California Micro First to Offer Three-in-One All-Linear DDR Regulator

12/9/2003 - California Micro Devices (NASDAQ: CAMD), announced the industry’s first fully integrated, all-linear DDR voltage regulator solution for cost-sensitive PC and consumer set-top applications. The CM3131 family of highly integrated all-linear voltage regulators provides a complete, single-chip power solution for Double Data Rate (DDR) and DDR II SDRAM memories and are the industry’s first products to integrate three separate linear regulators to provide VDDQ, VTT and VSTBY power from a single chip. When compared to existing switching regulator based solutions, the CM3131 family of solutions eliminates the need for multiple external FETs and inductors, allowing for a solution cost reduction of up to 70 percent and a 55 percent reduction in board space. The CM3131 also incorporates innovative intelligent power sequencing control logic to simplify transitions between various PC power states (S0-S5), providing further solution cost savings.

Because the CM3131 uses an all-linear integrated approach, an entire DDR power solution can be implemented using one CM3131 in a small PSOP-8 package with a single external N-FET, eliminating the need for the multiple FETs and inductors that are required in switching solutions. For high power systems, the CM3131 is also available in a PSOP-14 package that allows two external unmatched N-FETS to be connected, distributing heat dissipation between them while still providing lower cost, component count, and board space than competing solutions.

"We worked very closely with leading customers during the definition of this product to achieve their goal of the lowest cost and smallest footprint possible for a complete DDR and DDR II power subsystem," said Joe Salvador, director of marketing for computing and consumer electronics products at California Micro Devices. "This product family demonstrates our continued investment in developing unique application specific analog products for our PC and consumer customers."

How They Work
To provide the main power, a linear regulator driving an external N-FET provides up to 15A of current at 2.5V for DDR and 1.8V for DDR II. An optional external feedback resistor divider allows the system designer to adjust the output voltage for use with different memory controllers requiring other voltages. The VTT regulator is a linear sink source regulator powered from the VDDQ output that supplies the VTT supply required by DDR-I memory termination resistors. This regulator sinks or sources up to 2A to or from the DDR-I bus termination resistors, or 0.9A at 0.9V for the chipset in DDR-II, to support both single- and dual-channel memory configurations. The VTT output voltage accurately tracks VDDQ/2 to ±1%. The standby LDO is powered from a standby voltage, VSTBY, of 3.3V or 5V, and supplies a regulated output of up to 500mA to the VDDQ of the DDR memory to enable it to retain its contents during the standby mode.

Different Parts for Greater Design Flexibility
There are three initial members of the CM3131 family. The CM3131-01 and CM3131-11 are both available in a PSOP-8 package. The primary difference between these two parts is in the power sequencing control logic, allowing system designers greater flexibility in their system implementations. The CM3131-11 is optimized for applications where the main input power rail is automatically powered down during the transition to “suspend to RAM" sleep mode. The CM3131-11 autosenses this transition, switching from the main VDDQ linear controller to the standby LDO and also driving the output of the VTT regulator to 0.0V without the need for any additional control logic, simplifying the design and further reducing cost. For systems where the main power rail doesn’t necessarily shut down during system sleep modes, the CM3131-01 provides a select pin to explicitly control this transition. The third member of the family, the CM3131-02, provides both power sequencing options in a PSOP-14 package, and is designed to drive two external unmatched N-FETs for improved thermal characteristics in high-current designs.

Key Features and Benefits
Features of the CM3131 family of all-linear voltage regulators include:

Pricing and Availability
The CM3131-01 and CM3131-11 are currently sampling along with evaluation boards. The CM3131-02 will be sampling in January 2004. The CM3131-01 and CM3131-11 are priced at $0.73 each and the CM3131-02 is priced at $0.82 each in 10,000 unit quantities. Volume production is scheduled for Q1 CY2004.

About California Micro Devices Corporation
California Micro Devices Corporation is a leading supplier of application specific analog semiconductor products for the mobile, computing, and consumer electronics markets. Key products include Application Specific Integrated PassiveTM (ASIPTM) devices and power management ICs. Detailed corporate and product information may be accessed at

ASIPTM and Application Specific Integrated PassiveTM are trademarks of California Micro Devices.

Previous Page | News by Category | News Search

If you found this page useful, bookmark and share it on: