ADP1046DC1-EVALZ Analog Devices, ADP1046DC1-EVALZ Datasheet - Page 22

• Manufacturer Part Number: ADP1046DC1-EVALZ
• Description: Daughter Cards & OEM Boards ADP1046 Daughter Card
• Manufacturer: Analog Devices
• Series: ADP1046r

Specifications of ADP1046DC1-EVALZ

• Rohs: yes
• Product: Daughter Cards
• Description/function: 100 kHz daughter board
• Interface Type: I2C
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Operating Supply Voltage: 3.3 V
• Factory Pack Quantity: 1
• For Use With: ADP1046

ORFET CONTROL (GATE)
The GATE control signal drives an external OrFET. The OrFET
is used in redundant systems to protect against power flow into
the power supply from another supply’s output terminals. This
ensures that power flows only out of the power supply and that
the unit can be hot-swapped.
The GATE pin is a totem-pole output and does not require a
pull-up resistor. The GATE pin polarity can be programmed via
Register 0x2D[1] to be active high or active low. The GATE out-
put is CMOS level (0 V to 3.3 V). An external driver is required
to turn the OrFET on or off.
OrFET Turn-On
The turn-on process for the OrFET is controlled by the voltage
difference between VS1 and VS2. For this reason, the VS1 and
VS2 readings must be correctly calibrated for the OrFET func-
tion to perform properly.
The OrFET turn-on circuit detects the voltage difference between
VS1 and VS2 (see Figure 25). When the forward voltage drop from
VS1 to VS2 is greater than the programmable OrFET enable
threshold set in Register 0x30[6:5], the OrFET is enabled. The
OrFET enable threshold can be set to 0%, −0.5%, −1%, or −2%
of the nominal output voltage.
OrFET Turn-Off
The OrFET can be turned off by three methods:
•
ADP1046
Fault flag. Any flag in a fault configuration register
(Register 0x08 to Register 0x0D) can be programmed with
an action to turn off the OrFET. The OrFET is kept off for
as long as the flag is set.
CS2–
R
SENSE
CS2+
1kΩ
COMPARATOR
FAST OrFET
FAST OrFET
THRESHOLD
Figure 25. OrFET Control Circuit Internal Detailed Diagram
11kΩ
VS1
VS2
FAST OrFET
ENABLE THRESHOLD
DEBOUNCE
OrFET
Rev. B | Page 22 of 92
FAST OrFET
BYPASS
DEBOUNCE
FLAGS
•
•
OrFET GATE Control and Regulation Points
The GATE signal is enabled when the threshold configured
in Register 0x30[6:5]) is met. The GATE signal controls a very
important function of output voltage regulation: the control
loop sensing point.
•
•
Recommended Setup for a 12 V Application
In normal operating mode, follow this procedure:
•
•
In light load mode, follow this procedure:
•
•
In a 12 V application, when an internal short circuit occurs, use
CS1 OCP or VS1 UVP to shut down the unit and restart it.
OrFET programmable comparator. If the reverse voltage
present on CS2± exceeds the analog comparator threshold
programmed in Register 0x30[4:2], the OrFET is turned off.
This comparator can be disabled using Register 0x30[0].
GATE signal disable. When Register 0x5D[0] = 1, the
GATE signal is disabled and has no effect on the VSx
feedback point.
When the GATE signal is disabled, the OrFET is turned off
and the voltage regulation sensing point is VS1.
When the GATE signal is enabled, the OrFET is turned on
and the voltage regulation sensing point is VS3±.
When 12 V < V
circuit to turn off the OrFET.
When V
When 12 V < V
OrFET.
When V
ENABLE
OrFET
OUT
OUT
S
R
DISABLE
OrFET
> OVP, use load OVP to turn off the OrFET.
> OVP, use load OVP to turn off the OrFET.
Q
OUT
OUT
DISABLE
GATE
< OVP, use the fast OrFET control
< OVP, use ACSNS to turn off the
GATE
DRIVER
12V
11kΩ
1kΩ
V
OUT
Data Sheet