MIC2584/2585
Micrel
MIC2584/MIC2585
Dual-Channel Hot Swap Controller/Sequencer
General Description
Features
The MIC2584 and MIC2585 are dual-channel positive voltage hot swap controllers designed to facilitate the safe
insertion of boards into live system backplanes. The MIC2584
and MIC2585 are available in 16-pin and 24-pin TSSOP
packages, respectively. Using a few external discrete components and by controlling the gate drives of external NChannel MOSFET devices, the MIC2584/85 provides inrush
current limiting and output voltage slew rate control in harsh,
critical power supply environments. Additionally, the MIC2585
provides output turn-on sequencing and output tracking
during turn-on and turn-off. In combination, the devices’
many features provide a simplified, robust solution for many
network applications to meet the power sequencing and
protection requirements of multiple-voltage logic systems.
• 1.0V 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)
• Two sequenced output mode selections
(MIC2585 only)
• ∆250mV supply tracking mode during turn-on/turn-off
(MIC2585 only)
• Overvoltage and undervoltage output monitoring
(Overvoltage for MIC2585 only)
• Undervoltage lockout protection
• /FAULT status output
• Power-On Reset and Power-Good status output
(Power-Good for MIC2585 only)
Applications
•
•
•
•
•
RAID systems
Network servers
Base stations
Network switches
Hot-board insertion
Ordering Information
Standard
Part Number
Pb-Free
Output Sequencing
Fast Circuit Breaker
Threshold
Package
MIC2584-xBTS
MIC2584-xYTS
N/A
x = J, 100mV
x = K, 150mV *
16-pin TSSOP
MIC2585-1xBTS
MIC2585-2xBTS
MIC2585-1xYTS
MIC2585-2xYTS
OUT2 follows OUT1
OUT1 follows OUT2
x = L, 200mV *
x = M, Off *
24-pin TSSOP
* Contact Micrel for availability.
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
March 2005
1
MIC2584/2585
MIC2584/2585
Micrel
Typical Application
BACKPLANE PCB EDGE
CONNECTOR CONNECTOR
1
R1
10Ω
C1
0.47µF
RSENSE2
0.020Ω
D1
VCC2
3.3V
1
R2
10Ω
D2
Q1
Si7892DP
(PowerPAK™ SO-8)
RSENSE1
0.006Ω
**BZX84Cxx
VCC1
12V
2
3
R14
Q2
10.7kΩ
Si7892DP
1%
(PowerPAK™ SO-8)
2
3
CLOAD1
330µF
4
CLOAD2
330µF
4
C2
0.47µF
1
R3
47kΩ
R4
22kΩ
2
VCC2
SENSE2
24
23
VCC1
SENSE1
ON
GATE1
OUT2
R5
22kΩ
DIS2
/FAULT
Signal
R6
130kΩ
1%
R7
13kΩ
1%
*C5
R8 0.047µF
30.9kΩ
1%
R9
8.06kΩ
1%
14
/FAULT
12
CDLY
FB2
MIC2585-1
FB1
OUT1
21
OV1
DIS1
4
OV2
PG1
PG2
/POR
TRK
CPOR
GND
10
13
C6
0.02µF
VOUT2
3.3V
1.5A
C3
0.01µF
GATE2
8
VOUT1
12V
6A
CFILTER
R12
105kΩ
1%
3
22
5
6
R11
120Ω
C4
0.01µF
7
18
R15
4.42kΩ
1%
20
19
R10
560Ω
R13
14.7kΩ
1%
17
DOWNSTREAM
CONTROLLER(S)
16
15
Downstream Control Signals
9
11
C7
0.033µF
GND
Undervoltage (Output1) = 10.5V
Undervoltage (Output2) = 2.95V
Overvoltage (Input1) = 13.2V
Overvoltage (Input2) = 3.65V
START-UP Delay = 2.5ms
POR Delay = 10ms
Circuit Breaker Response Time = 16ms
*C5 (optional) is used to set the delay for VOUT2 with respect to VOUT1
VOUT2 Delay = 9.5ms
**D1 is BZX84C18 and D2 is BZX84C8V2
Resistor tolerances are 5% unless specified otherwise.
