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EL7558BC
EL7558BC
Integrated Adjustable 8 Amp Synchronous Switcher
Features
• EL7558C/EL7558AC pincompatible • Improved temperature and voltage ranges • 8A 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
General Description
The EL7558BC 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 HSOP package the EL7558BC can supply up to 8A continuous output current without the use of external power devices or externally attached 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 EL7558BC 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 3.50V 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 on-board sensor monitors die temperature (OT) for over-temperature conditions and can be connected directly to OUTEN to provide automatic thermal shutdown. Adjustable oscillator frequency and slope compensation allow added flexibility in overall system design. The EL7558BC is available in the 28-pin HSOP package and is specified for operation over the -40°C to +85°C temperature range.
Applications
• • • • • • PC motherboards Local high power CPU supplies 5V to 1.0V DC:DC conversion Portable electronics/instruments P54 and P55 regulators GTL+ Bus power supply
Connection Diagram
R4 R3 100Ω 150Ω
VIN
D3
1
FB1 CREF CSLOPE COSC VDD VIN VSSP VIN VSSP VSSP VSSP VSSP
FB2 28 CP C2V VSS
27
C4
0.1µF
2
C5 R1 1µF D2 D4* (Optional)
C7
220pF
3 26
C8 R5
330pF
4 5 25
20Ω R6 VHI 24 C6
6
D1
C11 0.22µF
5.1Ω LX LX LX LX VSSP VSSP TEST
23
39.2Ω
0.1µF
Ordering Information
Part No EL7558BCM EL7558BCM-T13 Package 28-Pin HSOP 28-Pin HSOP Tape & Reel 13”
7
22 21 20 19 18 17
VIN
Outline # MDP0042 MDP0042
C9 660µF C3 1µF
C12 1µF
8 9 10 11 12
L1
2.5µH C10 1mF
VOUT
Connect to VSSP for external feedback
13 14
VCC2DET 16 PWRGD OUTEN OT
15
April 27, 2001
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 EL7558ACM only
EL7558BC
Manufactured under U.S. Patents No. 5,723,974 and No. 5,793,126
Note: All information contained in this data sheet has been carefully checked and is believed to be accurate as of the date of publication; however, this data sheet cannot be a “controlled document”. Current revisions, if any, to these specifications are maintained at the factory and are available upon your request. We recommend checking the revision level before finalization of your design documentation.
© 2001 Elantec Semiconductor, Inc.
EL7558BC
EL7558BC
Integrated Adjustable 8 Amp Synchronous Switcher
Absolute Maximum Ratings (T
Storage Temperature Range Supply (VIN) Ambient Operating Temperature
A
= 25°C)
-65°C to +150°C 6V -40°C to +85°C
Output Pins Operating Junction Temperature Peak Output Current
-0.3V below GND, +0.3V above VDD 135°C 9A
Important Note: All parameters having Min/Max specifications are guaranteed. Typ 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 Characteristics
VDD = VIN = 5V, COSC = 1nF, CSLOPE = 470pF, TA = 25°C unless otherwise specified. Parameter General IDD IDDOFF IVIN VOUT1 VOUT2 VOUTLINE VOUTLOAD RSHORT II MAX VOUTTC TOT THYS VPWRGD VDDOFF VDDON VHYS MSS DMAX IPUP ICSLOPE IFB1 ROT VIH VIL VOH PWGD VOL PWGD VREF VREFTC VREFLOAD 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 VCC2DET, OUTEN Pull Up Current Cslope Charging Current FB1 Input Pull Up Current Over Temperature Pull Up Resistance VCC2DET, OUTEN Input High VCC2DET, OUTEN Input Low Powergood Drive High Powergood Drive Low Reference Accuracy Reference Voltage Tempco Reference Load Regulation 0.