AMIS--30532

http://onsemi.com

4

EQUIVALENT SCHEMATICS

Following figure gives the equivalent schematics of the user relevant inputs and outputs. The diagrams are simplified

representations of the circuits used.

IN

4K

IN

4K

TYPE 1: CLR input

TYPE 2: CLK , DI, CSB , NXT , DIR inputs

.

VDD

VDD

TYPE 3: VDD and VBB power supply inputs

VBB

VBB

OUT

TYPE 4: DO and ERRB open drain outputs

SLA

Rout

TYPE 5: SLA analog output

Figure 3. In-- and Output Equivalent Diagram

PACKAGE THERMAL CHARACTERISTICS

The AMIS--30532 is available in a NQFP32 package. For

cooling optimizations, the NQFP has an exposed thermal

pad which has to be soldered to the PCB ground plane. The

ground plane needs thermal vias to conduct the heat to the

bottom layer. Figure 3 gives an example for good power

distribution solutions.

For precise thermal cooling calculations the major

thermal resistances of the device are given. The thermal

media to which the power of the devices has to be given are:

The thermal resistances are presented in Table 5: DC

Parameters.

The major thermal resistances of the device are the Rth

from the junction to the ambient (Rthja) and the overall Rth

from the junction to exposed pad (Rthjp). In Table 5 below

one can find the values for the Rthja and Rthjp, simulated

according to JESD--51:

The Rthja for 2S2P is simulated conform JEDEC

JESD--51 as follows:

and outer (top and bottom) signal layers is used

The Rthja for 1S0P is simulated conform to JEDEC

JESD--51 as follows: