XC9206 / 9207/ 9208 Series PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In " APPLICATIONS # Mobile phones (PDC, GSM, CDMA, IMT2000 etc.) # PDA, Portable communication modem # Portable game # Camera, Digital camera, Camcorder # Cordless phone # Note book computer ! P-Channel Driver Transistor Built-In ! Input Voltage Range : 1.8V ~ 6.0V (XC9206/XC9207) ! Output Voltage Range : 0.9V ~ 4.0V ! Oscillation Frequency : 300kHz, 600kHz, 1.2MHz : 2.0V ~ 6.0V (XC9208) ! Output Current : 500mA ! Maximum Duty Ratio : 100% ! Small Package : SOT-25 September 17, 2003 Ver. 2 ! PWM/PFM Switching Control (XC9207 / XC9208) ! Ceramic Capacitor Compatible " GENERAL DESCRIPTION " FEATURES The XC9206/9207/9208 series is a group of DC/DC converters with a built-in 0.4Ω P-channel driver transistor, offered in a SOT-25 package. The ICs are designed to provide high efficiencies and a stable power supply with an output current of 500mA using only a coil, a diode and two ceramic capacitors connected externally. Minimum operating voltage of the XC9206/9207 is 1.8V and 2.0V for XC9208. Output voltage is internally programmable in a range from 0.9V to 4.0V in increments of 100mV (accuracy: ±2.0%). Oscillation frequency is selectable from 300kHz, 600kHz and 1.2MHz so that the frequency best suited to your particular application can be selected. Each series features different operation modes: PWM control (XC9206 series), automatic PWM/PFM switching control (XC9207 series) and manual PWM/PFM switching control (XC9208 series). The series gives fast transient response, low ripple and high efficiency over the full range of load (from light load to high output current conditions). The soft start and current control functions are internally optimized. During stand-by, all circuits are shutdown to reduce current consumption to as low as 1.0µA or less. With the built-in U.V.L.O. (Under Voltage Lock Out) function, the internal P-channel driver transistor is forced OFF when input voltage becomes 1.4V or lower. " TYPICAL APPLICATION CIRCUIT VOUT 4 CE/ MODE VSS CIN (ceramic) Lx Fixed output voltage accuracy ±2% Oscillation Frequency 300kHz, 600kHz, 1.2MHz Fixed oscillation frequency accuracy ±15% Stand-by function Istb = 1µA (MAX.) Current Limiter Circuit built-in 600mA Small Package SOT-25 Soft start circuit built-in " TYPICAL PERFORMANCE CHARACTERISTICS XC9208A18C VOUT=1.8V (Oscillation Frequency 1.2MHz) CIN:4.7µF,CL:10µF, L:4.7µH(CDRH3D16), SD:CRS02, Topr=25OC 2 L VIN 0.9V ~ 4.0V (100mV steps) 3 VIN 5 ON resistance 0.4Ω Output Voltage Range VOUT (500mA) 1 SD Efficiency EFFI (%) CE/MODE P ch driver Tr. Built-in CL (ceramic) 100 90 80 70 60 50 40 30 20 10 0 PWM/PFM Switching Control VIN=2.4V 3.6V 4.2V PWM Control 0.1 1 10 100 1000 Output Current IOUT (mA) Semiconductor Ltd. Data Sheet 1 XC9206 / 9207/ 9208 Series PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In " PIN CONFIGURATION " PIN ASSIGNMENT VIN CE/MODE 5 1 Lx PIN NUMBER PIN NAME FUNCTIONS 1 LX Switching Output 2 VSS Ground 4 2 3 3 VOUT Output Voltage Sense 4 CE/MODE Chip Enable/Mode Switch 5 VIN Power Input VSS VOUT SOT-25 (TOP VIEW) " PRODUCT CLASSIFICATION # Ordering Information XC9206 1 : PWM Control XC9207 1 23456 23456 XC9208 1 2 3 4 5 6 : PWM / PFM Automatic Switching Control : PWM control, PWM / PFM Automatic Switching Control Manually Selectable SYMBOL DESCRIPTION Transistor built-in, output voltage internally set (VOUT product), soft start internally set. 1 2, 3 A : Current Limiter 600mA Denotes output voltage : ex. ) 1.5V Output ! 1.85V Output ! 2.85V Output ! 