SC470ITSTRT Semtech, SC470ITSTRT Datasheet
SC470ITSTRT
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SC470ITSTRT Summary of contents
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... Industrial temperature range 0.85% DC accuracy Integrated gate drivers with soft-switching Applications Graphics Cards Embedded Graphics Processors High Performance Processors 5VSUS U1 SC470 EN/PSV BST TON DH VOUT LX VCCA ILIM FB VDDP PGD DL C4 VSSA PGND C6 1uF 1uF 1 VBAT D1 C1 0.1uF Q1 C2 10uF www.semtech.com SC470 VOUT C3 + ...
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... Calculated from package in still air, mounted to 3” to 4.5”, 4 layer FR4 PCB with thermal vias under the exposed pad per JESD51 standards. Electrical Characteristics Test Conditions 15V, EN/PSV = 5V, VCCA = VDDP = 5.0V, V BAT 2005 Semtech Corp. ( 1.25V 0.1% Resistor Dividers. OUT TON > > ...
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... NOT RECOMMENDED FOR NEW DESIGN POWER MANAGEMENT Electrical Characteristics (Cont 2005 Semtech Corp ° ° ° ° SC470 2 ° ° ° www.semtech.com µ A µ µ µ ...
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... This voltage will vary slightly with load and VBAT. (3) Using a current sense resistor, this measurement relates to PGND minus the voltage of the source on the low-side MOSFET. These values guaranteed by the ILIM Source Current and Current Comparator Offset tests. (4) clks = switching cycles. 2005 Semtech Corp ...
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... TON 2 13 VOUT 3 12 VCCA PGD 6 VSSA 7 (14 Pin TSSOP) 2005 Semtech Corp. Ordering Information Notes: (1) Only available in tape and reel packaging. A reel contains LX 11 2500 devices. (2) This product is fully WEEE and RoHS compliant. ILIM 10 (3) Lead-free product. This product is J-STD-020B compliant and all homogeneous subcomponents are RoHS compliant ...
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... NOT RECOMMENDED FOR NEW DESIGN POWER MANAGEMENT Pin Descriptions 2005 Semtech Corp SC470 µ www.semtech.com µ ...
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... NOT RECOMMENDED FOR NEW DESIGN POWER MANAGEMENT Block Diagram VCCA EN/SPV POR / SS TON TON VOUT TOFF 1.5V REF FB X3 PGD VSSA 2005 Semtech Corp OFF CONTROL LOGIC PWM OC ZERO FAULT UV MONITOR REF + 20% REF - 10% REF - 30% Figure 1: SC470 Block Diagram 7 SC470 BST DH HI ...
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... The SC470 requires an external +5V bias supply in addition to the battery. If stand-alone capability is required, the +5V supply can be generated with an external linear regulator such as the Semtech LP2951. For optimal operation, the controller has its own ground reference, VSSA, which should be tied by a single trace to PGND at the negative terminal of the output capacitor (see Layout Guidelines) ...
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... MOSFET equals the voltage across the RILIM resistor, positive current limit will activate. The high-side MOSFET 2005 Semtech Corp. will not be turned on until the voltage drop across the sense element (resistor or MOSFET) falls below the ...
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... There is a 5µs delay built into the UV protection circuit to prevent false transitions. Note: to reset from any fault, VCCA or EN/PSV must be toggled. 2005 Semtech Corp. POR, UVLO and Softstart An internal power-on reset (POR) occurs when VCCA ex- is the resistance ...
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... MOSFETs with lower R MOSFETs will cause the switching frequency to increase as the load current increases. This will reduce the ripple and thus the DC output voltage. 2005 Semtech Corp. Design Procedure Prior to designing an output and making component selections necessary to determine the input voltage range and the output voltage specifications ...
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... BAT ( MIN ) OUT and RIPPLE _ VBAT ( MAX ) BAT ( MAX ) OUT 2005 Semtech Corp. For our example RIPPLE_VBAT(MIN) ( MIN ) From this we can calculate the minimum inductor current rating for normal operation MAX ) INDUCTOR For our example The INDUCTOR(MIN) OUT Next we will calculate the maximum output capacitor ...
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... Z required: TOP R Z BOT V TOP RIPPLE _ VBAT ( MIN ) . 0 015 Secondly calculating the value of C this: 2005 Semtech Corp. maximum for our For our example we will use 14.3k , therefore: BOT Z TOP We will select a value of C value VBAT ( MIN ) For our example: V − ...
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... ILIM VALLEY 10 2005 Semtech Corp. For our example 5.13A, R VALLEY We select the next lowest 1% resistor value: 7.68k OUT Adding an Additional Output Voltage For Dynamic Voltage Switching If we design this output to be capable of dynamically switching between 1.2V and 1.0V, then we would repeat these calculations to determine if any components need changing ...
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... H IGH ) < LOW ) 2005 Semtech Corp. This means that the ratio is less than the worst-case U1 SC470 OVP threshold (worst-case in this case is the lowest EN/PSV BST threshold), then the direct drive (simplest) method may TON DH be used. Of course the indirect drive method may also ...
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... Q = FET gate charge, from the FET datasheet ( switching frequency (kHz) VBST = boost pin voltage during duty cycle 2005 Semtech Corp. Inserting the following values for VBAT this is the worst-case condition for power dissipation in the controller example (VOUT = 1.2V 85° 100°C/W (For TSSOP-14 46° ...
