PD - 95937 IRF7805/IRF7805APbF HEXFET(R) Chip-Set for DC-DC Converters * N Channel Application Specific MOSFETs * Ideal for Mobile DC-DC Converters * Low Conduction Losses * Low Switching Losses * Lead-Free Description These new devices employ advanced HEXFET Power MOSFET technology to achieve an unprecedented balance of on-resistance and gate charge. The reduced conduction and switching losses make them ideal for high efficiency DC-DC Converters that power the latest generation of mobile microprocessors. The IRF7805/IRF7805A offers maximum efficiency for mobile CPU core DC-DC converters. A D S 1 8 S 2 7 D S 3 6 D G 4 5 D SO-8 T o p V ie w Device Features IRF7805 IRF7805A Vds 30V 30V Rds(on) 11m 11m Qg 31nC 31nC Qsw 11.5nC Qoss 36nC 36nC Absolute Maximum Ratings Parameter Symbol Drain-Source Voltage Gate-Source Voltage 25C Current (VGS 4.5V) 70C Pulsed Drain Current 25C 12 13 13 10 10 IDM 100 100 2.5 PD W TJ, TSTG -55 to 150 C IS 2.5 2.5 Pulsed source Current ISM 106 106 www.irf.com A 1.6 Continuous Source Current (Body Diode) Thermal Resistance Parameter Maximum Junction-to-Ambient Units V ID 70C Junction & Storage Temperature Range IRF7805A 30 VGS Continuous Drain or Source Power Dissipation IRF7805 VDS RJA Max. 50 A Units C/W 1 11/9/04 IRF7805/IRF7805APbF Electrical Characteristics IRF7805 Min Typ Max Parameter Drain-to-Source Breakdown Voltage* V(BR)DSS Static Drain-Source on Resistance* RDS(on) Gate Threshold Voltage* VGS(th) Drain-Source Leakage Current* IDSS Gate-Source Leakage Current* IGSS Total Gate Charge* 30 - - 9.2 11 1.0 IRF7805A Min Typ Max Units 30 Conditions - - V VGS = 0V, ID = 250A 9.2 11 m VGS = 4.5V, ID = 7A V VDS = VGS,ID = 250A A VDS = 24V, VGS = 0 1.0 30 30 150 150 100 100 Qg 22 31 22 31 VGS = 5V, ID = 7A Pre-Vth Gate-Source Charge Q gs1 3.7 3.7 VDS = 16V, ID = 7A Post-Vth Gate-Source Charge Q gs2 1.4 1.4 Gate to Drain Charge Qgd 6.8 6.8 Switch Charge* (Qgs2 + Qgd) QSW 8.2 11.5 8.2 Output Charge* Q oss 30 36 30 VDS = 24V, VGS = 0, Tj = 100C nA VGS = 12V nC 36 VDS = 16V, VGS = 0 Gate Resistance Rg 1.7 1.7 Turn-on Delay Time td(on) 16 16 Rise Time tr 20 20 Turn-off Delay Time td (off) 38 38 Rg = 2 Fall Time tf 16 16 VGS = 4.5V Resistive Load VDD = 16V ns ID = 7A Source-Drain Rating & Characteristics Parameter Min Typ Max Min Typ Max Units Diode Forward Voltage* VSD Reverse Recovery Charge Qrr 88 88 Reverse Recovery Charge (with Parallel Schotkky) Notes: Qrr(s) 55 55 2 * 1.2 1.2 Conditions V IS = 7A, VGS = 0V nC di/dt = 700A/s VDS = 16V, VGS = 0V, IS = 7A di/dt = 700A/s (with 10BQ040) VDS = 16V, VGS = 0V, IS = 7A Repetitive rating; pulse width limited by max. junction temperature. Pulse width 300 s; duty cycle 2%. When mounted on 1 inch square copper board, t < 10 sec. Measured at VDS < 100mV. This approximates actual operation of a synchronous rectifier. Typ = measured - Q oss Devices are 100% tested to these parameters. www.irf.com IRF7805/IRF7805APbF Power MOSFET Selection for DC/DC Converters Drain Current Control FET This can be expanded and approximated by; VGTH t0 2 Drain Voltage Figure 1: Typical MOSFET