2 = 1, 3 = 5 2 = 1, 3 = L 2 = 2, 3 = L Denotes oscillation frequency : 4 3 : 300kHz 6 : 600kHz C : 1.2MHz Denotes package types : 5 M : SOT-25 Denotes device orientation : 6 R : Embossed Tape : Standard Feed L : Embossed Tape : Reverse Feed * Output voltage 0.9V ~ 4.0V (100mV steps), 1.85V and 2.85V are standard products. Output voltages other than these are available as semi-custom products. " PACKAGING INFORMATION $ SOT-25 Semiconductor Ltd. Data Sheet 2 XC9206 / 9207/ 9208 Series PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In " MARKING RULE $ SOT-25 1 5 4 1234 Represents the product name and the type of DC/DC converters DESIGNATOR PRODUCT NAME 6 XC9206A x x x M x 7 XC9207A x x x M x 8 XC9208A x x x M x * Character inversion is used. 1 2 SOT-25 (TOP VIEW) 3 2 Represents the integer of the output voltage and the oscillation frequency DESIGNATOR FOSC=300kHz (XC920 x x 2 x 3M x) 3 FOSC=600kHz (XC920 x x 2 x 6M x) FOSC=1.2MHz (XC920 x x 2 x CM x) OUTPUT VOLTAGE 0 0 A 0. X 1 1 B 1. X 2 2 C 2. X 3 3 D 3. X 4 4 E 4. X Represents the decimal number of output voltage and the oscillation frequency DESIGNATOR FOSC=300kHz (XC920 x x x 3 3M x) FOSC=600kHz (XC920 x x x 3 6M x) FOSC=1.2MHz (XC920 x x x 3 CM x) OUTPUT VOLTAGE 0 A A X. 0 1 B B X. 1 2 C C X. 2 3 D D X. 3 4 E E X. 4 5 F F X. 5 6 H H X. 6 7 K K X. 7 8 L L X. 8 Z Y Y X. 85 9 M M * Output voltage 0.9V ~ 4.0V (100mV steps), 1.85V and 2.85V are standard products. Output voltages other than these are available as semi-custom products. 4 X. 9 Represents the production lot number. 0 to 9, A to Z repeated (G, I, J, O, Q, W excepted) Semiconductor Ltd. Data Sheet 3 XC9206 / 9207/ 9208 Series PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In " BLOCK DIAGRAM Phase Compensation VOUT VIN Pch Driver Tr. PWM Comparator R1 Logic R2 Buffer Driver LX Error Amp. Vref with Soft Start, CE Current Limit & Feedback PWM/PFM Selector Ramp Wave Generator, OSC U.V.L.O Comp. CE/MODE Control Logic U.V.L.O CE/MODE VSS Note ) The signal from CE/MODE Control Logic to PWM/PFM Selector is being fixed to "L" level inside, and XC9206 series chooses PWM control. The signal from CE/MODE Control Logic to PWM/PFM Selector is being fixed to "H" level inside, and XC9207 series chooses only PWM/PFM automatic switching control. " ABSOLUTE MAXIMUM RATINGS Ta = 25OC PARAMETER SYMBOL RATINGS UNITS VIN Pin Voltage VIN V Lx Pin Voltage VLx - 0.3 ~ + 6.5 - 0.3 ~ VIN + 0.3 V VOUT Pin Voltage VOUT CE / MODE Pin Voltage VCE - 0.3 ~ + 6.5 - 0.3 ~ VIN + 0.3 V V Lx Pin Current ILx ± 1000 mA Continuous Power Dissipation Pd 250 mW Operating Temperature Range Topr - 40 ~ + 85 O Storage Temperature Range Tstg - 55 ~ + 125 O C C Semiconductor Ltd. Data Sheet 4 XC9206 / 9207/ 9208 Series PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In " ELECTRICAL CHARACTERISTICS XC9206A18CMR, XC9207A18CMR, XC9208A18CMR PARAMETER Output Voltage SYMBOL VOUT VOUT=1.8V, FOSC=1.2MHz, Ta=25OC CONDITIONS MIN TYP MAX UNIT CIRCUIT 1.764 1.800 1.836 V 1 (XC9206, 9207) 1.8 - 6.0 V 1 (XC9208) 2.0 - 6.0 500 - - mA 1 1.00 1.40 1.78 V 2 - 255 413 µA When connected to ext. components CE=VIN, IOUT=30mA Operating Voltage Range Maximum Output Current VIN IOUTMAX When connected to ext. components CE=VIN, VOUT=0V, Voltage which Lx pin voltage holding "L" level (*1) U.V.L.O Voltage VUVLO Supply Current 1 IDD1 CE=VIN, VOUT=fixed voltage x 0.9V Supply Current 2 IDD2 CE=VIN, VOUT=fixed voltage x 1.1V - 98 158 µA Stand-by Current Istb CE=VSS, VOUT=fixed voltage x 1.1V - 0 1 µA 3 3 3 1.020 1.200 1.380 MHz 1 24 30 36 % 1 100 - Oscillation Frequency FOSC When connected to ext. components CE=VIN, IOUT=30mA PFM pulse width