PWM Control, PWM/PFM Switching Control, XC9106 / 07 Series Step-up DC/DC Converters Preliminary Externally Applied Reference Voltage (Vref) May 23, 2002 Ver. 1-1 Externally Applied Reference Voltage (Vref) Ceramic Capacitors Compatible Input Voltage Range: 0.9V~10.0V Oscillation Frequency: 300kHz, 100kHz (±15%) PWM Control (XC9106) PWM/PFM Automatic Switching Control (XC9107) SOT-25 / USP-6B Package Applications z Power Supply for LCD z PDAs z Cellular Phones z Palmtop Computers z Portable Audio Systems z Various Multi-function Power Supplies Features General Description The XC9106 / 07 series are step-up DC/DC controller ICs with an externally applied reference voltage (Vref). Output voltage will be set with external resistors (RFB1 and 2) and Vref value. The series make it easy to control output voltage externally and are suited to software applications that need to vary voltage, such as LCD power supply for PDA. Output will be stable no matter which load capacitors are used but if a low ESR capacitor is used, RSENSE of about 0.1Ω will be required and phase compensation will be achieved. This makes the use of ceramic capacitors much easier, and allows for lower output ripple and reduced PCB area requirements. Tantalum and electrolytic capacitors can also be used, in which case, RSENSE becomes unnecessary. Oscillation frequencies of high clock, low ripple 300kHz and low supply current 100kHz are available. The XC9107 series are PWM/PFM automatic switching controlled. Control switches from PWM to PFM during light loads with the XC9107 and the series is highly efficient from light loads to large output currents. By bringing the whole circuit down while the series is in the stand-by mode (CE/PWM pin : low), supply current can be reduced to less than 1.0µA. Typical Application Circuit 0.9V ~ 10.0V Input Voltage Range: Power Supply Voltage Range: 1.8V ~ 10.0V and more than Vref+0.7V 0.8V ~ 2.5V (±2.0%) Vref x external split resistor ratio VOUT=Vref x (RFB1+RFB2)/RFB2 300kHz, 100kHz ±15% more than 30mA (VIN=3.3V, VOUT=20V, when peripheral components are used as in the circuits below .) VREF Input Range: Output Voltage: Oscillation Frequency: Output Current: PWM (XC9106) PWM/PFM auto-switching (XC9107) 85% (TYP.) ISTB=1.0µA (MAX.) Low ESR capacitors compatible SOT-25, USP-6B Controls: High Efficiency: Stand-by Current: Load Capacitors: Packages: Electrical Characteristics XC9107D003MR 25 L : 10µH VOUT (V) RSENSE : 100m Ω for Ceramic CL SD : MA737 * CFB : 27pF VOUT = 8V~25V RFB1 : IOUT = 30mA 270k Ω Circuit as left VDD=VIN=3.3V, I OUT=30mA 30 RFB2 : 30k Ω 20 15 10 5 0 CIN Ceramic CL : 10µF 1 5 2 3 CE/Vref VIN = 3.3V 0.0 Nch Power MOS FET 2SK2159 0.5 1.0 XC9107D003MR 30 4 1.5 2.0 Vref (V) 2.5 3.0 Circuit as left VDD=VIN=3.3V 25 VOUT (V) 0.8V~2.5V D/A converter * RSENSE is of no use in light load (uncontinuous mode) applications such as a small LCD, even using ceramic capacitor. 