APW1172KAI-TRL

APW1172 2.5A SWITCH STEP DOWN SWITCHING REGULATOR Features • • • • • • • • • • • • • • • • 2.5A Internal Switch Operating Input Voltage from 4.8V to 22V 3.3V ±2% Reference Voltage Output Voltage : APW1172 - adjustable from 1.235V to 20V Low Dropout Operation: 100% Duty Cycle 250KHz Internally Fixed Frequency Voltage Feed-Forward Zero Load Current Operation Internal Current Limit Inhibit for Zero Current Consumption Synchronization Protection Against Feedback Disconnection Thermal Protection External Soft-Start Over-Voltage Protection Lead Free Available (RoHS Compliant) General Description The APW1172 is a step down monolithic power switching regulator with a switching current limit of 3.8A so it is able to deliver more than 2.5A DC current to the load depending on the application conditions. The output voltage can be set from 1.235V to 22V.The high current level is also achieved utilize an SO8 package with exposed pad frame. The type of package allows to re-duce the Rth (j-amb) down to approximately 45°C/W. An internal oscillator fixes the switching frequency at 250KHz. Having a minimum input voltage of 4.8V only, it is particularly suitable for 5V bus, available in all computer related applications. Pulse by pulse current limit with the internal frequency modulation offers an effective constant current short circuit protection. Pin Description OUT SYNC 1 2 3 4 8 7 6 5 Applications • • • • Consumer: STB, DVD, TV, VCR, Car Radio, LCD monitors Networking: XDSL, Modems, DC-DC Modules Computer: Printers, Audio/Graphic Cards, Optical Storage, Hard Disk Drive Industrial: Chargers, Car Battery DC-DC Converters VCC GND VREF FB INH COMP SOP-8-P (Top View) = Thermal Pad (connected to GND plane for better heat dissipation) ANPEC reserves the right to make changes to improve reliability or manufacturability without notice, and advise customers to obtain the latest version of relevant information to verify before placing orders. Copyright © ANPEC Electronics Corp. Rev. A.4 - Aug., 2005 1 www.anpec.com.tw APW1172 Ordering and Marking Information APW1172 Lead Free Code Handling Code Temp. Range Package Code APW1172 KA : APW1172 XXXXX Package Code KA : SOP-8-P Operating Ambient Temp. Range C : 0 to 70 ° C I : -40 to 85 ° C Handling Code TU : Tube TR : Tape & Reel Lead Free Code L : Lead Free Device Blank : Orginal Device XXXXX - Date Code Note: ANPEC lead-free products contain molding compounds/die attach materials and 100% matte tin plate termination finish; which are fully compliant with RoHS and compatible with both SnPb and lead-free soldiering operations. ANPEC lead-free products meet or exceed the lead-free requirements of IPC/JEDEC J STD-020C for MSL classification at lead-free peak reflow temperature. Block Diagram VREF COMP FB E/A PWM V REF =1.235V VC C VREF Buffer Voltages Monitor Thermal Protection Peak to Peak Current Limit Driver D Q Ck OVP Oscillator Frequency Shifter 1.25V REF SYNC Inhibit OUT GND Absolute Maximum Ratings Symbol VCC VOUT VIO IOUT VREF PD TJ TSTG TSDR VESD Parameter Input voltage (VCC to GND) Output DC voltage COMP and FB to GND Output current VREF to GND Average Power Dissipation, TA < 50° Junction Temperature Storage Temperature Soldering Temperature, 10 seconds Minimum ESD rating (Human body mode) 2 INH Value 25 -1 to 25 -0.7 ~ VCC 0 to current limit 3.3 2.2 150 -65 ~ 150 300 ±3 Unit V V V A V W °C °C °C KV www.anpec.com.tw Copyright © ANPEC Electronics Corp. Rev. A.4 - Aug., 2005 APW1172 Pin Function Description No. 1 2 3 4 5 PIN OUT SYNC INH COMP FB Regulator Output. Master/Slave synchonization. A logical signal (active high) disables the device. If INH not used the pin must be connected to GND. When it is open an internal pull-up disable the device. E/A output for frequency compensation. Feedback input. Connecting directly to this pin results in an output voltage of 1.235V(APW1172). An external resistive divider is required for higher output voltages. 3.3V reference voltage output, no Capacitor Is requested for stability. Ground. Unregulated DC input voltage. Description 6 7 8 VREF GND VCC Thermal Characteristics Symbol θJA Parameter Junction to ambient thermal resistance in free air Value 45.7 Unit °C/W * The area of the thermal pad is 4.5mm X 2mm and the GND plane is 60mm X 60mm. Connect the thermal pad and the GND plane by 8 vias. TA=25°C. Electrical Characteristics The * denotes the specifications that apply over TA = -40 ~ 85oC. Typical values are at TA = 25oC. VCC = 12V unless otherwise specified. Symbol VCC V UVLO Vd ILIM fs Parameter Test condition Min Operating input voltage range V O = 1.235V; I O = 2A UVLO threshold voltage Hysteresis Dropout voltage Maximum limiting current Switching frequency Duty cycle Copyright © ANPEC Electronics Corp. Rev. A.4 - Aug., 2005 3 APW1172 Typ Max 22 4.2 0.3 4.6 Unit V V V 1.2 4.3 300 295 100 % V A KHz * * 4.7 3.8 V CC rising V CC = 4.8V; IO = 2 A V CC = 4.8V to 22V Main design * * * 3.3 200 205 0 1.0 3.8 250 250 www.anpec.com.tw APW1172 Electrical Characteristics (Cont.) The * denotes the specifications that apply over TA = -40 ~ 85oC. Typical values are at TA = 25oC. VCC = 12V unless otherwise specified. APW1172 Min Dynamic Characteristics VFB η Iqop Iq Voltage feedback APW1172 Efficiency 4.8V < VCC < 22V, 20Ma < IO < 2A VO = 5V, VCC = 12V, IOUT = 1A 1.22 1.235 1.25 V % Typ Max Symbol Parameter Test condition Unit * 1.198 1.235 1.272 84 DC Characteristics Total Operating Quiescent Current Quiescent Current Duty Cycle = 0; VFB = 1.5V VINH > 2.2V VCC = 22V; VINH > 2.2V * * 50 80 * 12 10 100 150 mA mA µA µA Iqst-by Total Stand-by Quiescent Current Inhibit VINH INH Threshold Voltage INH Pull-Up Current Maximum INH Voltage Error Amplifier VOH VOL High Level Output Voltage Low Level Output Voltage Device ON Device OFF VINH < 3V IINH = 0A 1.1 1.2 1.3 1.4 1 4.3 1.5 1.6 V V µA V VFB = 1V VFB = 1.5V VCOMP = 1.9V; VFB = 1V VCOMP = 1.9V; VFB = 1.5V VFB = 1.5V IFB = 0µA VFB = 1.255V to 1.215V, ICOMP = -0.1mA to 0.1mA VCOMP = 1.9V VCC = 4.8 to 22V VCC = 4.8V to 22V VSYNC = 0.74V VSYNC = 2.33V ISOURCE = 3mA No load, VSYNC = 1.65V 4 3.5 3.8 0.4 V V µA mA 4 µA V mA/V IO source Source Output Current IO sink Sink Output Current IFB Source Bias Current Maximum FB Voltage gm Trans-conductance 200 1 300 1.5 2.5 2.1 2.3 SYNC Function High Input Voltage Low