MIC2588/MIC2594
Micrel
Pin Description
Pin Number
1
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Pin Name
PWRGD
/PWRGD
MIC25XX-1
PWRGD
Active-High
MIC25XX-2
/PWRGD
Active-Low
OV
Threshold
ON
Turn-On Threshold
UV
Threshold
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Pin Function
Power-Good Output: Open-drain. Asserted when the voltage on the DRAIN
pin (V
DRAIN
) is within V
PGTH
of VEE, indicating that the output voltage is
within proper specifications.
MIC2588-1 and MIC2594-1: PWRGD will be high-impedance when
V
DRAIN
is less than V
PGTH
, and will pull-down to V
DRAIN
when V
DRAIN
is
greater than V
PGTH
. Asserted State: Open-Drain.
MIC2588-2 and MIC2594-2: /PWRGD will pull-down to V
DRAIN
when
V
DRAIN
is less than V
PGTH,
and will be high impedance when V
DRAIN
is
greater than V
PGTH
. Asserted State: Active-Low.
MIC2588: Overvoltage Threshold Input. When the voltage at the OV pin is
greater than the V
OVH
threshold, the GATE pin is immediately pulled low by an
internal 100µA current pull-down.
MIC2594: Turn-On Threshold. At initial system power-up or after the device
has been shut off by the OFF pin, the voltage on the ON pin must exceed
the V
ONH
threshold in order for the MIC2594 to be enabled.
MIC2588: Undervoltage Threshold Input. When the voltage at the UV pin is
less than the V
UVL
threshold, the GATE pin is immediately pulled low by an
internal 100µA current pull-down. The UV pin is also used to cycle the device
off and on to reset the circuit breaker. Taken together, the OV and UV pins
form a window comparator which defines the limits of V
EE
within which the
load may safely be powered.
MIC2594: Turn-Off Threshold. When the voltage at the OFF pin is less than
the V
OFFL
threshold, the GATE pin is immediately pulled low by an internal
100µA current pull-down. The OFF pin is also used to cycle the device off and
on to reset the circuit breaker. Taken together, the ON and OFF pins provide
programmable hysteresis for the turn-on command voltage.
Negative Supply Voltage Input.
Circuit Breaker Sense Input: The current-limit threshold is set by connecting
a resistor between this pin and V
EE
. When the current-limit threshold of
IR = 50mV is exceeded for an internal delay t
FLT
(400µs), the circuit breaker
is tripped and the GATE pin is immediately pulled low. Toggling UV or OV
will reset the circuit breaker. To disable the circuit breaker, externally
connect SENSE and VEE together.
Gate Drive Output: Connect to the gate of an external N-Channel MOSFET.
Drain Sense Input: Connect to the drain of an external N-Channel MOSFET.
Positive Supply Input.
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1
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1
2
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2
3
3
OFF
Turn-Off Threshold
4
5
VEE
SENSE
6
7
8
GATE
DRAIN
VDD
December 2003
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3
M9999-122303
MICREL [ MICREL SEMICONDUCTOR ]
