MIC2587-1BM TR Micrel Inc, MIC2587-1BM TR Datasheet - Page 11

• Manufacturer Part Number: MIC2587-1BM TR
• Description: IC CTRLR HOT SWAP POS HV 8-SOIC
• Manufacturer: Micrel Inc
• Type: Hot-Swap Controllerr

Specifications of MIC2587-1BM TR

• Applications: General Purpose
• Internal Switch(s): No
• Voltage - Supply: 10 V ~ 80 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: MIC2587-1BMTR; MIC2587-1BMTR

V
Capacitor C
the voltage across C
threshold, at which time another start cycle is initiated. This
will continue until either of the following occurs: a) the fault
condition is removed, b) the input supply voltage power is
removed/recycled, or c) the ON pin is toggled LOW then
HIGH. The duty cycle of the auto-restart function is
therefore fixed at 5% and the period of the auto-restart
cycle is given by:
The auto-restart period for the example above where the
worse-case C
Input Undervoltage Lockout
The MIC2587/MIC2587R have an internal undervoltage
lockout circuit that inhibits operation of the controller’s
internal circuitry unless the power supply voltage is stable
and within an acceptable tolerance. If the supply voltage to
the controller, with respect to ground is greater than the
V
internal circuits are enabled and the controller is then ready
for normal operation pending the state of the ON pin
voltage. Once in steady-state operation, the controller’s
internal circuits remain active so long as the supply voltage
with respect to ground is higher than the controller’s
internal V
Micrel
October 2004
TIMERH
UVH
t
t
t
t
AUTO-RESTART
AUTO
AUTO
AUTO
threshold voltage (8V typical), then the controller’s
threshold, and if exceeded, trip the circuit breaker.
−
-
-
RESTART
RESTART
UVL
RESTARt
TIMER
threshold voltage (7.5V typical).
TIMER
=
=
=
= 825ms
will then be discharged by I
20
20
C
was calculated to be 3.3µF is:
TIMER
×
×
t
(
FLT_AUTO
C
TIMER
×
TIMER
⎛
⎜ ⎜
⎝
250
) (
×
ms
µ
I
drops below the V
V
TIMERUP
F
TIMERH
⎞
⎟ ⎟
⎠
−
V
TIMERL
)
TIMERDN
(7)
TIMERL
until
11
Power-is-Good Output Signals
For the MIC2587-1 and MIC2587R-1, the power-good
output signal (PWRGD) will be high impedance when the
FB pin voltage is higher than the V
pull down to GND when the FB pin voltage is lower than
the V
the power-good output signal (/PWRGD) will pull down to
GND when the FB pin voltage is higher than the V
threshold and will be high impedance when the FB pin
voltage is lower than the V
parts have an active-HIGH PWRGD signal and the (-2)
parts have an active-LOW /PWRGD output. PWRGD (or
/PWRGD) may be used as an enable signal for one or
more following DC/DC converter modules or for other
system uses as desired. When used as an enable signal,
the time necessary for the PWRGD (or /PWRGD) signal to
pull-up (when in high impedance state) will depend upon
the (RC) load at the Power-is-Good pin.
The Power-is-Good output pin is connected to an open-
drain, N-channel transistor implemented with high-voltage
structures. These transistors are capable of operating with
pull-up resistors to supply voltages as high as 100V.
FBL
threshold. For the MIC2587-2 and MIC2587R-2,
FBL
threshold. Hence, the (-1)
FBH
MIC2587/MIC2587R
threshold and will
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M9999-102204
FBH