Input Voltage Slave Sink Current Master Output Amplitude Output Pulse Width Copyright © ANPEC Electronics Corp. Rev. A.4 - Aug., 2005 2.5 VREF 0.74 V V mA V µs 0.11 0.21 2.75 0.2 3 0.35 0.25 0.45 www.anpec.com.tw APW1172 Electrical Characteristics (Cont.) The * denotes the specifications that apply over TA = -40 ~ 85oC. Typical values are at TA = 25oC. VCC = 12V unless otherwise specified. APW1172 Min Reference Section IREF = 0mA VREF VREF Output Voltage Line Regulation Load Regulation Short Circuit Current Other Thermal Limiting Protection Hysteresis Over-Voltage Protection Threshold Voltage VCOMP = 0.8V * 120 160 30 125 130 °C °C % IREF = 0mA to 5mA, VCC = 4.4A to * 22V IREF = 0mA, VCC = 4.4A to 22V IREF = 0mA to 5mA 10 3.234 3.2 3.3 3.3 5 8 18 3.366 3.399 10 15 30 V V mV mV mA Typ Max Symbol Parameter Test condition Unit Typical Application Circuit VOUT = 3.3V L 22uH 1 2 3 4 OUT SYNC INH COMP VCC GND VREF FB 8 7 6 5 VREF = 3.3V COUT 100uF D1 1N5819 RC1 4.3K CC1 2.2nF D2 1N4148 APW1172 CIN 22uF VIN 4.8V to 22V C1 1uF CC2 220pF R1 137K RF2 3.3K RF1 5.6K Soft Start Circuit Copyright © ANPEC Electronics Corp. Rev. A.4 - Aug., 2005 5 www.anpec.com.tw APW1172 Other Application Circuits Dual output voltage application VOUT2 = 5V VOUT1 = 3.3V N1/N2=2 1N4148 VREF = 3.3V 1 OUT SYNC INH COMP VCC GND VREF FB 8 7 6 5 RF1 5.6K L 22uH 2 3 4 COUT2 47uF RF2 3.3K COUT1 100uF D1 1N5819 RC1 4.3K CC1 2.2nF CC2 220pF APW1172 CIN 22uF VIN =5V BuckBoost regulator VOUT = -12V VREF = 3.3V L 15uH 1 2 8 7 6 5 OUT SYNC INH COMP VCC GND VREF FB D1 1N5819 RC1 4.3K CC1 2.2nF 3 4 APW1172 CIN2 CIN1 22uF25V 22uF CC2 220pF VIN=5V RF2 24K RF1 2.7K COUT 100uF Copyright © ANPEC Electronics Corp. Rev. A.4 - Aug., 2005 6 www.anpec.com.tw APW1172 Typical Operating Characteristics Line regulation of VREF 12 0 -2 Load regulation of VREF 10 Line regulation (mV) 8 Load regulation (mV) -50 -25 0 25 50 75 100 125 -4 -6 -8 -10 -12 -14 6 4 2 0 -16 -50 -25 0 25 50 75 100 125 Junction Temperature (o C) Junction Temperature (o C) Short circuit current of VREF 0 -2 3.40 3.38 3.36 VREF Short circuit current (mA) -4 3.34 -6 3.32 VREF (V) -50 -25 0 25 50 75 100 125 -8 -10 -12 3.30 3.28 3.26 3.24 -14 -16 3.22 3.20 -50 -25 0 25 50 75 100 125 Junction Temperature (o C) Junction Temperature (o C) Copyright © ANPEC Electronics Corp. Rev. A.4 - Aug., 2005 7 www.anpec.com.tw APW1172 Typical Operating Characteristics (Cont.) Source ability of EA 300 0.0 Sink ability of EA 250 -0.5 Source current (uA) 200 Sink current (mA) -1.0 150 -1.5 100 -2.0 50 0 -50 -25 0 25 50 75 100 125 -2.5 -50 -25 0 25 50 75 100 125 Junction Temperature (o C) Junction Temperature (o C) Quiescent current 12 90 Quiescent standby current VCC=12V 10 80 70 VCC=12V 8 60 6 Iqst-by (V) IQ (mA) VCC=5V 50 40 30 20 4 VCC=5V 2 10 0 -50 -25 0 25 50 75 o 0 100 125 -50 -25 0 25 50 75 o 100 125 Junction Temperature ( C) Junction Temperature ( C) Copyright © ANPEC Electronics Corp. Rev. A.4 - Aug., 2005 8 www.anpec.com.tw APW1172 Typical Operating Characteristics (Cont.) Efficiency vs. Output Current at VIN=5V 80% 78% 76% Efficiency vs. Output Current at VIN=12V 86% 84% 82% 80% 74% 78% Efficiency (%) 72% 76% 74% 72% 