2.5V 20 2.0V 15 1.5V 10 Vref=0.8V 5 0 0.1 1 1 10 IOUT (mA) 100 1000 PWM Control, PWM/PFM Switching Control, XC9106 / 07 Series Step-up DC/DC Converters Preliminary Externally Applied Reference Voltage (Vref) Pin Configuration Pin Assignment PIN NUMBER PIN FUNCTION SOT-25 USP-6B NAME 5 1 4 2 1 6 2 5 3 4 3 USP-6B (TOP VIEW) SOT-25 (TOP VIEW) 1 2 6 2 FB VDD Output Resistor Connection Supply Voltage 3 4 CE/ Vref Serves as both Chip Enable pin and Reference Voltage Apply pin. 4 5 - 3 1 5 GND EXT NC Ground External Transistor Connection No Connection Ordering Information XC9106D12345 XC9107D12345 XC9106 Series: PWM Control XC9107 Series: PWM/PFM automatic switching control (Ordering information is the same as XC9106 Series) Reference Voltage (apply external) Fixed : 00 12 3 3 1 Oscillation Frequency: 300kHz 100kHz 4 M D Package: 5 R L Embossed Tape: SOT-25 (1 reel = 3000 pcs.) USP-6B (1 reel = 3000 pcs.) Standard Feed Reverse Feed Block Diagram Current Ripple Detect and FB FB Phase Compensation PWM Comparator Error Amp. Vref with Soft Start, CE VDD Buffer, Driver EXT Ramp Wave Generator, OSC PWM/PFM Controller GND CE / Vref FB, CE : CMOS INPUT EXT : CMOS OUTPUT Absolute Maximum Ratings PARAMETER VDD pin Voltage FB pin Voltage CE / Vref pin Voltage EXT pin Voltage EXT pin Current Power Dissipation Operating Ambient Temperature Storage Temperature SYMBOL VDD FB VCE / Vref VEXT IEXT/ Pd SOT-25 USP-6B Topr Tstg Ta = 25OC UNITS RATINGS -0.3 ~ 12.0 -0.3 ~ 12.0 -0.3 ~ 12.0 -0.3 ~ VDD + 0.3 ±100 150 100 -40 ~ +85 -55 ~ +125 V V V V mA mW O O 2 C C PWM Control, PWM/PFM Switching Control, XC9106 / 07 Series Step-up DC/DC Converters Preliminary Externally Applied Reference Voltage (Vref) Electrical Characteristics XC9106D001MR, XC9107D001MR PARAMETER Output Voltage Reference Voltage Range FB Control Voltage *1 *1 Operation Start Voltage SYMBOL VOUT Vref VFB VDD VST1 Oscillation Start Voltage VST2 Power Supply Voltage Range (FOSC=100 (kHz) MIN. 8.820 0.8 0.882 Vref = 0.9V VDD as shown right or (Vref applied voltage + 0.7V) 1.8 CONDITIONS Vref = 0.9V Ta=25OC TYP. 9.000 0.900 Recommended Circuit using 2SD1628, I OUT=1.0mA No external connections CE/Vref=0.9V, Voltage applied, FB=0V VHLD Operation Holding Voltage Recommended Circuit using 2SD1628, IOUT=1.0mA IDD1 Same as VST2, VDD=3.300V Supply Current 1 IDD2 Same as IDD1, FB=1.2V Supply Current 2 Same as IDD1, CE/Vref=0V ISTB Stand-by Current FOSC Same as IDD1 Oscillation Frequency MAXDTY Same as IDD1 Maximum Duty Ratio PFMDTY No Load PFM Duty Ratio (XC9106 series) EFFI Recommended Circuit using XP161A1355 Efficiency TSS Soft-start Time Vref=0.9V Same as IDD1 VCEH CE "High" Voltage Same as IDD1 VCEL CE "Low" Voltage EXT "High" ON Resistance REXTH Same as IDD1, VEXT=VOUT-0.4V REXTL Same as IDD1, VEXT=0.4V EXT "Low" ON Resistance ICEH Same as IDD2, CE=2.5V CE "High" Current Same as IDD2, CE=0V ICEL CE "Low" Current Same as IDD2, CE=VDD IFBH FB "High" Current Same as IDD2, CE=0V IFBL FB "Low" Current 29 14 85 75 20 5.0 0.65 100 81 28 85 10.0 24 16 0.0 MAX. 9.180 2.5 0.918 10.0 0.9 UNITS V V V V V Circuit 0.8 V 4 0.7 41 19 1.0 115 87 36 V µA µA µA KHz % % % mS V V Ω Ω µA µA µA µA 3 4 4 5 4 4 1 1 1 5 5 4 4 5 5 5 5 20.0 0.20 36 24 2.5 -0.1 0.1 -0.1 1 4 3 Test Conditions: Unless otherwise stated, CL: ceramic, recommended MOS FET should be connected. 0.09 (V) , RFB1, 2 x 10 VDD = 3.30 (V) D Vref = 50 (mA) VIN = 3.30 (V) D IOUT = Notes *1 Although the IC starts step-up operations from a VDD of 0.8V, the output voltage and oscillation frequency are stabilized at VDD ≥ 1.8V or (Vref applied voltage + 0.7V). Therefore, a VDD of more than 1.8V or (Vref applied voltage + 0.7V) is recommended when VDD is supplied from VIN or other power sources. 