max5945caxt Maxim Integrated Products, Inc., max5945caxt Datasheet - Page 34

• Manufacturer Part Number: max5945caxt
• Description: Max5945 Quad Network Power Controller For Power-over-lan
• Manufacturer: Maxim Integrated Products, Inc.

Use the program registers (Table 29) to set the nominal
value for t
the following formula:
where N is the decimal value of TF_PR[3:0] or
TS_PR[3:0], respectively.
A reset sets R28h = 77h, which sets t
60ms as shown in the Electrical Characteristics. Use
R28h in conjunction with the two TSTART and TFAULT
bits in register R16h to program the values of t
and t
2.72ms resolution.
Quad Network Power Controller
for Power-Over-LAN
Table 29. Program Register 3
34
SYMBOL
TF_PR
TS_PR
______________________________________________________________________________________
START
t
t
ADDRESS = 28h
FAULT
START
FAULT
from about 20ms to almost 330ms with a
BIT
7
6
5
4
3
2
1
0
nominal = 40.96ms + 2.72ms x N
nominal = 40.96ms + 2.72ms x N
and t
START
R/W
R
R
R
R
R
R
R
R
for all ports according to
TF_PR[3]. t
TF_PR[2]. t
TF_PR[1]. t
TF_PR[0]. t
TS_PR[3]. t
TS_PR[2]. t
TS_PR[1]. t
TS_PR[0]. t
FAULT
FAULT
FAULT
FAULT
FAULT
START
START
START
START
= t
nominal programming bit 3.
nominal programming bit 2.
nominal programming bit 1.
nominal programming bit 0.
nominal programming bit 3.
nominal programming bit 2.
nominal programming bit 1.
nominal programming bit 0.
START
FAULT
=
Example: Set TF_PR[3:0] = 1111b, TFAULT[1:0] = 11b
Then:
Note: The programmed value has the same percent-
age tolerance as the value specified in the Electrical
Characteristics.
DESCRIPTION
t
FAULT
= 4 x t
= 4 x (40.96ms + 2.72ms x 15)
= 327ms
FAULT
nominal