lt3510 Linear Technology Corporation, lt3510 Datasheet
lt3510
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lt3510 Summary of contents
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... SHDN pin the entire part can be placed in a low quiescent current shutdown mode. The LT3510 is available in a 20-lead TSSOP package with exposed leadframe for low thermal resistance. , LT, LTc, and LTM are registered trademarks of Linear Technology corporation. ...
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... T V ......................................................................±1mA C1/2 Operating Junction Temperature Range LT3510EFE (Notes 2, 8) ..................... –40°C to 125°C LT3510IFE (Notes 2, 8) ...................... –40°C to 125°C Storage Temperature Range ................... –65°C to 150°C Lead Temperature (Soldering, 10 sec) .................. 300°C elecTrical characTerisTics temperature range, otherwise specifications are at T unless otherwise specified ...
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... The LT3510IFE is guaranteed and tested over the full –40°C to 125°C operating junction temperature range. Note 3: Minimum input voltage is defined as the voltage where internal ...
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... LT3510 elecTrical characTerisTics Note 6: The IND to V maximum current is defined as the value of OUT current flowing from the IND pin to the V OUT latch when the V pin is at its high clamp. C Note 7: This is the minimum voltage across the boost capacitor needed to guarantee full saturation of the internal power switch. ...
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... FREQUENCY 175 170 1000 165 MINIMUM 160 500 SYNCHRONIZATION 155 FREQUENCY 150 0 125 –50 – TEMPERATURE (°C) LT3510 Power Good Threshold Voltage vs Temperature 800 780 760 740 RISING 720 700 FALLING 680 660 640 620 600 100 125 50 –50 – ...
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... LT3510 Typical perForMance characTerisTics External Sync Duty Cycle Range vs External Sync Frequency 100 90 MAXIMUM CLOCK 80 DUTY CYCLE MINIMUM CLOCK 20 DUTY CYCLE 10 0 250 500 750 1000 1250 1500 FREQUENCY (kHz) 3510 G17 Minimum Boost Voltage vs Temperature 2.5 2.0 1.5 1.0 0.5 0 –50 – ...
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... INPUT VOLTAGE (V) 3510 G28 undervoltage lockout or thermal shutdown, IN1 pin is the collector of channel 2’s IN2 (Pins 18, 13): The V pin is the output of the C LT3510 OUT RIPPLE L = 4.7µ 6.8µ 10µH 20 22.5 25 3510 G29 IN1 IN1 above the ...
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... LT3510 pin FuncTions This indicates that the output is overloaded and current is pulled from the SS pin, reducing the regulation point. FB1/FB2 (Pins 17, 14): The FB pin is the negative input to the error amplifier. The output switches regulate this pin to 0.8V, with respect to the exposed ground pad. Bias current flows out of the FB pin ...
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... If the SHDN pin is taken below its 1.28V threshold the LT3510 will be placed in a low quiescent current mode. In this mode the LT3510 typically draws 9µA from V and <1µA from shutdown mode the PG is active IN2 with a typical sink capability of 50µ ...
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... LT3510 block DiagraM will be generated at the incoming frequency on the rising edge of the synchronization pulse with switch 1 in phase with the synchronization signal. In addition, the internal slope compensation will be automatically adjusted to pre- vent subharmonic oscillation during synchronization. The two regulators are constant frequency, current mode step-down converters ...
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... V R2 should be 10k or less to avoid bias current errors. Refer- ence designators refer to the Block Diagram in Figure 1. Choosing the Switching Frequency The LT3510 switching frequecy is set by resistor R3 in Figure 1. The R /SYNC pin is internally regulated at 0.975V. T Setting resistor R3 sets the current in the R which determines the oscillator frequency as illustrated in Figure 2 ...
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... MAX ( ) D Dc MIN Note that the LT3510 will regulate if the input voltage is taken above the calculated maximum voltage as long as maximum ratings of the V and BST pins are not violated. IN However operation in this region of input voltage will exhibit pulse skipping behavior. Figure 3. Minimum Input Voltage vs Load Current ...
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... Then use these equations to check that the LT3510 will be able to deliver the required output current. Note again that these equations assume that the inductor current is continuous. ...
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... See Application Note 19 for more information. Input Capacitor Selection Bypass the inputs of the LT3510 circuit with a 4.7µF or higher ceramic capacitor of X7R or X5R type. A lower value or a less expensive Y5V type can be used if there is additional bypassing provided by bulk electrolytic or tantalum capacitors ...
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... The output capacitor filters the inductor current to generate an output with low voltage ripple. It also stores energy in order to satisfy transient loads and to stabilize the LT3510’s control loop. The switching frequency of the LT3510 deter- mines the value of output capacitance required. Also, the current mode control loop doesn’ ...
