the IC off after letting both ends of EN1 and EN2 pins down to low level, or by restoring power. (The P_VDD1 and P_VDD2 voltages should be less than the low level of the EN1 and EN2 pins when restoring power.) <Soft Start Function> The soft-start circuit protects against inrush current, when the power is switched on, and also to protect against voltage overshoot. It should be noted, however, that this circuit does not protect the load capacitor (CL) from inrush current. With the Vref voltage limited and depending upon the input to the error amps, the operation maintains a balance between the two inputs of the error amps and controls the EXT1 pin's ON time so that it doesn't increase more than is necessary. <UVLO Circuit> When the VIN pin voltage becomes1.8V (TYP.) or lower (for XC9515A, 2.7V or lower), the P-channel output driver transistor is forced OFF to prevent false pulse output caused by unstable operation of the internal circuitry. When the VIN pin voltage becomes 1.9V (TYP.) or higher (for XC9515A, 3.0V or lower), switching operation takes place. By releasing the UVLO function, the IC performs the soft-start function to initiate output startup operation. <Voltage Detector Block> The series' detector function monitors the voltage divided by resistors connected to the P_VDD1 pin, as well as monitoring the voltage of the internal reference voltage source via the comparator. Because of hysteresis at the detector function, output at the VDOUT pin will invert when the sense pin voltage of the detector block (P_VDD1) increases above the release voltage (105% of the detect voltage). The output configuration of the VDOUT pin is N-channel open drain, therefore, a pull-up resistor is required. The voltage detector block has a manual reset (MR) pin. By setting the MR pin at low level, the VDOUT pin is forced to be at low level. By connecting a capacitor (Cd) to the Cd pin, the XC9515 series can set a delay time to VDOUT pin’s output signal when releasing voltage. The delay time can be calculated from the internal resistance, Rdelay (2.5MΩ fixed TYP.) and the value of Cd as per the following equation. As selecting the capacitor (Cd), the delay time can be set freely. tDR (Delay time) =Cd x Rdelay x 0.69 ●Release Delay Delay Capacity Cd [μF] 0.01 0.022 0.047 0.1 0.22 0.47 1 Release Delay tDR (TYP.) [ms] 17 38 81 173 380 811 1725 Ta=25 oC Release Delay tDR (MIN.~MAX.) [ms] 10~24 23~53 49~113 103~242 228~532 487~1135 1035~2415 11/21 XC9515 Series ■NOTES ON USE 1. Please use this IC within the stated maximum ratings. The IC is liable to malfunction should the ratings be exceeded. 2. Please apply the same electrical potential to the P_VDD1 and P_VDD2 pins. Even where either CH1 or CH2 is used, both P_VDD1 and P_VDD2 pins should have the same electrical potential. Applying the electrical potential to only one side causes malfunction. Also the same electrical potential should be applied to the P_VSS1, P_VSS2 and A_VSS pins. 3. The XC9515 series is designed for use with ceramic output capacitors. If, however, the potential difference between dropout voltage or output current is too large, a ceramic capacitor may fail to absorb the resulting high switching energy and the output could be unstable. If the input-output potential difference is large, use a larger output capacitor to compensate for insufficient capacitance. 4. When the peak current, which exceeds limit current flows within the specified time, the built-in driver transistor is turned off (the integral latch circuit). During the time until it detects limit current and before the built-in transistor can be turned off, the current for limit current flows; therefore, care must be taken when selecting the rating for the coil. 5. When the input voltage is low, limit current may not be reached because of voltage falls caused by ON resistance or serial resistance of the coil. 6. Since the potential difference for input voltage has occurred to the both ends of a coil, the time changing rate of the coil