lt3741 Linear Technology Corporation, lt3741 Datasheet
lt3741
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lt3741 Summary of contents
Page 1
... CTRL pins and an external IN sense resistor. Due to its unique topology, the LT3741 is capable of sourcing and sinking current. The regulated voltage and overvoltage protection are set with a voltage divider from the output to the FB pin. Soft-Start is provided to allow a gradual increase in the regulated current during startup ...
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... LT3741IUF#PBF LT3741IUF#TRPBF LT3741EFE#PBF LT3741EFE#TRPBF LT3741IFE#PBF LT3741IFE#TRPBF Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: ...
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... CTRL1 = 1. 1.5V CTRL1 With OUT CTRL1 (Note 3) (Note 3) (Note 3) V – CBOOT CC_INT R = 40kΩ 200kΩ 1.3V – CTRL1 = 1.5V 23µA SENSE LT3741 MIN TYP MAX UNITS 1.8 2 1.49 1.55 1.61 130 mV 5.5 1.0 0 1.5 100 1. ...
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... The LT3741I is guaranteed to meet performance specifications over the –40°C to 125°C operating junction temperature range. Note 3: The minimum on and off times are guaranteed by design and are not tested ...
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... TEMPERATURE (°C) Soft-Start Pin Current 36V 125 –50 – TEMPERATURE (°C) LT3741 I in Shutdown Q 0.5 0.4 0.3 130°C 0.2 0.1 25°C 130°C 25°C –50° (V) IN 3741 G02 V Current Limit REF 1 ...
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... LT3741 Typical perFormance characTerisTics Internal UVLO 5.0 4.5 4.0 3.5 3.0 –50 – TEMPERATURE (°C) 3741 G10 V Load Reg at 12V CC_INT 6.0 5.6 5.2 25°C 4.8 4.4 4 (mA) LOAD 3741 G13 Overvoltage Timeout –50 – TEMPERATURE (°C) 3741 G16 CBOOT-SW UVLO Voltage 3.00 2.75 2.50 2.25 2.00 1.75 1.50 125 – ...
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... TEMPERATURE (°C) Current Regulation Accuracy CTRL1 = 1.5V 12V 25°C –1 –2 –3 3.0 0 2.5 5.0 7.5 OUTPUT VOLTAGE (V) LT3741 Minimum Off-Time 300 240 HG 180 120 125 –50 – TEMPERATURE (°C) 3741 G21 Oscillator Frequency 1.5 1.2MHz 1.2 900kHz 0.9 0.6 0.3 220kHz ...
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... LT3741 Typical perFormance characTerisTics OUT OUT 20V OUT I = 24A LIMIT OUT OUT OUT 24V 10V OUT I = 18A LIMIT ...
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... OUT 2V/DIV I L 5A/DIV 3741 G31 Shutdown and Recovery 1.5nF Soft-Start Capacitor EN/UVLO 5V/DIV I L 5A/DIV V OUT 2V/DIV 3741 G35 C = 1mF OUT OUT 10A LOAD 18A CURRENT LIMIT LT3741 100µs/DIV 3741 G34 100µs/DIV 3741 G32 3741f ...
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... LT3741 pin FuncTions (QFN/TSSOP) EN/UVLO (Pin 1/Pin 4): Enable Pin. The EN/UVLO pin acts as an enable pin and turns on the internal current bias core and subregulators at 1.55V. The pin does not have any pull-up or pull-down, requiring a voltage bias for normal part operation. Full shutdown occurs at approximately 0 ...
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... AMP CURRENT 450µA/V MIRROR 11µ 40µA OUT – 90k + VOLTAGE REGULATOR AMP g = 850µA/V m Figure 1. Block Diagram LT3741 1µF 47µF V CC_INT 19 AND HIGH SIDE CBOOT DRIVER 17 HG 0.1µ 2.4µH LOW SIDE DRIVER ...
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... The switching frequency is determined by a resistor at the RT pin. The RT pin is also limited to 60µA, while not recommended, this limits the switching frequency to 2MHz when the RT pin is shorted to ground. The LT3741 may also be synchronized to an external clock through the use of the SYNC pin. ...
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... O current in the inductor and f Using this equation, the inductor will have approximately 15% ripple at maximum regulated current. Table 2. Recommended Inductor Manufacturers . S POWER DISSIPATION (W) Würth Electronics 0.05 0.25 0.5 1. 3741 F02 LT3741 2 • V – • • V the maximum regulated O is the switching frequency ...
