LTC3417 Linear Technology, LTC3417 Datasheet
LTC3417
Available stocks
Related parts for LTC3417
LTC3417 Summary of contents
Page 1
... V OUT2 SW2 2.5V 22pF 800mA V IN 866k V FB2 412k 10µF I TH2 2.87k 6800pF 3417 TA01 LTC3417 www.DataSheet4U.com Dual Synchronous 1.4A/800mA 4MHz U 3417 is a dual constant frequency, synchronous OUT2 Efficiency (Burst Mode Operation) 100 10 REFER TO FIGURE EFFICIENCY 90 0.1 85 0.01 80 POWER LOSS ...
Page 2
... I = 0.36V (Note 3) TH1 TH2 0.84V (Note 3) TH1 TH2 = ±5µA (Note TH1 TH2(PINLOAD) www.DataSheet4U.com ORDER PART TOP VIEW NUMBER 20 GNDD 19 PGND1 LTC3417EFE 18 SW1 17 PHASE 16 GNDA 21 15 FREQ 14 PGOOD 13 SW2 12 MODE 11 PGND2 FE PACKAGE = 125°C, θ = 38° 25°C. ...
Page 3
... Note 2: The LTC3417 is guaranteed to meet specified performance from 0°C to 85°C. Specifications over the –40°C to 85°C operating ambient temperature range are assured by design, characterization and correlation with statistical process controls. Note 3: The LTC3417 is tested in feedback loop which servos V midpoint for the error amplifier (V = 0.6V) and V ITH1 the error amplifier ( ...
Page 4
... LTC3417 W TYPICAL PERFOR A CE CHARACTERISTICS OUT1 Burst Mode Operation V OUT 20mV/DIV I L 250mA/DIV V = 3.6V 2µs/DIV 1.8V OUT I = 100mA LOAD REFER TO FIGURE 4 OUT2 Burst Mode Operation V OUT 20mV/DIV I L 250mA/DIV V = 3.6V 2µs/DIV 2.5V OUT I = 60mA LOAD REFER TO FIGURE 4 OUT1 Efficiency vs Load Current ...
Page 5
... FREQUENCY (MHz) Frequency FREQ = 143k TO GROUND 0 –2 –4 FREQ = V IN –6 –8 –10 5.5 2 2.5 3 3.5 4 4.5 V (V) IN LTC3417 www.DataSheet4U.com Load Step OUT2 V OUT2 100mV/DIV I OUT2 500mA/DIV 3417 G11 V = 3.6V 100µs/DIV 2.5V OUT I = 0.25A to 0.8A LOAD REFER TO FIGURE OUT1 DS(ON ...
Page 6
... LTC3417 CTIO S (DFN/TSSOP) RUN1 (Pin 1/Pin 2): Enable for 1.4A Regulator. When at Logic 1, 1.4A regulator is running. When at 0V, 1.4A regulator is off. When both RUN1 and RUN2 are at 0V, the part is in shutdown. V (Pin 2/Pin 3): Supply Pin for P-Channel Switch of IN1 1.4A Regulator. I (Pin 3/Pin 4): Error Amplifier Compensation Point for TH1 1 ...
Page 7
... V FB2 – + 800mA REGULATOR W I TH1 I TH LIMIT – LOGIC V IN2 LOGIC + V B – LIMIT I TH2 LTC3417 www.DataSheet4U.com V IN1 + – SLOPE COMPENSATION ANTI-SHOOT- SW1 THROUGH + – – PGND1 + PGOOD PHASE OSCILLATOR FREQ PGND2 + – – + SW2 ANTI-SHOOT- THROUGH SLOPE COMPENSATION – ...
Page 8
... The mode selection for the LTC3417 is set using the MODE pin. The MODE pin sets the mode for both the 800mA and the 1.4A step-down DC/DC converters. ...
Page 9
... P- channel MOSFET and inductor APPLICATIO S I FOR ATIO A general LTC3417 application circuit is shown in Figure 4. External component selection is driven by the load requirement, and begins with the selection of the inductors L1 and L2. Once L1 and L2 are chosen and C can be selected ...
