MAXIM MAX5915EUI

19-2420; Rev 1; 4/04
Dual PCI 2.2 Hot-Swap Controllers
Features
♦ PCI 2.2 Compliant
The MAX5915/MAX5915A/MAX5916/MAX5916A dual
PCI 2.2 hot-swap controllers allow for safe insertion and
removal of two PCI cards into live PCI slots or backplanes by limiting the inrush current at startup. After
startup, these devices provide protection against shortcircuit, overcurrent, and undervoltage conditions.
The MAX5915/MAX5915A/MAX5916/MAX5916A provide independent power controls for +3.3V, +5V, ±12V,
and +3.3V auxiliary supplies of two PCI cards. These
devices provide intelligent selective thermal shutdown
control that shuts down the channel with an overcurrent
fault. All devices include internal power MOSFETs for the
+12V, -12V, and +3.3V auxiliary outputs. These devices
use internal charge pumps to activate the gates of the
internal FETs controlling the +3.3V auxiliary supply.
Internal FETs and current-sense circuitry regulate the
±12V and the +3.3V auxiliary supplies. Channels A and B
operate independently, allowing a single device to monitor two PCI card slots.
The MAX5915/MAX5915A offer latched fault protection
and the MAX5916/MAX5916A offer autorestart fault protection. The devices are available in the low-profile
28-pin TSSOP package and are specified over the
-40°C to +85°C extended temperature range.
♦ Independent Power Controls for +3.3V, +5V, ±12V,
and +3.3V Auxiliary Supplies of Two PCI Cards
♦ Internal MOSFET Switches for ±12V and +3.3V
Auxiliary Outputs
♦ Separate ON/OFF Control Input for Each Channel
♦ Independent +3.3V Auxiliary Output ON/OFF
Control
♦ Overcurrent Foldback with Timeout and Shutdown
Protection for ±12V and +3.3V Auxiliary Rails with
Status Report
♦ Brick Wall with Timeout and Shutdown Protection
for +5V and +3.3V Rails with Status Report
♦ Output Undervoltage Monitoring for +3.3V, +5V,
+12V, and +3.3V Auxiliary Rails with Status Report
♦ +3.3V Auxiliary Autorestart
♦ Intelligent Selective Thermal Shutdown Control
Shuts Down Only the Channel with an Overcurrent
Fault
♦ 28-Pin TSSOP Package
Ordering Information
Applications
PCI 2.2 Server
TEMP RANGE
PIN-PACKAGE
PCI Server
MAX5915EUI
PART
-40°C to +85°C
28 TSSOP
RAID
MAX5915AEUI
-40°C to +85°C
28 TSSOP
MAX5916EUI
-40°C to +85°C
28 TSSOP
MAX5916AEUI
-40°C to +85°C
28 TSSOP
Selector Guide, Pin Configuration, Functional Diagram, and
Typical Operating Circuit appear at end of data sheet.
Typical Application Circuit
FAIRCHILD
+3.3V FDS6670A
0.005Ω
470µF
FAIRCHILD
FDS6670A
+5V
0.005Ω
+12V
4.7µF 0.1µF
-12V
4.7µF 0.1µF
+3.3VAUX
3.3VGATE_
+12VIN
-12VIN
3.3VAUXIN
4.7µF 0.1µF
ON
ON_
OFF
10kΩ
ON
3.3VSEN_
3.3VO_
5VGATE_
5VSEN_
470µF
5VO_
+12VO_
-12VO_
3.3VAUXO_
MAX5915
MAX5915A
MAX5916
MAX5916A
47µF
47µF
47µF
5V
AUXON_
OFF
10kΩ
GND
PGOOD_
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MAX5915/MAX5915A/MAX5916/MAX5916A
General Description
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
ABSOLUTE MAXIMUM RATINGS
+12VIN to GND ...................................................-0.3V to +14.0V
-12VIN to GND........................................................-14V to +0.3V
-12VO_ to GND......................................+0.3V to (V-12VIN - 0.3V)
+12VO_, 3.3VGATE_, 5VGATE_
to GND..................................................-0.3V to (V+12VIN + 0.3V)
Any Other Pin to GND ...........................................-0.3V to +6.0V
Continuous Power Dissipation (TA = +70°C)
28-Pin TSSOP (derate 23.8mW/°C above +70°C) ...........1.9W
Maximum Junction Temperature .....................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V-12VIN = -12V, V+12VIN = +12V, V3.3VAUXIN = +3.3V, VON_ = VAUXON_ = +5V, TA = -40°C to +85°C, unless otherwise specified.
Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
10.8
12
13.2
V
9.6
10
10.8
V
POWER SUPPLIES
Main Supply Input Voltage
Range
V+12VIN
Main Supply Undervoltage
Lockout (UVLO)
V+12UVLO
Main Supply UVLO Hysteresis
VUVLO, HYS
Main Input UVLO Delay Time
tDEG, UVLO
Supply Current
V+12VIN rising
100
Figures 1 and 2 (Note 1)
mV
1.6
IQ
ms
2.5
5.0
mA
+3.3V SUPPLY CONTROL
Gate Charge Current
I3.3VGATE_, CHG
V3.3VGATE _ = +6V, V3.3VSEN_ = +3.3V,
V3.3VO_ = +3.3V
5
15
30
µA
Gate Discharge Current
I3.3VGATE_, DIS
V3.3VGATE _ = +12V, VON_ = 0V
50
150
250
µA
V+12VIN
V
0.4
V
Gate High Voltage
V3.3VGATE_, HIGH
I3.3VGATE _ = 1µA
Gate Low Voltage
V3.3VGATE_, LOW
I3.3VGATE _ = 1µA, VON_ = 0V
3.3VO_ Input Bias Current
I3.3VO_, BIAS
3.3VO_ Internal Pulldown
RPD
3.3VSEN_ Input Bias Current
V+12VIN 0.5
0.1
V3.3VO_ = +3.3V
20
VON_ = 0V
1
µA
kΩ
I3.3VSEN_, BIAS
V3.3VSEN_ = +3.3V
10
µA
Current-Limit Threshold
V3.3V, LIM
V3.3VGATE _ = +6V
41
46
51
mV
Output Undervoltage Threshold
V3.3VIN, UV
V3.3VGATE _ falling
2.79
2.89
2.99
V
Output Undervoltage Threshold
Hysteresis
2
30
_______________________________________________________________________________________
mV
Dual PCI 2.2 Hot-Swap Controllers
(V-12VIN = -12V, V+12VIN = +12V, V3.3VAUXIN = +3.3V, VON_ = VAUXON_ = +5V, TA = -40°C to +85°C, unless otherwise specified.
Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
5
15
30
µA
50
150
250
µA
V+12VIN
V
+5V SUPPLY CONTROL
Gate Charge Current
I5VGATE_, CHG
V5VGATE_ = +6V, V5VSEN_ = +5V,
V5VO_ = +5V
Gate Discharge Current
I5VGATE_, DIS
V5VGATE_ = +12V, VON_ = 0V
Gate High Voltage
V5VGATE_, HIGH
I5VGATE_ = 1µA
Gate Low Voltage
V5VGATE_, LOW
I5VGATE_ = 1µA, VON_ = 0V
5VO_ Input Bias Current
I5VO_, BIAS
V5VO_ = +5V
5VO_ Internal Pulldown
R5VO_, PD
VON_ = 0V
5VSEN_ Input Bias Current
I5VSEN_, BIAS
V5VSEN_ = +5V
Current-Limit Threshold
V5VO_, LIM
V5VGATE_ falling
Output Undervoltage Threshold
V5VO_, UV
Output falling
V+12VIN 0.5V
0.1
0.4
V
20
µA
1
kΩ
10
µA
27
31
35
mV
4.34
4.50
4.70
V
Output Undervoltage Threshold
Hysteresis
45
mV
+12V SUPPLY CONTROL
On-Resistance of Internal Switch
Foldback Current Limit
RDS(ON), +12V
TA = +25°C, ID = 0.5A
I+12VIN, LIM
V+12VO_ = 0V
Output Undervoltage Threshold
V+12VO_, UV
Output falling
+12VO_ Internal Pulldown
R+12VO_, PD
VON_ = 0V
Current-Foldback Threshold
0.32
TA = +85°C, ID = 0.5A
0.38
0.5
0.68
1
10.00
10.4
Output current rising (Note 2)
1.36
1.4
Ω
A
A
10.82
1
V
kΩ
-12V SUPPLY CONTROL
On-Resistance of Internal Switch
Foldback Current Limit
RDS(ON), -12V
I-12VIN, LIM
Current-Foldback Threshold
-12VO_ Internal Pullup
TA = +25°C, ID = 0.1A
0.58
TA = +85°C, ID = 0.1A
V-12VO_ = 0V
136
Output current rising (Note 2)
R-12VO_, PU
0.9
1.3
VON_ = 0V
205
273
Ω
mA
240
mA
1
kΩ
+3.3VAUX SUPPLY CONTROL
Input Voltage Range
V3.3VAUXIN
3.3VAUXIN Undervoltage
Lockout
VUVLO, AUX
Hysteresis
Supply Current
Input rising
3.0
3.3
3.6
V
2.65
2.75
2.85
V
VUVLO-AUX, HYS
30
IQ, 3.3VAUX
1
mV
2
mA
_______________________________________________________________________________________
3
MAX5915/MAX5915A/MAX5916/MAX5916A
ELECTRICAL CHARACTERISTICS (continued)
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
ELECTRICAL CHARACTERISTICS (continued)
(V-12VIN = -12V, V+12VIN = +12V, V3.3VAUXIN = +3.3V, VON_ = VAUXON_ = +5V, TA = -40°C to +85°C, unless otherwise specified.
Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
On-Resistance of Internal Switch
RDS(ON), 3.3VAUX
Foldback Current Limit
I3.3VAUXIN, LIM
Current-Foldback Threshold
CONDITIONS
TA = +25°C, ID = 0.4A
V3.3VAUXIN, UV
Auxiliary Input UVLO Delay Time
tDEG, UVLO
3.3VAUXO_ Internal Pulldown
R3.3VAUXO_
ON AND AUXON COMPARATORS
V3.3VAUXO_ = 0V
ON_ and AUXON_ Deglitch
Time
0.24
0.5
0.75
2.76
2.89
0.4
1.0
1.2
ON_ = 0V
VHYS
Ω
A
A
2.99
V
ms
1
kΩ
2.1
25
IB, COMP
V
mV
20
Figures 5–8 (Note 3)
UNITS
1.6
1.0
tDEG
MAX
0.6
(Note 1)
Threshold Voltage
Input Bias Current
TYP
TA = +85°C, ID = 0.4A
Output current rising (Note 2)
Output Undervoltage Threshold
Hysteresis
MIN
4
µA
µs
FAULT RESPONSE, PGOOD_ STATUS OUTPUT COMPARATORS
PGOOD_ Output Overcurrent
and Undervoltage Response
Time
tRESP
Figures 5–8
MAX5915/MAX5916
tRESP2
Figures 5–8
MAX5915A/MAX5916A
Output Overcurrent and
Undervoltage Deglitch Time
tDELAY
PGOOD_ Startup Timeout
tSTART
Autorestart Delay
PGOOD_ Output Low Voltage
PGOOD_ Output High Leakage
Current
tRESTART
VOL
ILEAK
Thermal Shutdown Threshold
TSD
Thermal Shutdown Hysteresis
THYS
Full Thermal Shutdown
Threshold
TSD, FULL
Full Thermal Shutdown
Hysteresis
THYS, FULL
Note 1:
Note 2:
Note 3:
Note 4:
Note 5:
4
0.5
1.5
ms
100
ns
Figures 3–7
16 x
tRESP
ms
See Figures 1, 2, 5, 6, 7, and 8
4x
tDELAY
ms
Delay time to restart after OC and/or
UV shutdown
64 x
tSTART
ms
ISINK = 2mA, ON_ = 0V
0.5
0.7
V
1
µA
VPGOOD_ = +5.5V
(Note 4)
(Note 5)
125
°C
5
°C
TSD +
20
°C
5
°C
tDEG, UVLO is negative edge triggered. There is no time delay when the inputs rise above the UVLO threshold.
