LM26480SQ-AA/NOPB National Semiconductor, LM26480SQ-AA/NOPB Datasheet
LM26480SQ-AA/NOPB
Specifications of LM26480SQ-AA/NOPB
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LM26480SQ-AA/NOPB Summary of contents
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... FB voltage accuracy ■ 2 MHz PWM switching frequency ■ PWM - PFM automatic mode change under low loads ■ Automatic soft start Typical Application Circuit © 2010 National Semiconductor Corporation LM26480 Linear Regulators (LDO) ■ 1.0V–3.5V OUT ■ ±3% FB voltage accuracy ■ ...
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FIGURE 1. Application Circuit 2 30040402 ...
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... UZXYTT format: ‘U’ – wafer fab code; ‘Z’ – assembly code; ’XY’ 2 digit date code; ‘TT” – die run code. See http://www.national.com/quality/ marking_conventions.html for more information on marking information. (**) Package received will have XXXXXXX replaced with the specific part version ordered. Ordering Information Part Number LM26480SQ-AA LM26480SQX-AA LM26480QSQ-CF LM26480QSQX-CF Default Options Oscillator Order Suffix ...
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... G/(D) Frequency Synchronization pin which allows the user to connect an external clock signal to synchronize the PMIC internal oscillator. Default OFF and must be grounded when not used. Part number LM26480SQ-BF has this feature enabled. Please contact National Semiconductor Sales Office/Distributors for availability of LM26480SQ-BF. ...
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... Absolute Maximum Ratings 2) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. VINLDO12, VIN1, AVDD, VIN2, VINLDO1, VINLDO2, ENSW1, FB1, FB2, ENSW2, ENLDO1, ENLDO2, SYNC, FBL1, FBL2 GND to GND SLUG Power Dissipation (P ...
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Symbol Parameter C Output Capacitor OUT Buck Converters SW1, SW2 Unless otherwise noted 3.6V apply for T = 25°C. Limits appearing in boldface type apply over the entire junction temperature range for operation, −40° ...
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Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the component may occur. Operating Ratings are conditions under which operation of the device is guaranteed. Operating Ratings do not imply guaranteed performance limits. For guaranteed performance limits and ...
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Typical Performance Characteristics — LDO Output Voltage Change vs Temperature (LDO1 3.6V 2.5V, 100 mA load IN OUT Load Transient 3 2. – 150 mA load IN OUT Line Transient (LDO1) 3.6 ...
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Enable Start-up time (LDO1) 0-3 2 load IN OUT 30040441 Enable Start-up time (LDO2) 0 – load IN OUT 9 30040442 www.national.com ...
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Typical Performance Characteristics — Buck Shutdown Current vs. Temp Output Voltage vs. Supply Voltage (V = 2.0V) OUT www.national.com V = 2.8V to 5.5V Output Voltage vs. Supply Voltage (V 30040443 Output Voltage vs. Supply Voltage (V 30040445 ...
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Typical Performance Characteristics — Buck mode for Buck 1 Efficiency vs. Output Current (V = 1.2V 2.2 µH) OUT Output Current transitions from PWM mode to PFM mode for Buck 2 Efficiency vs. Output Current (V = 3.0V, ...
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Typical Performance Characteristics — Buck noted Load Transient Response V = 1.2V (PWM Mode) OUT Line Transient Response V = 3.6 – 4.2V 1.2V, 250 mA load IN OUT Start up into PWM Mode V = 1.2V, 1.5A ...
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Start up into PFM Mode V = 1.2V load OUT 30040462 Start up into PFM Mode V = 3.0V load OUT 13 30040470 www.national.com ...
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... SYNC FUNCTION 30040404 The LM26480SQ-BF is the only version of the part that has the ability to use an external oscillator. The source must be 13 MHz nominal and operate within a range of 15.6 MHz and 10.4 MHz, proportionally the same limits as the 2.0 MHz in- ternal oscillator ...