current is large when the P-channel driver transistor is ON. On the other hand, since the VOUT pin short-circuits to the GND when the N-channel transistor is ON and there is almost no potential difference of the coil both ends, the time changing rate of the coil current becomes very small. This operation is repeated and the delay time of the circuit also influences, therefore, the coil current is converged on the current value beyond the amount of current which should be restricted essentially. The short-circuit protection does not operate during the soft-start time. As soon as the soft-start time finishes, the short-circuit protection starts to operate and the circuit becomes disable. The delay time of the circuit also influences when step-down ratio is large, as the result, a current more than over current limit may flow. Please do not exceed the absolute maximum ratings of the coil. ① ② ③ ④ ⑤ A current flows to the driver transistor up to the current limit (ILIM). For the delay time of the circuit, a current more than the ILIM flows after the ILIM decide until the P channel driver transistor turns off. Time changing rate of the coil current becomes very small because there is no potential difference between both ends of the coil. The Lx pin oscillates a narrow pulse during the soft-start time because of the current limit. The circuit is latched since the short-circuit protection operates and the P-channel driver transistor is turned off. # ms 12/21 XC9515 Series ■NOTES ON USE (Continued) 7. Driving current below the minimum operating voltage may lead malfunction to the UVLO circuit because of the noise. 8. Depending on the PC board condition, the latch function may be released from limit current detection state and the latch time may extend or fail to reach the latch operation. Please locate the input capacitance as close to the IC as possible. 9. Spike noise and ripple voltage arise in a switching regulator as with a DC/DC converter. These are greatly influenced by external component selection, such as the coil inductance, capacitance values, and board layout of external components. Once the design has been completed, verification with actual components should be done. 10. With the DC/DC converter block of the IC, the peak current of the coil is controlled by the current limit circuit. Since the peak current increases when dropout voltage or load current is high, current limit starts operating, and this can lead to instability. When peak current becomes high, please adjust the coil inductance value and fully check the circuit operation. In addition, please calculate the peak current according to the following formula: Peak current: Ipk = (VIN - VOUT) x OnDuty / (2 x L x fosc) + IOUT L: Coil Inductance Value, fOSC: Oscillation Frequency 11. When the load current is light in PWM control, very narrow pulses will be outputted, and there is the possibility that some cycles may be skipped completely. 12. When the difference between VIN and VOUT is small, and the load current is heavy, very wide pulses will be outputted and there is the possibility that some cycles may be skipped completely. 13. If the power input pin voltage is assumed to decrease rapidly (ex. from 6.0V to 0V) at the release of the operation although delay capacitance (Cd) pin is connected, please connect an Shottky barrier diode between the power input (P_VDD1) pin and the delay capacitance (Cd) pin. 14. Please connect a pull-up resistor with 100 to 200kΩ to the output pin of the voltage detector block (VDOUT). 15. The delay time of the voltage detector block in heavy load may extend because of the noise of the DC/DC block. Precipitous and large voltage fluctuation at the power input pin may cause malfunction of the IC. 16. Use of the IC at voltages below the minimum operating voltage may lead the output voltage drop before achieving over current limit. 