April 2003
1
MIC2582/MIC2583
MIC2582/MIC2583
Micrel
MIC2582/MIC2583
Single Channel Hot Swap Controllers
Final
General Description
The MIC2582 and MIC2583 are single channel positive
voltage hot swap controllers designed to allow the safe
insertion of boards into live system backplanes. The MIC2582
and MIC2583 are available in 8-pin SOIC and 16-pin QSOP
packages, respectively. Using a few external components
and by controlling the gate drive of an external N-Channel
MOSFET device, the MIC2582/83 provide inrush current
limiting and output voltage slew rate control in harsh, critical
power supply environments. Additionally, a circuit breaker
function will latch the output MOSFET off if the current limit
threshold is exceeded for a determined period. The MIC2583R
option includes an auto-restart function upon detecting an
overcurrent condition.
Typical Application
SENSE
DOWNSTREAM
CONTROLLER
Power-Good Output
Power-On Reset Output
VCC
GATE
DIS
PWRGD
/POR
EN
/RESET
FB
FAULT
C2
0.01
F
C1
1
F
C
LOAD
500
F
Q1
Si7892DP
(PowerPAKTM SO-8)
V
OUT
12V@6A
V
IN
12V
V
IN
/FAULT
Signal
GND
R5
93.1k
1%
R8
47k
R1
3.3
R2
76.8k
1%
R4
47k
R3
9.76k
1%
**D1
(18V)
R6
12.4k
1%
C4
8200pF
C3
0.1
F
CPOR
CFILTER
GND
PCB EDGE
CONNECTOR
BACKPLANE
CONNECTOR
Long Pin
Short Pin
Medium
(or Short) Pin
Long Pin
MIC2583/83R
V
IN
R7
47k
R
SENSE
0.006
2%
1
2
3
4
16
15
14
13
2
1
12
5
7, 8
4
11
ON
3
*Undervoltage (Input) = 10.5V
*Undervoltage (Output) &
Power-Good (Output) = 11.0V
*START-UP Delay = 12ms
*/POR Delay = 50ms
*Circuit Breaker Response Time = 1.5ms
**D1 is BZX84C18
*(See Functional Description and Applications Information)
Figure 1. MIC2583/83R Typical Application Circuit
Features
MIC2582:
Pin-for-pin functional equivalent to the LTC1422
2.3V to 13.2V supply voltage operation
Surge voltage protection up to 20V
Current regulation limits inrush current regardless of
load capacitance
Programmable inrush current limiting
Electronic circuit breaker
Dual-level overcurrent fault sensing eliminates false
tripping
Fast response to short circuit conditions (<1
s)
Programmable output undervoltage detection
Undervoltage Lockout (UVLO) protection
Auto-restart function (MIC2583R)
Power-On Reset and Power-Good status outputs
(Power-Good for the MIC2583 and MIC2583R only)
/FAULT status output (MIC2583 and MIC2583R)
Applications
RAID systems
Base stations
PC board hot swap insertion and removal
Hot swap CompactPCI cards
Network switches
Micrel, Inc. 1849 Fortune Drive San Jose, CA 95131 USA tel + 1 (408) 944-0800 fax + 1 (408) 944-0970 http://www.micrel.com
April 2003
3
MIC2582/MIC2583
MIC2582/MIC2583
Micrel
Pin Description
Pin Name
8-pin SOIC
16-pin QSOP
Pin Function
/POR
1
1
Power-On Reset Output: Open drain N-channel device, Active Low. This pin
remains asserted during start-up until a time period (t
POR
) after the FB pin
voltage rises above the power-good threshold (V
FB
). The timing capacitor
C
POR
determines t
POR
. When the output voltage monitored at the FB pin
falls below V
FB
, /POR is asserted for a minimum of one timing cycle (t
POR
).
The /POR pin requires a pull-up resistor (10k
minimum) to VCC.
ON
2
3
ON Input: Active High. The ON pin, an input to a Schmitt-triggered compara-
tor used to enable/disable the controller, is compared to a 1.24V reference
with 50mV of hysteresis. When a logic high is applied to the ON pin
(V
ON
> 1.24V), a start-up sequence begins when the GATE pin starts
ramping up towards its final operating voltage. When the ON pin receives a
logic low signal (V
ON
< 1.19V), the GATE pin is grounded and /FAULT
remains high if VCC is above the UVLO threshold. ON must be low for 20
s
in order to initiate a start-up sequence. Additionally, toggling the ON pin
LOW to HIGH resets the circuit breaker.