3 PWM Control, PWM/PFM Switching Control, XC9106 / 07 Series Step-up DC/DC Converters Preliminary Externally Applied Reference Voltage (Vref) Electrical Characteristics XC9106D003MR, XC9107D003MR PARAMETER Output Voltage Reference Voltage Range FB Control Voltage *1 *1 (FOSC=300 (kHz) Operation Start Voltage SYMBOL VOUT Vref VFB VDD VST1 Oscillation Start Voltage VST2 Power Supply Voltage Range CONDITIONS MIN. 8.820 0.8 Vref = 0.9V 0.882 VDD as shown right or (Vref applied voltage + 0.7V) 1.8 Vref = 0.9V Ta=25OC TYP. 9.000 0.900 Recommended Circuit using 2SD1628, I OUT=1.0mA MAX. 9.180 2.5 0.918 10.0 0.9 UNITS V V V V V Circuit 0.8 V 4 0.7 88 22 1.0 345 87 40 V µA µA µA KHz % % % mS V V Ω Ω µA µA µA µA 3 4 4 5 4 4 1 1 1 5 5 4 4 5 5 5 5 No external connections CE/Vref=0.9V, Voltage applied, FB=0V VHLD Operation Holding Voltage Recommended Circuit using 2SD1628, IOUT=1.0mA Same as VST2, VDD=3.300V IDD1 Supply Current 1 Same as IDD1, FB=1.2V IDD2 Supply Current 2 Same as IDD1, CE/Vref=0V ISTB Stand-by Current Oscillation Frequency FOSC Same as IDD1 Maximum Duty Ratio MAXDTY Same as IDD1 PFM Duty Ratio PFMDTY No Load (XC9106 series) Efficiency EFFI Recommended Circuit using XP161A1355 TSS Soft-start Time Vref=0.9V Same as IDD1 VCEH CE "High" Voltage Same as IDD1 VCEL CE "Low" Voltage EXT "High" ON Resistance REXTH Same as IDD1, VEXT=VOUT-0.4V REXTL Same as IDD1, VEXT=0.4V EXT "Low" ON Resistance Same as IDD2, CE=2.5V ICEH CE "High" Current Same as IDD2, CE=0V ICEL CE "Low" Current Same as IDD2, CE=VDD IFBH FB "High" Current Same as IDD2, CE=0V IFBL FB "Low" Current 62 16 255 75 24 5.0 0.65 300 81 32 85 10.0 24 16 0.0 20.0 0.20 36 24 2.5 -0.1 0.1 -0.1 1 4 3 Test Conditions: Unless otherwise stated, CL: ceramic, recommended MOS FET should be connected. 0.09 (V) , RFB1, 2 x 10 VDD = 3.30 (V) D Vref = VIN = 3.30 (V) D IOUT = 50 (mA) Notes *1 Although the IC starts step-up operations from a VDD of 0.8V, the output voltage and oscillation frequency are stabilized at VDD ≥ 1.8V or (Vref applied voltage + 0.7V). Therefore, a VDD of more than 1.8V or (Vref applied voltage + 0.7V) is recommended when VDD is supplied from VIN or other power sources. Standard Circuit RSENSE L SD VIN CFB VOUT RFB1 RFB2 1 CL 5 Nch Power MOS FET Rb 2 3 Cb 4 CE/Vref When obtaining VDD from a source other than VOUT, please insert a capacitor CDD between the VDD pin and the GND pin in order to provide stabler operations. Please wire CL & CIN between the VOUT/VDD pin and the GND pin. Strengthen the wiring sufficiently. When using a capacitor other than ceramic or low ESR at CL, please take away RSENSE and short. Insert Rb and CB when using a bipolar NPN Transistor. 4 PWM Control, PWM/PFM Switching Control, XC9106 / 07 Series Step-up DC/DC Converters Preliminary Externally Applied Reference Voltage (Vref) Operational Description The XC9106 / 07 series are reference voltage (Vref) apply external step-up DC/DC Controler ICs. Output voltage will be set with external resistors (RFB1 and 2) and Vref value. The series make it easy to control output voltage externally and are suited to software applications that need to vary voltage such as LCD power supply for PDA. <Error Amp.