17. When P_VDD1 and P_VDD2 power supply pins and EN1 and EN2 enable pins are in undefined states, the latch protection circuit may not be reset so that the IC operation does not start correctly. Power supply and enable pins (EN1,EN2) should be grounded before starting the IC operation. 【Undefined state conditions for each pin】 P_VDD1=P_VDD2=0.1V ~ 1.2V VEN1=VNE2= 0.4V ~ 1.2V 18. UVLO function works even if when VIN input voltage falls below the UVLO voltage in very short time period like a few ten nanoseconds. ●Instruction on Pattern Layout 1. In order to stabilize VIN's voltage level, we recommend that a by-pass capacitor (CIN1 and CIN2) be connected as close as possible to the P_VDD1・P_VDD2 pins and P_VSS1・P_VSS2 pins. 2. Please mount each external component as close to the IC as possible. 3. Wire external components as close to the IC as possible and use thick, short connecting traces to reduce the circuit impedance. 4. Make sure that the VSS traces are as thick as possible, as variations in the VSS potential caused by high VSS currents at the time of switching may result in instability of the DC/DC converter. 13/21 XC9515 Series ■TEST CIRCUITS Wave Form Measurement Point < Test Circuit No.1 > Wave Form Measurement Point A L CL LX1 EN1 PVDD1 EN2 PVSS1 PVSS2 VOUT1 MR AVSS CD VOUT2 VDOUT CIN CIN PVDD2 CL L LX2 V A V Wave Form Point Wave FormMeasurement Measurement Point ※ External Components L : 4.7μH(CDRH4D28C : SUMIDA) CIN : 10μF (ceramic) CL : 10μF (ceramic) Wave Form Measurement Point Wave Form Measurement Point < Test Circuit No.2 > A A 1μF V V LX1 EN1 PVDD1 EN2 PVSS1 PVSS2 VOUT1 MR AVSS CD VOUT2 VDOUT PVDD2 A LX2 V Wave Wave FormForm Measurement Point Measurement Point < Test Circuit No.3 > 100mA A V 1μF 100mA A 14/21 V LX1 EN1 PVDD1 EN2 PVSS1 PVSS2 VOUT1 MR AVSS CD VOUT2 VDOUT PVDD2 LX2 XC9515 Series ■TEST CIRCUITS (Continued) Wave Form Measurement Point Wave Form Measurement Point 15/21 XC9515 Series ■TYPICAL PERFORMANCE CHARACTERISTICS (1) Efficiency vs. Output Current VIN=5V,FOSC=1MHz L=4.7uH(CDRH4D28C),CIN=10uF(ceramic),CL=10uF(ceramic) 100 VOUT=3.3V 90 Efficiency[%] Efficiency: EFFI (%) 80 70 60 VOUT=1.5V 50 40 30 20 VOUT=1.8V 10 0 1 10 100 Output Current Current:: IIOUT OUT (mA) Output [mA] 1000 (2) Output Voltage vs. Output Current VOUT=1.5V VIN=5. 0V L:4.7uH(CDRH4D28C),CIN=10uF(ceramic),CL=10uF(ceramic) VOUT=1.8V VIN=5. 0V L:4.7uH(CDRH4D28C),CIN=10uF(ceramic), CL=10uF(ceramic) 1.90 Output Voltage : VOUT[V] OutputVoltage Voltage:: VOUT[V] VOUT (V) Output 1.60 1.55 1.50 1.45 1 10 100 Output Current : IOUT[mA] Output Current: IOUT (mA) 1000 VOUT=3.3V VIN=5. 0V L:4.7uH(CDRH4D28C),CIN=10uF(ceramic),CL=10uF(ceramic) 3.40 Output Voltage: VOUT (V) Output Voltage : VOUT[V] 1.80 1.75 1.70 1.40 3.35 3.30 3.25 3.20 1 16/21 1.85 10 100 Output Current : IOUT[mA] Output Current: IOUT (mA) 1000 1 10 100 Output Current : IOUT[mA] Output Current: IOUT (mA) 1000 XC9515 Series ■TYPICAL PERFORMANCE CHARACTERISTICS (Continued) (3) Output Voltage vs. Ambient Temperature VVout=1.2V OUT=1.2V VVout=1.5V OUT=1.5V V IN=2.5V,3.0V,4.0V,5.0 V,5.5V L:4.7 uH(CDRH 4D28C),CIN =10uF(ce ramic),CL=10uF(ceramic) 1.30 1.60 1.25 1.55 Output Voltage:Vout1[v] Output Voltage:Vout1[v] V IN=2.5V,3.0V,4.0V,5.0V,5.5 V L:4.7uH(CDRH 4D28C),CIN =10uF(c eram ic ),CL=10uF(ce ramic) 1.20 1.15 VIN=2.5V,3.0V,4.0V,5.0V,5.5V 1.10 1.05 1.50 1.45 VIN=2.5V,3.0V,4.0V,5.0V,5.5V 1.40 1.35 1.30 1.00 -50 -25 0 25 50 75 -50 100 -25 VVout=1.8V OUT=1.8V V IN=2.5V,3.0V,4.0V,5.0V,5.5 V L:4.7uH(CDRH 4D28C),CIN =10uF(c eram ic ),CL=10uF(ce ramic) 50 75 100 VOUT=3.3V Vout=3.3V VIN =4.0V,5.0 V,5.5V L:4.7 uH(CDRH 4D28C),CIN =10uF(ce ramic),CL=10uF(ceramic) 1.90 3.40 1.85 3.35 Output Voltage:Vout2[v] Output Voltage:Vout1[v] 25 Ambient T emperature:Ta[℃ ] Ambient Temperature:Ta[℃ ] 1.80 1.75 0 VIN=2.5V,3.0V,4.0V,5.0V,5.5V 1.70 1.65 3.30 3.25 VIN=4.0V,5.0V,5.5V 3.20 3.15 3.10 1.60 -50 -25 0 25 50 75 100 -50 -25 0 25 50 75 100 Ambient Temperature:Ta[℃ ] Ambient Temperature:Ta[℃ ] (4) Oscillation Frequency vs. Ambient Temperature OscillationFrequency: FrequencyfOSC (MHz) Oscillation :FOSC[MHz] fOSC=1MHz FOSC=1MHz