NX9548

NX9548 9A SINGLE CHANNEL MOBILE PWM SWITCHING REGULATOR PRELIMINARY DATA SHEET Pb Free Product DESCRIPTION The NX9548 is buck switching converter in multi chip module designed for step down DC to DC converter in portable applications. It is optimized to convert single supply up to 24V bus voltage to as low as 0.75V output voltage.The output current can be up to 9A. 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. Over current protection and FB UVLO followed by latch feature. Other features includes: internal boost schottky diode, 5V gate drive capability, power good indicator, over current protection, over voltage protection and adaptive dead band control.NX9548 is available in 5x5 MCM package. FEATURES n Internal Boost Schottky Diode n Ultrasonic mode operation available n Bus voltage operation from 4.5V to 24V n Less than 1uA shutdown current with Enable low n Excellent dynamic response with constant on time control n Selectable between Synchronous CCM mode and diode emulation mode to improve efficiency at light load n Programmable switching frequency n Current limit and FB UVLO with latch off n Over voltage protection with latch off n n n n APPLICATIONS UMPC, 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 D1 5V 10 1u 1u PVCC VCC BST 4.7 1u S1 D2 3.3uH Vout 1.5V/9A 2x10uF PGOOD 1M TON 1n VIN 8V~22V NX9 5 4 8 2R5TPE330MC 330uF 10k ENSW /MODE OCP HG HDRV GND VOUT 330p FB 7.5k S2 7.5k Figure 1 - Typical application of 9548 ORDERING INFORMATION Device NX9548CMTR Temperature 0 to 70oC Package 5X5 MCM-32L Pb-Free Yes Rev.1.6 03/06/09 1 NX9548 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 D1 to S1and D2 to S2 ........................................ 30V All other pins .................................................... -0.3V to VCC+0.3V or 6.5V Storage Temperature Range ............................... -65oC to 150oC Operating Junction Temperature Range ............... -40oC to 125oC ESD Susceptibility ........................................... 2kV Power Dissipation ............................................. TBD Output Current ...................................................TBD 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 32-LEAD PLASTIC MCM 5 x 5 PGOOD GND D1 D1 32 31 30 29 28 27 26 25 S1 S1 S1 D1 D2 D2 D2 D2 1 2 3 4 5 6 7 8 9 S2 10 11 12 13 14 15 16 S2 PVCC OCP S2 S2 S2 S2 D2 (PAD3) D1 (PAD2) GND (PAD1) 24 TON 23 VOUT 22 ENSW/MODE 21 GND 20 BST 19 D2 18 HDRV FB VCC 17 NC HG D1 Rev.1.6 03/06/09 2 NX9548 ELECTRICAL SPECIFICATIONS Unless otherwise specified, these specifications apply over Vcc = 5V, VIN = 12V and TA= 0 to 70oC. Typical values refer to TA = 25oC. Low duty cycle pulse testing is used which keeps junction and case temperatures equal to the ambient temperature. PARAMETER VIN recommended voltage range Shut down current VCC,PVCC Supply Input voltage range Operating quiescent current Shut down current 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 PGOOD hysteresis PGOOD output switch impedance PGOOD leakage current ENSW/MODE threshold and bias current PFM/Non Synchronous Mode Ultrasonic Mode Synchronous Mode Shutdown mode Input bias current Rev.1.6 03/06/09 SYM Test Condition Min 4.5 TYP MAX 24 Units V uA ENSW=GND Vin FB=0.85V, ENSW =5V ENSW=GND VCC_UVLO 4.5 1 5.5 1.8 1 V mA uA 4.1 3.9 VIN=15V, Rton=1Mohm VIN=9V,VOUT=0.75V,Rton= 1Mohm 15 390 590 0.75 VCC from 4.5V to 5.5V -1 0.75 ENSW/MODE=GND 30 1.5 90 1.6 2 5 13 1 200 1 3.3 V V uA ns ns V nA % V ohm ms % Vref ms us % ohm uA Vref NOTE1 NOTE1 80% VCC 60% VCC Leave it open or use limits in spec ENSW/MODE=VCC ENSW/MODE=GND 2 0 5 -5 VCC+0 .3V 80% VCC 60% VCC 0.8 V V V V uA uA 3 NX9548 PARAMETER SW zero cross comparator Offset voltage 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 Ouput Stage High Side MOSFET RDSON Low Side MOSFET R DSON Output Current 5 24 NOTE1 155 15 70 125 forward current=50mA 500 20 17 9 mV uA o o SYM Test Condition Min TYP MAX Units C C %Vref %Vref mV mohm mohm A NOTE1: This parameter is guaranteed by design but not tested in production(GBNT). Rev.1.6 03/06/09 4 NX9548 PIN DESCRIPTIONS