> Error Amplifier is designed to monitor the output voltage, comparing the feedback voltage (FB) with the reference voltage Vref. In response to feedback of a voltage lower than the reference voltage Vref, the output voltage of the error amp. decreases. <OSC Generator> This circuit generates the internal reference clock. <Ramp Wave Generator> The Ramp Wave Generator generates a saw-tooth waveform based on outputs from the OSC Generator. <PWM Comparator> The PWM Comparator compares outputs from the Error Amp. and saw-tooth waveform. When the voltage from the Error Amp's output is low, the external switch will be set to ON. <PWM/PFM Controler> This circuit generates PFM pulses. The PWM/PFM automatic switching mode switches between PWM and PFM automatically depending on the load. As the PFM circuit generates pulses based on outputs from the PWM Comparator, shifting between modes occurs smoothly. Noise is easily reduced with PWM control since the switching frequency is fixed. Because of the function, control suited to the application can easily be selected. <Vref 1 with Soft Start> The reference voltage of the XC9106/9107 series is adjusted and fixed by external applied voltage. (For output voltage settings, please refer to the output voltage setting on page 6.) To protect against inrush current, when the power is switched on, and also to protect against voltage overshoot, soft-start time is set internally to 10ms. 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 error amp, the operation maintains a balance between the two inputs of error amps and controls the EXT pin's ON time so that it doesn't increase more than is necessary. The XC9106/9107 series alters soft start times by the setting value of reference voltage in order to protect against voltage overshoot and also to protect against inrush current. Please determine soft start time by the formula equation. XC9106 / XC9107D xxx MR TSS = 8.65 x Vref + 2.21 30 Soft Start Time : TSS (ms) [Example Computation] Vref = 0.9V, TSS = 8.65 x 0.9 + 2.21 = 10.0 ms 25 20 15 10 5 0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Reference Voltage Vref (V) <Enable Function> This function controls the operation and shutdown of the IC. When the voltage of the CE pin drops to 0.2V or less, disable mode will be entered, the IC's operations will stop and the EXT pin will be kept at a low level (the external N-type MOSFET will be OFF) . When the IC is in a state of chip disable, current consumption will be no more than 1.0µA. When the CE pin's voltage rises to 0.65V or more, enable mode will be entered and operations will recommence. The CE pin also doubles with reference voltage in the XC9106/9107 series, and the range of reference voltage can be varied externally from 0.8V to 2.5V. 5 PWM Control, PWM/PFM Switching Control, XC9106 / 07 Series Step-up DC/DC Converters Preliminary Externally Applied Reference Voltage (Vref) Functional Settings < Output Voltage Setting> Output voltage can be set by adding external split resistors. Output voltage is determined by the following equation, based on the values of RFB1 and RFB2. The sum of RFB1 and RFB2 should normally