VIN=2.5V,3.0V,4.0V,5.0V,5.5V L:4.7uH(CD RH4D28C),CIN =10uF(ceramic),CL=10uF(ceramic) 1.2 1.1 1.0 0.9 VIN=2.5V,3.0V,4.0V,5.0V,5.5V 0.8 0.7 -50 -25 0 25 50 75 100 Ambient Temperature:Ta[℃ ] 17/21 XC9515 Series ■TYPICAL PERFORMANCE CHARACTERISTICS (Continued) (5) Load Transient Response VIN=5V, VOUT1=1.5V, VOUT2=3.3V, fOSC=1MHz VIN=5V,VOUT1=1.5V,VOUT2=3.3V,FOSC=1MHz, VOUT1=200mV/div VOUT1=200mV/div VOUT2=200mV/div VOUT2=200mV/div IOUT1=200mA IOUT1=1mA IOUT1=200mA IOUT1=1mA 50μs/div 50μs/div 200μs/div 200μs/div VIN=5V, VOUT1=1.5V, VOUT2=3.3V, fOSC=1MHz VIN=5V,VOUT1=1.5V,VOUT2=3.3V,FOSC=1MHz, VOUT1=200mV/div VOUT1=200mV/div VOUT2=200mV/div VOUT2=200mV/div IOUT1=800mA IOUT1=200mA IOUT1=800mA IOUT1=200mA 50μs/div 50μs/div 200μs/div 200μs/div VIN=5V, VOUT1=1.5V, VOUT2=3.3V, fOSC=1MHz VIN=5V,VOUT1=1.5V,VOUT2=3.3V,FOSC=1MHz, VOUT1=200mV/div VOUT1=200mV/div VOUT2=200mV/div VOUT2=200mV/div IOUT2=200mA IOUT2=1mA IOUT2=200mA IOUT2=1mA 50μs/div 50μs/div 200μs/div 200μs/div VIN=5V, VOUT1=1.5V, VOUT2=3.3V, fOSC=1MHz VIN=5V,VOUT1=1.5V,VOUT2=3.3V,FOSC=1MHz, VOUT1=200mV/div VOUT1=200mV/div VOUT2=200mV/div VOUT2=200mV/div IOUT2=800mA IOUT2=200mA IOUT2=200mA 50μs/div 50μs/div 18/21 IOUT2=800mA 200μs/div 200μs/div XC9515 Series ■PACKAGING INFORMATION Unit: mm ●QFN-20 (0.2) 4.00±0.10 1 PIN INDENT +0.03 0.02 -0.02 4.00±0.10 0.75±0.05 7 8 9 10 5 11 4 12 3 13 2 14 1 15 *The solder filet may not be formed because of no plating at side. (0.5) 2.70±0.05 6 0.20±0.05 0.40±0.05 2.70±0.05 19 18 17 16 ●QFN-20 Reference Pattern Layout ●QFN-20 Reference Metal Mask Design 4.6 3.2 0.3 3.3 4.6 3.2 2.7 0.3 1.1 4.5 3.3 4.5 20 2.7 0.5 0.3 0.5 0.3 1.1 Thickness of solder paste:120μm (reference) 19/21 XC9515 Series ■MARKING RULE ●QFN-20 ●Standard Product ①②③Represent product series MARK 1pin ①②③④⑤⑥ ⑦⑧⑨ ① ② ③ 5 1 5 PRODUCT SERIES XC9515******-G ④Input Voltage Range, UVLO Voltage MARK PRODUCT SERIES QFN-20 (TOP VIEW) A XC9515A*****-G B XC9515B*****-G ⑤EN Pin, MR Pin, Internal Control PRODUCT SERIES MARK A XC9515*A****-G B XC9515*B****-G C XC9515*C****-G D XC9515*D****-G OPTIONAL FUNCTIONS Input Voltage Range 5V±10%, UVLO Voltage 2.7V (TYP.) Input Voltage Range 2.5V~5.5V, UVLO Voltage 1.8V (TYP.) OPTIONAL FUNCTIONS EN1, EN2 Pin Open MR Pin Open Built-in EN1, EN2 Pin Pull-up Resistance Built-in MR Pin Pull-up Resistance EN1, EN2 Pin Open Built-in MR Pin Pull-up Resistance Built-in EN1, EN2 Pin Pull-up Resistance MR Pin Open ⑥⑦Represents integer number of setting voltage MARK PRODUCT SERIES ⑥ ⑦ 0 1 XC9515**01**-G ⑧⑨Represents production lot number Order of 01, …09, 10, 11, …99, 0A, …0Z, 1A, …9Z, A0, …Z9, AA, …ZZ. (G, I, J, O, Q, W excepted) *No character inversion used. 20/21 XC9515 Series 1. The products and product specifications contained herein are subject to change without notice to improve performance characteristics. Consult us, or our representatives before use, to confirm that the information in this datasheet is up to date. 2. We assume no responsibility for any infringement of patents, patent rights, or other rights arising from the use of any information and circuitry in this datasheet. 3. Please ensure suitable shipping controls (including fail-safe designs and aging protection) are in force for equipment employing products listed in this datasheet. 4. The products in this datasheet are not developed, designed, or approved for use with such equipment whose failure of malfunction can be reasonably expected to directly endanger the life of, or cause significant injury to, the user. (e.g. Atomic energy; aerospace; transport; combustion and associated safety equipment thereof.) 5. Please use the products listed in this datasheet within the specified ranges. Should you wish to use the products under conditions exceeding the specifications, please consult us or our representatives. 6. We assume no responsibility for damage or loss due to abnormal use. 7. All rights reserved. No part of this datasheet may be copied or reproduced without the prior permission of TOREX SEMICONDUCTOR LTD. 21/21