NX4110 1A SYNCHRONOUS BUCK SWITCHER WITH FET ON BOARD PRODUCTION DATA SHEET Pb Free Product DESCRIPTION FEATURES n n n n The NX4110 is a current mode PWM buck switcher with internal compensation, can provide up to 1A output current with FET on board. It operates from 2.8V to 5.5V and output as low as 0.6V which is ideal for the application with single cell Li-Ion battery as well as other 3.3V input bus supply applications. Switching frequency is n fixed 1MHz, small surface mount inductors and capaci- n tors are allowed to use, make it good for portable appli- n cations. NX4110 is available in 5-pin SOT23 package. n n n n SOT23-5L package Internal Digital Soft Start Internally-compensated Current mode controller Peak Current Limit with HICCUP Feature and Over Temperature Protection Prebias Start-up Operation Pgood Available Pb-free and RoHS compliant APPLICATIONS Li-Ion battery operated portable system Cellular Phones Portable applications USB Devices TYPICAL APPLICATION VIN=5V 5 VIN NX4110 FB 1 PGOOD SW GND 4 3 22uF(X5R,6.3V) 2.2uH 2 Vout=2.5V 10uF (X5R, 6.3V) 332k 105k Fig.1 - Typical application of NX4110CZ1TR ORDERING INFORMATION Device NX4110CZ1TR Rev. 2.0 12/30/09 Temperature -40oC to 85oC Package SOT23-5L Pb-Free Yes Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 1 NX4110 ABSOLUTE MAXIMUM RATINGS VIN to GND ..................................................................... -0.3V to 6V SW,FB,PGOOD to GND .................................................. -0.3V to VIN + 0.3V ESD Susceptibility ............................................................. 1kV Lead Temperature(Soldering,10sec.) .................................... 300oC Storage Temperature Range ................................................ -55oC to 150oC Operating Junction Temperature Range ................................ -40oC to 150oC 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 5-LEAD PLASTIC SOT23 θJA ≈ 110o C/W PGOOD 1 5 FB GND 2 SW 3 4 VIN ELECTRICAL SPECIFICATIONS VIN=3.5V. Typical data refers to TA= 25oC. Unless otherwise specified. PARAMETER Reference Voltage Ref Voltage Line Regualtion Line Regulation SYM Test Condition VFB TYP MAX Units 0.59 0.6 0.607 V VIN=3V to 5V,VOUT=1.8V, IOUT=10mA VIN UVLO VIN Rising Threshold VIN Falling Threshold Supply Voltage(VIN) VIN Input Voltage Range 2 2.3 VIN Quiescent Current Oscillator (Rt) Frequency Max Duty Cycle FS 2.8 No Load, switching 2.8 5.5 78 1000 86 1200 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 kHz % nS 0.05 500 V mA 100 Tss V V 4 800 Min ON time Error Amplifiers Feedback Input Bias Current SS Soft Start time 2.5 mV 2.3 Iq Rev. 2.0 12/30/09 Min uA uS 2 NX4110 PARAMETER Current Limit Current Limit Threshold SYM Test Condition Min TYP MAX Units 1.8 Thermal Shutdown Thermal shutdown trip point Hysteresis Internal Switch Rdson of Control FET Rdson of Synchronous FET A 155 o 15 o C C Vin=5V 400 mohm Vin=3.3V Vin=5V Vin=3.3V 480 300 360 mohm 85 90 %VREF %VREF PGOOD PGOOD low Threshold voltage PGOOD high Threshold voltage PIN DESCRIPTIONS PIN SYMBOL SW GND Ground Connection for Chip. Connect GND with large copper areas to the input and output supply returns, and negative terminals of the input and output capacitors. FB Error amplifier inverting input. Error amplifier inverting input. This pin is connected via resistor dividers to the output of the switching regulators to set the output DC voltage. A 332kohm resistor is recommended to be connected from VOUT and FB . VIN Supply voltage input for switcher. This pin needs minimum 22uF/X5R/6.3V as input capacitor. PGOOD Rev. 2.0 12/30/09 PIN DESCRIPTION SW output. Junction of the internal high-side and low-side power MOSFETs, and output inductor. PGOOD indicator. 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. Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 3 NX4110 BLOCK DIAGRAM Thermal Shutdown UVLO POR Vref Bias Generator 3 cycle counter POR VIN OCPB + - CLK VIN Soft start Hiccup timer OSC one shot S R + start Q Vref PWM FB PWM comparator OCPB POR Control Logic SW VIN PGOOD SS_finished FB 0.9*Vref GND Fig. 2 - Simplified block diagram of the NX4110 Rev. 2.0 12/30/09 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 4 NX4110 Typical Operating Characteristics R e ference voltage vs tem p e rature 0.604 0.603 Reference voltage(V) 0.602 0.601 0 .6 0.599 0.598 0.597 0.596 0.595 0.594 0.593 0 20 40 60 80 100 120 140 160 temperature(°C ) Fig.3 - Reference volateg vs temperature Normalized frequency vs temperature Normalized Frequency 1 0.98 0.96 0.94 0.92 0.9 0 20 40 60 80 100 120 140 160 temperature(°C) Fig.4 - Normalized frequency vs temperature Rev. 2.0 12/30/09 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 5 NX4110 D u ty C y c l e v s M a x i m u m O u tp u t C u r r e n t Output Current (mA) 1200 1000 800 600 400 200 0 0 20 40 60 80 D u ty c y c l e ( % ) Fig.5 - Duty cycle vs maximum output current Rev. 2.0 12/30/09 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 6 NX4110 Typical Application( VOUT=2.5V) VIN=5V 5 NX4110 FB 1 PGOOD VIN SW GND 4 3 22uF(X5R,6.3V) 2.2uH Vout=2.5V 10uF (X5R, 6.3V) 2 332k 105k Fig. 6 - Demo board schematic Fig. 7 - Output ripple Rev. 2.0 12/30/09 Fig. 8 - Transient response Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 7 NX4110 Typical Application( VOUT=1.8V) VIN=5V 5 NX4110 FB 1 PGOOD VIN SW GND 4 3 22uF(X5R,6.3V) 2.2uH Vout=1.8V 10uF (X5R, 6.3V) 2 332k 165k Fig. 9 - Demo board schematic Fig. 10 - Output ripple Fig. 11 - Transient response Fig. 12 - Efficiency Rev. 2.0 12/30/09 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 8 NX4110 Typical Application( VOUT=1.2V) VIN=5V 5 NX4110 FB 1 PGOOD VIN SW GND 4 3 22uF(X5R,6.3V) 2.2uH Vout=1.2V 10uF (X5R, 6.3V) 2 332k 332k Fig. 13 - Demo board schematic Fig. 14 - Output ripple Fig. 16 - Startup Rev. 2.0 12/30/09 Fig. 15 - Transient response Fig. 17 - Shutdown Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 9 NX4110 Typical Application( VOUT=1.2V) Fig. 18 - Efficiency Rev. 2.0 12/30/09 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 10 NX4110 Demoboard Layout Fig. 19 - Demoboard schematic Fig. 20- Top layer Rev. 2.0 12/30/09 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 11 NX4110 Fig. 21 - Gound layer Fig. 22 - Power layer Rev. 2.0 12/30/09 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 12 NX4110 Fig. 23 - Bottom layer Rev. 2.0 12/30/09 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 13 NX4110 SOT23 5 PIN PACKAGE OUTLINE DIMENSIONS Top View Side View Rev. 2.0 12/30/09 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 14