168.0 158.4 146.3 134.2 125.7 120.7 112.7 104.9 98.0 94.1 88.6 83.8 79.9 78.9 68.3 63.0 59.8 58.5 55.9 54 .1
Case Grounding The copper case serves not only as a heat sink but also as a EMI shield. The 0.25 inch thick case provides >30 dB of absorption loss to both electric and magnetic fields at 220 kHz, while at the same time providing 20 t0 40 % better heat sin king over competitive thin steel, alu minu m or plastic desig ns. The case shield is tied to the output CMN pin. This connection is shown on the block diagram. The case is floating from the input sections. The input is coupled to the outputs only by the low 500 pF of isolation capacitance. This low I/O capacitance insures that anyAC common mode noise on the inputs is not coupled to your output circuits. Compare this isolation to the more usual 1000 - 2000 pF found on competitive designs and you will see that CALEX provides the very best DC and AC isolation available. After all, you are buying an isolated DC/DC to cut ground loops. Don't let the isolation capacitance add them back in.
The channel filter section is a seven-pole 0.05 degree error, equal ripple filter. It utilizes the Kost pulse slimming tech- nique similar to that which is employed on the DP8491/92 integrated read channel devices. The amount of pulse slim- ming is control register selectable in 8 steps up to a maxi- mum of 9 dB measured from the base frequency. The band- width of the filter is derived from the XTLIN frequency; from this point, the - 3 dB frequency is selectable via 7 bits in the control register (FILT_3 dB_O-FILT_3 dB_6).
| PARAMETER | SYMBOL | TEST CONDITIONS | MIN | TYP | MAX | UNITS |
| Source to Drain Diode Voltage | VSD | ISD= 45A | | | 1.5 | V |
| Diode Reverse Recovery Time | trr | ISD = 45A, dISD/dt = 100A/as | | | 125 | ns |
| | | | | | |
