XC9303 Series
High Efficiency, Synchronous Step-Up & Down DC / DC Controller ICs
ETR0602_001
GO-Compatible
GENERAL DESCRIPTION
The XC9303 series is highly efficient, synchronous PWM, PWM/PFM switchable step-up & down DC/DC controller ICs. A versatile, large output current and high efficiency, step-up/down DC/DC controller can be realized using only basic external components - transistors, coil, diode, capacitors, and resistors for detecting voltages. High efficiency is obtained through the use of a synchronous rectification topology. The operation of the XC9303 series can be switched between PWM and PWM/PFM (auto switching) externally using the PWM pin. In PWM/PFM mode, the XC9303 automatically switches from PWM to PFM during light loads and high efficiencies can be achieved over a wide range of output loads conditions. Output noise can be easily reduced with PWM control since the frequency is fixed. Synchronous rectification control can be switched to non-synchronous by using external signals (MODE pin). High efficiency can be regulated at heavy loads when synchronous operation. The XC9303 has a 0.9V (2.0%) internal voltage supply and using externally connected components, output voltage can be set freely between 2.0V to 6.0V. With an internal 300kHz switching frequency smaller external components can be used. Soft-start time is internally set to 10msec and offers protection against in-rush currents when the power is switched on and prevents voltage overshoot.
APPLICATIONS
PDAs Palmtop computers Portable audios Various power supplies
FEATURES
Input Voltage Range Output Voltage Range : 2.0V ~ 10V : 2.0V ~ 6.0V : Can be set freely with 0.9V (2.0%) of reference voltage supply and external components. : 300kHz (15%) : More than 800mA (VIN = 4.2V, VOUT=3.3V) : 3.0A (MAX.) : 78% (TYP.)
Oscillation Frequency Output Current Stand-By Function Maximum Duty Cycle
Synchronous Step-Up & Down DC / DC Controller PWM, PWM/PFM Switching Control Synchronous Rectification Control High Efficiency Soft-Start Time Package : 84% (TYP.) : 10ms (internally set) : MSOP-8A
TYPICAL APPLICATION CIRCUIT
<XC9303B093K OUTPUT= 3.3V>
Tr1:Pch MOSFET :CPH6315 Tr2:Nch M OSFET :CPH3409 Tr3:Nch M OSFET :CPH3409 CFB : 62pF L:22uH CDRH127/LD SD:CMS02 V OUT : 3 . 3 V
TYPICAL PERFORMANCE CHARACTERISTICS
Efficiency vs. Output Current
XC9303B093K(300kHz, VOUT =3.3V)
100 90 80 Efficiency EFFI (%) 70 60 50 40 30 20 10 0 0.1 1 10 100 1000 10000 Output Current IOUT (mA) PW M Control VIN=2.7V 4.2V
L=22uH(CDRH127/LD), CL=94uF(Tantalum),SD:CMS02 Tr1:CPH6315, Tr2:CPH3409, Tr3:CPH3409
PW M/PFM Switching Control
CIN :47uF
EXT 1 V DD PWM CE V IN :2.0V~10V PWM CE
EXT 2 GND FB NC
RFB :200 k
CL : 47uF X 2
RFB :75 k
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XC9303 Series
PIN CONFIGURATION
1 EXT1 2 VDD 3 PW M 4 CE EXT2 8 GND 7 FB 6 NC 5
MSOP-8A (TOP VIEW)
PIN ASSIGNMENT
PIN NUMBER 1 2 3 4 5 6 7 8 PIN NAME EXT 1 / VDD PWM CE NC FB GND EXT2 Supply Voltage PWM/PFM Switching Pin Chip Enable Pin No Connection Output Voltage Monitor Feedback Pin Ground External Transistor Drive Pin FUNCTIONS External Transistor Drive Pin
PRODUCT CLASSIFICATION
Ordering Information
XC9303 DESIGNATOR DESCRIPTION Type of DC/DC Controller Output Voltage Oscillation Frequency Package Devise Orientation SYMBOL B 09 3 K R L DESCRIPTION : Standard type : FB Voltage: 0.9V : 300kHz : MSOP-8A : Embossed tape, standard feed : Embossed tape, reverse feed
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XC9303
Series
BLOCK DIAGRAM
EXT1/
Synchronou s Blank Logic PWM Com pa rator
EXT2
FB
Error Am p
+ -
+ -
PWM /PFM Con trol l er
PWM
VIN CE
Vref=0.9V with Soft-Start, CE CE to i nterna l ci rcui t R am p Wave Gene rator, OSC
GND
ABSOLUTE MAXIMUM RATINGS
Ta = 25 PARAMETER VDD Pin Voltage FB Pin Voltage CE Pin Voltage PWM Pin Voltage MODE Pin Voltage EXT1, 2 Pin Voltage EXT1, 2 Pin Current Power Dissipation Operating Temperature Range Storage Temperature Range SYMBOL VDD VFB VEN VPWM MODE VEXT IEXT Pd Topr Tstg RATINGS - 0.3 ~ 12.0 - 0.3 ~ 12.0 - 0.3 ~ 12.0 - 0.3 ~ 12.0 - 0.3 ~ 12.0 - 0.3 ~ VDD + 0.3 100 150 - 40 ~ + 85 - 55 ~ +125 UNITS V V V V V V mA mW
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XC9303 Series
ELECTRICAL CHARACTERISTICS
