XC9120/XC9121/XC9122 Series
Step-Up DC/DC Controller IC, MAXDUTY: 93%
ETR0409 002
GO-Compatible
GENERAL DESCRIPTION
XC9120/9121/9122 Series are PWM, PWM/PFM auto/external switching controlled step-up DC/DC converter controller ICs. Since maximum duty ratio is as large as 93%, the series is the best for the applications used as high step-up ratios, such as the LCD panels and OLED. In this series, even if it is a high step-up ratio, the output voltage stabilized at high efficiency can be obtained. With 0.9V (2.0%) of reference voltage supply internal, and using external resistors, RFB1 and 2, output voltage can be set up freely within a range of 1.5V to 30V. For a current sense, with the use of RSENSE, ceramic capacitors can be used as load capacitors and allows for lower output ripple and reduced PCB area requirements. Control automatically switches from PWM to PFM during light loads with the XC9121 series and the XC9122 series can switch the control from PWM to PFM using external signals depending on the circuit conditions.. During stand-by (when the CE pin is low), all circuits are shutdown to reduce current consumption to as low as 1.0 A or less. The overcurrent limit circuit of this IC is designed to monitor the ripple voltage of the FB pin and operates the IC to stop when the ripple voltage runs over 250mV. The IC resumes its operation with a toggle of the CE pin or by turning the power supply back on.
APPLICATIONS
Power Supply for the LCDs. High Step-Up Ratio Equipment (OLED, etc.)
Input Voltage Range : 0.9V~6.0V Operating Voltage Range : 1.8V~6.0V Output Voltage Range : 1.5V~30V (externally set) Reference voltage 0.9V (2.0%) Oscillation Frequency : 100kHz (15%) Output Current : 80mA (VIN=3.6V, VOUT=15V)* Control : XC9120 (PWM) : XC9121 (PWM/PFM Automatic) : XC9122 (PWM/PFM Externally) High Efficiency : 85% (TYP.) : (VIN=3.6V, VOUT=15V, IOUT=10mA)* Stand-by Function : ISTB=1.0A (MAX.) Load Capacitors : Low ESR capacitor compatible Current Limiter : Operates when ripple is 250mV Maximum Duty Ratio : 93% (TYP.) for High Step-up Ratio Package : SOT-25, USP-6C
* When using external components showing in the circuit below.
FEATURES
TYPICAL APPLICATION CIRCUIT
RSENSE: 50m for Ceramic CL SD: XB01SB04A2
TYPICAL PERFORMANCE CHARACTERISTICS
XC9122D091 (100kHz, 15.0V) 100
L=47uH(CDRH5D28),SD:XB01SB04A2 CL=40uF(Ceramic),Tr:161A11A1 4.2V
L: 47uH
VOUT=15V
Efficiency: EFFI(%)
RFB1: 470k RFB2: 30k 1 5 Nch Power MOS FET XP161A1355
CFB: 33pF
80 60 40 20 0 0.1
PWM/PFM
VIN=2.7V 3.2V PWM 3.6V
CIN
Ceramic CL: 10uF x 4 CE
2 3 4
VIN= 2.7V~4.2V
1
10
100
Output Current: IOUT(mA)
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XC9120/XC9121/XC9122 Series
PIN CONFIGURATION
EXT 5 5 GND 4 4
* The dissipation pad for the USP-6C package should be solder-plated in recommended mount pattern and metal masking so as to enhance mounting strength and heat release. If the pad needs to be connected to other pins, it should be connected to the VDD pin (Pin #2).
1
FB
2 2 VDD
3 3 CE
USP-6C (BOTTOM VIEW)
SOT-25 (TOP VIEW)
PIN ASSIGNMENT
PIN NUMBER SOT-25 1 2 3 4 5 USP-6C 6 2 4 3 1 5 PIN NAME FB VDD CE CE (/PWM) GND EXT NC FUNCTION Output Voltage Setting Resistor Connection Supply Voltage Chip Enable (Operates when "H" Level) PWM/PFM Switch* Ground External Transistor Drive Connection No Connection
* The XC9122 series combines the CE pin and PWM/PFM switch pin.
