Data Sheet No. PD60206 Rev.D IR2085S & (PbF) HIGH SPEED, 100V, SELF OSCILLATING 50% DUTY CYCLE, HALF-BRIDGE DRIVER Features • • • • • • • • • • Simple primary side control solution to enable half-bridge DC-Bus Converters for 48V distributed systems with reduced component count and board space Integrated 50% duty cycle oscillator & half-bridge driver IC in a single SO-8 package Programmable switching frequency with up to 500kHz max per channel +/- 1A drive current capability optimized for low charge MOSFETs Adjustable dead-time 50ns – 200ns Floating channel designed for bootstrap operation up to +100Vdc High and low side pulse width matching to +/- 25ns Adjustable overcurrent protection Undervoltage lockout and internal soft start Also available Leadfree Product Summary Topology VOFFSET Io+ & I o- (typical) Half-Bridge ≤ 100 V 1.0A & 1.0A fOSC (max) 500kHz Deadtime 50ns – 200ns HO/LO Pulse Matching +/- 25ns Package 8 - Lead SOIC Description The IR2085S is a self-oscillating half-bridge driver IC with 50% duty cycle ideally suited for 36V – 75V halfbridge DC-bus converters. This product is also suitable for push-pull converters without restriction on input voltage. Each channel frequency is equal to fOSC, which can be set by selecting RT & CT, where fOSC = 1/(2*RT.CT). Dead-time can be controlled through proper selection of CT and can range from 50ns to 200ns. Internal soft-start increases the pulse width during power up and maintains pulse width matching for the high and low outputs throughout the start up cycle. The IR2085S initiates a soft start at power up and after every overcurrent condition. Undervoltage lockout prevents operation if VCC is less than 7.5V. Typical Connection Diagram www.irf.com 1 IR2085S & (PbF) Absolute Maximum Ratings Absolute maximum ratings indicate sustained limits beyond which damage to the device may occur. All voltage parameters are absolute voltages referenced to COM. All currents are defined positive into any lead. The thermal resistance and power dissipation ratings are measured under board mounted and still air conditions. Symbol Vb VCC VS Definition High side floating supply voltage Low side supply voltage Min. Max. -0.3 150 — 25 Units High side floating supply offset voltage Vb - 25 Vb + 0.3 VHO High side floating output voltage Vb - 0.3 Vb + 0.3 VLO Low side output voltage -0.3 VCC + 0.3 OSC OSC pin voltage -0.3 VCC + 0.3 VCS Cs pin voltage -0.3 VCC + 0.3 dVS/dt V Allowable offset voltage slew rate -50 +50 V/ns ICC Supply current — 20 mA PD Package power dissipation — 1.0 W Thermal resistance, junction to ambient — 200 °C/W TJ Junction temperature -55 150 TS Storage temperature -55 150 TL Lead temperature (soldering, 10 seconds) — 300 Min. Max. RthJA °C Recommended Operating Conditions For proper operation the device should be used within the recommended conditions. Symbol Definition Units Vb High side floating supply voltage Vdd -0.7 15 VS Steady state high side floating supply offset voltage -5 100 VCC Supply voltage 10 15 ICC Supply current (Note 2) — 5 RT Timing resistor 10 100 KΩ CT Timing capacitor 47 1000 pF 500 KHz fosc(max) TJ Operating frequency (per channel) — Junction temperature -40 125 Vdc mA °C Note1: Care should be taken to avoid output switching conditions where the Vs node flies inductively below ground by more than 5V. 2 www.irf.com IR2085S & ( PbF) Dynamic Electrical Characteristics VBIAS (VCC, VBS) = 12V, CLOAD = 1000 pF, and TA = 25°C unless otherwise specified. Symbol Min. Typ. tr Turn-on rise time — 40 60 tf Turn-off fall time — 