70% 68% 66% Efficiency (%) 70% 68% 66% 64% 62% 60% 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 VO=2.5V VO=3.3V VO=5V VO=1.8V VO=2.5V VO=3.3V 64% 62% 60% 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 Output Current (A) Output Current (A) VCE vs. ICE 1.5 1.4 1.3 1.2 VFB vs. Temperature 1.241 1.240 1.239 VIN=5V 1.238 1.237 VCE (V) 1.1 1.0 0.9 VFB (V) 3.0 1.236 1.235 1.234 1.233 VIN=12V 0.8 0.7 0.0 0.5 1.0 1.5 2.0 2.5 1.232 1.231 -50 -25 0 25 50 75 o 100 125 ICE (A) Junction Temperature ( C) Copyright © ANPEC Electronics Corp. Rev. A.4 - Aug., 2005 9 www.anpec.com.tw APW1172 Typical Operating Characteristics (Cont.) Switching Frequency 258 Switching Frequenct (KHz) 256 254 252 250 248 246 244 -50 -25 0 25 50 75 100 125 Junction Temperature (o C) Operating waveforms 1. Power ON (no SS) : - VIN = 12V,VOUT = 3.3V - CIN = 22µF, COUT = 220µF, L = 15 µH 2. Power ON (external SS) : - VIN = 12V,VOUT = 3.3V - CIN = 22µF, COUT = 220µF, L = 15 µH IL IL V OUT V IN V OUT V IN COMP Ch1 : VOUT,1V/div Ch2 : COMP,2V/div Ch3 : VIN,5V/div Ch4 : IL,2A/div Time : 400us/div Ch1 : VOUT,1V/div Ch2 : COMP,2V/div Ch3 : VIN,5V/div Ch4 : IL,2A/div Time : 1ms/div COMP Copyright © ANPEC Electronics Corp. Rev. A.4 - Aug., 2005 10 www.anpec.com.tw APW1172 Operating waveforms (Cont.) 3. Current Limit : - VIN = 12V,VOUT = 3.3V - CIN = 22µF, COUT = 220µF, L = 15 µH 4. Load Transient : - VIN = 12V,VOUT = 3.3V - CIN = 22µF, COUT = 220µF, L = 15 µH IOUT IOUT V OUT V OUT COMP Ch1 : VOUT,2V/div Ch2 : COMP,2V/div Ch3 : IOUT,2A/div Time : 2ms/div Ch1 : VOUT,200mV/div,offset 3.3V Ch2 : IOUT,1A/div,100mA-3A Ch2 rising time : 4us Ch2 falling time : 4us Time : 10us/div Functional Description Power-On-Reset A Power-On-Reset circuit monitors input voltages at VCC pin to prevent wrong logic controls. The POR function initiates immediately by the inductor current with it’ limit after the supply voltage exceed firstly it’ s s threshold voltage after powering on. Output Voltage Regulation An error amplifier working with a temperature-compensated 1.235V reference. The error amplifier designed with high bandwidth and DC gain provides very fast transient response and less load regulation. It compares the reference with the feedback voltage and amplifies the difference in it’ output called error signal. The s error signal feeds into the input terminal of PWM comparator and compared with internal saw tooth wave. It generates a PWM control signal by the PWM comparator. The PWM signal feeds into the logic circuit and turns on or off the pass element. The Buck type output stage regulates the correct output voltage depends on the previous mechanism. Current Limit The APW1172 monitors the current flow through the pass element and limits the maximum output current to prevent damages during overload or short-circuit conditions. Over-Voltage Protection (OVP) The over voltage protection is realized by using an Copyright © ANPEC Electronics Corp. Rev. A.4 - Aug., 2005 11 www.anpec.com.tw APW1172 Functional Description (Cont.) Over-Voltage Protection (OVP) (Cont.) internal comparator. The input of the OVP comparator connects to the feedback, that turns off the