max5957letnt Maxim Integrated Products, Inc., max5957letnt Datasheet - Page 12

• Manufacturer Part Number: max5957letnt
• Description: Triple Pci Express, Hot-plug Controllers
• Manufacturer: Maxim Integrated Products, Inc.

Triple PCI Express, Hot-Plug Controllers
12
23, 48, 49
24, 46
______________________________________________________________________________________
PIN
22
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
PRES-DETB
PRES-DETA
3.3VAUXIN
3.3AUXOC
OUTPUT3
AUXONA
PORADJ
INPUT3
NAME
12SA+
PGND
12VIN
FONB
FONA
12SA-
12GA
GND
ONA
N.C.
TIM
Slot C 3.3V Auxiliary Power-Supply Output
3.3V Auxiliary Supply Input. 3.3VAUXIN is the input to a charge pump that drives the internal
MOSFETs connecting 3.3VAUXIN to 3.3AUXO_. V
logic and analog references of the MAX5957/MAX5958 and must always be connected to a supply
between 3V and 3.6V. Bypass 3.3AUXIN with a 0.1µF capacitor to GND.
Power Ground. Connect externally to GND.
Overcurrent Timeout Programming Input. Connect a resistor between 500Ω and 500kΩ from TIM to
GND to program t
Power-On-Reset Programming Input. Connect a resistor between 500Ω and 500kΩ from PORADJ to
GND to program the POR timing. Leave unconnected for a default value of 160ms. Connect
PORADJ to GND to completely skip the POR time delay for PWGD_. Connect PORADJ to GND to
completely skip the POR time delay for PWRGD_ assertion.
Ground
12V Supply Input. V
internal charge pump that drives the gates of the MOSFETs connected to 12G_. Bypass 12VIN with
a 1µF capacitor to GND.
No Connection. Not internally connected.
Slot B Present-Detect Input. PRES-DETB accepts inputs from PRSNT#_# on a PCIe connector.
PRES-DETB has an internal 50kΩ pullup to 3.3VAUXIN. When PRES-DETB is low, the outputs follow
the command from ONB and AUXONB after a 4ms debounced time. When PRES-DETB goes from
low to high, all outputs of the respective slot shut down with no delay.
Slot B Forced-On Input. FONB has a 50kΩ internal pullup to 3.3VAUXIN. A logic-low on FONB turns
on all slot B outputs as long as the power inputs are within their operating range, regardless of the
status of the other input signals. Leave FONB unconnected for normal operation.
Slot A Present-Detect Input. PRES-DETA accepts inputs from PRSNT#_# on a PCIe connector.
PRES-DETA has an internal 50kΩ pullup to 3.3VAUXIN. When PRES-DETA is low, the outputs follow
the command from ONA and AUXONA after a 4ms debounced time. When PRES-DETA goes from
low to high, all outputs of the respective slot shut down with no delay.
Slot A Forced-On Input. FONA has a 50kΩ internal pullup to 3.3VAUXIN. A logic-low on FONA turns
on all slot A outputs as long as the power inputs are within their operating range, regardless of the
status of the other input signals. Leave FONA unconnected for normal operation.
Digital Output 3. 4ms debounced digital output of INPUT3.
Digital Logic Gate Input 3
Slot A 12V and 3.3V Outputs Enable. A logic-high at ONA turns on the 12V and 3.3V outputs of slot
A (see Table 2).
Slot A 3.3V Auxiliary Output Enable. A logic-high at AUXONA turns on the slot A auxiliary output.
Slot A 12V Positive Current-Sense Input. Connect the positive terminal of the current-sense resistor
to 12SA+ using the Kelvin-sensing technique to ensure accurate current sensing.
Slot A 12V Negative Current-Sense Input. Connect 12SA- to the negative side of the current-sense
resistor using the Kelvin-sensing technique to ensure accurate current sensing.
Slot A 12V Gate-Drive Output. Connect 12GA to the gate of slot A’s 12V MOSFET. At power-up,
V
12GA
is raised to the internal charge-pump voltage level by a constant current.
FAULT
12VIN
. Leave TIM unconnected for a default timeout of 11ms.
drives the gates of the MOSFETs connected to 3.3G_. 12VIN powers an
FUNCTION
3.3AUXIN
Pin Description (continued)
is also used to power the internal control