NX2139A

NX2139A SINGLE CHANNEL MOBILE PWM AND LDO CONTROLLER PRELIMINARY DATA SHEET Pb Free Product DESCRIPTION The NX2139A controller IC is a compact Buck controller IC with 16 lead MLPQ package designed for step down DC to DC converter in portable applications. It can be selected to operate in synchronous mode or non-synchronous mode to improve the efficiency at light load.Constant on time control provides fast response, good line regulation and nearly constant frequency under wide voltage input range. The NX2139A controller is optimized to convert single supply up to 24V bus voltage to as low as 0.75V output voltage. Over current protection and FB UVLO followed by latch feature. A built-in LDO controller can drive an external NMOSFET to provide a second output voltage from either PWM output source or other power source. Both PWM controller and LDO controller have separate EN feature. Other features includes: 5V gate drive capability, power good indicator, over voltage protection, internal Boost schottky diode and adaptive dead band control. n n n n n n FEATURES Internal Boost Schottky Diode Ultrasonic mode operation available Bus voltage operation from 4.5V to 24V Less than 1uA shutdown current with Enable low Excellent dynamic response with constant on time control Selectable between Synchronous CCM mode and diode emulation mode to improve efficiency at light load Programmable switching frequency Current limit and FB UVLO with latch off Over voltage protection with latch off LDO controller with seperate enable Two independent Power Good indicator available Pb-free and RoHS compliant n n n n n n n n n n APPLICATIONS Notebook PCs and Desknotes Tablet PCs/Slates On board DC to DC such as 12V to 3.3V, 2.5V or 1.8V Hand-held portable instruments TYPICAL APPLICATION PGOOD 100k 2x10uF 5V 10 1u 1u SW 11 9 2 PVCC HDRV 12 VCC 2.2 BST 13 1u 1.5uH Vout 1.8V/7A IRF7807 4 PGOOD TON 16 1n 1MEG VIN 7V~22V NX2139A 2R5TPE330MC 330uF LDRV 8 AO4714 15 ENSW /MODE OCSET 10 1 VOUT FB 3 5k 330p 10.5k 7.5k 14 5V 100k LDOPG 5 LDODRV ENLDO 7 50 33n 1n 20k 7.5k 7.5k M3 SI4800 1.5V@2A LDOPG GND LDOFB 6 2x10uF PAD Figure1 - Typical application of NX2139A ORDERING INFORMATION Device Temperature NX2139ACMTR -10o C to 100o C Rev. 2.3 03/19/09 Package 3X3 MLPQ-16L Pb-Free Yes 1 NX2139A ABSOLUTE MAXIMUM RATINGS VCC,PVCC to GND & BST to SW voltage ............ -0.3V to 6.5V TON to GND ......................................................... -0.3V to 28V HDRV to SW Voltage .......................................... -0.3V to 6.5V SW to GND ......................................................... -2V to 30V All other pins ........................................................ VCC+0.3V St age Tem per ur Range .................- oC to 150oC or at e .................65 Operating Junction Temperature Range .................-40oC to 150oC ESD Susceptibility ............................................... 2kV CAUTION: Stresses above those listed in "ABSOLUTE MAXIMUM RATINGS", may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. PACKAGE INFORMATION 3x3 16-LEAD PLASTIC MLPQ ENSW/MODE θ JA ≈ 46o C/W ENLDO 14 TON 16 VO 1 VCC FB 2 3 15 13 12 HDRV BST 11 SW 10 OCSET 9 PVCC 8 LDRV SYM VIN ENLDO=GND, ENSW=GND VCC VFB=0.85V, ENLDO=GND, E NSW=5V ENLDO=GND, ENSW=GND 4.5 1.8 1 17 AGND PGOOD 4 5 LDOPG 6 LDOFB 7 LDODRV ELECTRICAL SPECIFICATIONS Unless otherwise specified, these specifications apply over Vcc =5V, VIN=15V and TA =25oC, unless otherwise specified. PARAMETER VIN recommended voltage range Shut down current VCC,PVCC Supply Input voltage range Operating quiescent current Shut down current Rev. 2.3 03/19/09 Test Condition Min 4.5 TYP MAX 24 Units V uA 1 5.5 V mA uA 2 NX2139A PARAMETER VCC UVLO Under-voltage Lockout threshold Falling VCC threshold ON and OFF time TON operating current ON -time Minimum off time FB voltage Internal FB voltage Input bias current Line regulation OUTPUT voltage Output range VOUT shut down discharge resistance Soft start time PGOOD Pgood high rising threshold PGOOD delay after