ir3637s International Rectifier Corp., ir3637s Datasheet
ir3637s
Available stocks
Related parts for ir3637s
ir3637s Summary of contents
Page 1
... C2 Q1 HDrv D1 Q2 LDrv Fb Figure 1 - Typical application of IR3637. PIN PARTS PARTS COUNT PER TUBE PER REEL ------- www.irf.com Data Sheet No. PD94713 IR3637SPBF & R Oriantation ------ Fig A 2500 Vout 1 ...
Page 2
... IR3637SPBF ABSOLUTE MAXIMUM RATINGS Vcc Supply Voltage ................................................ Vc Supply Voltage .................................................. Storage Temperature Range ..................................... Operating Junction Temperature Range ..................... ESD Classification ................................................. Moisture Sensitivity Level ........................................ Caution: Stresses above those listed in “Absolute Maximum Rating” may cause permanent damage to the device. These are stress ratings only and function of the device at these or any other conditions beyond those indicated in the operational sections of the specifica- tions is not implied. Exposure to “ ...
Page 3
... Rev. 1.1 06/16/05 TEST CONDITION SS=3V, Fb=0.6V FB1 SS=0V, Fb=0.6V FB2 m RAMP C =1500pF, Vcc=12V, =1500pF, Vcc=12V Vcc=12V Fb=0.6V, Freq=400kHz ON Fb=1V OFF www.irf.com IR3637SPBF MIN TYP MAX UNITS µA -0.1 µA -64 µmho 450 600 800 360 400 440 kHz 1. ...
Page 4
... IR3637SPBF BLOCK DIAGRAM 3V 25uA SS/SD 64uA Max 8 POR 0.8V 25K Error Amp 25K Fb 1 Comp 7 Figure 2 - Simplified block diagram of the IR3637. THEORY OF OPERATION Introduction The IR3637 is a fixed frequency, voltage mode synchro- nous controller and consists of a precision reference voltage, an error amplifier, an internal oscillator, a PWM comparator, 0 ...
Page 5
... C /1V SS START Output of UVLO POR Soft-Start 0V Voltage 64uA Current flowing into Fb pin ≅ 1.6V Voltage at negative input of Error Amp and Feedback UVLO comparator 0V Voltage at Fb pin Figure 4 - Theoretical operational waveforms during soft-start. www.irf.com IR3637SPBF HDrv LDrv POR 3V ≅ 2V ≅ 1V 0uA 0.8V 0.8V 5 ...
Page 6
... IR3637SPBF APPLICATION INFORMATION Design Example: The following example is a typical application for IR3637. Appliaction circuit is shown in page 12 Vcc = 5V IN Vc=12V V = 1.8V OUT OUT ∆V = 50mV OUT F = 400kHz S Output Voltage Programming Output voltage is programmed by reference voltage and external voltage divider. The Fb pin is the inverting input of the error amplifier, which is internally referenced to 0 ...
Page 7
... DS(ON) ered for the worst case operation. This is typically given in the MOSFET data sheet. Ensure that the conduction losses and switching losses do not exceed the package ratings or violate the overall thermal budget. www.irf.com IR3637SPBF ---(4) =2. gate- DSS ), maximum output current, On- GS and thermal management ...
Page 8
... IR3637SPBF For this design, IRF8910 is a good choice. The device provides two N-MOSFETs in a compact SOIC 8-Pin pack- age. The IRF8910 has the following data 20V DSS I = 10A D R =18.3Ω =4.5V (Lower FET) DS(onh =13.4Ω =10V (Upper FET) DS(on) GS The total conduction losses will be: ...
Page 9
... The pole sets to one half of switching frequency which results in the capacitor POLE 1 6 × ---(12 for F << P www.irf.com IR3637SPBF = Resistor Dividers for Output Voltage 6 Programming =16.06KΩ. Choose R =16KΩ ---(13) × C 2π get 1.8nF ...
Page 10
... IR3637SPBF For a general solution for unconditionally stability for any type of output capacitors wide range of ESR values we should implement local feedback with a compensa- tion network. The typically used compensation network for voltage-mode controller is shown in Figure 10. V OUT ...
Page 11
... The goal is to localize the high current path to a separate loop that does not interfere with the more sensitive analog control function. These two grounds must be connected together on the PC board layout at a single point. Typical Output Capacitor /2 Electrolytic, Tantalum /2 Tantalum, Ceramic Ceramic ESR www.irf.com IR3637SPBF 11 ...