rate PFMDTY When connected to ext. components (XC9207, XC9208 only), CE=VIN, IOUT=1mA Maximum Duty Cycle MAXDTY CE=VIN, VOUT=0V Minimum Duty Cycle MINDTY CE=VOUT=VIN - - Efficiency (*2) EFFI When connected to ext. components, CE=VIN, IOUT=100mA - 86 Lx SW ON Resistance RLx CE=VIN, VOUT=0V, ILx=400mA (*3) - 0.4 Current Limit ILIM CE "H" Voltage VCEH VCEL PWM "H" Voltage VPWMH mA V 5 % % - 600 - 1.2 - VIN (XC9208) 0.9 - VIN VSS - 0.3 V 5 VIN-0.3 - - V 1 - - VIN-1.0 V 1 -0.1 - 0.1 µA 5 5 applied Lx determine "H" CE "L" Voltage Ω 0 (XC9206, XC9207) VIN=CE=5.0V, VOUT=0V VOUT=0V, When CE voltage is 0.9 2 2 1 4 4 % VOUT=0V, When CE voltage is applied Lx determine "L" When connected to ext. components (XC9208 only) IOUT=1mA (*4) PWM "L" Voltage VPWML When connected to ext. components (XC9208 only) IOUT=1mA (*4) CE "H" Current CE "L" Current ICEH ICEL Soft start time TSS Latch Time Tlat CE=VIN=5.5V, VOUT=0V CE=0V, VIN=5.5V, VOUT=0V When connected to ext. components CE=0V ! VIN, IOUT=1mA When connected to ext. components -0.1 - 0.1 µA 0.8 - 6.0 ms 1 - - 12.0 ms 6 VIN=CE=5.0V, short VOUT by 1Ω resistance (*5) Test condition : Unless otherwise stated, VIN = 3.6V *1 Including Hysteresis operating voltage range. *2 EFFI = [ (Output Voltage x Output Current) / (Input Voltage x Input Current) ] x 100 *3 On resistance = VLx (measurement voltage) / 0.4 The CE/MODE pin of the XC9208A series works also as an external PWM control and PWM/PFM control switching pin. When the IC is in the operation, control is switched to the PWM mode when the CE/MODE pin voltage is equal to or greater than VIN minus 0.3 V, and to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0 V and equal to or greater than VCEH. *4 *5 Time until it short-circuits VOUT with GND through 1 Ω of resistance from a state of operation and is set to VOUT=0V from current limit pulse generating. Semiconductor Ltd. Data Sheet 5 XC9206 / 9207/ 9208 Series PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In " ELECTRICAL CHARACTERISTICS XC9206A25CMR, XC9207A25CMR, XC9208A25CMR PARAMETER Output Voltage MIN TYP MAX UNIT CIRCUIT 2.450 2.500 2.550 V 1 (XC9206, 9207) 1.8 - 6.0 V 1 (XC9208) 2.0 - 6.0 500 - - mA 1 1.00 1.40 1.78 V 2 - 255 413 µA CONDITIONS SYMBOL VOUT VOUT=2.5V, FOSC=1.2MHz, Ta=25OC When connected to ext. components CE=VIN, IOUT=30mA Operating Voltage Range Maximum Output Current VIN IOUTMAX When connected to ext. components CE=VIN, VOUT=0V, Voltage which Lx pin voltage holding "L" level (*1) U.V.L.O Voltage VUVLO Supply Current 1 IDD1 CE=VIN, VOUT=fixed voltage x 0.9V Supply Current 2 IDD2 CE=VIN, VOUT=fixed voltage x 1.1V - 98 158 µA Stand-by Current Istb CE=VSS, VOUT=fixed voltage x 1.1V - 0 1 µA 3 3 3 1.020 1.200 1.380 MHz 1 24 30 36 % 1 100 - Oscillation Frequency FOSC When connected to ext. components CE=VIN, IOUT=30mA PFM pulse width rate PFMDTY When connected to ext. components (XC9207, XC9208 only), CE=VIN, IOUT=1mA Maximum Duty Cycle MAXDTY CE=VIN, VOUT=0V Minimum Duty Cycle MINDTY CE=VOUT=VIN - - Efficiency (*2) EFFI When connected to ext. components, CE=VIN, IOUT=100mA - 91 Lx SW ON Resistance RLx CE=VIN, VOUT=0V, ILx=400mA (*3) - 0.4 Current Limit ILIM VIN=CE=5.0V, VOUT=0V CE "H" Voltage VCEH VOUT=0V, When CE voltage is PWM "H" Voltage VCEL VPWMH Ω mA V 5 0 % % - 600 - (XC9206, XC9207) 1.2 - VIN (XC9208) 0.9 - VIN VSS - 0.3 V 5 VIN-0.3 - - V 1 - - VIN-1.0 V 1 -0.1 - 0.1 µA 5 5 applied Lx determine "H" CE "L" Voltage 0.9 2 2 1 4 4 % VOUT=0V, When CE voltage is applied Lx determine "L" When connected to ext. components (XC9208 only) IOUT=1mA (*4) PWM "L" Voltage VPWML When connected to