pass element when the OVP threshold is reached. This threshold is typically 25% higher than the feedback voltage. Thermal protection The thermal protection function generates a control signal to shut off the APW 1172. It prevents the damages caused by over heat situation. The thermal function was acted when the temperature of chip reaching 160°C. A hysteresis of the thermal protection function is approximately 30°C, in order to avoid pass element turns on and off immediately. Voltage Feed Forward The Voltage Feed Forward is acting when VCC goes higher than 10V. This will increases the upper bond of the internal sawtooth wave and results duty keeping constant. The change of the upper bond is linear and proportion with VCC. Frequency Fold Back The Frequency Fold Back function acts when both the current limit function acting and VOUT dropping. This results the switching frequency decreased. In the practical application, when the load current increase big enough such that current limit occurring. In this situation,more load current cause the output voltage get away the regulatory point and begin dropping until it’ limitation. In this time, the actual duty was very s small in general. But the on time period limited by the minimum on time limitation of the control circuit. This on time limitation induce the load current runs away the limiting boundary. To prevent this drawback, the frequency fold back is used to ensure that load current was limited by the setup value. Inhibit Function The Inhibit function disables when the Inhibit voltage lower than 1.3V. APW1172 entered the standby mode with Inhibit voltage higher than 1.4V. The quiescent current in the standby mode is less than 100uA to saving power. If the Inhibit pin left floating, the Inhibit voltage will be pull up by internal current source. Application Description Input Capacitor The APW1172 requires proper input capacitors to supply current surge during stepping load transients to prevent the input rail from dropping.Due to the wide range of input voltage, the input capacitor must be able to support the input operating voltage. Ultra-lowESR capacitors, such as ceramic chip capacitors, are very good for the input capacitors. An aluminum electrolytic capacitor(>100 µ F, ESR 1 00mA Carrier Tape t P P1 D Po E F W Bo Ao Ko D1 Copyright © ANPEC Electronics Corp. Rev. A.4 - Aug., 2005 20 www.anpec.com.tw APW1172 Carrier Tape(Cont.) T2 J C A B T1 Application SOP-8-P Application SOP-8-P A 330±1 F 5.5 ± 0.1 B 62 ± 1.5 C 12.75 + 0.1 5 J 2 + 0.5 T1 12.4 +0.2 T2 2± 0.2 W 12 + 0.3 - 0.1 Bo 5.2± 0.1 P 8± 0.1 E 1.75± 0.1 D D1 Po 1.55±0.1 1.55+ 0.25 4.0 ± 0.1 P1 Ao 2.0 ± 0.1 6.4 ± 0.1 Ko t 2.1± 0.1 0.3±0.013 (mm) Cover Tape Dimensions Application SOP- 8-P Carrier Width 12 Cover Tape Width 9.3 Devices Per Reel 2500 Customer Service Anpec Electronics Corp. Head Office : 5F, No. 2 Li-Hsin Road, SBIP, Hsin-Chu, Taiwan, R.O.C. Tel : 886-3-5642000 Fax : 886-3-5642050 Taipei Branch : 7F, No. 137, Lane 235, Pac Chiao Rd., Hsin Tien City, Taipei Hsien, Taiwan, R. O. C. Tel : 886-2-89191368 Fax : 886-2-89191369 Copyright © ANPEC Electronics Corp. Rev. A.4 - Aug., 2005 21 www.anpec.com.tw