Figure 1. Typical Application Circuit
MIC2584/2585
2
March 2005
MIC2584/2585
Micrel
Pin Configuration
VCC2 1
24 VCC1
SENSE2 2
23 SENSE1
GATE2 3
22 GATE1
OV2 4
VCC2 1
SENSE2 2
16 VCC1
15 SENSE1
21 OV1
OUT2 5
20 OUT1
DIS2 6
19 DIS1
GATE2 3
14 GATE1
FB2 7
18 FB1
OUT2 4
13 OUT1
ON 8
17 PG1
TRK 9
16 PG2
FB2 5
ON 6
CPOR 7
CFILTER 8
12 FB1
11 /POR
CPOR 10
10 /FAULT
CFILTER 11
9 GND
CDLY 12
MIC2584
16-Pin TSSOP (TS)
15 /POR
14 /FAULT
13 GND
MIC2585
24-Pin TSSOP (TS)
Pin Description
Pin Number
MIC2584
Pin Number
MIC2585
Pin Name
16
24
VCC1
Positive Supply (Input), Channel 1: This input is the main supply to the
internal circuitry and must be in the range of 2.3V to 13.2V. The GATE1 pin
is held low by an internal undervoltage lockout circuit until VCC1 and VCC2
exceed their respective undervoltage lockout threshold of 2.165V and 0.8V.
This input is protected up to 20V.
1
1
VCC2
Positive Supply (Input), Channel 2: The GATE2 pin is held low by an
internal undervoltage lockout circuit until VCC1 and VCC2 exceed their
respective undervoltage lockout threshold of 2.165V and 0.8V. This input
must be in the range of 1.0V to 13.2V and less than or equal to VCC1. This
input is protected up to 20V.
2, 15
2, 23
SENSE2, SENSE1
Circuit Breaker Sense (Inputs): A resistor between this pin and VCC1 and
VCC2 sets the current limit threshold for each channel. Whenever the
voltage across either sense resistor exceeds the slow trip current limit
threshold (VTRIPSLOW), the GATE voltage is adjusted to ensure a constant
load current. If VTRIPSLOW (50mV) is exceeded for longer than time period
tOCSLOW, then the circuit breaker is tripped and both GATE outputs are
immediately pulled low. If the voltage across either sense resistor exceeds
the fast trip circuit breaker threshold, VTRIPFAST, at any point due to fast,
high amplitude power supply faults, then both GATE outputs are immediately
brought low without delay. To disable the circuit breaker for either channel,
the SENSE and VCC pins can be tied together.
The default VTRIPFAST for either device is 100mV. Other fast trip thresholds
are available: 150mV, 200mV, or OFF (VTRIPFAST disabled). Please contact
factory for availability of other options.
6
8
ON
Enable (Input): Active High. The ON pin, an input to a Schmitt-triggered
comparator used to enable/disable the controller, is compared to a 1.235V
reference with 25mV of hysteresis. When a logic high is applied to the ON
pin (VON > 1.235V), a start-up sequence begins when the GATE1 and
GATE2 pins begin ramping up towards their final operating voltage. When
the ON pin receives a logic low signal (VON < 1.21V), the GATE pins are
grounded and /FAULT remains high if both inputs are above their respective
UVLO thresholds. The ON pin must be low for at least 20µs in order to
initiate a start-up sequence. Additionally, toggling the ON pin LOW to HIGH
resets the circuit breaker.
March 2005
Pin Function
3
MIC2584/2585
MIC2584/2585
Micrel
Pin Number
MIC2584
Pin Number
MIC2585
Pin Name
3, 14
3, 22
GATE2, GATE1
9
13
GND
7
10
CPOR
Power-On Reset Timer (Input): A capacitor connected between this pin and
ground sets the start-up delay (tSTART) and the power-on reset interval
(tPOR). Once the lagging supply rises above its UVLO threshold and ON
asserts, the capacitor connected to CPOR begins to charge. When the
voltage at CPOR crosses 0.3V, the start-up threshold (VSTART), a start cycle
is initiated as the GATE outputs begin to ramp while capacitor CPOR is
immediately discharged to ground. When the voltage at the lagging FB pin
rises above its threshold (VFB), capacitor CPOR begins to charge again.
When the voltage at CPOR rises above the power-on reset delay threshold
(VPOR) of 1.235V, the timer resets by pulling CPOR to ground and /POR is
deasserted. If CPOR = 0, then tSTART defaults to 20µs.