ext. components (XC9208 only) IOUT=1mA (*4) CE "H" Current CE "L" Current ICEH ICEL Soft start time TSS Latch Time Tlat CE=VIN=5.5V, VOUT=0V CE=0V, VIN=5.5V, VOUT=0V When connected to ext. components CE=0V ! VIN, IOUT=1mA When connected to ext. components -0.1 - 0.1 µA 0.8 - 6.0 ms 1 - - 12.0 ms 6 VIN=CE=5.0V, short VOUT by 1Ω resistance (*5) Test condition : Unless otherwise stated, VIN = 3.6V *1 Including Hysteresis operating voltage range. *2 EFFI = [ (Output Voltage x Output Current) / (Input Voltage x Input Current) ] x 100 *3 On resistance = VLX (measurement voltage) / 0.4 The CE/MODE pin of the XC9208A series works also as an external PWM control and PWM/PFM control switching pin. When the IC is in the operation, control is switched to the PWM mode when the CE/MODE pin voltage is equal to or greater than VIN minus 0.3 V, and to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0 V and equal to or greater than VCEH. *4 *5 Time until it short-circuits VOUT with GND through 1 Ω of resistance from a state of operation and is set to VOUT=0V from current limit pulse generating. Semiconductor Ltd. Data Sheet 6 XC9206 / 9207/ 9208 Series PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In " ELECTRICAL CHARACTERISTICS XC9206A33CMR, XC9207A33CMR, XC9208A33CMR PARAMETER SYMBOL Output Voltage VOUT VOUT=3.3V, FOSC=1.2MHz, Ta=25OC MIN TYP MAX UNIT CIRCUIT 3.234 3.300 3.366 V 1 (XC9206, 9207) 1.8 - 6.0 V 1 (XC9208) 2.0 - 6.0 500 - - mA 1 1.00 1.40 1.78 V 2 CE=VIN, VOUT=fixed voltage x 0.9V - 370 585 µA - 120 180 µA 3 3 3 CONDITIONS When connected to ext. components CE=VIN, IOUT=30mA Operating Voltage Range Maximum Output Current VIN IOUTMAX When connected to ext. components CE=VIN, VOUT=0V, Voltage which Lx pin voltage holding "L" level (*1) U.V.L.O Voltage VUVLO Supply Current 1 IDD1 Supply Current 2 IDD2 CE=VIN, VOUT=fixed voltage x 1.1V Istb CE=VSS, VOUT=fixed voltage x 1.1V Stand-by Current Oscillation Frequency FOSC When connected to ext. components - 0 1 µA 1.020 1.200 1.380 MHz 1 26 32 38 % 1 100 - - - CE=VIN, IOUT=30mA PFM pulse width rate PFMDTY When connected to ext. components (XC9207, XC9208 only), CE=VIN, IOUT=1mA Efficiency (*2) EFFI When connected to ext. components, CE=VIN, IOUT=100mA - 92 Lx SW ON Resistance RLx CE=VIN, VOUT=0V, ILx=400mA (*3) - 0.4 0.9 Ω Current Limit ILIM VIN=CE=5.0V, VOUT=0V - 600 - mA 2 2 1 4 4 CE "H" Voltage VCEH (XC9206, XC9207) 1.2 - VIN V 5 (XC9208) 0.9 - VIN VSS - 0.3 V 5 VIN-0.3 - - V 1 - - VIN-1.0 V 1 -0.1 - 0.1 µA 5 5 Maximum Duty Cycle MAXDTY CE=VIN, VOUT=0V Minimum Duty Cycle MINDTY CE=VOUT=VIN VOUT=0V, When CE voltage is applied Lx determine "H" CE "L" Voltage VCEL VOUT=0V, When CE voltage is applied % 0 % % Lx determine "L" PWM "H" Voltage VPWMH When connected to ext. components (XC9208 only) IOUT=1mA (*4) PWM "L" Voltage VPWML When connected to ext. components (XC9208 only) IOUT=1mA (*4) CE "H" Current CE "L" Current ICEH ICEL Soft start time TSS Latch Time Tlat CE=VIN=5.5V, VOUT=0V CE=0V, VIN=5.5V, VOUT=0V When connected to ext. components CE=0V ! VIN, IOUT=1mA When connected to ext. components -0.1 - 0.1 µA 0.8 - 6.0 ms 1 - - 12.0 ms 6 VIN=CE=5.0V, short VOUT by 1Ω resistance (*5) Test condition : Unless otherwise stated, VIN = 5.0V *1 Including Hysteresis operating voltage range. *2 EFFI = [ (Output Voltage x Output Current) / (Input Voltage x Input Current) ] x 100 *3 On resistance = VLX (measurement voltage) / 0.4 The CE/MODE pin of the XC9208A series works also as an external PWM control and PWM/PFM control switching pin. When the IC is in the operation, control is switched to the PWM mode when