FUNCTION
XC9120/9121 Series CE PIN H L XC9122 Series CE/PWM PIN H More than VDD - 0.2 (V) M 0.65 ~ VDD - 1.0 (V) L 0 ~ 0.2 (V) IC OPERATIONAL STATE Operation Shut-Down
IC OPERATIONAL STATE Operation (PWM control) Operation (PWM/PFM automatic switching control Shut-Down
PRODUCT CLASSIFICATION
Ordering Information
XC9120 XC9121 XC9122 DESIGNATOR : PWM Control : PWM/PFM Automatic Switching Control : PWM/PFM Externally Switching Control DESCRIPTION Type of DC/DC Controller Output Voltage Oscillation Frequency Package Device Orientation SYMBOL B D 09 1 M E R L DESCRIPTION : With current limiter : No current limiter : FB Voltage (ex. FB Voltage=0.9V=0, =9) : 100kHz : SOT-25 (SOT-23-5) : USP-6C : Embossed tape, standard feed : Embossed tape, reverse feed
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XC9120/XC9121/XC9122
Series
BLOCK DIAGRAM
ABSOLUTE MAXIMUM RATINGS
Ta=25 PARAMETER VDD Pin Voltage FB Pin Voltage CE Pin Voltage EXT Pin Voltage EXT Pin Current Power Dissipation SOT-25 USP-6C SYMBOL VDD VFB VCE VEXT IEXT Pd Topr Tstg 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 UNIT V V V V mA mW
Operating Temperature Range Storage Temperature Range
* Voltage is all ground standardized.
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XC9120/XC9121/XC9122 Series
ELECTRICAL CHARACTERISTICS
XC9120B091, XC9121B091, XC9122B091 XC9120D091, XC9121D091, XC9122D091 PARAMETER FB Voltage Supply Voltage Range (*1) Output Voltage Setting Range Operation Start Voltage Oscillation Start Voltage (*1) Operation Hold Voltage Supply Voltage 1 Supply Voltage 2 Stand-by Current Oscillation Frequency Maximum Duty Ratio PFM Duty Ratio Over Current Sense Voltage (*2) Efficiency (*3) Soft-Start Time CE "H" Voltage CE "L" Voltage EXT "H" ON Resistance EXT "L" ON Resistance PWM `H' Voltage (*4) PWM `L' Voltage (*4) CE "H" Current CE "L" Current FB "H" Current FB "L" Current SYMBOL VFB VDD VOUTSET VST1 VST2 VHLD IDD1 IDD2 ISTB FOSC MAXDTY PFMDTY VLMT EFFI TSS VCEH VCEL REXTH REXTL VPWMH VPWML ICEH ICEL IFBH IFBL Same as IDD1 Same as IDD1 Same as IDD1, VEXT=VOUT-0.4V Same as IDD1, VEXT=0.4V IOUT=1mA IOUT=1mA (XC9122B/D type) (XC9122B/D type) Recommended circuit using 2SD1628, VIN=VOUTSET 0.6, VDD=3.0V, IOUT=1.0mA Recommended circuit using 2SD1628 VOUT=3.3V, IOUT=1.0mA No external components, CE connected to VDD, Voltage applied, FB=0V Recommended circuit using 2SD1628 VOUT=3.3V, IOUT=1.0mA Same as VST2, VDD=3.0V Same as IDD1, FB=1.2V Same as IDD1, CE=0V Same as IDD1 Same as IDD1 No Load (XC9121B/D, XC9122B/D types) Step input to FB (Pulse width: 2.0 s or more) EXT= Low level voltage (XC9120/9122/9122B type) IOUT=10mA CONDITIONS MIN. 0.882 1.8 1.5 85 89 24 150 5.0 0.65 VDD-0.2 (FOSC=100kHz) TYP. 0.900 25 13 100 93 32 250 85 10.0 24 16 MAX. 0.918 6.0 30.0 0.9 0.8 0.7 50 30 1.0 115 96 40 400 20.0 0.20 36 24 VDD-1.0 0.1 -0.1 0.1 -0.1 V V A A A A UNIT V V V V V V A A A kHz % % mV % ms V V Ta=25 CIRCUIT
Same as IDD2, CE=VDD Same as IDD2, CE=0V Same as IDD2, FB=VDD Same as IDD2, FB=0V
Test Conditions: Unless otherwise stated, CL: ceramic, recommended MOSFET should be connected. When VOUT is set at 15V, VIN=VDD=3.6V. NOTE: *1: Although the IC starts step-up operations from a VDD=0.8V, the output voltage and oscillation frequency are stabilized at VDD>1.8V. Therefore, a VDD of more than 1.8V is recommended when VDD is supplied from VIN or other power sources. *2: The overcurrent limit circuit of this IC is designed to monitor the ripple voltage so please select your external components carefully to prevent VLMT being reached under low temperature conditions as well as normal operating conditions. Following current limiter circuit operation, which in turn causes the IC's operations to stop, the IC resumes its operation with a toggle of the CE pin or by turning the power supply back on. *3: EFFI: {(output voltage) x (output current)} / {(input voltage) x (input current)} x 100 *4: The XC9122 series' CE pin combines PWM/PFM external switch pin. In the operation state, PWM control becomes effective when the CE pin is more than VDD-0.2V. When the CE pin is less than VDD-1.0V and more than VCEH, PWM/PFM automatic switching control becomes effective with 32% duty.