PIN # 1-3 4,30-32 PAD2 5-8,19, PAD3 9-14 15 16 PIN SYMBOL PIN DESCRIPTION S1 Source of high side MOSFET.These pins must be connected directly to the drain of low side MOSFET via a plane connection. D1 D2 S2 PVCC OCP Drain of high side MOSFET. Drain of low side MOSFET and the controller pin out SW. Source of low side MOSFET and need to be directly connected to power ground via multiple vias. This pin provides the voltage supply to the lower MOSFET drivers. Place a high frequency decoupling capacitor 1uF X5R from this pin to GND. This pin is connected to the drain of the external low side MOSFET via resistor and is the input of the over current protection(OCP) comparator. An internal current source is flown from this pin to the external resistor which sets the OCP voltage across the Rdson of the low side MOSFET. Current limit point is this voltage divided by the Rdson. Once this threshold is reached the chip is latched out. Not used. High side gate driver output which needs to be connected to high side MOSFET gate HG pin. A small value resistor may be placed between two pins to slow down the high side MOSFET, reducing the ringing on SW nodes. This pin supplies voltage to high side FET driver. A minimum high freq 0.47uF ceramic capacitor is placed as close as possible to and connected to this pin and respected pin 19.A 4.7ohm resister is recommended in series with this capacitor. 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. 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. 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. 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. Ground pin. High side MOSFET gate. 5 17 18 NC HDRV 20 BST 22 ENSW/ MODE 23 24 25 26 VOUT TON VCC FB 27 PGOOD 21,28 PAD1 29 Rev.1.6 03/06/09 GND HG NX9548 BLOCK DIAGRAM BST HDRV HG D1 VCC Bias 4.3/4.1 Disable_B Thermal shutdown ON time pulse genearation R S Q POR TON VOUT start HD ODB FET Driver HD_IN S1 D2 FB OCP_COMP Mini offtime 400ns S2 POR FBUVLO_latch VREF=0.75V start soft start VCC ENSW /MODE 1M 1M MODE SELECTION Disable PFM_nonultrasonic Sync FB 1.25*Vref/0.7VREF OCP_COMP Diode emulation HD PVCC OCP OVP GND FB FBUVLO_latch 0.7*Vref VOUT start 0.9*Vref VOUT SS_finished PGOOD Figure 2 - Simplified block diagram of the NX9548 Rev.1.6 03/06/09 6 NX9548 Demoboard design and waveforms sdfd PGOOD R6 10k 27 PGOOD TON 24 C3 1n R1 1M D1 5V R5 10 C6 1u C7 1u 15 PVCC BST 4,30-32,PAD2 C1 2 x 4.7uF,25V,X5R 20 R6 4.7 C4 1u VIN 8V~22V C2 10uF,25V,X5R 25 VCC NX9548 S1 1-3 5-8,19,PAD3 D2 DO5010H-332MLD L1 3.3uH Vout 1.5V/9A 2R5TPE330MC C5 330uF ENSW 22 /MODE OCP 16 R2 10k 29 18 HG HDRV VOUT 23 C8 330p R3 7.5k R4 7.5k FB 26 GND S2 9-14 21,28,PAD1 Figure 3 - Demoboard schematic of NX9548 Rev.1.6 03/06/09 7 NX9548 Bill of Materials Item 1 2 3 4 5 6 7 8 9 10 11 12 13 Quantity 2 1 1 3 1 1 1 2 2 1 1 1 1 Reference C1 C2 C3 C4,C6,C7 C5 C8 R1 R2,R6 R3,R4 R5 R6 L1 U1 Part 4.7uF,25V,X5R 10uF,25V,X5R 1nF,50V,X7R 1uF,10V,X7R 2R5TPE330MC 330pF 1MEG 10k 7.5k 10 4.7 DO5010H-332MLD NX9548 Manufacturer SANYO COILCRAFT NEXSEM INC. Rev.1.6 03/06/09 8 NX9548 Demoboard Waveforms Fig.4 Startup when 5V is present and 12V bus is started up, output load current is at 1.5A. Fig.5 Startup when 12V bus is present and 5V is started up. Fig.6 Shutdown when 12V bus is present and 5V is shuted down. Fig.7Output ripple (VIN=15V IOUT=1.2A) Fig.8 5A step response(VIN=5V) Rev.1.6 03/06/09 Fig.9 5A step response(VIN=20V) 9 NX9548 Demoboard Waveforms(Cont') VIN=12V, VOUT=1.5V 92.00% 90.00% 88.00% EFFICIENCY 86.00% 84.00% 82.00% 80.00% 78.00% 10 100 1000 10000 OUTPUT CURRENT(mA) Fig.10 Output efficiency at different load IOUT=10A, VOUT=1.5V 79.00% 78.60% EFFICIENCY 78.20% 77.80% 77.40% 77.00% 0 5 10 VIN(V) 15 20 25 Fig.11 Output efficiency at different VIN bus voltage Rev.1.6 03/06/09 10 NX9548 APPLICATION INFORMATION Symbol Used In Application Information: VIN VOUT IOUT FS - Input voltage - Output voltage - Output current - Working frequency 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 NX9548, the schematic is figure 1. VIN = 8 to 22V VOUT=1.5V FS=220kHz IOUT=9A DVRIPPLE