softstart PGOOD propagation delay filter Power good hysteresis Pgood output switch impedance Pgood leakage current SW zero cross comparator Offset voltage HighNSide Driver (CL=3300pF) Output Impedance , Sourcing Current Output Impedance , Sinking Current Rise Time Fall Time Deadband Time Low Side Driver (CL=3300pF) Output Impedance, Sourcing Current Output Impedance, Sinking Current Rise Time Fall Time Deadband Time NOTE1 NOTE1 Vref VCC from 4.5V to 5.5V SYM VCC_UVLO 3.9 3.7 VIN=15V, Rton=1Mohm VIN=9V,VOUT=0.75V, Rton=1Mohm 4.1 3.9 15 312 380 0.739 -1 0.75 ENSW/MODE=GND 30 1.5 90 1.6 2 5 13 1 5 390 590 0.75 468 800 0.761 100 1 3.3 4.5 4.3 V V uA ns ns V nA % V ohm ms % Vref ms us % ohm uA mV Test Condition Min TYP MAX Units R source(Hdrv) Rsink(Hdrv) I=200mA I=200mA 1.5 1.5 50 50 30 ohm ohm ns ns ns THdrv(Rise) 10% to 90% THdrv(Fall) 90% to 10% Tdead(L to Ldrv going Low to Hdrv going H) High, 10% to 10% R source(Ldrv) Rsink(Ldrv) I=200mA I=200mA 1.5 0.5 50 50 10 ohm ohm ns ns ns TLdrv(Rise) 10% to 90% TLdrv(Fall) 90% to 10% Tdead(H to SW going Low to Ldrv going L) High, 10% to 10% Rev. 2.3 03/19/09 3 NX2139A PARAMETER ENSW/MODE threshold and bias current PFM/Non Synchronous Mode Ultrasonic Mode Synchronous Mode Shutdown mode Input bias current LDO Controller Quiescent current LDOEN logic high voltage LDOEN logic low voltage LDOFB reference voltage Output UVLO threshold Open loop gain LDOFB input bias current LDODrv sourcing current LDODrv sinking current LDO PGOOD threshold LDO PGOOD propagation delay filter LDO PGOOD impedance Current Limit Ocset setting current Over temperature Threshold Hysteresis Under voltage FB threshold Over voltage Over voltage tripp point Internal Schottky Diode Forward voltage drop NOTE1 LDOFB=0.72V LDOFB=0.78V Leave it open or use limits in spec ENSW/MODE=VCC ENSW/MODE=GND PWM OFF, LDOEN=HI, IOUT=0mA 2 0.728 0.75 70 60 1 2 2 90 NOTE1 2 13 20 NOTE1 24 155 15 70 125 Forward current=50mA 500 28 0.8 0.773 SYM Test Condition Min TYP MAX Units 80% V CC 60% V CC 2 0 5 -5 VCC+0 .3V 80% VCC 60% VCC 0.8 V V V V uA uA 1 mA V V V %Vref DB uA mA mA %Vref us ohm uA o o C C %Vref %Vref mV NOTE1: This parameter is guaranteed by design but not tested in production(GBNT). Rev. 2.3 03/19/09 4 NX2139A PIN DESCRIPTIONS PIN NUMBER PIN SYMBOL 1 VOUT PIN DESCRIPTION This pin is directly connected to the output of the switching regulator and senses the VOUT voltage. An internal MOSFET discharges the output during turn off. This pin supplies the internal 5V bias circuit. A 1uF X7R ceramic capacitor is placed as close as possible to this pin and ground pin. This pin is the error amplifiers inverting input. This pin is connected via resistor divider to the output of the switching regulator to set the output DC voltage from 0.75V to 3.3V. PGOOD indicator for switching regulator. It requires a pull up resistor to Vcc or lower voltage. When FB pin reaches 90% of the reference voltage PGOOD transitions from LO to HI state. PGOOD indicator for LDO, requires a pull up resistor to Vcc or lower voltage. When LDOFB pin reaches 90% of the reference voltage PGOOD transitions from LO to HI state. This pin is the error amplifiers inverting input. This pin is connected via resistor divider to the output of the LDO to set the output DC voltage. The drive signal for external LDO N channel MOSFET. Low side gate driver output. Provide the voltage supply to the lower MOSFET drivers. Place a high frequency decoupling capacitor 1uF X5R to this pin. This pin is connected to the drain of the external low side MOSFET and is the input of over current protection(OCP) comparator. An internal current source is flown to the external resistor which sets the OCP voltage across the Rdson of the low side MOSFET. This pin is connected to source of high side FETs and provide return path for the high side driver. It is also the input of zero current sensing comparator. High side gate driver output. This pin supplies voltage to high side FET driver. A high freq 1uF X7R ceramic capacitor and 2.2ohm resistor in series are recommended to be placed as close as possible to and connected to this pin and SW pin. LDO enable input functions only when ENSW/MODE is not shutdown. Switching converter enable input. Connect to VCC for PFM/Non synchronous mode, connected to an external resistor divider equals to 70%VCC for ultrasonic, connected to GND for shutdown mode, floating or connected to 2V for the synchronous mode. VIN sensing input. A resistor connects from this pin to VIN will set the frequency. A 1nF capacitor from this pin to GND is recommended to ensure the proper operation. Power ground. 