ADP1043A Analog Devices, ADP1043A Datasheet - Page 16

• Manufacturer Part Number: ADP1043A
• Description: Digital Controller for Isolated Power Supply Applications
• Manufacturer: Analog Devices

ADP1043A
Accurate OrFET control also uses the reverse voltage across the
CS2+ and CS2− pins to disable the OrFET (see Figure 16). If the
voltage difference between CS2+ and CS2− is greater than 0 mV,
the OrFET is disabled. The accurate OrFET circuit is more accu-
rate, but it is slower than the fast OrFET circuit.
The OrFET turn-on circuit looks at the voltage difference
between VS1 and VS2 (see Figure 16). When the forward
voltage drop from VS1 to VS2 is greater than the program-
mable OrFET enable threshold (Register 0x30[5:4]), the
OrFET is enabled. The OrFET enable threshold can be set to
−0.5%, 0%, 1%, or 2% of the nominal output voltage (12 V).
100µA
CS2–
10kΩ
R
SENSE
Figure 16. OrFET Control Circuit Internal Detailed Diagram
10kΩ
DIFFERENTIAL
DIFFERENTIAL
CS2+
TO SINGLE-
TO SINGLE-
100µA
ENDED
ENDED
REG 0x30[3:2]
THRESHOLD
FAST OrFET
COMPARATOR
FAST OrFET
CS2 ADC
11kΩ
VS1
1kΩ
Rev. 0 | Page 16 of 72
REG 0x18[15:4]
CS2 VALUE
REGISTER
VS2
FAST OrFET
REG 0x30[1]
DEBOUNCE
OrFET ENABLE
ACCURATE OrFET
REG 0x30[5:4]
THRESHOLD
REG 0x30[7:6]
THRESHOLD
Recommended Setup
In a 12 V application, while in normal operating mode
•
•
In a 12 V application, while in light load mode
•
•
In a 12 V application, when an internal short circuit occurs,
follow this procedure:
1.
2.
When 12 V < V
circuit to turn off the OrFET.
When V
When 12 V < V
OrFET.
When V
Use fast OrFET to turn off the OrFET.
Use CS1 OCP or VS1 UVP to shut down the unit and
restart it.
FAST OrFET
REG 0x30[0]
BYPASS
ACCURATE
DISABLE
ENABLE
OrFET
OrFET
FLAG
OUT
OUT
> OVP, use load OVP to turn off the OrFET.
> OVP, use load OVP to turn off the OrFET.
S
R
OUT
OUT
FLAGS
DISABLE
< OVP, use the accurate OrFET control
< OVP, use ACSNS to turn off the
OrFET
Q
DRIVER
GATE
12V
V
11kΩ
1kΩ
OUT