MINT2270 Series Signal Application Note AN-140

MINT2270 Series Signal Application Note
AN-140
The signals provided in CON3 and CON4 allow the system designer to monitor and
control the output of the MINT2270.
CON4 – Fan Output
CON4 provides a convenient connection to the main 24 V output to support a
system cooling fan. These connections are tied directly to the 24 V output. The fan will
operate when the main output is enabled. Care must be taken not to short this output since
the main output will also be effected.
CON3 – Standby Power and Signals
CON3 provides output status and control signals and a convenient Standby +5 V
power source.
1. 5V Standby – The +5 V power supply is always available when AC input is active.
This output provides 5 V +/- 5% @ 200mA. The standby return is tied to the Main output
Return.
2. PS-ON – Logic level control of the main 24 V output is provided via PS-ON. When
the PS-ON level is 0~2.5 V, the 24 V output is disabled. When the PS-ON level is
2.5~5.25 V, 24 V output is enabled. (Ref. figure 1, table 1)
PS-ON level
0~2.5 V
2.5~5.25 V
24V output
OFF
ON
Table 1. PS-ON logic
Figure 1. PS-ON Circuit
Note: PS-ON can be tied directly to the 5 V
standby for ‘Always On’ applications or
connected by a switch for easy control of
the output.
3. AC-OK – The AC-OK signal will be high when a normal sinusoidal AC input
exceeds 68 Vac. The output is driven by the 5 V standby and includes a 20 kΩ pull-down.
Care should be taken not to short this output to Return and the input should not be pulled
above the 5V standby output. (Ref. figure 2, figure 3, figure4, table 2)
AC Input level
0~68 V
68V~264 V
AC-OK level
Lo 0 V
Hi 4.25~5 V
Table 2. AC-OK logic
AC-OK will delay 60ms after the turnoff AC input.
Figure 2. AC-OK Circuit
Figure 3. Typical AC turn-on with full load @ 120 V
Channel 1: AC input, channel 2: AC-OK
Figure 4. Typical AC turn-off with full load @ 120 V
Channel 1: AC input, channel 2: AC-OK
3. DC-OK – The DC-OK signal provides a logic level high signal when the main 24 V
output is normal range. The signal is driven by the 5 V Standby output and has a source
impedance of 10 kΩ. The output should typically be buffered in the system interface.
(Ref. figure5, figure6, table 3)
24Voutput level
22.8~25.2 V
Out of 22.8~25.2 V
Figure 5. DC-OK circuit
DC-OK level
Hi 4.25~5.25 V
Lo 0 V
Table 3. DC-OK logic
Figure 6. Typical DC output with full load @ 120 V Figure 7. Typical output with full load @ 120 V
Channel 1-PS-ON signal, channel 2-24 V output
Channel 1-5 V standby output,
Channel 3- DC-OK signal.
Channel 2-24 V output.
4. 5V Standby power and 24V output ramp up sequence
PS-ON can be tied directly to the 5 V standby for ‘Always On’ applications or connected
by a switch for easy control of the output. The 5V standby comes up before the main 24
V output. (Ref. figure7,)
5. Timing sequence overall (Ref. figure8, figure 9, figure 10, table 4)
\
Figure 8. Typical turn on and turn off timing sequence
Ref
T1
Typical
25ms
T2
240ms
T3
10ms
T4
58ms
Description
AC input until 5 V
standby turn on
PS-ON until main
output turn on
PS-ON until main
output turn off
AC input until 5 V
standby turn off
Table 4. Typical timing sequence with
full load @ 120 V
Figure 9. typical turn on overall sequence with full
load @ 120 V, PS-ON tied directly to 5Vstandby.
Channel 1 AC input, channel 2 AC-OK signal,
channel 3 PS-ON signal , channel 4 DC-OK signal
Figure 10. typical turn off overall sequence with full
load @ 120 V, PS-ON tied directly to 5Vstandby
Channel 1 AC input, channel 2 AC-OK signal,
channel 3 PS-ON signal, channel 4 DC-OK
signaChannel 1 AC input , channel 2 PS-ON signal ,
6, Additional notice-Ac input drop to 40% of normal input, 5 cycle dropout of
main output with 6A load (Ref. figure 11)
Figure 11. 5 cycle dropout of main output
@ 40% normal input dip with half load
Channel 1 AC input, Channel 2 5V standby, Channel
3 24V output