switching waveform Ploss = (Irms 2 x Rds(on ) ) Synchronous FET Qgs2 f + I x x Vin x ig f + (Qg x Vg x f ) Q + oss x Vin x f 2 This simplified loss equation includes the terms Qgs2 and Qoss which are new to Power MOSFET data sheets. Qgs2 is a sub element of traditional gate-source charge that is included in all MOSFET data sheets. The importance of splitting this gate-source charge into two sub elements, Qgs1 and Qgs2, can be seen from Fig 1. Qgs2 indicates the charge that must be supplied by the gate driver between the time that the threshold voltage has been reached (t1) and the time the drain current rises to Idmax (t2) at which time the drain voltage begins to change. Minimizing Qgs2 is a critical factor in reducing switching losses in Q1. Qoss is the charge that must be supplied to the output capacitance of the MOSFET during every switching cycle. Figure 2 shows how Qoss is formed by the parallel combination of the voltage dependant (non-linear) capacitance's Cds and Cdg when multiplied by the power supply input buss voltage. www.irf.com t3 t1 QGD Ploss = Pconduction+ Pswitching+ Pdrive+ Poutput Qgd +I x x Vin x ig Gate Voltage t2 QGS1 Power losses in the control switch Q1 are given by; 1 QGS2 Special attention has been given to the power losses in the switching elements of the circuit - Q1 and Q2. Power losses in the high side switch Q1, also called the Control FET, are impacted by the Rds(on) of the MOSFET, but these conduction losses are only about one half of the total losses. 4 The power loss equation for Q2 is approximated by; * Ploss = Pconduction + Pdrive + Poutput ( 2 Ploss = Irms x Rds(on) ) + (Qg x Vg x f ) Q + oss x Vin x f + (Qrr x Vin x f ) 2 *dissipated primarily in Q1. 3 IRF7805/IRF7805APbF For the synchronous MOSFET Q2, Rds(on) is an important characteristic; however, once again the importance of gate charge must not be overlooked since it impacts three critical areas. Under light load the MOSFET must still be turned on and off by the control IC so the gate drive losses become much more significant. Secondly, the output charge Qoss and reverse recovery charge Qrr both generate losses that are transfered to Q1 and increase the dissipation in that device. Thirdly, gate charge will impact the MOSFETs' susceptibility to Cdv/dt turn on. The drain of Q2 is connected to the switching node of the converter and therefore sees transitions between ground and Vin. As Q1 turns on and off there is a rate of change of drain voltage dV/dt which is capacitively coupled to the gate of Q2 and can induce a voltage spike on the gate that is sufficient to turn 4 the MOSFET on, resulting in shoot-through current . The ratio of Qgd/Qgs1 must be minimized to reduce the potential for Cdv/dt turn on. Spice model for IRF7805 can be downloaded in machine readable format at www.irf.com. Figure 2: Qoss Characteristic www.irf.com IRF7805/IRF7805APbF Typical Characteristics IRF7805 IRF7805A Figure 3. Normalized On-Resistance vs. Temperature Figure 4. Normalized On-Resistance vs. Temperature Figure 5. Typical Gate Charge vs. Gate-to-Source