8
11
CFILTER
Current Limit Response Timer (Input): A capacitor connected to this pin
defines the period of time, tOCSLOW, in which an overcurrent event must last
to signal a fault condition and trip the circuit breaker. When an overcurrent
condition occurs, a 2.5µA current source begins to charge this capacitor. If
the voltage at this pin reaches 1.235V, the circuit breaker is tripped, both
GATE pins immediately shut off, and /FAULT is asserted. If CFILTER = 0,
then tOCSLOW defaults to 20µs.
5, 12
7, 18
FB2, FB1
Power-Good Threshold Input (Undervoltage Detect): FB1 and FB2 are
internally compared to 1.235V and 0.80V references with 25mV of hysteresis, respectively. External resistive divider networks may be used to set the
voltage at these pins. If either FB input momentarily goes below its threshold, then /POR is activated for one timing cycle, tPOR, indicating an output
undervoltage condition. The /POR signal deasserts one timing cycle after the
FB pin exceeds its power-good threshold by 25mV. A 5µs filter on these pins
prevents glitches from inadvertently activating the /POR signal.
10
14
/FAULT
Circuit Breaker Fault Status (Output): Active-Low, weak pull-up to VCC1 or
open-drain. Asserted when the circuit breaker is tripped due to an
overcurrent, undervoltage lockout, or overvoltage event. When deasserted,
the MIC2585 will initiate a new start cycle by toggling the ON pin.
11
15
/POR
Power-On Reset (Output): Active Low, weak pull-up to VCC1 or open drain.
This pin remains asserted during start-up until a time period (tPOR) after the
lagging FB pin threshold (VFB1 or VFB2) is exceeded. The timing capacitor
CPOR determines tPOR. When the output voltage monitored at either FB pin
falls below VFB, /POR is asserted for a minimum of one timing cycle (tPOR).
4, 13
5, 20
OUT2, OUT1
Output Voltage Monitor (Inputs): For output tracking, connect these pins to
their respective output to sense the output voltage.
N/A
12
CDLY
Output Sequence Delay Timer (Input): This pin is internally clamped to 6V.
A capacitor connected to this pin sets a timer delay, tDLY, between VOUT1
and VOUT2 as shown in Figure 5. With this pin pulled up to VCC1 through a
resistor, and if CGATE1 = CGATE2, both VOUT1 and VOUT2 ramp up and down
with the same dv/dt as depicted in the Tracking Mode diagram while
maintaining a maximum voltage differential between VOUT1 and VOUT2.
N/A
9
TRK
MIC2584/2585
Pin Function
Gate Drive (Outputs): Connect each output to the gates of external
N-Channel MOSFETs. When ON is asserted, a 14µA current source is
activated and begins to charge the gate of the N-Channel MOSFET connected
to this pin. An internal clamp ensures that no more than 10V is applied
between the GATE and Source when VCC1 or VCC2 is above 5V. When the
circuit breaker trips or when an input undervoltage lockout condition is
detected, the GATE1 and GATE2 pins are immediately brought low.
Ground: Tie to analog ground.
Discharge Tracking Mode Pin (Input): Tie this pin to OUT1 or OUT2 to
enable tracking during turn-off cycle. Ground this pin to disable tracking
during turn-off. The TRK pin is not to be used as a digital input.
4
March 2005
MIC2584/2585
Micrel
Pin Number
MIC2584
Pin Number
MIC2585
Pin Name
Pin Function
N/A
4, 21
OV2, OV1
Overvoltage Detect Inputs: Whenever the threshold voltage (VOV1, VOV2) on
either input is exceeded, the circuit-breaker is tripped while /FAULT is
asserted and the GATE1 and GATE2 outputs are immediately brought low.
N/A
6, 19
DIS2, DIS1
Discharge Outputs: When the ON pin receives a logic low signal
(deasserts), these pins provide a low impedance path to ground in order to
allow the discharging of any load capacitance. The DIS pins assert low if
TRK is less than 0.3V once ON has been deasserted. The typical DIS pin
resistance varies between 50Ω to 170Ω dependent upon input supply
voltage (see Electrical Table). An external resistor is required. See “Fast
Output Discharge for Capacitive Load” section in the Applications Information for more detail.