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... Current sense connections must always be made using Kelvin connections to ensure an accurate signal, with the current limit resistor located at the device. We will examine the reference design used in the Design Procedure section while explaining the layout guidelines in more detail. 2005 Semtech Corp. 5VSUS 5VSUS D1 ...
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... PGOOD In Figure 10 above, all components referenced to VSSA have been placed and have been connected using 0.020” traces. Decoupling capacitors C9 and C10 are as close as possible to their pins. C9 should connect to the ground plane using two vias 2005 Semtech Corp. VBAT 5VSUS R1 R2 ...
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... IRF7811AV FDS6676S The input capacitors should be placed with the highest frequency capacitors closest to the loop to reduce EMI. Use large copper pours to minimize losses and parasitics. See Figure 13 on Page 20 for an example. 2005 Semtech Corp. U2 SC470 1 14 ...
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... BST is also a noisy node and should be kept as short as possible. 4) Connect PGND pin on the chip directly to the VDDP decoupling capacitor and then drop vias directly to the ground plane. 2005 Semtech Corp. resistor at the bottom of the output capacitor to connect and ground at high frequencies, ...
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... NOT RECOMMENDED FOR NEW DESIGN POWER MANAGEMENT Application Information (Cont EN/PSV 2 TON 3 VOUT 4 VCCA PGD 7 VSSA Figure 14: Connecting The Control and Power Sections 2005 Semtech Corp. SC470 14 BST IRF7811AV 7k87 11 ILIM 0402 10 VDDP FDS6676S PGND 21 SC470 Q1 L1 2u2 Q2 www.semtech.com ...
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... BAT 350 300 250 V = 20V BAT 200 150 100 (A) OUT Please refer to Figure 8 on Page 17 for test schematic 2005 Semtech Corp. 1.2V Efficiency (Continuous Conduction Mode) vs. Output Current vs. Input Voltage 100 1.2V Output Voltage (Continuous Conduction Mode) vs. Output Current vs. Input Voltage 1 ...
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... Load Transient Response, Continuous Conduction Mode Zoomed Load Transient Response, Continuous Conduction Mode Zoomed Please refer to Figure 8 on Page 17 for test schematic 2005 Semtech Corp. Trace 1: 1.2V, 50mV/div., AC coupled Trace 2: LX, 20V/div Trace 3: not connected Trace 4: load current, 5A/div Timebase: 40µs/div. ...
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... Load Transient Response, Power Save Mode Zoomed Load Transient Response, Power Save Mode Zoomed Please refer to Figure 8 on Page 17 for test schematic 2005 Semtech Corp. Trace 1: 1.2V, 50mV/div., AC coupled Trace 2: LX, 20V/div Trace 3: not connected Trace 4: load current, 5A/div Timebase: 40µs/div. ...
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... Dynamic Output Voltage Switching From 1V to 1.2V Zoomed, No Load Dynamic Output Voltage Switching From 1. Zoomed, No Load Please refer to Figure 8 on Page 17 for test schematic 2005 Semtech Corp. Trace 1: toggle signal (for reference only) Trace 2: LX, 20V/div Trace 3: VOUT, 50mV/div, offset 1V Trace 4: not connected Timebase: 200µ ...
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... Dynamic Output Voltage Switching From 1V to 1.2V Zoomed, 6A Load Dynamic Output Voltage Switching From 1. Zoomed, 6A Load Please refer to Figure 8 on Page 17 for test schematic 2005 Semtech Corp. Trace 1: toggle signal (for reference only) Trace 2: LX, 20V/div Trace 3: VOUT, 50mV/div, offset 1V Trace 4: not connected Timebase: 200µ ...
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... NOT RECOMMENDED FOR NEW DESIGN POWER MANAGEMENT Typical Characteristics (Cont.) Startup (PSV), EN/PSV Going High Startup (CCM), EN/PSV 0V to Floating Please refer to Figure 8 on Page 17 for test schematic 2005 Semtech Corp. Trace 1: 1.2V, 0.5V/div. Trace 2: LX, 10V/div Trace 3: EN/PSV, 5V/div Trace 4: PGD, 5V/div. Timebase: 1ms/div. ...
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... COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS THE TERMINALS. Marking Information - MLPQ-16 SC470 yyww xxxxx xxxxx Marking for the 4 x 4mm MLPQ 16 Lead package: nnnnn = Part Number (Example: SC470) yyww = Date Code (Example: 0552) xxxxx = Semtech Lot No. (Example: E9010 xxxxx 2005 Semtech Corp. DIM MIN .031 ...
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... NOT RECOMMENDED FOR NEW DESIGN POWER MANAGEMENT Land Pattern - MLPQ- (C) X NOTES: 1. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. 2005 Semtech Corp. DIM INCHES SC470 DIMENSIONS MILLIMETERS (.152) (3.85) .114 2 ...
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... NOT RECOMMENDED FOR NEW DESIGN POWER MANAGEMENT Marking Information - TSSOP-14 Top Mark SC470I xxxxxx yyww yyww = Datecode (Example: 9812) xxxxxx = Semtech Lot # (Example: 81101) Outline Drawing - TSSOP-14 2X E/2 PIN 1 INDICATOR ccc C 2X N/2 TIPS aaa C SEATING PLANE C NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). ...
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... NOT RECOMMENDED FOR NEW DESIGN POWER MANAGEMENT Land Pattern - TSSOP-14 X (C) P NOTES: 1. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. Contact Information Phone: (805) 498-2111 FAX (805)498-3804 2005 Semtech Corp. DIM INCHES Semtech Corporation ...