the CE/MODE pin voltage is equal to or greater than VIN minus 0.3 V, and to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0 V and equal to or greater than VCEH. *4 *5 Time until it short-circuits VOUT with GND through 1 Ω of resistance from a state of operation and is set to VOUT=0V from current limit pulse generating. Semiconductor Ltd. Data Sheet 7 XC9206 / 9207/ 9208 Series PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In " TYPICAL APPLICATION CIRCUIT CE/MODE VOUT 4 CE/ MODE VSS 3 2 VOUT (500mA) L VIN 5 VIN Lx $ FOSC = 1.2MHz $ FOSC = 600kHz L: 4.7µH (CDRH3D16 SUMIDA) L: 10µH (CDRH4D18C SUMIDA) SD : CRS02 (TOSHIBA) SD : CRS02 (TOSHIBA) CIN : 4.7µF (Ceramic) CIN : 4.7µF (Ceramic) CL : 10µF (Ceramic) CL : 10µF (Ceramic) 1 CIN (ceramic) CL (ceramic) SD * XC9206/9207/9208 series wire connection $ FOSC = 300kHz L: 22µH (CDRH4D28C SUMIDA) SD : CRS02 (TOSHIBA) CIN : 4.7µF (Ceramic) CL : 10µF (Ceramic) " NOTES ON USE # Application Information 1. The XC9206/9207/9208 series are designed for use with an output ceramic capacitor. If, however, the potential difference between input and output is too large, a ceramic capacitor may fail to absorb the resulting high switching energy and oscillation could occur on the output. If the inputoutput potential difference is large, connect an electrolytic capacitor in parallel to compensate for insufficient capacitance. 2. 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. 3. When the difference between VIN and VOUT is large and the load current is light, very narrow pulses will be outputted, and there is the possibility that some cycles may be skipped completely. $ Oscillation Wave Form (FOSC=1.2MHz) 1 VIN = 5.5V, VOUT=1.8V, IOUT=10mA CH1 : Lx CH2 : VOUT L : 4.7µH CDRH3D16 SUMIDA SD : CRS02 TOSHIBA CIN : 4.7µF Ceramic CL : 10µF Ceramic AC-COUPLED 4. 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: in this case, the Lx pin may not go low at all. $ Oscillation Wave Form (FOSC=1.2MHz) 2 VIN = 2.0V, VOUT=1.8V, IOUT=60mA CH1 : Lx CH2 : VOUT AC-COUPLED L : 4.7µH CDRH3D16 SUMIDA SD : CRS02 TOSHIBA CIN : 4.7µF Ceramic CL : 10µF Ceramic Semiconductor Ltd. Data Sheet 8 XC9206 / 9207/ 9208 Series PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In # Application Information (Continued) 5. With 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: Ipk = (VIN - VOUT) x On Duty / (2 x L x FOSC) + IOUT OnDuty : OnDuty ratio of Pch Driver Transistor L : Coil Inductance Value FOSC : Oscillation Frequency 6. When the peak current which exceeds limit current flows within the specified time, the built-in Pch driver transistor is turned off. 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 or the schottky diode. 7. When VIN is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance. 8. Care must be taken when laying out the PC Board, in order to prevent misoperation of the current limit mode. 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. 9. Use of the IC at voltages below the recommended voltage range may lead to instability. 10. This IC should be used within the stated absolute maximum ratings in order to prevent damage to the device. 