N/A
16, 17
PG2, PG1
Power-Good Outputs: Active-HIGH, weak pull-up to VCC1 or open-drain.
These outputs are asserted whenever the FB1 and FB2 thresholds are
exceeded and will not be asserted when FB1 and FB2 are below their
thresholds.
March 2005
5
MIC2584/2585
MIC2584/2585
Micrel
Absolute Maximum Ratings (Note1)
Operating Ratings (Note 2)
All voltages are referred to GND)
Supply Voltage (VCC1/VCC2) .......................... –0.3V to 20V
SENSE1/SENSE2 pins .............................. –0.3V to VCC1/2
TRK, ON, DIS1, DIS2, OUT1, OUT2,
/POR, /FAULT, PG1, PG2 pins .................. –0.3V to 15V
GATE1/GATE2 pin ......................................... –0.3V to 25V
All other input pins ........................................... -0.3V to 15V
DIS1/DIS2 current .................................................... ±25mA
Junction Temperature ............................................... 125°C
ESD Rating
Human body model ............................................... 1500V
Machine model ........................................................ 100V
Supply Voltage
VCC1 ......................................................................... 2.3V to 13.2V
VCC2 ......................................................................... 1.0V to 13.2V
Operating Temperature Range .................. –40°C to +85°C
Package Thermal Resistance
Rθ(JA), 16-pin TSSOP ....................................... 99.1°C/W
Rθ(JA), 24-pin TSSOP ....................................... 83.8°C/W
Electrical Characteristics (Note 4)
2.3V ≤ VCC1 ≤ 13.2V, 1.0V ≤ VCC2 ≤ 13.2V, TA = 25°C unless otherwise noted. Bold values indicate –40°C ≤ TA ≤ 85°C.
Symbol
Parameter
VCC1
Supply Voltage
ICC1
Supply Current
VCC2
Supply Voltage
ICC2
Supply Current
VUV1
VCC1 Undervoltage Lockout
Threshold
VUV1HYS
VCC1 Undervoltage Lockout
Hysteresis
VUV2
VCC2 Undervoltage Lockout
Threshold
VUV2HYS
VCC2 Undervoltage Lockout
Hysteresis
VTRIPSLOW
Slow Trip Overcurrent Threshold
VTRIPHYS
Slow Trip Overcurrent Hysteresis
VTRIPFAST
Fast Trip Overcurrent Threshold
Condition
Min
External Gate Drive
VCC2 ≤ VCC1
2.050
0.7
3
mA
13.2
V
0.05
0.15
mA
2.165
2.275
V
0.8
mV
0.9
30
VCCx – VSENSEx, VCC1 = VCC2 = 5V
42.5
50
x=J
VGATEx – VCCx
IGATEOFF
GATE Pin Sink Current
/FAULT asserted
90
100
V
mV
57.5
2.5
Start cycle
mV
mV
110
mV
x=K
150
mV
x=L
200
mV
VCC1 or VCC2 > 5V
6
8
10
V
VCC1 or VCC2 < 5V
3.5
4.5
8
V
–25
–14
–8
µA
50
Turn off (ON deasserted)
VTMR
V
200
GATE Pin Pull-up Current
ITMR
13.2
1.0
IGATE
Discharge Pin Resistance
Units
1.7
(GATE1 and GATE2)
RDIS
Max
2.3
VCC1 = VCC2 = 5V
VGATE
Typ
30
45
mA
70
µA
ON deasserted
VCCx = 2.3V
170
Ω
TRK < 0.3V
VCCx = 5.0V
70
Ω
VCCx = 13.2V
50
Ω
Overcurrent Timer Pin Charge
Current
VCCx – VSENSEx = 50mV
–3.5
–2.5
–1.5
µA
Overcurrent Timer Pin Discharge
Current
VCCx – VSENSEx = 25mV
1.5
2.5
