ML6554CU datasheet(5/14 Pages) MICRO-LINEAR

5 / 14 page

ML6554

NOVEMBER, 1999

HEAT SLUG

Figure 2. Cutaway view of PSOP Package

APPLICATIONS

USING THE ML6554 FOR SSTL BUS TERMINATION

The circuit schematic in Figure 1 shows a recommended

approach for an constructing a bus terminating solution for

an SSTL-2 bus. This circuit can be used in PC memory and

Graphics memory applications as shown in Figures 3 and

4. Note that the ML6554 can provide the voltage

reference (VREF) and terminating voltages (VTT). Using

the layout as shown in Figures 5, 6, and 7, and measuring

the VTT performance using the test setup as described in

Figure 8, the ML6554 delivered a VTT ± 20mV for 1A to

3A loads (see Figure 9). Table 1 provides a recommended

parts list. For more recent Applications Notes or

Evaluation Boards contact Micro Linear.

POWER HANDLING CAPABILITY OF THE PSOP PACKAGE

Using the board layout shown in Figures 5,6, and 7;

soldering the ML6554 to the board at zero LFPM the

temperature around the package measured 55

ºC for 3A

loads. Note that a 1ounce copper plane was used in the

board construction.

Airflow is not likely to be needed in the operation of this

device (assuming a board layout similar to that described

above). The power handling performance of the PSOP

package is shown by a study of the package manufacturer

for various airflow vs.

qJA conditions in Figure 10.

BUS TERMINATION SOLUTIONS FOR OTHER BUSES

Table 2 provides a summary of various bus termination

VREF & VTT requirements. The ML6554 can be used for

those applications.

ML6554CU Datasheet(PDF) 5 Page - Micro Linear Corporation