EL7556B

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



Application

• 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 1



Pinout




Specifications

Storage Temperature Range . . . . . . . . . . . . . . . . .           .-65°C to +150°C
Supply (V_IN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .           6.0V
Ambient Operating Temperature . . . . . . . . . . . . . . . .          -40°C to +85°C
Output Pins . . . . . . . . . . . . . . .               -0.3V below GND, +0.3V above V_DD
Operating Junction Temperature . . . . . . . . . . . . . . . . . . . . . . .            135°C
Peak Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .            9A



Description

   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 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°Ctemperature range.