20 30 fosc tdt Definition Per channel output frequency High/low output dead time Max. Units Test Conditions 500 — — 50 — — tdcs Overcurrent shut down delay — 200 — PM High/low pulse width mismatch -25 — 25 nsec VS = 0V KHz CT =100pF, RT =10Kohm nsec pulse on CS VS = 0V ~ 100V Static Electrical Characteristics VBIAS (VCC, VBS) = 12V, CLOAD = 1000 pF and TA = 25°C unless otherwise specified. Symbol Definition VOH High level output voltage, (VBIAS - VO) Min. Typ. Max. Units Test Conditions — — 1.5 VOL Low level output voltage — — 0.1 Ileak IQBS Offset supply leakage current — — 50 Quiescent VBS supply current — — 150 IQCC Quiescent VCC supply current — — 1.5 mA VCS+ VCS- 250 150 300 200 350 250 mV mV UVCC+ Overcurrent shutdown threshold Overcurrent shutdown threshold Undervoltage positive going threshold 6.8 7.3 7.8 UVCC- Undervoltage negative going threshold 6.3 6.8 7.3 UVBS+ High side undervoltage positive going threshold 6.8 7.3 7.8 UVBS- High side undervoltage negative going threshold 6.3 6.8 7.3 IO+ Output high short circuit current — 1.0 — IO- Output low short circuit current — 1.0 — www.irf.com V μA V A 3 IR2085S & (PbF) Functional Block Diagrams VCC UVLO BIAS RT OSC Vb IR2085S BLOCK DIAGRAM UVLO AND RS LATCH OSC BLOCK CT HO PULSE STEERING CS + OVC - VS SOFT START VREF (250mV) VCC LO 10PF GND Lead Definitions Lead Assignments Symbol Description 4 Logic supply Logic supply return Vb VS HO LO CS OSC High side floating supply Floating supply return High side output Low side output Current sense input Oscillator pin 1 CS Vb 8 2 OSC HO 7 3 GND VS 6 4 LO VCC 5 IR2085S VCC GND Also available LEAD-FREE (PbF) www.irf.com IR2085S & ( PbF) 500 250 450 225 400 200 175 300 Time (ns) Frequency (kHz) 350 250 200 CT = 470pF 150 CT = 220pF 125 CT = 47pF CT = 100pF 150 100 CT = 100pF 100 CT = 220pF CT = 470pF 50 CT = 47pF 75 50 0 10 20 30 40 50 60 RT (kohms) 70 80 90 100 10 20 30 40 50 60 70 80 90 100 RT (kohms) Fig. 2 Typical Dead Time (@25oC) Fig. 1 Typical Output Frequency (-25oC to 125oC) 180 160 Dead Time (ns) 140 120 100 DT(CT=100pF, RT=100k) 80 60 -40 -20 0 20 40 60 80 100 120 Temperature Fig. 3 Typical Dead Time vs Temperature www.irf.com 5 IR2085S& (PbF) Pin Descriptions Cs: The input pin to the overcurrent comparator. Exceeding the overcurrent threshold value specified in “Static Electrical Parameters” Section will terminate output pulses and start a new soft start cycle as soon as the voltage on the pin reduce below the threshold value. OSC: The oscillator-programming pin. Only two components are required to program the internal oscillator frequency: a resistor connected between the VCC pin and the OSC pin, and a capacitor connected from the OSC to COM. The approximate oscillator frequency is determined by the following simple formula: fOSC = 1 / (2 · RT · CT) Where frequency is in Hertz (Hz), RT resistance in Ohms (Ω) and CT capacitance in Farads (F). The recommended range of timing resistors is between 10kΩ and 100kΩ and range of time capacitances is between 47pF and 470pF. The timing resistors less than 10kΩ should be avoided. The value of the timing capacitor determines the amount of dead time between the two output drivers: lower the CT, shorter the dead time and vice versa. It is not recommended to use a timing capacitor below 47pF, for best performance keep the timing components physically as close as possible to the IR2085S. Separated ground and VCC traces to the timing components are encouraged. COM: Signal ground and power ground for all functions. Due to high current and high frequency