11. Depending on the input-output voltage differential, or load current, some pulses may be skipped, and the ripple voltage may increase. When the series' duty cycle is digitally signalized, the linear duty cycle and the digitally signalized duty cycle cannot carry out completely the same change, which means that the duty cycle does not change linearly. The output is stabilized by applying the phase compensation and adjusting the duty cycle, even when the duty cycle loses the linear change in the whole circuit. When the state where the output was stabilized is continued by applying phase compensation to duty cycle which lost linearity, ripple voltage does not increase more than it. The ripple voltage may increase to about several 10mV according to operating conditions. It is possible, by increasing the capacitance values, to reduce the ripple voltage. The operating conditions are greatly influenced by the dropout voltage, the load current, the delay-time, or the external components, such as the coil inductance, and the capacitance values. Verification with actual parts should be done. $ The increase of ripple voltage (1.2MHz) 1 2 VIN=4.2V, VOUT=1.8V, IOUT=180mA VIN=4.2V, VOUT=1.8V, IOUT=60mA CH1:Lx CH1:Lx CH2:VOUT CH2:VOUT AC-COUPLED AC-COUPLED 3 VIN=3.6V, VOUT=1.8V, IOUT=30mA CH1:Lx CH2:VOUT AC-COUPLED L : 4.7µH CDRH3D16 SUMIDA SD : CRS02 TOSHIBA CIN : 4.7µF Ceramic CL : 10µF Ceramic Semiconductor Ltd. Data Sheet 9 XC9206 / 9207/ 9208 Series PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In CE/ MODE VIN # Instructions on Pattern Layout 1. In order to stabilize VDD's voltage level, we recommend that a by-pass capacitor (CIN) be connected as close as possible to the VIN & VSS pins. 2. Please mount each external component as close to the IC as possible, and connect it to GND with the shortest possible PCB traces. 3. Wire external components as close to the IC as possible and use thick, short connecting traces to reduce the circuit impedance. 5 GND 4 CIN CL 1 2 3 SD Lx VIN Line L 4. Make sure that the PCB GND traces are as thick as possible, as variations in ground potential caused by high ground currents at the time of switching may result in instability. GND Line VOUT " OPERATIONAL EXPLANATION Other Line ( Through Hole to SD ) Each unit of the XC9206/9207/9208 series consists of a reference voltage source, ramp wave circuit, error amplifier, PWM comparator, phase compensation circuit, output voltage adjustment resistors, driver transistor, current limiter circuit, U.V.L.O. circuit and others. The series ICs compare, using the error amplifier, the voltage of the internal voltage reference source with the feedback voltage from the VOUT pin through resistors R1 and R2. 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 MOS 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 ICs. < Ramp Wave Circuit > The ramp wave circuit determines switching frequency. The frequency is fixed internally and can be selected from 300kHz, 600 kHz and 1.2 MHz. 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 resistors (R1 and R2). When a voltage lower than the reference voltage 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 XC9206/9207/9208 series monitors the current flowing through the P-channel MOS driver transistor connected to the Lx pin, and features a combination of the constant-current type current limit mode and the operation suspension mode. 1 When the driver current is greater than a specific level, the constant-current type current limit function operates to turn off the pulses from the Lx pin at any given timing. 2 When the driver transistor is turned off, the limiter circuit is then released from the current limit detection state. 3 At the next pulse, the driver transistor is turned on. However, the transistor is immediately turned off in the case of an over current state. 