Ordering number : ENA2001 LV56351JA Bi-CMOS IC 1ch DC/DC boost converter http://onsemi.com Overview LV56351JA integrates 1ch DC/DC boost converter and 1ch LDO. It is suitable as the power supply for BS/CS antennas of LCD/PDP TV and BD recorders that require automatic recovery without IC destruction and malfunction when the output is short-circuited. Functions DC/DC boost converter • Soft-start time: 2.8ms • Frequency 425kHz operation • Pulse by pulse over current limiter • Short circuit protector (SCP) LDO • Over current limiter (Fold back) All • Under voltage lockout • Thermal shutdown protector • Power good Specifications Maximum Ratings at Ta = 25°C Parameter Symbol Conditions Ratings Unit VCC maximum supply voltage VCC max -0.3 to 25 V LDOIN maximum input voltage VLDOIN -0.3 to 30 V SW maximum voltage VSW Allowable power dissipation Pd max Operating temperature Operating junction temperature Storage temperature Allowable pin voltage -0.3 to 30 V 1.1 W Topr -30 to 85 °C Tjopr -30 to 125 °C Tstg -40 to 150 °C VCC, EN 25 V SW, LDOIN, LDOOUT 30 V 6 V IN1, IN2, FB, SCP, PGOOD, DDCTL *1 *1: When mounted on the specified printed circuit board (32mm × 38mm × 1.6mm), glass epoxy, double side board Caution 1) Absolute maximum ratings represent the value which cannot be exceeded for any length of time. Caution 2) Even when the device is used within the range of absolute maximum ratings, as a result of continuous usage under high temperature, high current, high voltage, or drastic temperature change, the reliability of the IC may be degraded. Please contact us for the further details. Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability. Semiconductor Components Industries, LLC, 2013 August, 2013 20112 SY 20111129-S00001 No.A2001-1/8 LV56351JA Recommended Operating Conditions at Ta = 25°C Parameter Symbol Conditions Ratings Unit VCC supply voltage VCC 8 to 23 V LDOIN input voltage VLDOIN 8 to 28 V SW voltage VSW -0.3 to 28 V EN voltage VEN 0 to 23 V Electrical Characteristics at Ta = 25°C, VCC = 12V, VEN=2V, LDOIN=16V, LDOOUT=15V Parameter Symbol Conditions Ratings min typ Unit max All Supply current ICC Switching is turned off IOFF EN=0V Reference voltage VREF Enable voltage VEN Disable voltage VDIS 1.8 1.2348 1.26 3.5 mA 10 μA 1.2852 V 2.0 EN input current IEN VEN=2.0V PGOOD threshold VPG IN1≥VREF×85% and IN2≥VREF×85% PGOOD sink current IPG VPGOOD=0.5V PGOOD leak current IPGLK VPGOOD=2V UVLO on voltage VUVLO Thermal shutdown temperature TTSD *2 TSD hysteresis THYS *2 V 0.4 V 10 μA VREF×0.85 V 1.0 mA 10 7.0 μA V °C 130 °C 30 DC/DC boost converter FB output voltage ”Low” FBLOW IN1=2.0V, IFB=-20μA (Sink) FB output voltage “High” FBHIGH IN1=0.2V, IFB=20μA (Sink) 0.2 1.8 V V Soft-start time TSS 2.8 ms Oscillator frequency FOSC 425 kHz Max on duty DMAX SW on resistance RON SW peak current IPK SCP source current ISCP 78 85 92 % 1.5 1.8 A 4.8 μA VREF V Ω 0.7 SCP threshold VSCP DDCTL on voltage VDDCTLON DC/DC OFF DDCTL off voltage VDDCTLOFF DC/DC ON 0.4 V DDCTL input current IDDCTL VDDCTL=2V 20 μA 670 mA 20 mV 20 mV 2.0 V LDO Maximum output current IOMAX Line regulation RLN 16V<LDOIN<21V 350 Load regulation RLD 10mA<IO<300mA Dropout voltage VDROP IO=300mA Short current ISHORT LDOOUT=GND 520 0.25 0.4 V 100 mA *2: Design guarantee value. No.A2001-2/8 LV56351JA Package Dimensions unit : mm (typ) 3179C 6.5 Pd max -- Ta 0.5 6.4 11 4.4 20 Allowable power dissipation, Pd max - W 1.5 1 10 0.65 0.15 0.22 1.5max 1.1 