SC1470EVB SEMTECH [Semtech Corporation], SC1470EVB Datasheet
SC1470EVB
Related parts for SC1470EVB
SC1470EVB Summary of contents
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POWER MANAGEMENT Description The SC1470 is a single output, constant on-time synchronous-buck PWM controller intended for use in notebook computers and other battery operated portable devices. Features include high efficiency and fast dynamic response with no minimum on time. The ...
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POWER MANAGEMENT Absolute Maximum Ratings Exceeding the specifications below may result in permanent damage to the device, or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not implied. Exposure to Absolute Maximum rated conditions ...
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POWER MANAGEMENT Electrical Characteristics (Cont.) Test Conditions 15V, EN/PSV = 5V, VCCA = VDDP = 5V, V BAT ...
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POWER MANAGEMENT Electrical Characteristics (Cont.) Test Conditions 15V, EN/PSV = 5V, VCCA = VDDP = 5V, V BAT ...
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POWER MANAGEMENT Pin Configuration Top View EN/PSV 1 14 TON 2 13 VOUT 3 12 VCCA PGD 6 9 VSSA 7 8 (14 Pin TSSOP) Pin Descriptions ...
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POWER MANAGEMENT Shoot-Through Delay Timing Diagram LX DL tplhDL Block Diagram VCCA (4) POR / SS EN/SPV (1) TON (2) VOUT (3) 1.5V REF FB (5) X3 PGD (6) VSSA (7) 2005 Semtech Corp TON OFF ...
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POWER MANAGEMENT Application Information +5V Bias Supplies The SC1470 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 ...
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POWER MANAGEMENT Output Voltage Selection The output voltage is set by the feedback resistors R3 & Figure 2 below. The internal reference is 1.5V, so the voltage at the feedback pin is multiplied by three to match the ...
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POWER MANAGEMENT The current limit circuitry also protects against negative over-current (i.e. when the current is flowing from the load to PGND through the inductor and bottom MOSFET). In this case, when the bottom MOSFET is turned on, the phase ...
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POWER MANAGEMENT The IC duty-factor limitation is given by MIN ) DUTY MIN ) OFF ( MAX ) Be sure to include inductor resistance and MOSFET on- state voltage drops when performing worst-case ...
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POWER MANAGEMENT V via R , converting this to a current. This current is BAT tON used to charge an internal 3.3pF capacitor to V equations above reflect this along with any internal components or delays that influence t we ...
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POWER MANAGEMENT 3 R ESR ( MIN ) OUT SW This criteria should be checked once the output capacitance has been determined. Now that we know the output ESR we can calculate the output ripple voltage: V ...
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POWER MANAGEMENT 660µF may be used. Alternatively, one 15m 220µF, 330µF or 470µF capacitor may be used (with the appropriate change to the calculation for C depending upon the load transient requirements. Next we calculate the RMS input ripple current, ...
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POWER MANAGEMENT As can be seen, the heating effects due to internal power dissipation are practically negligible, thus requiring no special consideration thermally during layout. 2005 Semtech Corp. 14 SC1470 www.semtech.com ...
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POWER MANAGEMENT Layout Guidelines VBAT 5VSUS 10R 0402 0402 VOUT C5 R3 20k0 56p 0402 0402 PGOOD R7 C8 14k3 C10 0402 1nF 1uF 0402 0603 VBAT = 8V to 20V VOUT = 1. One ...
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POWER MANAGEMENT The layout can be considered in two parts, the control section referenced to VSSA and the power section. Looking at the control section first, locate all components referenced to VSSA on the schematic and place these components at ...
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POWER MANAGEMENT As shown below, VOUT and VSSA should be routed as a differential pair to the output capacitor(s). VOUT VOUT C6 R4 20k0 56p 0402 0402 R8 14k3 C11 0402 1uF 0603 VOUT Figure 7: Differential Routing of Feedback ...
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POWER MANAGEMENT Figure 9: Power Component Placement and Copper Pours Key points for the power section: 1) there should be a very small input loop, well decoupled. 2) the phase node should be a large copper pour, but compact since ...
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POWER MANAGEMENT U1 1 EN/PSV 2 TON 3 VOUT 4 VCCA PGD 7 VSSA Figure 10: Connecting the Control and Power Sections 2005 Semtech Corp. SC470 14 Q1 BST IRF7811AV 7k87 11 ...
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POWER MANAGEMENT Typical Characteristics 1.2V Efficiency (Power Save Mode) vs. Output Current vs. Input Voltage 100 BAT 20V BAT (A) ...
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POWER MANAGEMENT Typical Characteristics (Cont.) Load Transient Response, Continuous Conduction Mode Load Transient Response, Continuous Conduction Mode Zoomed Load Transient Response, Continuous Conduction Mode Zoomed Please refer to Figure ...
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POWER MANAGEMENT Typical Characteristics (Cont.) Load Transient Response, Power Save Mode Load Transient Response, Power Save Mode Zoomed Load Transient Response, Power Save Mode Zoomed Please refer to Figure ...
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POWER MANAGEMENT Typical Characteristics (Cont.) Startup (PSV), EN/PSV Going High Startup (CCM), EN/PSV 0V to Floating Please refer to Figure 4 on Page 15 for test schematic 2005 Semtech Corp. Trace 1: 1.2V, 0.5V/div. Trace 2: LX, 10V/div Trace 3: ...
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POWER MANAGEMENT Marking Information Top Mark yy = two-digit year of manufacture ww = two-digit week of manufacture Outline Drawing - TSSOP-14 2X E/2 PIN 1 INDICATOR ccc C 2X N/2 TIPS aaa C SEATING PLANE C NOTES: 1. CONTROLLING ...
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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. ...