Summit’s Programmable 10A and 20A Buck Regulators Deliver 96% Efficiency and Advanced Power Management with Integrated MOSFETs and Digital Control

Like Summit’s entire programmable DC-DC family the SMB220 and SMB221 deliver advanced power management functions along with class-leading power regulation at an unbeatable bill-o-material cost. Many applications can benefit from the application of these products including Enterprise Servers and Storage Systems, Enterprise and Carrier Switches/Routers/BaseStations as well as emerging Consumer Digital Media (IP Digital Television and Set-Top Box).

The SMB220/SMB221 are 10A/20A single-output integrated DC-DC buck regulators combining Summit’s digital programmability with high integration, ultra-compact size, and cost-effective bill-of-materials (BoM) necessary for dense system applications. Ultra high efficiency of up to 96% and 1% output regulation meets the most stringent digital core power requirements. With a serial digital interface and on-board non-volatile memory, the SMB220/SMB221 family can be easily configured during development and re-programmed in system by host software. The result is a flexible, digitally controlled power supply design that is easily customizable without tedious hardware design cycles or complex microcontroller-style GPIO-based control. The integration of advanced power control functions eliminates external components and cost, improves functionality and performance, and minimizes development time.

“Summit again expands its line of programmable DC-DC products with the SMB220 and SMB221 buck regulators,” stated Abid Hussain, Summit vice-president of marketing and applications. “The unique combination of integrated high current MOSFETs, digital programmability and low cost bill-of-materials is clearly an ‘industry first’ making true digital power affordable for many new applications.”

Features
The SMB220 and SMB221 are integrated step-down DC-DC buck regulators with on-board MOSFET(s) supplying up to 10A (SMB220), or 20A (SMB220) output current. Input voltage range is +4.5V to +16V and output voltage range is +0.5V to VIN, accurate to +/-1.5% over load/line/temperature. Output voltage is digitally programmable in 10mV steps up to 2.5V and 20mV steps up to 5.0V while other custom voltages are supported with external resistors. PWM switching frequency is programmable from 250kHz to 1MHz and light load efficiency is supported by automatic pulse-skipping (PFM) operation.

Output enable, sequence delay, softstart and output voltage (UV) monitoring are all programmable as well. Output voltage monitoring is coupled to “PowerGood” or “RESET” signals with programmable output assignment and the output can be enabled via the serial I2C interface or by the ENABLE pins. Nominal output voltages maybe changed once the system is powered up, enabling the latest SoC’s/ASICs to reduce platform power using advanced voltage/clock scaling modes. The output voltage programming also allows for easy voltage margining to support easy system validation and characterization of these same advanced SoC’s/ASICs.

Tiny 5mm x 6mm QFN packaging and minimal external components yield an ultra-compact (typically <200mm2) solution size. Programmed configuration is held in the OTP non-volatile memory but may be changed in system by host software via the I2C port. The rated operating temperature range is -40C to +85C.

Packaging, Price and Availability
The SMB220/SMB221 are available in a tiny thermally-enhanced, RoHS-compliant , lead-free 5mm X 6mm, 28-pad QFN. Available now in production quantities, the SMB220 is priced $1.80 each while the SMB221 is priced at $2.50 respectively in quantities of 10,000 units.

DESIGN SOFTWARE AND PROGRAMMER FOR PROTOTYPE DEVELOPMENT
To speed user product development, Summit offers customers the SMB220/221EV companion evaluation boards and a graphical user interface (GUI) software so designers can quickly see the features and benefits and design a prototype intelligent power supply solution. This is a complete development tool that lets designers easily manipulate the characteristics of their systems. The SMB220/221EV design kits includes menu-driven Microsoft Windows (R) GUI software to automate programming tasks and also includes all necessary hardware to interface to the USB port of a laptop or PC.

Once a user completes design and prototyping, the SMB220/221 GUI automatically generate a HEX data file that can be transmitted to Summit for review and approval. Summit then assigns a unique customer identification code to the HEX file and programs the customer’s production devices prior to final electrical test operations. This ensures that the device will operate properly in the end application.