CPOR
3
4
Power-On Reset Timer: A capacitor connected between this pin and ground
sets the supply contact start-up delay (t
START
) and the power-on reset
interval (t
POR
). When VCC rises above the UVLO threshold, the capacitor
connected to CPOR begins to charge. When the voltage at CPOR crosses
0.3V, the start-up threshold (V
START
), a start cycle is initiated if ON is
asserted while capacitor C
POR
is immediately discharged to ground. When
the voltage at FB rises above V
FB
, capacitor CPOR begins to charge again.
When the voltage at CPOR rises above the power-on reset delay threshold
(V
TH
), the timer resets by pulling CPOR to ground, and /POR is de-asserted.
If C
POR
= 0, then t
START
defaults to 20
s.
GND
4
7,8
Ground connection: Tie to analog ground.
FB
5
12
Power-Good Threshold Input (Undervoltage Detect): This input is internally
compared to a 1.24V reference with 30mV of hysteresis. An external
resistive divider may be used to set the voltage at this pin. If this input
momentarily goes below 1.24V, then /POR is activated for one timing cycle,
t
POR
, indicating an output undervoltage condition. The /POR signal de-
asserts one timing cycle after the FB pin exceeds the power-good threshold
by 30mV. A 5
s filter on this pin prevents glitches from inadvertently
activating this signal.
GATE
6
14
Gate Drive Output: Connects to the gate of an external N-channel MOSFET.
An internal clamp ensures that no more than 9V is applied between the
GATE pin and the source of the external MOSFET. The GATE pin is
immediately brought low when either the circuit breaker trips or an
undervoltage lockout condition occurs.
SENSE
7
15
Circuit Breaker Sense Input: A resistor between this pin and VCC sets the
current limit threshold. Whenever the voltage across the sense resistor
exceeds the slow trip current limit threshold (V
TRIPSLOW
), the GATE voltage
is adjusted to ensure a constant load current. If V
TRIPSLOW
(50mV) is
exceeded for longer than time period t
OCSLOW
, then the circuit breaker is
tripped and the GATE pin is immediately pulled low. If the voltage across the
sense resistor exceeds the fast trip circuit breaker threshold, V
TRIPFAST
, at
any point due to fast, high amplitude power supply faults, then the GATE pin
is immediately brought low without delay. To disable the circuit breaker, the
SENSE and VCC pins can be tied together.
The default V
TRIPFAST
for either device is 100mV. Other fast trip thresholds
are available: 150mV, 200mV, or OFF (V
TRIPFAST
disabled). Please contact
factory for availability of other options.
VCC
8
16
Positive Supply Input: 2.3V to 13.2V. The GATE pin is held low by an
internal undervoltage lockout circuit until VCC exceeds a threshold of 2.2V. If
VCC exceeds 13.2V, an internal shunt regulator protects the chip from
transient voltages up to 20V at the VCC and SENSE pins.
MIC2582/MIC2583
Micrel
MIC2582/MIC2583
4
April 2003
Pin Name
8-pin SOIC
16-pin QSOP
Pin Function
PWRGD
N/A
2
Power-Good Output: Open drain N-channel device, Active High. When the
voltage at the FB pin is lower than 1.24V, PWRGD output is held low. When
the voltage at the FB pin exceeds 1.24V, then PWRGD is asserted immediately.
The PWRGD pin requires a pull-up resistor (10k
minimum) to VCC.
CFILTER
N/A
5
Current Limit Response Timer: A capacitor connected to this pin defines the
period of time (t
OCSLOW
) in which an overcurrent event must last to signal a
fault condition and trip the circuit breaker. If no capacitor is connected, then
t
OCSLOW
defaults to 5
s.
/FAULT
N/A
11
Circuit Breaker Fault Status Output: Open drain N-channel device, Active
Low. The /FAULT pin is asserted when the circuit breaker trips due to an
overcurrent condition or when an undervoltage lockout condition exists. The
/FAULT pin requires a pull-up resistor (10k
minimum) to VCC.
