MIC2588/MIC2594
Micrel
MIC2588/MIC2594
Single-Channel, Negative High-Voltage Hot
Swap Power Controllers
General Description
The MIC2588 and the MIC2594 are single-channel, nega-
tive-voltage hot swap controllers designed to address the
need for safe insertion and removal of circuit boards into “live”
high-voltage system backplanes, while using very few exter-
nal components. The MIC2588 and the MIC2594 are each
available in an 8-pin SOIC package and work in conjunction
with an external N-Channel MOSFET for which the gate drive
is controlled to provide inrush current limiting and output
voltage slew-rate control. Overcurrent fault protection is also
provided for which the overcurrent threshold is program-
mable. During an output overload condition, a constant-
current regulation loop is engaged to ensure that the system
power supply maintains regulation. If a fault condition ex-
ceeds a built-in 400µs nuisance-trip delay, the MIC2588 and
the MIC2594 will latch the circuit breaker’s output off and will
remain in the off state until reset by cycling either the UV/OFF
pin or the power to the IC. A master Power-Good signal is
provided to indicate that the output voltage of the soft-start
circuit is within its valid output range. This signal can be used
to enable one or more DC-DC converter modules.
All support documentation can be found on Micrel’s web
site at www.micrel.com.
Features
• MIC2588:
Pin-for-pin functional equivalent to the
LT1640/LT1640A/LT4250
• Provides safe insertion and removal from live –48V
(nominal) backplanes
• Operates from –19V to –80V
• Electronic circuit breaker function
• Built-in 400µs “nuisance-trip” delay (t
FLT
)
• Regulated maximum output current into faults
• Programmable inrush current limiting
• Fast response to short circuit conditions (< 1µs)
• Programmable undervoltage and overvoltage lockouts
(MIC2588-xBM)
• Programmable UVLO hysteresis (MIC2594-xBM)
• Fault reporting:
Active-HIGH (-1BM) and Active-LOW
(-2BM) Power-Good signal output
Applications
• Central office switching
• –48V power distribution
• Distributed power systems
Typical Application
–48V
RETURN
(Long Pin)
–48V
RETURN
(Short Pin)
R1
698kΩ
1%
3
MIC2588-2BM
8
VDD
UV
/PWRGD
DRAIN
DC-DC Converter
IN+
OUT+
+5V
OUT
5V
RETURN
1
/ON/OFF
IN–
OUT–
R2
11.8kΩ
1%
2
OV
VEE
4
7
SENSE
5
GATE
6
R3
12.4kΩ
1%
C
FDBK
C
GATE
R4
M1
R
FDBK
0.1µF
100µF
–48V
INPUT
(Long Pin)
R
SENSE
Input Overvoltage = 71.2V
Input Undervoltage = 36.5V
(See "Functional Description" for more detail)
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
December 2003
1
M9999-122303
MICREL [ MICREL SEMICONDUCTOR ]