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... For proper start-up, the minimum input voltage is also limited by the boost circuit. If the input voltage is ramped slowly, or the LT3510 is turned on with its SS pin when the output is already in regulation, then the boost capacitor may not be fully charged. Because the boost capacitor is charged ...
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... The LT1375 data sheet contains a more thorough discus- sion of loop compensation and describes how to test the stability using a transient load. Figure 6 shows an equivalent circuit for the LT3510 control loop. The error amp is a transconductance amplifier with finite output impedance. The power section, consisting of ...
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... If the synchronization signal powers undetermined state (V to the LT3510 as shown in Figure 7. The circuit as shown will isolate the synchronization signal when the output voltage is below 90% of the regulated output. The LT3510 will start-up with a switching frequency determined by the ...
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... Soft-Start The output of the LT3510 regulates to the lowest voltage present at either the SS pin or an internal 0.8V reference. A capacitor from the SS pin to ground is charged by an internal 3.25µA current source resulting in a linear output + – ...
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... V Output Tracking/Sequencing Complex output tracking and sequencing between chan- pin is pulled C nels can be implemented using the LT3510’s SS and PG pins. Figure 9 shows several configurations for output tracking/sequencing for a 3.3V and 1.8V application. pin is re- C Independent soft-start for each channel is shown in Figure 9a ...
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... OUT1 + EXTERNAL – SOURCE PG1 V 1.8V OUT2 PG2 Figure 9 LT3510 Absolute Start-Up V OUT1 0.5V/DIV PG1 V OUT2 0.5V/DIV PG2 10ms/DIV 3.3V SS1 V OUT1 0.22µF LT3510 PG1 1.8V SS2 V OUT2 PG2 R1 13.7k R2 8.08k (9c) V OUT1 0.5V/DIV PG1 V OUT2 0.5V/DIV SS1/2 10ms/DIV 3.3V SS1 V OUT1 LT3510 PG1 SS2 V 1 ...
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... OUT ≥ • 4.7µ IN1 IN2 SHDN FSET BST1 BST2 3.3µH 0.47µF SW1 SW2 B360A LT3510 IND1 IND2 V V OUT1 OUT2 PG1 PG2 FB1 FB2 SS/TRACK1 SS/TRACK2 470pF GND 40.2k 0.1µF Single Step Down: Frequency must be ...
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... Thermal Considerations The PCB must also provide heat sinking to keep the LT3510 cool. The exposed metal on the bottom of the package must be soldered to a ground plane. This ground should be tied to other copper layers below with thermal vias; these layers will spread the heat dissipated by the LT3510 ...
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... IC sees as ambient temperature. See the LT1767 data sheet’s Thermal Considerations section. Single, Low Ripple 4A Output The LT3510 can generate a single, low ripple 4A output if the outputs of the two switching regulators are tied together and share a single output capacitor. By tying the two FB pins together and the two V two channels will share the load current ...
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... SW1 SW2 B360A LT3510 IND1 IND2 V V OUT1 OUT2 PG1 PG2 FB1 FB2 SS/TRACK1 SS/TRACK2 1000pF GND 22pF 17.8k 0.1µF LT3510 2.2µH PMEG4005 B360A V OUT2 2.5V 47µF 100k 16.9k 470pF 40.2k 10pF 8.06k 3510 TA02 20.5k 1.5µH 0.47µF B360A PMEG4005 3510 TA03 3510fb ...
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... LT3510 Typical applicaTions V IN PMEG4005 V OUT1 3.3V 4A 47µF 24.9k ×2 8.06k Dual LT3510 Synchronized 3.3V/8A Output, 3MHz Effective Switch Frequency V IN 5.5V TO 24V 10µF PMEG4005 V OUT1 3.3V 1.25MHz Single 3.3V/4A Low Ripple Output 4. 4.7µF 1µ IN1 IN2 SHDN R /SYNC T PMEG4005* BST1 BST2 1.5µH 0.47µF ...
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... DO NOT INcLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXcEED 0.150mm (.006") PER SIDE 6.40 – 6.60* (.252 – .260) 4.95 (.195 6.40 2.74 (.252) (.108) BSc 1.20 (.047) MAX 0.05 – 0.15 (.002 – .006) 0.195 – 0.30 FE20 (cA) TSSOP 0204 TYP LT3510 3510fb ...
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... LT3510 relaTeD parTs PART NUMBER DESCRIPTION LT1766 60V, 1. 200kHz High Efficiency Step-Down DC/DC OUT Converter LT1933 500mA (I ), 500kHz Step-Down Switching Regulator in OUT SOT-23 LT1936 36V, 1. 500kHz High Efficiency Step-Down DC/DC OUT Converter LT1940 Dual 25V, 1. 1.1MHz High Efficiency Step-Down OUT DC/DC Converter LT1976/LT1977 60V, 1.2A (I ...