DIS
N/A
13
Discharge Output: When the MIC2583/83R is turned off, a 500
internal
resistor at this output allows the discharging of any load capacitance to ground.
NC
N/A
6,9,10
No internal connection.
April 2003
5
MIC2582/MIC2583
MIC2582/MIC2583
Micrel
Absolute Maximum Ratings
(Note 1)
All voltages are referred to GND
Supply Voltage (V
CC
) .................................... 0.3V to 20V
/POR, /FAULT, PWRGD pins ....................... 0.3V to 15V
SENSE pin ........................................... 0.3V to V
CC
+0.3V
ON pin .................................................. 0.3V to V
CC
+0.3V
GATE pin ...................................................... 0.3V to 20V
FB input pins ................................................... 0.3V to 6V
Junction Temperature .............................................. 125
C
ESD Rating ........................................................................
Human body model ............................................... 2kV
Machine model .................................................... 100V
Operating Ratings
(Note 2)
Supply Voltage (V
CC
) ................................... 2.3V to 13.2V
Thermal Resistance (R
(J-A)
)
8-pin SOIC ........................................................ 163
C/W
16-pin QSOP .................................................... 112
C/W
Operating Temperature Range ................. 40
C to +85
C
Electrical Characteristics
(Note 3)
V
CC
= 5.0V, T
A
= 25
C unless otherwise noted. Bold values indicate 40
C
T
A
+85
C.
Symbol
Parameter
Condition
Min
Typ
Max
Units
V
CC
Supply Voltage
2.3
13.2
V
I
CC
Supply Current
V
ON
= 2V
1.5
2.5
mA
V
TRIP
Circuit Breaker Trip Voltage
V
TRIP
= V
CC
V
SENSE
V
TRIPSLOW
42
50
59
mV
(Current Limit Threshold)
V
TRIPFAST
(MIC2582)
100
mV
V
TRIPFAST
x = J
85
100
110
mV
(MIC2583/83R) x = K
130
150
170
mV
x = L
175
200
225
mV
V
GS
External Gate Drive
V
GATE
V
CC
V
CC
> 3V
7
8
9
V
V
CC
= 2.3V
3.5
4.8
6.5
V
I
GATE
GATE Pin Pull-Up Current
Start Cycle, V
GATE
= 0V, V
CC
=13.2V
30
17
8
A
V
CC
= 2.3V
26
17
8
A
I
GATEOFF
GATE Pin Sink Current
V
GATE
>1V
V
CC
= 13.2V, Note 4
100
mA
V
CC
= 2.3V, Note 4
50
mA
/FAULT = 0
(MIC2583/83R only)
Turn off
110
A
I
TIMER
Current Limit/Overcurrent Timer
V
CC
V
SENSE
> V
TRIPSLOW
(timer on)
8.5
6.5
4.5
A
(CFILTER) Current
V
CC
V
SENSE
< V
TRIPSLOW
(timer off)
4.5
6.5
8.5
A
I
CPOR
Power-On-Reset Timer Current
timer on
3.5
2.5
1.5
A
timer off
0.5
1.3
mA
V
TH
POR Delay and Overcurrent
V
CPOR
rising
Timer (CFILTER) Threshold
V
CFILTER
rising (MIC2583/83R only)
1.19
1.245
1.30
V
V
UV
Undervoltage Lockout Threshold
V
CC
rising
2.1
2.2
2.3
V
V
CC
falling
1.90
2.05
2.20
V
V
UVHYS
Undervoltage Lockout Hysteresis
150
mV
V
ON
ON Pin Threshold Voltage
ON rising
1.19
1.24
1.29
V
ON falling
1.14
1.19
1.24
V
V
ONHYS
ON Pin Hysteresis
50
mV
I
ON
ON Pin Input Current
V
ON
= V
CC
0.5
A
V
START
Start-Up Delay Timer
V
CPOR
rising
0.26
0.31
0.36
V
Threshold
V
AUTO
Auto-Restart Threshold Voltage
upper threshold
1.19
1.24
1.30
V
(MIC2583R only)
lower threshold
0.26
0.31
0.36
V
I
AUTO
Auto-Restart Current
charge current
10
13
16
A
(MIC2583R only)
discharge current
1.4
2
A
(MIC2583/83R)
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