ATX12VO (12V Only) Desktop Power Supply
Design Guide
Timing, Housekeeping, and Control – REQUIRED
Figure 4-2: Power on Timing
Table 4-9: Power Supply Timing
Parameter | Description | Value | |
Required | Recommended | ||
T0 | AC power on time7 | <2s | |
T1 | Power-on time6 | <150ms1 | <100 ms |
T2 | Rise time | 0.2–20 ms | |
T3 | PWR_OK delay6 | 1ms – 150ms1 | 1–100 ms |
T4 | PWR_OK rise time | < 10 ms | |
T5 | AC loss to PWR_OK hold-up time | > 11 ms2 | > 16 ms3 |
T6 | PWR_OK inactive to DC loss delay | > 1 ms4 | > 1 ms5 |
- T1 and T3 required values are set to meet timing requirement for computers that use ALPM.
- T5 Required value to be defined for both Full/Light load condition.
- T5 Recommended value is defined for 80% of full load condition.
- T6 Required value to be defined for coming from both Full/Light load conditions.
- T6 Recommended value is defined for coming from 80% of full load condition.
- PSUs are recommended to label or indicate the timing value for system designer and integrator reference for T1 and T3. This allows system designers to optimize “turn on” time within the system.
- T0 is shown in Section 4.3.3, Figure 4-4.