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... Another power loss related to switching MOSFET selection is the power lost to driving the gates. The total gate charge must be charged and discharged each switching cycle. G The power is lost to the internal LDO within the LT3741. The power lost to the charging of the gates is Power loss to the GS ...
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... C Capacitor Selection BOOT The C www.nxp.com BOOT more than 50nF to ensure proper operation of the LT3741. Use 220nF for high current switching MOSFETs with high gate charge. V Capacitor Selection CC_INT The bypass capacitor for the V than 5µF for stability and has no ESR requirement recommended that the ESR be lower than 50mΩ ...
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... CTRL Figure 5. Sense Voltage vs CTRL Voltage Voltage Regulation and Overvoltage Protection The LT3741 uses the FB pin to regulate the output voltage and to provide a high speed overvoltage lockout to avoid high voltage conditions. The regulated output voltage is programmed using a resistor divider from the output and ground (Figure 7) ...
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... In addition, many applications have thermal limitations that will require the regulated current to be re- duced based on load and/or board temperature. To achieve this, the LT3741 uses the CTRL2 pin to reduce the effective regulated current in the load. While CTRL1 programs the regulated current in the load, CTRL2 can be configured to reduce this regulated current based on the analog voltage at the CTRL2 pin ...
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... Figure 11. LT3741 Average Current Mode Control Scheme To design the compensation network, the maximum com- pensation resistor needs to be calculated. In current mode controllers, the ratio of the sensed inductor current ramp to the slope compensation ramp determines the stability of the current regulation loop above 50% duty cycle. In ...
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... SS SENSE 10nF FB VC L1: IHLP4040DZER1R0M01 47.5k M1: RJK0365DPA M2: RJK0346DPA 4.7nF R1: VISHAY WSL25122L500FEA 20V OUT 3741 TA02b LT3741 V IN 10V TO 36V 100µ OUT 1.0µH 20A MAXIMUM 2.5m 150µ 38.3k 12.1k 3741 TA02 OUT OUT ...
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... CONTROL R HOT 45.3k R NTC 470k 10nF 0 20A LED Driver EN/UVLO V IN 1µ 150nF SYNC CBOOT 1.1µ REF LT3741 V CC_INT 22µ CTRL1 INPUT GND + CTRL2 SENSE 33nF – SENSE SS FB VCH 82.5k 4.7nF LED Current Waveforms 10A to 20A Current Step 1.5V CTRL1 1V/DIV 0 ...
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... Single-Cell Lithium-Ion Battery Charger EN/UVLO V IN 1µF CTRL1 HG 220nF RT CBOOT 2.2µH SYNC SW LT3741 V V CC_INT REF 2.2µF 22µF LG GND + CTRL2 SENSE 20nF – SENSE 82.5k 8.2nF LT3741 V IN 24V 33µ OUT 5m 4.2V, 10A MAXIMUM + 3. 30.1k 12.1k 3741 TA04 3741f ...
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... LT3741 package DescripTion 4.50 ± 0.05 3.10 ± 0.05 2.45 ± 0.05 2.00 REF 2.45 ± 0.05 RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 4.00 ± 0.10 PIN 1 TOP MARK (NOTE 6) 4.00 ± 0.10 NOTE: 1. DRAWING IS PROPOSED TO BE MADE A JEDEC PACKAGE OUTLINE MO-220 VARIATION (WGGD-1)—TO BE APPROVED 2 ...
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... BSC 0.195 – 0.30 (.0077 – .0118) 4. RECOMMENDED MINIMUM PCB METAL SIZE FOR EXPOSED PAD ATTACHMENT MILLIMETERS (INCHES) *DIMENSIONS DO NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.150mm (.006") PER SIDE LT3741 6.40 – 6.60* (.252 – .260) 3.86 (.152 6.40 2.74 (.252) ( ...
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... McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 ● 20V Regulated Output with 5A Current Limit EN/UVLO V IN 1µF 22µ 100nF SYNC L1 CBOOT 8.2µH 10m V SW REF LT3741 V CC_INT 10 22µ CTRL1 GND + CTRL2 SENSE 10nF – SS SENSE FB VC 30.1k 3.9nF COMMENTS 92% Efficiency, I ...