The current threshold when the output current starts to fold back. See the Typical Operating Characteristics.
tDEG is negative edge triggered. ON_ or AUXON_ transition from low to high has no delay.
Temperature threshold at which the outputs of the channel with overcurrent shut down.
The temperature threshold at which both channels shut down.
_______________________________________________________________________________________
Dual PCI 2.2 Hot-Swap Controllers
+12VO_ VOLTAGE
vs. OUTPUT CURRENT
+12VO_ CURRENT FOLDBACK
vs. DIFFERENTIAL SWITCH VOLTAGE
11.6
11.5
11.4
0.1
1.5
1.0
4
2
-12VO_ CURRENT FOLDBACK
vs. DIFFERENTIAL SWITCH VOLTAGE
5VO_ VOLTAGE
vs. OUTPUT CURRENT
5VO_ VOLTAGE (V)
MAX5915 toc05
4.98
4.96
4.94
4.92
4.90
4.88
4.86
50
0
4.82
4.80
4
2
6
8
10
4
3.3VO_ VOLTAGE
vs. OUTPUT CURRENT
3.3VO_ SENSE RESISTOR VOLTAGE
vs. DIFFERENTIAL SWITCH VOLTAGE
3.26
3.24
3.22
3.20
FAIRCHILD
FDS6670A
0
2
6
4
OUTPUT CURRENT (A)
8
36
34
32
30
28
26
24
DURING CURRENT LIMIT
FAIRCHILD
FDS6670A
22
1.0
48
46
44
40
38
36
DURING CURRENT LIMIT
FAIRCHILD
FDS6670A
32
2.0
2.5
3.0
3.5
4.0
4.5
5.0
3.3VAUX_ VOLTAGE
vs. OUTPUT CURRENT
42
34
1.5
VIN - V5VSEN_ (V)
3.5
3.4
3.3
3.2
3.1
3.0
2.9
2.8
2.7
2.6
30
3.16
250
40
3.3VAUX_ VOLTAGE (V)
MAX5915 toc07
3.28
200
100
150
OUTPUT CURRENT (mA)
38
5
V-12VIN - V-12VO_ (V)
3.30
50
20
1
2
3
OUTPUT CURRENT (A)
3.32
3.18
FAIRCHILD
FDS6670A
0
12
3.3VO_ CURRENT-LIMIT THRESHOLD (mV)
0
0
5VO_ SENSE RESISTOR VOLTAGE
vs. DIFFERENTIAL SWITCH VOLTAGE
5.00
4.84
-11.9
12
10
5.02
MAX5915 toc04
100
-11.8
-12.1
0
OUTPUT CURRENT (A)
150
-11.7
-12.0
8
6
V+12VIN - V+12VO_ (V)
200
MAX5915 toc03
MAX5915 toc02
0.3
5VO_ CURRENT-LIMIT THRESHOLD (mV)
0.5
250
-12VO_ CURRENT FOLDBACK (mA)
0.5
-0.1
0
3.3VO_ VOLTAGE (V)
0.7
MAX5915 toc06
11.7
-11.6
MAX5915 toc09
11.8
0.9
-12VO_ VOLTAGE (V)
11.9
-11.5
MAX5915 toc08
+12VO_ VOLTAGE (V)
12.0
1.1
+12VO_ CURRENT FOLDBACK (A)
MAX5915 toc01
12.1
-12VO_ VOLTAGE
vs. OUTPUT CURRENT
2.5
1.0
1.5
2.0
2.5
VIN - V3.3VSEN_ (V)
3.0
3.5
0
0.15 0.30 0.45 0.60 0.75 0.90 1.05 1.20
OUTPUT CURRENT (A)
_______________________________________________________________________________________
5
MAX5915/MAX5915A/MAX5916/MAX5916A
Typical Operating Characteristics
(V+12VIN = +12V, V3.3VAUXIN = +3.3V, V-12VIN = -12V, V5V = +5V, V3.3V = +3.3V, R5VSEN_ = 0.005Ω, R3.3VSEN_ = 0.005Ω, C3.3VO_ =
C5VO_ = 470µF, C+12VO_ = C-12VO_ = C3.3VAUXO_ = 47µF, TA = +25°C, unless otherwise noted. See Typical Application Circuit.)
