Integrated Adjustable 6 Amp Synchronous Switcher

® F MAT F OR D IN 6D TE Data Sheet PDA EL755 OR U I EE ON S EL7556B October 5, 2001 FN7292 Integrated Adjustable 6 Amp Synchronous Switcher The EL7556B is an adjustable synchronous DC:DC switching regulator optimized for a 5V input and 1.0V-3.8V output. By combining integrated NMOS power FETs with a fused-lead package, the EL7556B can supply up to 6A continuous output current without the use of external power devices or discrete heat sinks, thereby minimizing design effort and overall system cost. On-chip resistorless current sensing is used to achieve stable, highly efficient, current-mode control. The EL7556B also incorporates the VCC2DET function to directly interface with the Intel P54 and P55 microprocessors. Depending on the state of VCC2DET, the output voltage is internally preset to 3.5V or a user-adjustable voltage using two external resistors. In both internal and external feedback modes the active-high PWRGD output indicates when the regulator output is within ±10% of the programmed voltage. An onboard sensor monitors die temperature (OT) for overtemperature conditions and can be connected directly to OUTEN to provide automatic thermal shutdown. Adjustable www.DataSheet4U.com oscillator frequency and slope compensation allow added flexibility in overall system design. The EL7556B is available in a 28-pin SO package and is specified for operation over the full -40°C to +85°C temperature range. Features • EL7556/EL7556A Pin-compatible • Improved temperature and voltage ranges • 6A continuous load current • Precision internal 1% reference • 1.0V to 3.8V output voltage • Internal power MOSFETs • >90% efficiency • Synchronous switching • Adjustable slope compensation • Over-temperature indicator • Pulse-by-pulse current limiting • Operates up to 1MHz • 1.5% typical output accuracy • Adjustable oscillator with sync • Remote enable/disable • Intel P54- and P55-compatible • VCC2DET interface • Internal soft-start Applications • PC motherboards • Local high power CPU supplies • 5V to 1.0V DC:DC conversion • Portable electronics/instruments Pinout EL7556B (28-PIN SO) TOP VIEW R4 R3 100Ω 150Ω VIN D3 • P54 and P55 regulators • GTL + Bus power supply 1 C4 0.1µF 2 C7 39pF 3 C8 R5 5 5.1Ω 6 7 C9 C12 1µF C3 1µF 8 9 10 11 12 Connect to VSSP for external feedback 13 14 220pF 4 FB1 CREF CSLOPE COSC VDD VIN VSSP VIN VSSP VSSP VSSP VSSP FB2 28 CP C2V VSS 27 R1 26 20Ω 25 R6 VHI 24 C6 LX LX LX LX VSSP VSSP TEST 23 0.1µF 22 21 20 19 18 17 L1 2.5µH C10 1mF 39.2Ω D1 C11 0.22µF C5 1µF D2 D4* (Optional) Ordering Information VOUT = 1V*(1+R3/R4) VIN 660µF PART NUMBER EL7556BCM EL7556BCM-T13 PACKAGE 28-Pin SO 28-Pin SO TAPE & REEL 13” PKG. NO. MDP0027 MDP0027 VCC2DET 16 PWRGD OUTEN OT 15 C12 - 1µF C3, C4, C5, C6, C7 C8 - ceramic C5, C11 - ceramic or tantalum C9 - Sprague 293D337X96R3 2X330µF C10 - Sprague 293D337X96R3 3X330µF L1 - Pulse Engineering, PE-53681 D1-D4: BAT54S fast diode D4 Required for EL7556ACM Only Manufactured under U.S. Patents No. 5,723,974 and No. 5,793,126 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 321-724-7143 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright © Intersil Americas Inc. 2003. All Rights Reserved. Elantec is a registered trademark of Elantec Semiconductor, Inc. All other trademarks mentioned are the property of their respective owners. EL7556B Absolute Maximum Ratings (TA = 25°C) Storage Temperature Range . . . . . . . . . . . . . . . . . .-65°C to +150°C Supply (VIN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.0V Ambient Operating Temperature . . . . . . . . . . . . . . . .-40°C to +85°C Output Pins . . . . . . . . . . . . . . . -0.3V below GND, +0.3V above VDD Operating Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . 135°C Peak Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9A 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. IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typical values are for information purposes only. Unless otherwise noted, all tests are at the specified temperature and are pulsed tests, therefore: TJ = TC = TA Electrical Specifications PARAMETER GENERAL IDD IDDOFF IVIN VOUT1 VOUT2 VOUTLINE VOUTLOAD RSHORT II MAX VOUTTC TOT THYS VPWRGD VDDOFF VDDON VHYS MSS DMAX VDD = VIN = 5V, COSC = 1nF, CSLOPE = 470pF, TA = 25°C unless otherwise specified. CONDITIONS MIN TYP MAX UNIT DESCRIPTION VDD Supply Current VDD Standby Current VIN No Load Current Output Initial Accuracy Output Initial Accuracy Output line Regulation Output Load Regulation Short Circuit Load Resistance Current Limit Output Tempco Over Temperature Threshold Over Temperature Hysteresis Power Good Threshold Relative to Programmed Output Voltage Minimum VDD for Shutdown Maximum VDD for Startup Input Hysteresis Soft start slope Maximum duty cycle OUTEN = 4V, FOSC = 120kHz OUTEN = 0 OUTEN = 0 VCC2DET = 4V, IL = 3A (See Fig. 1) VCC2DET = 0V, IL = 3A R3 = 150Ω, R4 = 100Ω VDD = 5V, ±10% 0A