Page 10
... LTC3417 is the maximum requires to operate. Table 1 shows some typical surface , occurs at the mount inductors that work well in LTC3417 applications. L Input Capacitor (C In continuous mode, the input current of the converter can be approximated by the sum of two square waves with ...
Page 11
... An excellent choice is the AVX TPS series of surface tantalums, available in case heights ranging from 2mm to 4mm. Aluminum electrolytic capacitors have a for IN significantly larger ESR, and are often used in extremely cost-sensitive applications provided that consideration is LTC3417 www.DataSheet4U.com and C ) Selection OUT1 OUT2 and C ...
Page 12
... Panasonic specialty polymer (SP) capacitors. In most cases, 0.1µF to 1µF of ceramic capacitors should also be placed close to the LTC3417 in parallel with the main capacitors for high frequency decoupling. Ceramic Input and Output Capacitors Higher value, lower cost ceramic capacitors are now becoming available in smaller case sizes ...
Page 13
... Soft-start reduces surge currents from V increasing the peak inductor current. Power supply se- quencing can also be accomplished by controlling the I pin. The LTC3417 has an internal digital soft-start for each regulator output, which steps up a clamp on I clock cycles, as can be seen in Figures 2 and 3. As the ...
Page 14
... Efficiency = 100% – (P1 +…) where P1, P2, etc. are the individual losses as a percentage of input power. Although all dissipative elements in the circuit produce losses, four main sources account for most of the losses in LTC3417 circuits: 1) LTC3417 I losses The I S electrical characteristics which excludes MOSFET driver and control currents ...
Page 15
... In a majority of applica- tions, the LTC3417 does not dissipate much heat due to its high efficiency. However, in applications where the LTC3417 is running at high ambient temperature with low ...
Page 16
... A close 1% resistor is 866k. The compensation should be optimized for these compo get IN nents by examining the load step response, but a good : 2 place to start for the LTC3417 is with a 5.9kΩ and 2200pF filter on I ⎞ V capacitor may need to be increased depending on the = µ ...
Page 17
... KEMET C1206C106K4PAC OUT2 IN OUT1 Efficiency vs Load Current 100 1.8V OUT FREQ = 1MHz 95 REFER TO FIGURE 4 90 EFFICIENCY 85 POWER LOSS 0.001 0.01 0.1 1 LOAD CURRENT (A) LTC3417 www.DataSheet4U.com L2 2.2µH V OUT2 2.5V C2 22pF 800mA R3 866k C R4 OUT2 10µF 412k R6 2.87k C4 6800pF 3417 F04 10 1 0.1 0.01 0.001 10 3417 F04a ...
Page 18
... APPLICATIO S I FOR ATIO Board Layout Considerations When laying out the printed circuit board, the following checklist should be used to ensure proper operation of the LTC3417. These items are also illustrated graphically in the layout diagram of Figure 5. Check the following in your layout. 1. Does the capacitor C ...
Page 19
... BSC 0.195 – 0.30 (.0077 – .0118) TYP 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 LTC3417 www.DataSheet4U.com R = 0.115 TYP 0.20 TYP 3.00 ±0.10 1.65 ± 0.10 (2 SIDES) ...
Page 20
... LTC3417 RELATED PARTS PART NUMBER DESCRIPTION LTC3404 600mA (I ), 1.4MHz, Synchronous Step-Down DC/DC OUT Converter LTC3405/LTC3405A 300mA (I ), 1.5MHz, Synchronous Step-Down DC/DC OUT Converters LTC3406/LTC3406B 600mA (I ), 1.5MHz, Synchronous Step-Down DC/DC OUT Converters LTC3407 Dual 600mA (I ), 1.5MHz, Synchronous Step-Down DC/DC 95% Efficiency, V OUT Converter LTC3407-2 Dual 800mA (I ), 2.25MHz, Synchronous Step-Down ...