XC9303B093 PARAMETER Supply Voltage Maximum Input Voltage Output Voltage Range (*1) Supply Current 1 Supply Current 2 Stand-by Current Oscillation Frequency FB Voltage Minimum Operation Voltage Maximum Duty Ratio Minimum Duty Ratio PFM Duty Ratio Efficiency (*2) Soft-Start Time EXT1 "High" ON Resistance EXT1 "Low" ON Resistance EXT2 "High" ON Resistance EXT2 "Low" ON Resistance PWM "High" Voltage PWM "Low" Voltage CE "High" Voltage CE "Low" Voltage CE "High" Current CE "Low" Current PWM "High" Current PWM "Low" Current FB "High" Current FB "Low" Current SYMBOL VDD VIN VOUTSET IDD1 IDD2 ISTB FOSC VFB VINmin MAXDTY MINDTY PFMDTY EFFI TSS REXTBH1 REXTBL1 REXTBH2 REXTBL2 VPWMH VPWML VCEH VCEL ICEH ICEL IPWMH IPWML IFBH IFBL FB = 1.0V PWM=0V CE = 0V Same as IDD1 Same as IDD2 No Load, VPWM=0V IOUT1=100mA (*3) VOUTx0.95V, CE=0V0.65V CE = 0, EXT1= VDD - 0.4V FB = 0V, EXT1 = 0.4V EXT2 = VDD - 0.4V CE = 0V, EXT2 = VDD - 0.4V No Load No Load FB = 0V FB = 0V VIN2.0V, IOUT=1mA FB = 0V FB = 1.0V Same as IDD1, CE = 0V Same as IDD1 VIN=3.0V, IOUT=10mA VOUT CONDITIONS (FOSC = 300kHz) MIN. 2.0 10.0 2.0 255 0.882 72 22 5.0 0.65 0.65 TYP. 90 55 300 0.900 78 30 84 10.0 26 19 23 19 MAX. 10.0 6.0 170 110 3.0 345 0.918 2.0 88 0 38 20.0 37 30 31 30 0.20 0.2 0.5 - 0.5 0.5 - 0.5 0.50 - 0.50 UNITS V V V A A A kHz V V % % % % ms V V V V A A A A A A Ta=25
CIRCUIT
NOTE *1: Please be careful not to exceed the breakdown voltage level of the external components. *2: EFFI={ [ (output voltage) x (output current) ] / [ (input voltage) x (input current) ] } x 100 *3: Tr1: CPH6315 (SANYO) Tr2: CPH3409 (SANYO) Tr3: CPH3409 (SANYO) SD: CMS02 (TOSHIBA) L: 22H (CDRH127/LD, SUMIDA) CL: 16V, 47F x 2 (Tantalum MCE Series, NICHICEMI) CIN: 16V, 47F (Tantalum MCE Series, NICHICEMI) RFB1: 200k RFB2: 75k CFB: 62pF
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XC9303
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OPERATIONAL EXPLANATION
The XC9303 series are synchronous step-up & down DC/DC converter controller ICs with built-in high speed, low ON resistance drivers. The error amplifier is designed to monitor the output voltage and it compares the feedback voltage (FB) with the reference voltage. In response to feedback of a voltage lower than the reference voltage, the output voltage of the error amp. decreases. This circuit generates the oscillation frequency, which in turn generates the source clock. The ramp wave generator generates a saw-tooth waveform based on outputs from the phase shift generator. 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. This circuit generates PFM pulses. Control can be switched between PWM control and PWM/PFM automatic switching control using external signals. The PWM/PFM automatic switching mode is selected when the voltage of the PWM pin is less than 0.2V, and the control 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. PWM control mode is selected when the voltage of the PWM pin is more than 0.65V. Noise is easily reduced with PWM control since the switching frequency is fixed. Control suited to the application can easily be selected which is useful in audio applications, for example, where traditionally, efficiencies have been sacrificed during stand-by as a result of using PWM control (due to the noise problems associated with the PFM mode in stand-by). The synchronous, blank logic circuit is to prevent penetration of the transistor connected to EXT1 and EXT2. The reference voltage, Vref (FB pin voltage)=0.9V, is adjusted and fixed by laser trimming (for output voltage settings, please refer to next page). 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 the error amps, the operation maintains a balance between the two inputs of the error amps and controls the EXT pin's ON time so that it doesn't increase more than is necessary. This function controls the operation and shutdown of the IC. When the voltage of the CE pin is 0.2V or less, the mode will be chip disable, the channel's operations will stop. The EXT1 pin will be kept at a high level (the external P-ch MOSFET will be OFF) and the EXT2 pin will be kept at a low level (the external N-ch MOSFET will be OFF). When CE pin is in a state of chip disable, current consumption will be no more than 3.0A. When the CE pin's voltage is 0.65V or more, the mode will be chip enable and operations will recommence. With soft-start, 95% of the set output voltage will be reached within 10ms (TYP.) from the moment of chip enable. |
