SC411EVB SEMTECH [Semtech Corporation], SC411EVB Datasheet
SC411EVB
Related parts for SC411EVB
SC411EVB Summary of contents
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POWER MANAGEMENT Description The SC411 is a constant on-time synchronous buck PWM controller in a space-saving MLPQ package intended for use in notebook computers and other battery operated portable devices. Features include high effi ciency and a fast dynamic response ...
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POWER MANAGEMENT Absolute Maximum Ratings Exceeding the specifi cations below may result in permanent damage to the device or device malfunction. Operation outside of the parameters specifi the Electrical Characteristics section is not implied. Exposure to Absolute Maximum ...
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POWER MANAGEMENT Electrical Characteristics (Cont.) Parameter Input Supplies (Cont.) TON Operating Current Shutdown Current Controller Error Comparator Threshold (FB Turn-on Threshold) internal x3 gain stage, com- (1) Output Voltage Range On-Time 2.5V BAT Minimum Off-Time VOUT Input Resistance ...
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POWER MANAGEMENT Electrical Characteristics (Cont.) Parameter (PGND - LX), R Current Limit (Positive) (2) (PGND - LX), R (PGND - LX), R Fault Protection (Cont.) Current Limit (Negative) Output Under-Voltage Fault With respect to internal ref. Output Over-Voltage Fault With ...
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POWER MANAGEMENT Electrical Characteristics (Cont.) Parameter Soft-Start Soft-Start Ramp Time EN/PSV High to PGD High Under-Voltage Blank Time EN/PSV High to UV High Gate Drivers Shoot-Through Delay (4) DL Pull-Down Resistance DL Sink Current DL Pull-Up Resistance DL Source Current ...
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POWER MANAGEMENT Block Diagram VCCA (2) POR / SS EN/PSV (15) DSCHG TON (16) TON VOUT (1) TOFF DSCHG 1.5V REF FB (3) X3 Error Comparator PGD (4) VSSA (6) Note: the Error Comparator tolerances are approximately x3 gain stage ...
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... Semtech Corp. Ordering Information SC411MLTRT Notes: 1) Only available in tape and reel packaging. A reel contains 3000 LX 11 devices. ILIM (2) Lead free product. This product is fully WEEE, RoHS and 10 J-STD-020B compliant. VDDP Device Package MLPQ-16 (2) SC411EVB Evaluation Board www.semtech.com SC411 (1) ...
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POWER MANAGEMENT Pin Descriptions (Cont Gate drive output for the high side MOSFET switch. 13 BST Boost capacitor connection for the high side gate drive Not connected. Enable/Power Save input. Pull down to VSSA to shut ...
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POWER MANAGEMENT Application Information +5V Bias Supplies The SC411 requires an external +5V bias supply in addi- tion to the battery. If stand-alone capability is required, the +5V supply can be generated with an external linear regulator such as the ...
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POWER MANAGEMENT Application Information (Cont.) 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 ...
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POWER MANAGEMENT Application Information (Cont.) The current limit circuitry also protects against negative over-current (i.e. when the current is fl owing from the load to PGND through the inductor and bottom MOSFET). In this case, when the bottom MOSFET is ...
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POWER MANAGEMENT Application Information (Cont.) Dropout Performance The output voltage adjust range for continuous-conduction operation is limited by the fi xed 550ns (maximum) mini- mum off-time one-shot. For best dropout performance, use the slowest on-time setting of 200kHz. When work- ...
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POWER MANAGEMENT Application Information (Cont.) and ON_VBAT(MAX) From these values of tON we can calculate the nominal switching frequency as follows OUT ( SW _ VBAT ( ...
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POWER MANAGEMENT Application Information (Cont.) For our example: ERR = 96mV and ERR = 26.4mV, therefore 9.8mΩ for a full 6A load transient ESR_TR(MAX) We will select a value of 12.5mΩ maximum for our de- sign, ...
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POWER MANAGEMENT Application Information (Cont.) Where TOL is the transient tolerance. For our example: TR POSLIM = 1.296V TR The minimum output capacitance is calculated as follows: I RIPPLE_VBAT(MAX OUT COUT(MIN) POSLIM TR 2 This ...
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POWER MANAGEMENT Application Information (Cont gate drive operating current (A) VDDP V = gate drive voltage, typically 5V ( FET gate charge, from the FET datasheet ( switching frequency (kHz) VBST = ...
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POWER MANAGEMENT Layout Guidelines VBAT 5VSUS R1 1M 0402 R2 10R 0402 VOUT C5 R3 20k0 56p 0402 0402 PGOOD R5 C8 14k3 C9 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 fi rst, locate all components referenced to VSSA on the schematic and place these components ...
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POWER MANAGEMENT As shown below, VOUT should be routed away from noisy traces (such as BST, DH, DL and LX) and in a quiet layer (if possible) to the output capacitor(s). C5 56p 0402 Next, the schematic in Figure 8 ...
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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 VOUT 2 VCCA SC411 PGD Figure 10: Connecting the Control and Power Sections Phase nodes (black copper islands (preferred) or wide copper traces. Gate drive traces (red) and phase node traces ...
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POWER MANAGEMENT Typical Characteristics For effi ciency charts, refer to High Effi ciency Design, Figure 11 on page 21. For all other data, refer to the Reference Design, Figure 4 on Page 17. 1.2V Effi ciency (Power Save Mode) (High ...
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POWER MANAGEMENT Typical Characteristics Load Transient Response, Continuous Conduction Mode Load Transient Response, Continuous Conduction Mode Zoomed Load Transient Response, Continuous Conduction Mode Zoomed Please refer to Figure 4 ...
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POWER MANAGEMENT Typical Characteristics Load Transient Response, Power Save Mode Startup (CCM), EN/PSV 0V to Floating Load Transient Response, Power Save Mode Zoomed Please refer to Figure 4 on Page 17 for ...
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POWER MANAGEMENT Typical Characteristics Startup (PSV), EN/PSV Going High Startup (CCM), EN/PSV 0V to Floating Please refer to Figure 4 on Page 17 for test schematic © 2007 Semtech Corp. Trace 1: 1.2V, 0.5V/div. Trace 2: LX, 10V/div Trace 3: ...
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POWER MANAGEMENT Outline Drawing - MLPQ-16 INDICATOR (LASER MARK) aaa C NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS THE TERMINALS. Marking Information Top Marking SC411 yyww xxxxx ...
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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. Contact Information Phone: (805) 498-2111 Fax: (805) 498-3804 ...