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XC9120/XC9121/XC9122
Series
TYPICAL APPLICATION CIRCUIT
RSENSE CFB VOUT RFB1 1 CL 2 3 CE NPM Tr 4 CB RFB2 5 Nch Power MOS FET CIN VIN RB SD
When obtaining VDD from a source other than VIN (VOUT), please insert a by-pass capacitor CDD between the VDD pin and the GND pin in order to provide stable operations. Please place CL and CIN as close as to the VOUT and VDD pins respectively and also close to the GND pin. Strengthen the wiring sufficiently. RSENSE should be removed and shorted when the CL capacitor except for ceramic or low ESR capacitor is used.
Insert RB and CB when using a bipolar NPN transistor.
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XC9120/XC9121/XC9122 Series
OPERATIONAL EXPLANATION
The XC9120/9121/9122 series consists of a reference voltage source, ramp wave circuit, error amplifier, PWM comparator, phase compensation circuit, and current limiter circuit. The series ICs compare, using the error amplifier, the voltage of the internal voltage reference source with the feedback voltage from the FB pin. 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 EXT pin to output a switching duty cycle. This process is continuously performed to ensure stable output voltage. 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. The circuit generates the internal reference clock. The frequency is set to 100kHz (TYP.). The ramp wave generator generates a saw-tooth waveform based on outputs from the OSC 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. The circuit generates PFM pulses. The XC9122 series can switch PWM control and PWM/PFM switching control by external signal. The PWM/PFM automatic switching control becomes effective when the voltage of the CE pin is less than VDD-1.0V, and the control switches between PWM and PFM automatically depending on the load. The PWM/PFM control turns into the PFM control when threshold voltage becomes lower then voltage of error amps. The PWM control becomes effective when the CE pin voltage is more than VDD-0.2V. Noise is easily reduced with the PWM control since the switching frequency is fixed. Because of this, the series gives the best control suitable for your application. The reference voltage, Vref (FB pin voltage) =0.9V, is adjusted and fixed by laser trimming (for output voltage settings, please refer to the output voltage setting.). Soft-start circuit protects against inrush current, when the power is switched on, and also protects against voltage overshoot. It should be noted, however, that this circuit does not protect the load capacitor (CL) form inrush current. With the Vref voltage limited and depending on 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 does not increase more than is necessary. The 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 disable, the channel's operations will stop and the EXT pin will be kept at a low level (the external N-ch MOSFET will be OFF). When the IC is in a state of disable, current consumption will be no more than 1.0 A. When the CE pin's voltage is 0.65V or more, the mode will be enabled and operations will recommence. The current limiter circuit of the XC9120 series is designed to monitor a ripple output voltage. Following current limiter circuit operation, which in turn causes the IC's operations to stop, the IC resumes its operation with a toggle of the CE pin or by turning the power supply back on.
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XC9120/XC9121/XC9122
Series
OPERATIONAL EXPLANATION (Continued)
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