MAX5040EUB Maxim Integrated Products, MAX5040EUB Datasheet - Page 18

• Manufacturer Part Number: MAX5040EUB
• Description: Other Power Management V-Track Ctlr for PowerPC DSPs & ASICs
• Manufacturer: Maxim Integrated Products

See the application circuit examples in Figures 9 and 10.
I/O_SENSE is used to monitor the I/O output voltage or
any other voltage. The result is reported by the POK out-
put signal. Choose the I/O_SENSE trip point such that
the minimum monitored voltage at I/O_SENSE exceeds
the maximum I/O_SENSE rising threshold.
Follow the guidelines below to program the I/O_SENSE
voltage:
1) Determine the tolerance of the output voltage to be
2) Determine V
3) Set V
Voltage-Tracking Controllers for
PowerPC, DSPs, and ASICs
18
monitored, V
I/O sense trip-point threshold, V
1.230V ±2.5%
Resistor error tolerance build-up is the same as that
calculated in the Programming UVLO Voltage sec-
tion.
Total = ±6.6%.
value - (V
______________________________________________________________________________________
I/O_SENSE
O
Programming I/O_SENSE Voltage
tolerance + V
I/O_SENSE
O
: 5% is common.
rising nominal value to: V
rising threshold tolerance:
I/O_SENSE
(MAX5040 Only)
IO_REF
tolerance).
, tolerance:
O
nominal
4) Calculate using the following equation:
where R6 is typically 10kΩ.
Example: V
nominal value to 3.3V - (5% + 6.6%) = 2.9172V.
Choose R6 = 10.0kΩ, 1%:
Use the next lower 13.7kΩ standard value.
For more detailed information, go to Maxim’s website
for the Application Note, "Dual Voltage Tracking Circuit
for I/O, Microprocessor, and DSP Core Voltages." A link
in the application note has a downloadable component
selection spreadsheet for calculating component val-
ues. This spreadsheet calculates values for all passive
components in Figure 10 and lists the resulting
min/max values of V
core voltages. DIY options are included for other core
and I/O voltages.
I/O
R
R
R
5
5
5
=
=
Calculating Component Values
nominal value = 3.3V, set V
=







 

V
2 9172
1 230
I O SENSENOM
V
.
/ _
.
I O SENSENOM
/ _
V
REGNOM
I O REF
V
/ _
I O REF
V
/ _
V
−
1 10



for standard PowerPC
k
−
Ω
1 6



−
=
R
1 6
13 72

 

R
.
k
Ω
I/O_SENSE