Case Studies

SUMMIT MICROELECTRONICS CHOOSES TANNER TOOLS TO DESIGN ITS FIRST HOT-SWAP CONTROLLER IC SMH4044

SMH4044 Hot-Swap Controller IC

Summit Microelectronics, Inc. developed one of the world's first hot-swap Controller ICs. The SMH4044 is a fully integrated hot-swap controller that provides complete power control for add-in cards, ranging in use from basic hot-swap systems to high-availability systems. It detects proper insertion of the card and senses valid supply voltage levels at the backplane.

Utilizing external low on-resistance N-channel MOSFETs (Metal-Oxide Semiconductor Field-Effect Transistors), card power is ramped by two high-side driver outputs that are slew-rate limited at 250V/sec. The SMH4044 (see the functional block diagram in Figure 1) continuously monitors the host supplies, the add-in card supplies and the add-in card current. If the SMH4044 detects that the current is higher than the programmed value, it will shut down the MOSFETs and issue a fault status back to the host. The on-board Electrically Erasable Programmable Read-Only Memory (E2PROM) can be used as configuration memory for the card or as general purpose memory.

Figure 1

The proprietary Data Download mode provides a more direct interface to the E2PROM, simplifying access by the add-in cardÕs controller or ASIC (Application-Specific Integrated Circuit). Designing such a highly integrated mixed-signal IC requires hierarchical design tools that are not only very accurate and powerful, but also compatible with the foundry, in order to reduce the number of prototypes and shorten the time to market.

Complete Design Suite Solution

Tanner EDA was able to meet Summit Microelectronics' needs for the SMH4044 with its Tanner Tools Pro package. The package provides a seamless design flow to integrate the analog blocks with the digital blocks in a mixed-signal chip.

Figure 2

The Tanner Tools Pro package enhances the accuracy of the manual analog block layout creation by implementing parameterized cells (T-Cells). T-Cells provide the ability to create parameterized cells based on user-written C-language code. With T-Cells, a designer can create versatile source cells that consist of user-defined input parameters and layout-generating code, as well as optional fixed geometry. Once created, T-Cells can be instanced using a simple dialog to enter parameters that are used to run the layout generation code. They can also be used to place an instance into the design.

0.8u 2p/2m Chartered Semiconductor Process

The package also includes a device layout generator (DevGen), which is utilized for devices such as MOSFETs, resistors, inductors and capacitors. The DevGen features a user-friendly interface and powerful device variation capabilities, which allows mixed-signal design engineers to streamline processes when they create off-the-shelf device layouts.

Figure 3

The SMH4044 was implemented in 0.8u 2p/2m Chartered Semiconductor process and quickly found its share in the CompactPCI market.

Tanner EDA has delivered an enhanced design tool package, Tanner Tools Pro, which features all the necessary modules and meets the requirements for this kind of cutting-edge mixed-signal design. Summit Microelectronics successfully used this design package to create the worldÕs first hot-swap Controller IC, SMH4044.