DP8105 datasheet(28/35 Pages) POWER-ONE

28 / 35 page

DP8105 5A DC-DC Intelligent dPOL Data Sheet

8V to 14V Input •••• 0.7V to 5.5V Output

BCD.00261 Rev. 1.0, 12 Feb 2013

www.power-one.com

Page 28 of 35

7.9

Monitoring

Along with status information, dPOL converters can

monitor their own performance parameters such as

output voltage, output current, and temperature.

The output voltage is measured at the output sense

pins, output current is measured using the ESR of

the output inductor and temperature is measured by

the thermal sensor built into the controller IC. Output

current readings are adjusted based on temperature

readings to compensate for the change of ESR of

the inductor with temperature.

A 12-Bit Analog to Digital Converter (ADC) converts

the output voltage, output current, and temperature

into a digital signal to be transmitted via the serial

interface (12Bits for the Voltage, 8 Bits for the

Current and Temperature).

Monitored parameters are stored in registers (VOM,

IOM, and TMON) that are continuously updated in

the DPM at a fixed refresh rate of 1sec. These

monitoring values can be accessed via the I

interface with high and low level commands as

described in the ‘”DPM Programming Manual”.

Figure 50 is a capture of the GUI System Monitor

while operating the ZM7300 Evaluation board.

1.2.1

In System Monitoring

In system parametric and status monitoring is

implemented

through

the

I2C

interface.

The

appropriate protocols are covered in the ZM7300

DPM Programming Manual. The GUI uses the

published commands.

In writing software for I2C bus transactions, it is

important to note that I2C responses are lower in

priority in DPM operation than SD bus transactions.

If an I2C transaction overlaps an SD bus transaction,

the DPM will put the I2C bus on "hold" until it

completes its SD activity. The GUI is aware of this

and such delays are transparent.

When directly polling dPOLs for information, setting

I2C bus timeouts too low can cause hangups where

the DPM is waiting for the I2C master to complete a

transaction and the master has timed out. To avoid

such timeout related problems, set I2C interface

timeout to greater than the time required for polling

all dPOLs, or 150ms (whichever is greater). See the

programming manual referenced above for the

equation used to calculated worst case polling

duration.

Figure 50. DPM Monitoring Window

DP8105 Arkusz danych(PDF) 28 Page - Power-One

DP8105 Arkusz danych(HTML) 28 Page - Power-One

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

Arkusz danych Pobierz

Link URL