1.0 0.5 0.44 0 -30 0.1 (1.3) (0.33) Mounted on a specifid board : 32 × 38 × 1.6mm3 , glass epoxy, double side board 0 30 60 90 120 Ambient temperature, Ta - C SANYO : SSOP20(225mil) Specified board (32×38×1.6mm3, glass epoxy, double side board) SCP PGOOD V1 R1 R3 R7 L1 DDCTL C4 C6 R6 R2 R4 C5 R5 C7 LDOIN EN C1 C2 C3 D1 VCC LDOOUT GND « front » « back » Pin assignment 1 PGND PGND 20 2 NC PGND 19 3 NC NC 18 4 LDOOUT SW 17 NC 16 15 IN2 VCC EN 14 8 IN1 DDCTL 13 9 FB SCP 12 PGOOD 11 5 LDOIN 6 NC 7 10 SGND No.A2001-3/8 LV56351JA Pin function Pin No. Pin name Function 4 LDOOUT LDO output 5 LDOIN LDO input 10 SGND Signal ground(*3) Equivalent circuit 5 LDOIN 4 LDOOUT 10 SGND 7 IN2 LDO feedback input IN2 7 SGND 10 8 IN1 DC/DC error amplifier input IN1 8 SGND 10 9 FB DC/DC error amplifier output FB 9 SGND 10 11 PGOOD Power good output 11 PGOOD 10 SGND 12 SCP DC/DC SCP capacitor connect pin for timer setting 12 SCP 10 SGND 13 DDCTL DC/DC on and off control DDCTL 13 VREG SGND 10 14 EN Enable 15 VCC Power supply VCC 15 EN 14 SGND 10 Continued on next page. No.A2001-4/8 LV56351JA Continued from preceding page. Pin No. Pin name Function 17 SW DC/DC open drain output 1 PGND Power ground(*3) Equivalent circuit VREG 19 17 SW 1 19 PGND 20 20 *3: When you use this IC, Please short-circuit all the pins of SGND and PGND on the IC mounting side. Function overview (1) UVLO (Under Voltage Lockout) UVLO stops outputs of both DC/DC and LDO to prevent malfunction when VCC decreases. UVLO operates when VCC falls below the UVLO voltage. This function is a non-latch-type, and recovers these outputs automatically when VCC exceeds the UVLO voltage. (2) Power good Power good notifies that the output voltages of DC/DC and LDO are within the range of the setting voltage. The two output voltages are monitored through the voltage of IN1 and IN2. The output is judged to be “power good” when both outputs are 85% or higher compared to the setting voltages. If either IN1 or IN2 voltage falls below VREF×85%, PGOOD output becomes L → H (No Good). When IN1 and IN2 voltages become (VREF×85%) + 30mV or higher, PGOOD output becomes H → L (Good). During soft start, the output is H (No Good). « Power good circuit diagram » Power supply (6V or less) P. Good Comp. IN1 IN2 PGOOD Pin 10kΩ(Example) Good No Good + + - L output H output (Hysteresis=30mV) (3) Pulse-by-Pulse over current protection (P by P) The P by P stops switch-on operation of a certain cycle by force when the current of power MOSFET reaches the maximum output peak current. « P by P circuit diagram » Error Amp. PWM Comp. SW_pin Logic Triangular wave P by P Comp. Power The current of power_Tr is constantly monitored. If the peak current > 1.8A, switching_on operation during the cycle stops compulsorily (4) Short Circuit Protector (SCP) When output voltage of DC/DC decreases due to short-circuit; for example, SCP latches off the outputs of DC/DC and LDO by timer. When output voltage of DC/DC decreases and FB turns to H, which is the error amplifier output, charge at 4.8μA constant current starts to SCP capacitor for timer setting. When SCP voltage exceeds the threshold voltage (=VREF), latch-off occurs. If the output voltage recovers until the time the SCP voltage reaches to the threshold voltage, SCP capacitor is discharged and timer is reset. To restart the output after latch-off, you need to input EN signal again. If you do not use the SCP function, make sure to short SCP and