nx2138 Microsemi Corporation, nx2138 Datasheet
nx2138
Related parts for nx2138
nx2138 Summary of contents
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... SINGLE CHANNEL MOBILE PWM CONTROLLER DESCRIPTION The NX2138 controller compact Buck controller IC with 16 lead MLPQ package designed for step down converter in portable applications. It can be selected to operate in synchronous mode or non-syn- chronous mode to improve the efficiency at light load.Constant on time control provides fast response, good line regulation and nearly constant frequency un- der wide voltage input range ...
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... Operating quiescent current Shut down current Rev. 1.6 12/09/ 150 150 HDRV OCSET PVCC 9 8 SYM Test Condition ENSW=GND switching, ENSW=5V ENSW=GND NX2138 = unless otherwise A Min TYP MAX Units V 4 4.5 5 ...
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... I=200mA (Hdrv) I=200mA sink 10% to 90% 90% to 10% Ldrv going Low to Hdrv going H) High, 10% to 10% (Ldrv) I=200mA source (Ldrv) I=200mA sink 10% to 90% 90% to 10% SW going Low to Ldrv going L) High, 10% to 10% NX2138 Min TYP MAX Units 3.9 4.1 4.5 V 3.7 3.9 4 312 390 468 ns 380 590 ...
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... Hysteresis Under voltage FB threshold Over voltage Over voltage tripp point Internal Schottky Diode Forward voltage drop Rev. 1.6 12/09/09 SYM Test Condition Leave it open or use limits in spec ENSW/MODE=VCC ENSW/MODE=GND forward current=50mA NX2138 Min TYP MAX Units 80% VCC+0 VCC .3V V 60% 80% VCC VCC V 60% ...
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... VIN sensing input. A resistor connects from this pin to VIN will set the fre- quency. A 1nF capacitor from this pin to GND is recommended to ensure the proper operation. 17 PAD Used as thermal pad. Connect this pad to ground plane through multiple vias. Rev. 1.6 12/09/09 PIN DESCRIPTION NX2138 5 ...
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... VOUT VOUT FB(3) OCP_COMP VREF=0.75V start soft start VCC 1M ENSW /MODE(15) MODE 1M SELECTION OVP AGND(6) FBUVLO_latch SS_finished PGOOD(4) Figure 2 - Simplified block diagram of the NX2138 Rev. 1.6 12/09/09 4.3/4.1 Disable_B POR Thermal shutdown start ODB HD FET Driver R HD_IN Q S Mini offtime 400ns POR HD Diode ...
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... TON 100k 9 PVCC 12 HDRV R8 2 BST VCC LDRV ENSW 15 /MODE OCSET VOUT PGND AGND 6 7 Figure 3 - Demo board schematic NX2138 VIN 7V~22V CI1 2x10uF M1 IRF7807 Lo Vout 1.8V/7A 1.5uH CO1 2R5TPE330MC M2 330uF AO4714 R3 2.2 C5 1.5n R6 10.5k R7 7.5k 7 ...
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... CO1 3 2 C1,C2, R3, Rev. 1.6 12/09/09 Value Manufacture 10uF/X5R/25V 2R5TPE330MC SANYO 1uF 1nF 1.5nF DO5010H-152 COILCRAFT IRF7807 IR AO4714 IR 100k 10 2 10.5k 7.5k NX2138 NEXSEM INC. NX2138 8 ...
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... OUTPUT AC, CH4 OUTPUT CURRENT) Fig. 9 Output ripple at full load (CH1 SW, CH2 1.8V OUTPUT AC, CH4 OUTPUT CURRENT) Rev. 1.6 12/09/09 Fig.5 Turn off (CH2 1.8V OUTPUT, CH3 PGOOD) Fig.8 Start into short (CH3 VOUT, CH4 OUTPUT CURRENT) Fig. 10 Output ripple at light load in PFM mode(CH1 SW, CH2 1.8V OUTPUT AC) NX2138 9 ...
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... Fig. 15 Dynamic response in PFM mode (CH2 1.8V OUTPUT AC, CH4 OUTPUT CURRENT) Rev. 1.6 12/09/09 Fig. 12 Dynamic response in synchronous mode (CH2 1.8V OUTPUT AC, CH4 OUTPUT CURRENT) Fig. 14 Dynamic response in PFM mode (CH2 1.8V OUTPUT AC, CH4 OUTPUT CURRENT) VIN=12V, VOUT=1.8V 95.00% 90.00% 85.00% 80.00% 75.00% 70.00% 65.00% 60.00% 55.00% 50.00% 10 100 OUTPUT CURRENT(mA) Fig. 16 Output efficiency NX2138 1000 10000 10 ...
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... Input voltage Output voltage OUT I - Output current OUT DV - Output voltage ripple RIPPLE F - Working frequency Inductor current ripple RIPPLE Design Example The following is typical application for NX2138, the schematic is figure 22V IN V =1.8V OUT F =220kHz S I =7A OUT DV <=60mV RIPPLE DV < ...
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... The selected inductor is 1.5uH which is smaller ...(8) than critical inductance. In that case, the output volt- OUT age transient mainly dependent on the ESR. number of capacitor is ESR ...(9 N crit 12m 60mV 0.6 Choose N=1. NX2138 V ESR C V OUT OUT E E OUT ...(10 step step and C ...
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... One 10uF/X5R/25V and two 4.7uF/ X5R/25V ceramic capacitors are chosen as input capacitors. Power MOSFETs Selection The NX2138 requires at least two N-Channel power MOSFETs. The selection of MOSFETs is based on maximum drain source voltage, gate source volt- age, maximum current rating, MOSFET on resistance Rev ...
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... R value can be set by voltage divider. 1 Mode Selection NX2138 can be operated in PFM mode, ultrasonic PFM mode, CCM mode and shutdown mode by apply- ing different voltage on ENSW/MODE pin. When VCC applied to ENSW/MODE pin, NX2138 is In PFM mode. The low side MOSFET emulates the function of diode when discontinuous continuous mode happens, often in light load condition ...
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... When the FB pin voltage is sensed over 112 the high side MOSFET will be turned off REF and low side MOSFET will be turned on to discharge the V . NX2138 resumes its switching operation after OUT FB pin voltage drops REF If FB pin voltage keeps rising and is sensed over ...
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... PIN MLPQ OUTLINE DIMENSIONS NOTE: ALL DIMENSIONS ARE DISPLAYED IN MILLIMETERS. Rev. 1.6 12/09/09 NX2138 16 ...