参数资料
型号: SMS66
厂商: Summit Microelectronics, Inc.
英文描述: Six-Channel Power Supply Supervisor and Cacsade Sequence Controller
中文描述: 6通道电源监控和Cacsade序控制器
文件页数: 14/26页
文件大小: 1039K
代理商: SMS66
SMS66
Preliminary Information
Summit Microelectronics, Inc
2070 1.0 7/16/03
14
The HEALTHY and FAULT outputs of the SMS66 are
active as long as the triggering limit remains in a fault
condition. The RST output also remains active as long
as the triggering limit remains in a fault condition;
however, once the trigger source goes away the RST
will remain active for a reset timeout period (t
PRTO
).
POWER-OFF SEQUENCING
The SMS66 can be programmed to perform Power-off
sequencing in either the same order or reverse order
of Power-on sequencing.
Power-off sequencing is the same as power-on
sequencing and can be initiated by the PWR_ON/OFF
pin, via I
C control or triggered by a fault condition on
any of the monitored inputs. Toggling the
PWR_ON/OFF pin to its inactive state will initiate the
Power-off sequence. To enable software control of
the Power-off sequencing feature, the SMS66 offers
an I
2
C command to initiate Power-off sequencing
regardless of the state of the PWR_ON/OFF pin.
Furthermore, Power-off sequencing can be initiated by
a fault condition on a monitored input.
Once Power-off sequencing begins, the SMS66 will
wait a Power-off delay time (t
DPOFF
) for any channel in
the last sequence position (reverse order) and then
deactivate the PUP outputs for those channels. The
Power-off delay times are individually programmable
for each channel. The SMS66 will then wait until all
VM
X
inputs of the channels assigned to that sequence
position are below their programmed OFF thresholds.
At this point, the SMS66 will decrement to the next
sequence position and begin to timeout the Power-off
delay times for the associated channels. This process
continues until all of channels in the sequence have
turned off and are below their OFF thresholds. The
status register reveals that all sequenced channels
have turned off. The Power-off sequencing mode
ends when all sequenced supplies are below their
OFF thresholds.
The programmable sequence termination timer can be
used to protect against a stalled Power-off sequence.
This timer resets itself at the beginning of each
sequence position. All channels in the sequence
position must go below their OFF threshold before the
sequence termination timer times out (t
STT
) or the
sequence will terminate and all PUP outputs will be
switched to their inactive state. This timer has four
settings of OFF, 100ms, 200ms and 400ms. The
sequence termination timer can be disabled separately
for Power-off sequencing.
While the SMS66 is in the Power-off sequencing mode
the RST output is held active and the HEALTHY
output is held inactive regardless of trigger sources.
The Force Shutdown trigger option is also disabled
while in this mode. Furthermore, the SMS66 will not
respond to activity on the PWR_ON/OFF pin or to a
Power-on I
C command during Power-off sequencing
mode.
FORCE SHUTDOWN
The Force Shutdown operation brings all PUP
X
outputs to their inactive state. This operation is used
for an emergency shutdown when there is not enough
time to sequence the supplies off. The Force
Shutdown operation shuts off all sequenced channels
and waits for the supply voltages to drop below their
respective OFF thresholds.
A Force Shutdown operation can be initiated by any
one of four events. The first two methods for initiating
a Force Shutdown are always enabled. Simply taking
the FS pin to its active state will initiate a Force
Shutdown operation and maintain it until the pin is
brought to its inactive state. An I
2
C Force Shutdown
command allows the Force Shutdown operation to be
initiated via software control. This I
2
C Force Shutdown
command sets a volatile register bit that triggers a
Force Shutdown. This bit is cleared after all
sequenced channels have dropped below their OFF
voltage threshold. During Power-on and Power-off
sequencing, the sequence termination timer can
initiate a Force Shutdown operation.
As described in the previous sections, the sequence
termination timer triggers a Force Shutdown operation
if it times out before the power supply voltages
surpass their voltage thresholds. This Force
Shutdown will remain active until all sequenced power
supply channels have dropped below their OFF
voltage threshold. While the SMS66 is in monitor
mode, a programmed fault condition on any power
supply channel or on the 12VIN or VDD inputs can
trigger a Force Shutdown. A Force Shutdown
resulting from this will remain active until all
sequenced power supply channels have dropped
below their OFF voltage threshold.
APPLICATIONS INFORMATION (CONTINUED)
相关PDF资料
PDF描述
SMS66FR0C Six-Channel Power Supply Supervisor and Cacsade Sequence Controller
SMS66FR0D Six-Channel Power Supply Supervisor and Cacsade Sequence Controller
SMS66FR0E Six-Channel Power Supply Supervisor and Cacsade Sequence Controller
SMS66FR10 Six-Channel Power Supply Supervisor and Cacsade Sequence Controller
SMS66FR11 Six-Channel Power Supply Supervisor and Cacsade Sequence Controller
相关代理商/技术参数
参数描述
SMS66FR0C 制造商:SUMMIT 制造商全称:SUMMIT 功能描述:Six-Channel Power Supply Supervisor and Cacsade Sequence Controller
SMS66FR0D 制造商:SUMMIT 制造商全称:SUMMIT 功能描述:Six-Channel Power Supply Supervisor and Cacsade Sequence Controller
SMS66FR0E 制造商:SUMMIT 制造商全称:SUMMIT 功能描述:Six-Channel Power Supply Supervisor and Cacsade Sequence Controller
SMS66FR10 制造商:SUMMIT 制造商全称:SUMMIT 功能描述:Six-Channel Power Supply Supervisor and Cacsade Sequence Controller
SMS66FR11 制造商:SUMMIT 制造商全称:SUMMIT 功能描述:Six-Channel Power Supply Supervisor and Cacsade Sequence Controller