3.5
µA
1.190
1.235
1.290
V
Overcurrent Timer Pin Threshold
MIC2584/2585
6
March 2005
MIC2584/2585
Micrel
Symbol
Parameter
Condition
ICPOR
Power-on Reset Current
VCC1 = 5V, CPOR = 0.5V
Charge current
Min
Typ
Max
Units
–3.5
–2.5
–1.5
µA
1.290
V
Sink current
Start-up cycle
2.5
VPOR
Power-on Reset Delay Threshold
1.190
1.235
VPORHYS
Power-on Reset Delay Threshold
Hysteresis
VSTART
Start-up Threshold
Start-up cycle
0.25
0.30
0.35
V
VTRK
TRK Pin Threshold
(MIC2585 only)
ON deasserted, IGATE > 10µA
VCC1 = VCC2 = 5V
0.25
0.30
0.35
V
VTRKOFF
TRK Pin Turn-off Voltage
(MIC2585 only)
ON asserted, VSENSE2 – VOUT2
VCC1 = VCC2 = 5V
150
250
400
mV
VFB1
FB1 Threshold
1.190
1.235
1.290
V
VFB1HYS
FB1 Threshold Hysteresis
VFB2
FB2 Threshold
VFB2HYS
FB2 Threshold Hysteresis
VOV1
OV1 Threshold
(MIC2585 only)
VOV1HYS
OV1 Threshold Hysteresis
(MIC2585 only)
VOV2
OV2 Threshold
(MIC2585 only)
VOV2HYS
OV2 Threshold Hysteresis
(MIC2585 only)
IDELAY
Delay Timer Pin Current
25
mV
25
0.75
0.80
mV
0.85
25
1.190
1.235
mV
1.290
25
0.75
0.80
(MIC2585 only)
Timer charge current
–9
Timer discharge current
VDELAY
Delay Timer Pin Threshold
(MIC2585 only)
VDLYHYS
Delay Timer Pin Threshold
Hysteresis (MIC2585 only)
VON
ON Pin Input Threshold
VONHYS
ON Pin Hysteresis
ION
ON Pin Input Current
VON = VCCX
VOL
/FAULT , /POR , PG1, PG2 Output
Low Voltage (PG1 and PG2 for
MIC2585 only)
IOUT = 1.6mA, VCC1 = 5V
IPULLUP
/FAULT , /POR , PG1, PG2 Active
Output Pull-up Current
(PG1 and PG2 for MIC2585 only)
ON asserted, VFB1 > 1.25V, VFB2 > 0.8V
/POR = VCC1 – 1V
VGATEWIN
GATE1 and GATE2 ON/OFF
Voltage Window (Tracking enabled)
Note 3
See Timing Diagram (Figure 2)
–6
V
mV
0.85
25
VCC1 = VCC2 = 5V
V
V
mV
–3
µA
1.290
V
200
1.190
1.235
25
1.190
1.235
mV
1.290
25
mV
0.5
µA
0.4
V
12
22
µA
100
250
mV
0.1
7
V
AC Parameters
tOCFAST
Fast Overcurrent Sense to GATE
Low Trip Time
VCCx – VSENSEx = 100mV, CGATE = 10nF
See Timing Diagram (Figure 3)
1
µs
tOCSLOW
Slow Overcurrent Sense to GATE
Low Trip Time
VCCx – VSENSEx = 50mV, CFILTER = 0
20
µs
Note 1.
Exceeding the absolute maximum rating may damage the device.
Note 2.
The device is not guaranteed to function outside its operating rating.
Note 3.
For the MIC2584, VGATEWIN is specified only when ON is asserted.
Note 4.
Specification for packaged product only.
March 2005
7
MIC2584/2585
MIC2584/2585
Micrel
Timing Diagrams
GATE1
GATE2
ON
OFF
GATE1 ON
GATE2 ON
GATE1 ON
GATE2 OFF
100mV
GATE1 OFF
GATE2 ON
VOUT1 - VOUT2
ON Pin Asserted
ON
OFF
GATE1 OFF
GATE2 OFF
100mV
GATE1 ON
GATE2 OFF
GATE1 OFF
GATE2 ON
VOUT1 - VOUT2
ON Pin Deasserted
Figure 2. Gate Voltage Window — Tracking Mode
VTRIPFAST
50mV
(VCCx – VSENSEx)
tOCFAST
tOCSLOW
VGATEx
0.5V
0.5V
Figure 3. Current Limit Response
VPOR
ON
VSTART
CPOR
tSTART
VPG[1/2]
VOUT[1,2]
PG[1/2]
tPOR
/POR
Figure 4. Start-Up Cycle Timing
VOUT1
∆V