4 When the over current state is eliminated, the IC resumes its normal operation. The IC waits for the over current state to end by repeating the steps 1 through 3 . If an over current state continues for several msec and the above three steps are repeatedly performed, the IC performs the function of latching the OFF state of the driver transistor, and goes into operation suspension mode. Once the IC is in suspension mode, operations can be resumed by either turning the IC off via the CE /MODE pin, or by restoring power to the VIN pin. The suspension mode does not mean a complete shutdown, but a state in which pulse output is suspended; therefore, the internal circuitry remains in operation. The constant-current type current limit of the XC9206A/9207A/9208A series can be set at 600 mA. Limit< #mS Limit> #mS Current Limit LEVEL IOUT 0mA VOUT VSS LX CE/MODE Restart VIN Semiconductor Ltd. Data Sheet 10 XC9206 / 9207/ 9208 Series PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In " OPERATIONAL EXPLANATION (Continued) < U.V.L.O. Circuit> When the VIN pin voltage becomes 1.4 V 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 1.8 V or higher, switching operation takes place. By releasing the U.V.L.O. function, the IC performs the soft start function to initiate output startup operation. The soft start function operates even when the VIN pin voltage falls momentarily below the U.V.L.O. operating voltage. The U.V.L.O. circuit does not cause a complete shutdown of the IC, but causes pulse output to be suspended; therefore, the internal circuitry remains in operation. < Function of CE/MODE pin > The XC9206/9207/9208 series will enter into shut down state by inputting a low level signal to the CE/MODE pin. During a shut down state, the current consumption of the IC becomes 0 µA (TYP.), with a state of high impedance at the Lx pin and VOUT pin. The IC starts its operation by inputting a high level signal to the CE/MODE pin. The input of the CE/MODE pin is a CMOS input and the sink current is 0 µA (TYP.). # XC9206A / 07A series - Examples of how to use CE/MODE pin V IN V DD VIN VDD R1 (A) SW_CE STATUS ON Chip Disable OFF PWM control (XC9206), PWM/PFM automatic switching control (XC9207) SW_CE CE/MODE CE/ MODE R2 SW_CE (A) (B) SW_CE STATUS ON PWM control (XC9206), PWM/PFM automatic switching control (XC9207) OFF Chip Disable (B) # XC9208A series - Examples of how to use CE/MODE pin (A) SW_CE SW_PMW/PFM VIN VIN VDD VDD SW _ PW M/ PFM RM1 SW_CE RM1 CE/MODE CE/MODE STATUS * Synchronous PWM control OFF ON Non-synchronous PWM/PFM automatic switching control OFF OFF Chip Disable ON RM2 (B) SW_ PWM/PFM RM2 SW_CE SW_CE SW_PMW/PFM (A) (B) STATUS ON * Chip Disable OFF ON Non-synchronous PWM/PFM automatic switching control OFF OFF Synchronous PWM control Intermediate voltage can be generated by RM1 and RM2. Please set the value of each R1, R2, RM1, RM2 at around 100kΩ. For switches, CPU open-drain I/O port and transistor can be used. < PWM / PFM > XC9207/9208 series features PWM/PFM automatic switching control. With the automatic PWM/PFM switching control function, the series ICs are automatically switched from PWM control to PFM control mode under light load conditions. If during light load conditions the coil current becomes discontinuous and on-time rate falls lower than PFM duty, the PFM circuit operates to output a pulse with a fixed on-time rate from the Lx pin. During PFM operation with this fixed on-time rate, pulses are generated at different frequencies according to conditions of the moment. This causes a reduction in the number of switching operations per unit of time, resulting in efficiency improvement under light load conditions. However, since pulse output frequency is not constant, consideration should be given if a noise filter or the like is needed. Necessary