be 2 MΩ or less. The range of reference voltage of the series can be varied externally from 0.8V to 2.5V. VOUT = Vref applied voltage x (RFB1 + RFB2) / RFB2 The value of CFB1, speed-up capacitor for phase compensation, should result in fzfb = 1/(2 π × CFB × RFB1) equal to 5 to 30kHz. Adjustments are required depending on the application, value of inductance (L), and value of load capacity (CL). fzfb = 30kHz (L=10µH) RFB1 : 270kΩ fzfb = 20kHz (L=22µH) CFB : fzfb = 10kHz (L=47µH) RFB2 : 30kΩ 20pF (fzfb = 30kHz, L = 10µH) 27pF (fzfb = 20kHz, L = 22µH) 56pF (fzfb = 10kHz, L=47µH) < The use of ceramic capacitor CL > The circuit of the XC9106/9107 series is organized by a specialized circuit which reenacts negative feedback of both voltage and current. Also by insertion of approximately 100mΩ of a low and inexpensive sense resistor as current sense, a high degree of stability is possible even using a ceramic capacitor, a condition which used to be difficult to achieve. Compared to a tantalum condenser, because the series can be operated in a very small capacity, it is suited to use of the ceramic capacitor which is cheap and small. Recommended Components Tr: *When a MOSFET is used : 2SK2159 (NEC N-Channel Power MOSFET) Note* : With direct voltages over 4.5V, use the XP161A11A1PR. *When a NPN Tr. Is used : 2SD1628 (Sanyo) Rb : 500Ω (adjust with Tr's HFE or load) Cb : 2200pF (ceramic type) Cb ≤ 1 / (2π × Rb× FOSC × 0.7) SD: L, CL : MA2Q737 (Schottky Diode type, MATSUSHITA) Adjust as below according to the condition and peripheral components When Ceramic capacitor is used : L: 22µH (SUMIDA CDRH5D28, FOSC = 100kHz) 10µH (SUMIDA CDRH5D18, FOSC = 300kHz) CL : 10V 10µF (Ceramic capacitor, LMK325BJ106ML, TAIYOYUDEN) Use the formula below when step-up ratio and output current is large. CL = (CL standard value) × (IOUT(mA) / 300mA × VOUT / VIN) RSENSE : 100mΩ (FOSC = 300kHz) D Look up "Low Chip Resistor" for the selection 50mΩ (FOSC = 100kHz) When Tantalum condenser is used : L: 22µH (SUMIDA CDRH5D28, FOSC = 300kHz) 47µH (SUMIDA CDRH5D28, FOSC = 100kHz) Except when IOUT(mA) / 100mA × VOUT / VIN > 2 → 22µH CL: 16V 47µF (tantalum type NIPPONCHEMI 16MCE476MD2) Use the formula below when step-up ratio and output current is large. CL = (CL standard value) × (IOUT(mA) / 300mA × VOUT / VIN) RSENSE: Not required, but short out the wire. When AL Electrolytic condenser is used : L: 22µH (SUMIDA CDRH5D28, FOSC = 300kHz) 47µH (SUMIDA CDRH5D28, FOSC = 100kHz) Except when IOUT(mA) / 100mA × VOUT / VIN > 2 → 22µH CL: 16V 100µF (AL electrolytic type) + 10V 2.2µF (ceramic type) Strengthen appropriately when step-up ratio and output current is large. RSENSE: Not required, but short out the wire. CFB: Set up so that fzfb = 100kHz. 6 PWM Control, PWM/PFM Switching Control, XC9106 / 07 Series Step-up DC/DC Converters Preliminary Externally Applied Reference Voltage (Vref) Test Circuits Circuit 4 Circuit 1 SD RP RSENSE VOUT CP L OSC A CFB RFB1 VDD EXT VIN A CL Tr V FB CE CIN GND OSC EXT RFB2 RL VDD CE A CDD FB GND Circuit 2 Circuit 5 A VDD EXT A SD RSENSE OSC CB EXT CIN VDD RFB1 A CL Tr VIN CFB V FB CE RB GND RFB2 RL Circuit 3 SD RSENSE L CB A OSC CFB EXT VDD VIN CIN RFB1 A CL Tr RB V FB CE GND FB GND L A C CE E RFB2 RL 7 A A