nx2114 Microsemi Corporation, nx2114 Datasheet
nx2114
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nx2114 Summary of contents
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... SYNCHRONOUS PWM CONTROLLER DESCRIPTION The NX2114 controller synchronous Buck con- troller IC designed for step down converter applications. Synchronous control operation replaces the traditional catch diode with an Nch MOSFET result- ing in improved converter efficiency. Although the NX2114 controller is optimized to convert single 5V bus voltages to supplies as low as 0 ...
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... REF V CC (Static) Outputs not switching I C =3300pF F =300kHz CC LOAD S (Static) Outputs not switching I C =3300pF F =300kHz BST LOAD S _UVLO V Rising CC CC _Hyst V Falling CC CC NX2114/2114A Typical values refer Min TYP MAX Units 0 4.5 5 4.2 V 0.22 V ...
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... Ldrv going Low to Hdrv H) going High, 10%-10% R (Ldrv) I=200mA source R (Ldrv) I=200mA sink V -V =5V PVCC LDRV V -PGND=5V LDRV TLdrv(Rise) 10% to 90% TLdrv(Fall) 90% to 10% Tdead going Low to Ldrv L) going High, 10% to 10% NX2114/2114A Min TYP MAX Units 3.4 mS 1.7 300 kHz 600 kHz 1 1900 umho 10 nA 0.3 V 0.4 V 1.1 ohm 0 ...
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... This pin is also used as a shut down pin. When this pin is pulled below 0.3V, both drivers are turned off and internal soft start is reset. This pin is connected to the source of the high side MOSFET and provides 8 SW return path for the high side driver. Rev. 4.0 06/20/06 PIN DESCRIPTION NX2114/2114A 4 ...
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... BLOCK DIAGRAM 5 VCC UVLO Figure 1 - Simplified block diagram of the NX2114 Rev. 4.0 06/20/06 DRIVER OSC 0.3V LATCH TIMER 0.4V VREF DIGITAL SS NX2114/2114A 1 BST 2 Hdrv Ldrv 3 GND 7 COMP ...
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... Demoboard design and waveforms Vin +5V C4 47uF,70mohm C6 C8 1uF 47uF,70mohm 7 Comp C2 1.5nF C1 R4 47pF 22. 10.2k Figure 2 - demoboard design on NX2114 Bill of Material Name Component de scription R1 10.2k 1% chip resistor R2 10. hip resistor R3 1. hip resistor R4 22. hip resistor R5 10 chip resistor C1 47pF ceramic C2 1.5nF ceramic C3 2 ...
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... C u rrent (A ) Figure 3: Output efficiency Figure 5: Start up time Figure 7: Output voltage droop during transient(0A-6A) Rev. 4.0 06/20/ Figure 4: Voltage ripple @1.6 V output voltage, 7A output current Figure 6: Output voltage transient response for load curent 0A-6A Figure 8: Startup operation waveform NX2114/2114A 7 ...
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... 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 NX2114, the schematic is figure =1.6V OUT I =6A OUT DV <=20mV RIPPLE DV <=60mV @ 6A step DROOP ...
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... ESR OUT ...(8) 15m I step 60mV 2 1.5 H 220 F 60mV 1.7 The number of capacitors has to satisfied both ripple and transient requirement. Overall, we can choose N=2. NX2114/2114A true. In that case, the crit step 2 OUT tran E tran crit I step ...
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... OUT in To achieve the same effect as voltage amplifier, the compensator of transconductance amplifier must satisfy this condition: R4>>2/gm. R1||R2||R3>>1/gm is desirable. Vout Zin Figure 9 - Type III compensator using transconductance amplifier NX2114/2114A 1 ...(11 ...(12 ...(13 ...
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... 1.55nF Choose C 6. Calculate C half the switching frequency 48pF Choose C 7. Calculate 1.5k Choose R = 10. ESR NX2114/2114A 10k 6.2kHz 48kHz out C 3 30kHz 1.5uH 440uF 2 ...
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... LC double pole F and ESR zero 3.5kHz F ESR Gain 5.7kHz 2.Set R equal to10.2k . Using equation 18, the 2 final selection Set crossover frequency at 1/10~ 1/5 of the swithing frequency, here F 4.Calculate R NX2114/2114A Vref C2 C1 has to satisfy ESR OUT OUT 1 1 ...
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... OUT 5V (19), the result of input RMS current is 2.80A. For higher efficiency, low ESR capacitors are rec- ommended. One Sanyo TPD series POSCAP 6TPD220M 6V 220uF with 12m is chosen as input bulk capacitor. NX2114/2114A is 10k . 1 Fb Vref 1.6V 1.6V /(1/16W ...(19) =1.6V, I =6A, using equation ...
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... Rev. 4.0 06/20/06 dependent. Soft Start, Enable and shut Down The NX2114 has a digital start up based on digital counter with 1024 cycles. For NX2114 with 300kHz operation, the start up time is about 3.5ms. For NX2114A with 600kHz operation, the start up time is about half of NX2114, 1.75mS. ...
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... MOSFETs should be close to each other as possible. This helps to reduce the EMI radiated by the power loop due to the high switching currents through them. 2. Low ESR capacitor which can handle input RMS ripple current and a high frequency decoupling ceramic NX2114/2114A 15 ...
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... In multilayer PCB, separate power ground and analog ground. These two grounds must be connected together on the PC board layout at a single point. The goal is to localize the high current path to a separate loop that does not interfere with the more sensitive ana- log control function. Rev. 4.0 06/20/06 touch- NX2114/2114A 16 ...
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... C4 22uF C6 C3 1uF 22uF 5 Vcc 7 Comp C2 330pF C1 R4 4.7pF k 120 Figure 18 - Application of NX2114 A for 5V input and 1.2V output with ceramic output capacitors Rev. 4.0 06/20/06 L2 1uH MBR0530T1 1uF BST Vcc 0.1uF M1 2 Hdrv L1 1.5uH Ldrv ...
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... Vin +12V C3 33uF Vin + 270pF 2N3904 2N3904 R6 680 3.24 Figure 19 -Application of NX2114 for 5V bias and 12V input bus Single power supply (+11V to +24V BUS) Vin +11~25V C4 R5 33uF 3 k 2N3904 TL431 220pF Figure 20 -Application of NX2114 for high input bus application Rev ...
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... SOIC8 PACKAGE OUTLINE DIMENSIONS Rev. 4.0 06/20/06 NX2114/2114A 19 ...
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... Rev. 4.0 06/20/06 NX2114/2114A 20 ...