ADM1041-EVAL Analog Devices Inc, ADM1041-EVAL Datasheet - Page 27

• Manufacturer Part Number: ADM1041-EVAL
• Description: BOARD EVALUATION ADM1041
• Manufacturer: Analog Devices Inc

Specifications of ADM1041-EVAL

• Main Purpose: AC/DC, Secondary Side
• Outputs And Type: 1, Non-Isolated
• Power - Output: 24W
• Voltage - Output: 12V
• Current - Output: 2A
• Voltage - Input: 85 ~ 132VAC
• Board Type: Fully Populated
• Utilized Ic / Part: ADM1041
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Frequency - Switching: -
• Regulator Topology: -
• Lead Free Status / Rohs Status: Not Compliant

PULSE/AC
When configured, PULSE and AC
the power main transformer. See Figure 16.
PULSE
Providing the output of the pulse function (PULSE_OK) is
high, the FET in the ORing circuit can be turned on. If the
pulses stop for any reason, about 1 second later the PULSE_OK
goes low and the OrFET drive is disabled. This delay allows
passage of all expected pulse skipping modes that might occur
in no load or very light load situations. See Figure 16.
AC
This is rarely used to measure directly the ac input to the supply.
AC
voltage across the bulk capacitor so that the system can be
signaled that power is normal. Also if power is actually lost,
AC
shutdown of the power supply. See Figure 16.
SENSE
SENSE
SENSE
1 or AC
represents when just enough energy is left for an orderly
SENSE
SENSE
2 are usually used to indirectly measure the
2
AC
SENSE
AC
SENSE
PULSE
SENSE
monitor the output of
2
1
10
9
5.3kΩ
5.3kΩ
AC
SELECT
Figure 16. Pulse In and AC Sense Circuit
SENSE
HYSTERESIS
1.5V
Rev. A | Page 27 of 64
TRIM
0.525V
TO OrFET SOURCE
SENSE RESISTOR
AND OrFET GATE
TO CURRENT
The ac sense function monitors the amplitude of the incoming
pulse and, if sufficiently high, generates a flag to indicate ac, or
strictly speaking, the voltage on the bulk capacitor, is okay. Since
the envelope of the pulse has a considerable amount of 100 Hz
ripple, hysteresis is available on this input pin. Internally there is
a 20 µA to 80 µA current sink. With a 909R external thevenin
resistance, this current range translates to a voltage hysteresis of
200 mV to 500 mV. The internal hysteresis current is turned off
when the voltage exceeds the reference on the comparator. This
form of hysteresis allows simple scaling to be implemented by
changing the source impedance of the pulse conditioning
circuit. Some trimming of hysteresis and threshold voltage is
provided. The ac sense function can be configured to be derived
from AC
input from various locations to be used to generate AC_OK for
better flexibility or accuracy.
SENSE
R
R
CLK
CLK
1 SEC
1 mS
2 rather than AC
Q
Q
S
R
S
R
Q
Q
PULSEOK
SENSE
AC_OK
1. This allows a separate dc
ADM1041