conditions for switching to PFM operation depend on input voltage, load current, coil value and other factors. Semiconductor Ltd. Data Sheet 11 XC9206 / 9207/ 9208 Series PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In " TEST CIRCUITS Circuit 1 Circuit 2 4 CE VOUT /MODE 3 4 VSS 2 Lx 1 VOUT CE /MODE 3 VSS 2 Lx 1 L 5 VIN V CL CIN VIN 5 SD RL 200Ω 1µF Circuit 3 Circuit 4 4 A 5 CE VOUT /MODE 3 VSS 2 Lx 1 VIN 4 5 VOUT CE /MODE 3 VSS 2 Lx 1 VIN # 1µF V 1µF Circuit 5 Circuit 6 H A 4 CE VOUT /MODE L 4 3 VSS 2 Lx 1 CE VOUT /MODE 3 VSS 2 Lx 1 L 5 VIN 5 VIN SD 1kΩ CIN 1µF 1.2MHz 600kHz 300kHz CIN 4.7µF (ceramic) 4.7µF (ceramic) 4.7µF (ceramic) CL 10µF (ceramic) 10µF (ceramic) 10µF (ceramic) L 4.7µH 10µH 22µH SD Schottky Diode Schottky Diode Schottky Diode V CL 1Ω Semiconductor Ltd. Data Sheet 12 XC9206 / 9207/ 9208 Series PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In " TYPICAL PERFORMANCE CHARACTERISTICS (1) Output Voltage vs. Output Current XC9208A18C VOUT=1.8V (Oscillation Frequency1.2MHz) CIN:4.7µF,CL:10µF, L:4.7µH(CDRH3D16), SD:CRS02, Topr=25OC 1.9 PWM/PFM Switching Control VIN=2.4V 1.8 PWM Control 1.7 3.6V CIN:4.7µF,CL:10µF, L:10µH(CDRH4D18C), SD:CRS02, Topr=25OC 2 Output Voltage VOUT (V) 2 Output Voltage VOUT (V) XC9208A186 VOUT=1.8V (Oscillation Frequency 600kHz) 4.2V 1.6 1.5 1.9 PWM/PFM Switching Control 3.6V, 4.2V 1.8 PWM Control 1.7 VIN=2.4V 1.6 1.5 0.1 1 10 100 1000 0.1 Output Current IOUT (mA) 1 10 100 1000 Output Current IOUT (mA) XC9208A183 VOUT=1.8V (Oscillation Frequency 300kHz) CIN:4.7µF,CL:10µF, L:22µH(CDRH4D28C), SD:CRS02, Topr=25OC Output Voltage VOUT (V) 2 1.9 PWM/PFM Switching Control 3.6V, 4.2V 1.8 PWM Control 1.7 VIN=2.4V 1.6 1.5 0.1 1 10 100 1000 Output Current IOUT (mA) Semiconductor Ltd. Data Sheet 13 XC9206 / 9207/ 9208 Series PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In (2) Efficiency vs. Output Current XC9208A186 VOUT=1.8V (Oscillation Frequency 600kHz) CIN:4.7µF,CL:10µF, L:4.7µH(CDRH3D16), SD:CRS02, Topr=25OC 100 90 80 70 60 50 40 30 20 10 0 PWM/PFM Switching Control Efficiency EFFI (%) Efficiency EFFI (%) XC9208A18C VOUT=1.8V (Oscillation Frequency 1.2MHz) VIN=2.4V 3.6V 4.2V PWM Control 0.1 1 10 100 1000 100 90 80 70 60 50 40 30 20 10 0 CIN:4.7µF,CL:10µF, L:10µH(CDRH4D18C), SD:CRS02, Topr=25OC PWM/PFM Switching Control 3.6V 4.2V PWM Control 0.1 Output Current IOUT (mA) VIN=2.4V 1 10 100 1000 Output Current IOUT (mA) Efficiency EFFI (%) XC9208A183 VOUT=1.8V (Oscillation Frequency 300kHz) CIN:4.7µF,CL:10µF, L:22µH(CDRH4D28C), SD:CRS02, Topr=25OC 100 90 80 70 60 50 40 30 20 10 0 PWM/PFM Switching Control 4.2V 3.6V VIN=2.4V PWM Control 0.1 1 10 100 1000 Output Current IOUT (mA) Semiconductor Ltd. Data Sheet 14 XC9206 / 9207/ 9208 Series PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In (3) Ripple Voltage vs. Output Current XC9208A18C VOUT=1.8V (Oscillation Frequency 1.2MHz) CIN:4.7µF,CL:10µF, L:4.7µH(CDRH3D16), SD:CRS02, Topr=25OC 80 60 PWM Control 4.2V PWM/PFM Switching Control 40 3.6V VIN=2.4V 20 0 0.1 1 10 100 CIN:4.7µF,CL:10µF, L:10µH(CDRH4D18C), SD:CRS02, Topr=25OC 100 Ripple Voltage Vr (mV) 100 Ripple Voltage Vr (mV) XC9208A186 VOUT=1.8V (Oscillation Frequency 600kHz) 80 60 PWM Control PWM/PFM Switching Control 40 3.6V 4.2V VIN=2.4V 20 0 1000 0.1 Output Current IOUT (mA) 1 10 100 1000 Output Current IOUT (mA) XC9208A183 VOUT=1.8V (Oscillation Frequency 300kHz) CIN:4.7µF,CL:10µF, L:22µH(CDRH3D28C), SD:CRS02, Topr=25OC Ripple Voltage Vr (mV) 100 80 60 PWM Control PWM/PFM Switching Control 40 3.6V VIN=2.4V 4.2V 20 0 0.1 1 10 100 1000 Output Current IOUT (mA) Semiconductor Ltd. Data Sheet 15