MAX5954 Maxim Integrated Products, MAX5954 Datasheet - Page 16

• Manufacturer Part Number: MAX5954
• Description: Hot-Plug Controller
• Manufacturer: Maxim Integrated Products

When the die temperature goes above +150°C (T
overtemperature fault occurs and the MAX5954 shuts
down all outputs. The device waits for the junction temper-
ature to decrease below T
fault management (see the Fault Management section).
Single PCI Express, Hot-Plug
Controller
Figure 4. 12V Output Overcurrent/Short Circuit During Normal
Operation
16
Figure 2. Power-Up Timing, No Fault
3.3AUXIN
RISING
EDGE
PWRGD IS PULLED UP TO 3.3VAUXO.
FAULT IS PULLED UP TO 3.3VAUXIN.
A FAULT ON THE 3.3V OUTPUT OR 3.3VAUXO OUTPUT PRODUCES SIMILAR RESULTS.
______________________________________________________________________________________
V
V
PGTH3.3AUX
ON_,TH
V
12ILIM,TH
R
SENSE
PWRGD IS PULLED UP TO 3.3.
FAULT IS PULLED UP TO 3.3AUXIN.
V
V
PGTH12
PGTH3.3
SD
t
FAULT
- Hysteresis before entering
Thermal Shutdown
t
POR_HL
FAULT
12G
12V OUTPUT
CURRENT
PWRGD
ON, AUXON
12G, 3.3G
12VO, 3.3VO
3.3VAUXO
PWRGD
FAULT
SD
), an
A fault occurs when an overcurrent lasts longer then
t
ature condition.
•
•
The MAX5954A automatically restarts from a fault shut-
down after the t
latches off. If an overcurrent fault occurred on a main
output, bring ON low for at least t
high again to reset the fault and restart the outputs. If
the overcurrent fault occurred on an auxiliary output or
an overtemperature fault occurred, bring both ON and
AUXON low for a minimum of t
Bring ON and/or AUXON high again to restart the
respective outputs. As an extra protection, the
MAX5954L waits a minimum of t
be restarted.
INPUT accepts an input from a mechanical switch. The
corresponding output (OUTPUT) is debounced for
4.4ms. When INPUT goes from high to low, OUTPUT
goes low right away and stays low for at least 4.4ms.
After the debounce time OUTPUT follows INPUT. If INPUT
goes from low to high, OUTPUT goes high right away and
Figure 3. 12V Power-Up Timing (Turn-On into Output
Overcurrent/Short Circuit)
FAULT
3.3VAUXIN
RISING
EDGE
A fault on a main output (12V or 3.3V) shuts down
both main outputs. The 3.3V auxiliary is not affected.
A fault on the 3.3V auxiliary output shuts down all
three outputs.
V
PWRGD IS PULLED UP TO 3.3VAUXO.
FAULT IS PULLED UP TO 3.3VAUXIN.
A FAULT ON THE 3.3V OUTPUT OR 3.3VAUXO OUTPUT PRODUCES SIMILAR RESULTS.
V
12ILIM,TH
ON_,TH
or when the device experiences an overtemper-
R
SENSE
RESTART
2 x t
period, while the MAX5954L
Debounced Logic Gate
FAULT
Fault Management
RESET
(Input and Output)
RESTART
RESET
to reset the fault.
before it can
(100µs) and
ON
12G
12V OUTPUT
CURRENT
3.3VAUXO
PWRGD
FAULT