Voltage Figure 6. Typical Gate Charge vs. Gate-to-Source Voltage Figure 7. Typical Rds(on) vs. Gate-to-Source Voltage Figure 8. Typical Rds(on) vs. Gate-to-Source Voltage www.irf.com 5 IRF7805/IRF7805APbF IRF7805 IRF7805A 10 ISD , Reverse Drain Current (A) ISD , Reverse Drain Current (A) 10 TJ = 150 C 1 TJ = 25 C V GS = 0 V 0.1 0.4 0.5 0.6 0.7 0.8 1 TJ = 25 C 0.1 0.4 0.9 VSD ,Source-to-Drain Voltage (V) Figure 9. Typical Source-Drain Diode Forward Voltage TJ = 150 C V GS = 0 V 0.5 0.6 0.7 0.8 0.9 VSD ,Source-to-Drain Voltage (V) Figure 10. Typical Source-Drain Diode Forward Voltage Thermal Response (Z thJA ) 100 D = 0.50 10 0.20 0.10 0.05 1 0.1 0.001 0.02 0.01 P DM SINGLE PULSE (THERMAL RESPONSE) t1 t2 Notes: 1. Duty factor D = t 1 / t 2 2. Peak T J = P DM x Z thJA + TA 0.01 0.1 1 10 100 1000 t1 , Rectangular Pulse Duration (sec) Figure 11. Maximum Effective Transient Thermal Impedance, Junction-to-Ambient 6 www.irf.com IRF7805/IRF7805APbF SO-8 Package Outline Dimensions are shown in milimeters (inches) D DIM B 5 A 8 6 7 6 E 1 2 3 MIN .0532 .0688 1.35 1.75 A1 .0040 0.25 b H 0.25 [.010] 4 A e e1 0.25 [.010] .0098 0.10 .013 .020 0.33 0.51 c .0075 .0098 0.19 0.25 .189 .1968 4.80 5.00 E .1497 .1574 3.80 4.00 e .050 BASIC 1.27 BASIC .025 BASIC 0.635 BAS IC H .2284 .2440 5.80 6.20 K .0099 .0196 0.25 0.50 L .016 .050 0.40 1.27 y 0 8 0 8 K x 45 A C 8X b MAX D e1 6X MILLIMET ERS MAX A 5 INCHES MIN y 0.10 [.004] A1 8X L 8X c 7 C A B FOOT PRINT NOT ES : 1. DIMENS IONING & T OLERANCING PER AS ME Y14.5M-1994. 8X 0.72 [.028] 2. CONT ROLLING DIMENS ION: MILLIMETER 3. DIMENS IONS ARE SHOWN IN MILLIMET ERS [INCHES ]. 4. OUT LINE CONFORMS T O JEDEC OUT LINE MS-012AA. 5 DIMENS ION DOES NOT INCLUDE MOLD PROT RUSIONS . MOLD PROT RUSIONS NOT T O EXCEED 0.15 [.006]. 6 DIMENS ION DOES NOT INCLUDE MOLD PROT RUSIONS . MOLD PROT RUSIONS NOT T O EXCEED 0.25 [.010]. 6.46 [.255] 7 DIMENS ION IS T HE LENGT H OF LEAD FOR SOLDERING T O A S UBS T RAT E. 3X 1.27 [.050] 8X 1.78 [.070] SO-8 Part Marking Information (Lead-Free) EXAMPLE: T HIS IS AN IRF7101 (MOSFET ) INTERNAT IONAL RECT IFIER LOGO XXXX F7101 DAT E CODE (YWW) P = DESIGNAT ES LEAD-FREE PRODUCT (OPT IONAL) Y = LAST DIGIT OF T HE YEAR WW = WEEK A = ASS EMBLY SIT E CODE LOT CODE PART NUMBER www.irf.com 7 IRF7805/IRF7805APbF SO-8 Tape and Reel Dimensions are shown in milimeters (inches) TERMINAL NUMBER 1 12.3 ( .484 ) 11.7 ( .461 ) 8.1 ( .318 ) 7.9 ( .312 ) FEED DIRECTION NOTES: 1. CONTROLLING DIMENSION : MILLIMETER. 2. ALL DIMENSIONS ARE SHOWN IN MILLIMETERS(INCHES). 3. OUTLINE CONFORMS TO EIA-481 & EIA-541. 330.00 (12.992) MAX. 14.40 ( .566 ) 12.40 ( .488 ) NOTES : 1. CONTROLLING DIMENSION : MILLIMETER. 2. OUTLINE CONFORMS TO EIA-481 & EIA-541. Data and specifications subject to change without notice. This product has been designed and qualified for the Consumer market. Qualifications Standards can be found on IR's Web site. IR WORLD HEADQUARTERS: 233 Kansas St., El Segundo, California 90245, USA Tel: (310) 252-7105 TAC Fax: (310) 252-7903 Visit us at www.irf.com for sales contact information.11/04 8 www.irf.com