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CURRENT LIMITING A current limit feature allows the converter to protect itself and external components during overload conditions. PWM mode implements current limiting using an ...
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SHUTDOWN MODE During shutdown the PFET switch, reference, control and bias circuitry of the converters are turned off. The NFET switch will shutdown to discharge the output. When the converter is enabled, soft start is activated. It ...
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The above diagram shows the simplest application of the Power-On Reset, where both switcher enables are tied to- gether. In Case 1, EN1 causes nPOR to transition LOW and triggers the nPOR delay counter. If the power supply for Buck2 ...
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The above timing diagram details the Power Good with delay with respect to the enable signals EN1, and EN2. The RDY1, RDY2 are internal signals derived from the output of two com- parators. Each comparator has been trimmed as follows: ...
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In Case 1, we see that case where EN2 and RDY2 are initi- ated after triggered programmable delay. To prevent the nPOR being asserted again, a masked window (5 ms) counter delay is triggered off the EN2 rising edge. NPOR ...
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Design Implementation of the Flexible Power-On Reset Design implementation of the flexible power-on reset. An in- ternal power-on reset of the IC is used with EN1 and EN2 to produce a reset signal (LOW) to the delay timer nPOR. EN1 ...
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Application Notes EXTERNAL COMPONENT SELECTION Ideal Resistor Values Common R Values Target R1 (KΩ) R2 (KΩ) R1 (KΩ) Vout (V) 0.8 120 200 0.9 160 200 1 200 200 1.1 240 200 1.2 280 200 1.3 320 200 1.4 360 ...
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... Over-current ruggedness. The LM26480 has been optimized for use with nominal values 2.2 µH and 10 µF. If other values are needed for the design, please contact National Semiconductor sales with any con- cerns. INDUCTOR SELECTION FOR SW1 AND SW2 A nominal inductor value of 2.2 µH is recommended im- portant to guarantee the inductor core does not saturate during any foreseeable operational situation ...
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INPUT CAPACITOR SELECTION FOR SW1 AND SW2 It is required to use a ceramic input capacitor of at least 4.7 μF and 6.3V with an ESR of less than 500 mΩ. The input power source supplies average current continu- ously. ...
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FEEDBACK RESISTORS FOR LDOs Target V (V) Ideal Resistor Values OUT R1 (KΩ) 1 200 1.1 240 1.2 280 1.3 320 1.4 360 1.5 400 1.6 440 1.7 480 1.8 520 1.9 560 2 600 2.1 640 2.2 680 2.3 ...
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LDO CAPACITOR SELECTION Input Capacitor An input capacitor is required for stability recommended that a 1.0 μF capacitor be connected between the LDO input pin and ground (this capacitance value may be increased without limit). This capacitor must ...
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Analog Power Signal Routing All power inputs should be tied to the main VDD source (i.e. battery), unless the user wishes to power it from another source. (i.e. powering LDO from Buck output). The analog VDD inputs power the internal ...
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Board Layout Considerations PC board layout is an important part of DC-DC converter de- sign. Poor board layout can disrupt the performance of a DC- DC converter and surrounding circuitry by contributing to EMI, ground bounce, and resistive voltage loss ...
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High VIN-High Load Operation Additional inforamtion is provided when the IC is operated at extremes of VIN and regulator loads. These are described in terms of the junction temperature and buck output ripple man- agement. Junction Temperature The maximum junction ...
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Physical Dimensions inches (millimeters) unless otherwise noted For ordering, refer to Ordering Information table 0.8 mm 24-Pin LLP Package NS Package SQA24A 29 www.national.com ...
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... For more National Semiconductor product information and proven design tools, visit the following Web sites at: www.national.com Products Amplifiers www.national.com/amplifiers Audio www.national.com/audio Clock and Timing www.national.com/timing Data Converters www.national.com/adc Interface www.national.com/interface LVDS www.national.com/lvds Power Management www.national.com/power Switching Regulators www.national.com/switchers LDOs www.national.com/ldo LED Lighting www ...