operation, a low impedance circuit board ground plane is highly recommended. HO, LO: High side and low side gate drive pins. The high and low side drivers can directly drive the gate of a power MOSFET. The drivers are capable of 1A peak source and sink currents. It is recommended that the high and low drive pins be very close to the gates of the high side and low side MOSFETs to prevent any delay and distortion of the drive signals. VB: The high side power input connection. The high side supply is derived from a bootstrap circuit using a low-leakage Schottky diode and a ceramic capacitor. To prevent noise, the Schottky diode and bypass capacitor should be very close to the IR2085S. VS: The high side power return connection. VS should be connected directly to the source terminal of high side MOSFET with a trace as short as possible. VCC: The IC bias input connection for the device. Although the quiescent VCC current is very low, total supply current will be higher, depending on the gate charge of the MOSFETs connected to the HO and LO pins, and the programmed oscillator frequency, total VCC current is the sum of quiescent VCC current and the average current at HO and LO. Knowing the operating frequency and the MOSFET gate charge (Qg) at selected VCC voltage, the average current can be calculated from: Iave = 2 x Qg X fOSC To prevent noise problem, a bypass ceramic capacitor connected to VCC and COM should be placed as close as possible to the IR2085S. IR2085S has an under voltage lookout feature for the IC bias supply, VCC. The minimum voltage required on VCC to make sure that IC will work within specifications must be higher than 8.5V (9.5V minimum VCC is recommended to prevent asymmetrical gates signal on HO and LO pins that are expected when VCC is between 7.5V and 8.5V). 6 www.irf.com IR2085S & ( PbF) Case outline D DIM B 5 A FOOTPRINT 8 6 7 6 5 H E 1 6X 2 3 0.25 [.010] 4 e A 6.46 [.255] 3X 1.27 [.050] e1 8X b 0.25 [.010] A A1 8X 1.78 [.070] MIN .0532 .0688 1.35 1.75 A1 .0040 .0098 0.10 0.25 b .013 .020 0.33 0.51 c .0075 .0098 0.19 0.25 D .189 .1968 4.80 5.00 .1574 3.80 4.00 E .1497 e .050 BASIC e1 MAX 1.27 BASIC .025 BASIC 0.635 BASIC 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° C y 0.10 [.004] 8X L 8X c 7 C A B NOTES: 1. DIMENSIONING & TOLERANC ING PER ASME Y14.5M-1994. 2. CONTROLLING DIMENSION: MILLIMETER 3. DIMENSIONS ARE SHOWN IN MILLIMETERS [INC HES]. 4. OUTLINE C ONFORMS TO JEDEC OUTLINE MS-012AA. 8-Lead SOIC www.irf.com MILLIMETERS MAX A 8X 0.72 [.028] INCHES MIN 5 DIMENSION DOES NOT INCLUDE MOLD PROTRUSIONS. MOLD PROTRUSIONS NOT TO EXCEED 0.15 [.006]. 6 DIMENSION DOES NOT INCLUDE MOLD PROTRUSIONS. MOLD PROTRUSIONS NOT TO EXCEED 0.25 [.010]. 7 DIMENSION IS THE LENGTH OF LEAD FOR SOLDERING TO A SUBSTRATE. 01-6027 01-0021 11 (MS-012AA) 79 IR2085S & (PbF) LEADFREE PART MARKING INFORMATION Part number Date code IRxxxxxx YWW? Pin 1 Identifier ? P MARKING CODE Lead Free Released Non-Lead Free Released IR logo ?XXXX Lot Code (Prod mode - 4 digit SPN code) Assembly site code Per SCOP 200-002 ORDERING INFORMATION PKG DESIG S S PART LEADFREE NUMBER PART NUMBER IR2085S IR2085SPbF IR2085STR IR2085STRPbF PIN COUNT 8 8 PARTS PER TUBE 95 ------ PARTS PER REEL -----4000 This product has been designed and qualified for the industrial market. Qualification Standards can be found on IR’s Web Site http://www.irf.com/ . Data and specifications subject to change without notice WORLD HEADQUARTERS: 233 Kansas Street, El Segundo, California 90245 Tel: (310) 252-7105 1/7/2006 8 10 www.irf.com