GND. No.A2001-5/8 LV56351JA To define timer, you need to calculate a value of SCP capacitor using the following formula because timer (tSCP) depends on capacitance. CSCP = (ISCP×tSCP) / VREF < SCP circuit diagram > < Waveform of SCP_Pin > ISCP=4.8 A DC/DC Output SCP Comp. SCP_Pin DC/DC OFF(≈VCC) Logic CSCP for timer setting tSCP Threshhold voltage (VREF) VREF SCP Voltage Time Discharge Tr Latch-OFF Reset (5) DC/DC on and off control This function controls on and off of DC/DC during the operation of IC. « Turning on DC/DC » Where DDCTL=Low or open, DC/DC and LDO operate at the same time. « Turning off DC/DC » Where DDCTL=High, DC/DC is compulsorily stopped and only LDO operates. When DDCTL is switched from H to L (or open), LDO stops temporarily and DC/DC starts with soft start and then LDO restart. If you switch DDCTL during IC operation, make sure that the output waveforms of DC/DC and LDO are normal. Output voltage setting Output voltages are given by the following formulas. DCDCOUT = (1+R2/R1 ) × VREF [V] LDOOUT = (1+R4/R3 ) × VREF [V] « Resistance for output setting » DC/DC OUT LDOOUT R2 IN1 R4 IN2 R1 R3 Start and stop Start: Make sure to input EN signal (L → H) after supplying VCC=12V. Stop: Reverse-operation of start. « Output waveform during start and stop » Softstart 2.8ms DC/DC OUT LDOOUT 16V 15V 12V(=VCC) 5ms 0V Delay 500μs Time EN No.A2001-6/8 LV56351JA Block Diagram and Application circuit 1 (for BS antenna) Condition: VCC=12V, DCDCOUT=16V, LDOOUT=15V VCC=12V L1 C1 VCC DC/DC Boost Converter VREG C5 DC/DC OUT=16V SW VREF DC/DCOUT (LDOIN) D1 C7 + + - R2 R6 IN1 R1 C6 R5 Soft Start + OSC P by P LDOIN FB + SCP C4 PGOOD VREG LDOOUT ILimit R7 High Enable PGOOD SCP UVLO TSD EN DDCTL C2 DC/DC Control R4 LDOOUT=15V C3 IO=270mA IN2 R3 LDO SGND PGND « Note » When LDOOUT is in the over current state or the short-circuit state, IC and external parts are protected by over current limiter of LDO. And when DCDCOUT is short-circuited, IC stops by timer latch-off type SCP function. Application circuit 2 (for BS/CS antenna) BS condition: VCC=12V, DCDCOUT=16V, LDOOUT=15V CS condition: VCC=12V, DCDC=OFF, LDOOUT=11V VCC=12V VCC DC/DC Boost Converter VREG + + - IN1 Soft Start + OSC P by P LDOIN FB + SCP PGOOD EN 2V DDCTL DDCTL=L : LDOOUT=15V DDCTL=H : LDOOUT=11V DC/DC OUT=16V/11.7V SW VREF DC/DCOUT (LDOIN) VREG ILimit PGOOD SCP UVLO TSD DC/DC Control LDOOUT LDOOUT=15V/11V IO=270mA IN2 Tr for LDO output switching SGND PGND LDO No.A2001-7/8 LV56351JA « Addition » The above application circuit enables switching between 15V for BS and 11V for CS. Where DDCTL=L, DC/DC booster is turned on and set as follows: DCDCOUT=16V, LDOOUT=15V. Where DDCTL=H, DC/DC booster is turned off and set as follows: DCDCOUT=11.7V, LDOOUT=11V. (because the resistance value of output setting of LDO is switched) « Output waveform at switching » LDOOUT=15V → 11V LDOOUT=15V → 11V 5ms 16V 15V DC/DC OUT LDOOUT Delay+Softstart 3.3ms 16V 15V 12V(=VCC) 11V 12V(=VCC) 11V LDOOUT Time Time DDCTL DC/DC OUT DDCTL ON Semiconductor and the ON logo are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC owns the rights to a number of patents, trademarks, copyrights, trade secrets, and other intellectual property. A listing of SCILLC’s product/patent coverage may be accessed at www.onsemi.com/site/pdf/Patent-Marking.pdf. SCILLC reserves the right to make changes without further notice to any products herein. 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