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.
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 (<1µs)
• 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
Typical Application
BACKPLANE PCB EDGE
CONNECTOR CONNECTOR
V
IN
12V
**D1
(18V)
Long Pin
R1
3.3Ω
C1
1µF
3
R
SENSE
0.006Ω
2%
2
1
4
Q1
Si7892DP
(PowerPAK™ SO-8)
V
OUT
12V@6A
C
LOAD
500µF
16
15
VCC
Short Pin
3
SENSE
GATE
ON
DIS
PWRGD
11
14
R2
76.8kΩ
1%
R3
R4
9.76kΩ
47kΩ
1%
/FAULT
Signal
Medium
(or Short) Pin
C2
0.01µF
13
R5
93.1kΩ
1%
V
IN
R7
47kΩ
V
IN
R8
47kΩ
DOWNSTREAM
CONTROLLER
MIC2583/83R
2
Power-Good Output
1
EN
/RESET
FAULT
/POR
FB
CPOR
4
Power-On Reset Output
12
GND
7, 8
CFILTER
5
Long Pin
GND
C3
0.1µF
C4
8200pF
R6
12.4kΩ
1%
*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
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
1
MIC2582/MIC2583
MIC2582/MIC2583
Micrel
Ordering Information
Part Number
MIC2582-JBM
MIC2583-xBQS
Fast Circuit
Breaker Threshold
100mV
x = J, 100mV
x = K, 150mV
x = L, 200mV
x = M, Off
MIC2583R-xBQS
x = J, 100mV
x = K*, 150mV
x = L*, 200mV
x = M*, Off
* Contact factory for availability.
Circuit Breaker
Latched off
Latched off
Package
8-pin SOIC
16-pin QSOP
Auto-retry
16-pin QSOP
Pin Configuration
/POR 1
PWRGD 2
16 VCC
15 SENSE
14 GATE
13 DIS
12 FB
11 /FAULT
10 NC
9 NC
/POR 1
ON 2
CPOR 3
GND 4
8 VCC
7 SENSE
6 GATE
5 FB
ON 3
CPOR 4
CFILTER 5
NC 6
GND 7
GND 8
8-Pin SOIC (M)
16-Pin QSOP (QS)
MIC2582/MIC2583
2
April 2003
MIC2582/MIC2583
Micrel
Pin Description
Pin Name
/POR
8-pin SOIC
1
16-pin QSOP
1
Pin Function
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 (10kΩ minimum) to VCC.
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 20µs
in order to initiate a start-up sequence. Additionally, toggling the ON pin
LOW to HIGH resets the circuit breaker.
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 20µs.
Ground connection: Tie to analog ground.
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 5µs filter on this pin prevents glitches from inadvertently
activating this signal.
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.
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.
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.
ON
2
3
CPOR
3
4
GND
FB
4
5
7,8
12
GATE
6
14
SENSE
7
15
VCC
8
16
April 2003
3
MIC2582/MIC2583
MIC2582/MIC2583
Pin Name
PWRGD
8-pin SOIC
N/A
16-pin QSOP
2
Pin Function
Micrel
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 (10kΩ minimum) to VCC.
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 5µs.
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 (10kΩ minimum) to VCC.
Discharge Output: When the MIC2583/83R is turned off, a 500Ω internal
resistor at this output allows the discharging of any load capacitance to ground.
No internal connection.
CFILTER
N/A
5
/FAULT
N/A
11
DIS
NC
N/A
N/A
13
6,9,10
MIC2582/MIC2583
4
April 2003
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
Electrical Characteristics
(Note 3)
Symbol
V
CC
I
CC
V
TRIP
Parameter
Supply Voltage
Supply Current
Circuit Breaker Trip Voltage
(Current Limit Threshold)
V
ON
= 2V
Condition
Operating Ratings
(Note 2)
Supply Voltage (V
CC
) ................................... 2.3V to 13.2V
Thermal Resistance (R
θ(J-A)
)
8-pin SOIC ........................................................ 163°C/W
16-pin QSOP .................................................... 112°C/W
Operating Temperature Range ................. –40°C to +85°C
V
CC
= 5.0V, T
A
= 25°C unless otherwise noted.
Bold
values indicate –40°C
≤
T
A
≤
+85°C.
Min
2.3
1.5
V
TRIPSLOW
V
TRIPFAST
(MIC2582)
V
TRIPFAST
x = J
(MIC2583/83R) x = K
x=L
V
GS
I
GATE
I
GATEOFF
External Gate Drive
V
GATE
– V
CC
V
CC
> 3V
V
CC
= 2.3V
GATE Pin Pull-Up Current
Start Cycle, V
GATE
= 0V, V
CC
=13.2V
V
CC
= 2.3V
GATE Pin Sink Current
V
GATE
>1V
/FAULT = 0
(MIC2583/83R only)
I
TIMER
I
CPOR
V
TH
V
UV
V
UVHYS
V
ON
V
ONHYS
I
ON
V
START
V
AUTO
I
AUTO
Current Limit/Overcurrent Timer
(CFILTER) Current
(MIC2583/83R)
Power-On-Reset Timer Current
V
CC
= 13.2V,
Note 4
V
CC
= 2.3V,
Note 4
Turn off
–8.5
4.5
–3.5
0.5
1.19
2.1
1.90
85
130
175
7
3.5
–30
–26
42
50
100
100
150
200
8
4.8
17
17
100
50
110
–6.5
6.5
2.5
1.3
1.245
2.2
2.05
150
ON rising
ON falling
ON Pin Hysteresis
ON Pin Input Current
Start-Up Delay Timer
Threshold
Auto-Restart Threshold Voltage
(MIC2583R only)
Auto-Restart Current
(MIC2583R only)
V
ON
= V
CC
V
CPOR
rising
upper threshold
lower threshold
charge current
discharge current
0.26
1.19
0.26
10
0.31
1.24
0.31
13
1.4
1.19
1.14
1.24
1.19
50
–0.5
0.36
1.30
0.36
16
2
1.29
1.24
1.30
2.3
2.20
–4.5
8.5
–1.5
110
170
225
9
6.5
–8
–8
Typ
Max
13.2
2.5
59
Units
V
mA
mV
mV
mV
mV
mV
V
V
µA
µA
mA
mA
µA
µA
µA
µA
mA
V
V
V
mV
V
V
mV
µA
V
V
V
µA
µA
V
TRIP
= V
CC
– V
SENSE
V
CC
– V
SENSE
> V
TRIPSLOW
(timer on)
V
CC
– V
SENSE
< V
TRIPSLOW
(timer off)
timer on
timer off
POR Delay and Overcurrent
Timer (CFILTER) Threshold
Undervoltage Lockout Threshold
V
CPOR
rising
V
CFILTER
rising (MIC2583/83R only)
V
CC
rising
V
CC
falling
Undervoltage Lockout Hysteresis
ON Pin Threshold Voltage
April 2003
5
MIC2582/MIC2583
DIY/Open Source Hardware
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