5 2 3 VCC FB 4 PGOOD 5 LDOPG 6 7 8 9 10 LDOFB LDODRV LDRV PVCC OCSET 11 12 13 14 15 SW HDRV BST ENLDO ENSW/ MODE 16 TON PAD Rev. 2.3 03/19/09 GND NX2139A BLOCK DIAGRAM VCC(2) Bias 4.3/4.1 Disable_B Thermal shutdown ON time pulse genearation R S Q POR BST(13) VIN start HD ODB HDRV(12) FET Driver HD_IN SW(11) 5V PVCC(9) LDRV(8) OCP_COMP Mini offtime 400ns PGND 1.8V VIN TON(16) VOUT VOUT FB(3) VREF=0.75V start soft start VCC ENSW /MODE(15) 1M 1M MODE SELECTION Disable PFM_nonultrasonic Sync FB 1.25*Vref/0.7VREF OCP_COMP POR FBUVLO_latch Diode emulation HD OCSET(10) OVP GND(17 PAD) FB FBUVLO_latch PGOOD(4) SS_finished 0.9*Vref start 0.7*Vref VOUT(1) VOUT LDOFBUVLO_latch LDOPG(5) LDOSS_finished 0.7*Vref 1.5V@2A~5A 0.9*Vref LDO_POR LDOFBUVLO_latch ENLDO(14) LDO_EN soft start LDODRV(7) LDOFB(6) Figure 2 - Simplified block diagram of the NX2139A Rev. 2.3 03/19/09 6 NX2139A TYPICAL APPLICATION (VIN=7V to 22V, SW VOUT=1.8V/7A, LDO VOUT=1.5V/2A) PGOOD R1 100k 5V R2 10 C1 1u C2 1u 4 PGOOD TON 16 C3 1n R4 1MEG VIN 7V~22V CI1 2x10uF 9 2 PVCC VCC HDRV 12 R13 2.2 BST 13 C4 1u SW 11 M1 IRF7807 Lo 1.5uH Vout 1.8V/7A CO1 2R5TPE330MC 330uF R12 2.2 C7 1.5n NX2139A M2 LDRV 8 R5 5k OCSET 10 1 VOUT FB 3 C8 330p R6 10.5k R7 7.5k AO4714 ENSW 15 /MODE M3 SI4800 1.5V@2A 14 5V R3 100k LDOPG LDODRV ENLDO 7 R8 50 C6 33n C5 1n R9 20k R10 7.5k R11 7.5k 5 LDOPG GND LDOFB 6 CO2 2x10uF PAD Figure 3 - Demo board schematic Rev. 2.3 03/19/09 7 NX2139A Bill of Materials Item 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Quantity 2 2 1 3 2 1 1 1 1 1 1 1 2 1 1 1 1 3 1 1 2 1 Reference CI1 CO2 CO1 C1,C2,C4 C3,C5 C6 C7 C8 Lo M1 M2 M3 R1,R3 R2 R4 R5 R6 R7,R10,R11 R8 R9 R12,R13 U1 Value 10uF/25V/X5R 10uF/6.3V/X5R 2R5TPE330MC 1uF 1nF 33nF 1.5nF 330pF DO5010H-152 IRF7807 AO4714 SI4800 100k 10 1M 5k 10.5k 7.5k 50 20k 2.2 NX2139A Manufacture SANYO COILCRAFT IR AOS PHILIPS NEXSEM INC. Rev. 2.3 03/19/09 8 NX2139A Demoboard Waveforms Fig.4 Startup (CH1 1.8V OUTPUT, CH2 1.5V LDO, CH3 SW PGOOD, CH4 LDO PGOOD) Fig.5 Turn off (CH1 1.8V OUTPUT, CH2 1.5V LDO, CH3 SW PGOOD, CH4 LDO PGOOD) Fig.6 LDO output transient with SW in PFM mode (CH1 1.8V OUTPUT AC, CH2 1.5V LDO AC, CH4 LDO OUTPUT CURRENT) Fig.7 SW output transient (CH1 1.8V OUTPUT AC, CH2 1.5V LDO AC, CH4 1.8V OUTPUT CURRENT) Fig.8 Start into short (CH1 VIN, CH2 5V VCC, CH4 INDUCTOR CURRENT) Fig. 9 VOUT ripple @ VIN=12V,IOUT=4A (CH1 SW, CH3 VOUT AC) 9 Rev. 2.3 03/19/09 NX2139A VIN=12V, VOUT=1.8V 100.00% OUTPUT EFFICIENCY(%) 90.00% 80.00% 70.00% 60.00% 50.00% 10 100 1000 10000 OUTPUT CURRENT(mA) Fig. 10 Output efficiency Rev. 2.3 03/19/09 10 NX2139A APPLICATION INFORMATION Symbol Used In Application Information: VIN VOUT IOUT FS - Input voltage - Output voltage - Output current - Working frequency FS is around 220kHz. Output Inductor Selection The value of inductor is decided by inductor ripple current and working frequency. Larger inductor value normally means smaller ripple current. However if the inductance is chosen too large, it brings slow response and lower efficiency. The ripple current is a design freedom which can be decided by design engineer according to various application requirements. The inductor value can be calculated by using the following equations: DVRIPPLE - Output voltage ripple DIRIPPLE - Inductor current ripple Design Example The following is typical application for NX2139A, the schematic is figure 1. VIN = 7 to 22V VOUT=1.8V FS=220kHz IOUT=7A DVRIPPLE