Page 12
... IR3637SPBF TYPICAL APPLICATION Two Supplies Application: Vc=12V, Vin=Vcc= Gnd 12V Vcc C3 1uF SS/SD U1 IR3637 C6 0.1uF Comp C9 Gnd 1.8nF C11 R4 47pF 16K 150uF 150uF C4 C5 1uF 1uF Vc Q1 IRF8910 HDrv L1 D1 1.5uH DO3316P-152 LDrv R6 Fb 1.24K R5 1K Figure 11 - Typical Application for IR3637. ...
Page 13
... TYPICAL APPLICATION Single 5V Application C3 C4 Vcc Vc HDrv U1 SS/SD C8 IR3637 LDrv Comp C9 Fb Gnd R4 Figure 12 - Typical application for single 5V Rev. 1.1 06/16/ www.irf.com IR3637SPBF 5V L1 Vout C7 13 ...
Page 14
... IR3637SPBF TYPICAL APPLICATION Two Supplies Application, Vcc=Vc=12V, Vin=5V 12V C3 Vcc Vc HDrv U1 SS/SD C8 IR3637 LDrv Comp C9 Gnd R4 Figure 13 - Typical application using 12V for biasing both Vcc and Vc and 5V for Bus Voltage For proper start up the 5V rail needs to start before 12V 14 C4 ...
Page 15
... Temp, C Rev. 1.1 06/16/05 -19 -20 -21 -22 -23 -24 -25 -26 -27 0 100 120 140 4.5 4.25 4 3.75 3.5 3.25 3 2.75 2.5 100 125 0 7 6.75 6.5 6.25 6 5.75 5.5 100 125 0 www.irf.com IR3637SPBF Soft Start Charge Current 100 125 Temp, C Static Vcc Current 100 125 Temp, C Dynamic Vcc Current 100 125 Temp ...
Page 16
... IR3637SPBF TYPICAL OPERATING CHARACTERISTICS Dynamic Vc Current 12.75 12.5 12.25 12 11.75 11 Temp, C Fall Time-HDrv Temp 100 125 100 125 Fall Time-HDrv 100 125 Temp, C www.irf.com Rise Time-HDrv ...
Page 17
... Ch1: Vin=Vcc, Ch2: Vc, Ch3: Vss, Ch4: Vout Figure 16 - Gates waveforms Ch1: Hdrv, Ch2: Ldrv, Ch4: Inductor Current ILoad=5A Rev. 1.1 06/16/05 Figure 15 - Start up waveforms Ch1: Vin=Vcc, Ch3: Vss, Ch4: Vout Figure 17 - Gates waveforms Ch1: Hdrv, Ch2: Ldrv, Ch3: Inductor Point ILoad=5A www.irf.com IR3637SPBF 17 ...
Page 18
... IR3637SPBF TYPICAL OPERATING WAVEFORMS Test Conditions: Vcc=Vin=5V, Vc=12V, Vout=1.8V, Iout=0-7A, Ta=Room Temp, No Air Flow. Unless otherwise specified. Figure 18 - Shutdown by shorting the SS pin Ch1: Hdrv, Ch2: Ldrv, Ch3:SS ILoad=5A Figure 20 - Load Transient (0-5A) Ch1: Vout, Ch4: Step Load Current 18 Figure 19 - Output Voltage Ripple ...
Page 19
... Vcc=Vin=5V, Vc=12V, Vout=1.8V, Iout=0-8A, Ta=Room Temp, No Air Flow. Unless otherwise specified. V c=12V , V cc t=0-8A, F s=40 0kHz Rev. 1.1 06/16/05 E fficien Figure 22 - Efficiency using IRF8910 Dual MOSFET www.irf.com IR3637SPBF ...
Page 20
... IR3637SPBF 8-Pin Surface Mount, Narrow Body PIN NO NOTE: ALL MEASUREMENTS ARE IN MILLIMETERS. 20 (S) SOIC Package DETAIL-A 0.38 ± 0.015 8-PIN SYMBOL MIN MAX A 4.80 4.98 1.27 BSC B C 0.53 REF D 0.36 0.46 E 3.81 3.99 F 1.52 1.72 G 0.10 0.25 7 BSC H I 0.19 0.25 J 5.80 6. 0.41 1.27 T 1.37 1.57 www.irf.com H L DETAIL-A ...
Page 21
... IR WORLD HEADQUARTERS: 233 Kansas St., El Segundo, California 90245, USA Tel: (310) 252-7105 Rev. 1.1 06/16/05 PIN PARTS PARTS COUNT PER TUBE PER REEL 8 95 Visit us at www.irf.com for sales contact information Data and specifications subject to change without notice. 6/16/2005 www.irf.com IR3637SPBF T & R ORIENTATION 2500 FigA TAC Fax: (310) 252-7903 21 ...