Typical Operating Characteristics (continued)
(V+12VIN = +12V, V3.3VAUXIN = +3.3V, V-12VIN = -12V, V5V = +5V, V3.3V = +3.3V, R5VSEN_ = 0.005Ω, R3.3VSEN_ = 0.005Ω, C3.3VO_ =
C5VO_ = 470µF, C+12VO_ = C-12VO_ = C3.3VAUXO_ = 47µF, TA = +25°C, unless otherwise noted. See Typical Application Circuit.)
5VGATE_ AND 3.3VGATE_
CHARGE CURRENT vs. TEMPERATURE
600
23.5
21.5
19.5
17.5
15.5
13.5
3.3VGATE_
11.5
550
175
CGATE = 1nF
9.5
500
180
1.0 1.5
2.0 2.5
V3.3VAUXIN - V3.3VAUXO_ (V)
3.0
3.5
-40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0
-15
10
35
60
-15
10
35
60
85
150
145
CGATE = 1nF
-40
-15
10
35
60
TEMPERATURE (°C)
3.3V AUXILIARY INTERNAL SWITCH RON
vs. TEMPERATURE
-12V INTERNAL SWITCH RON
vs. TEMPERATURE
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0
-40
-15
10
35
60
85
-40
-15
10
35
60
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
TIME-TO-CHARGE GATE
(CGATE = 0.1nF)
TIME-TO-CHARGE GATE
(CGATE = 1nF)
TIME-TO-CHARGE GATE
(CGATE = 10nF)
MAX5915 toc17
ON_
5V/div
ON_
5V/div
3.3VGATE_
5V/div
3.3VGATE_
5V/div
3.3VGATE_
5V/div
5VGATE_
5V/div
5VGATE_
5V/div
5VGATE_
5V/div
200µs/div
85
MAX5915 toc18
ON_
5V/div
100µs/div
85
0.1
MAX5915 toc16
6
5VGATE_
140
85
0
-40
155
TEMPERATURE (°C)
MAX5915 toc14
MAX5915 toc13
0.40
3.3V AUXILIARY INTERNAL SWITCH RON (Ω)
+12V INTERNAL SWITCH RON
vs. TEMPERATURE
0.45
3.3VGATE_
160
130
-12V INTERNAL SWITCH RON (Ω)
0.5
165
135
5VGATE_
7.5
0
170
MAX5915 toc15
650
25.5
GATE DISCHARGE CURRENT (µA)
700
MAX5915 toc11
750
27.5
GATE CHARGE CURRENT (µA)
MAX5915 toc10
3.3VAUX_ CURRENT FOLDBACK (mA)
800
5VGATE_ AND 3.3VGATE_
DISCHARGE CURRENT vs. TEMPERATURE
MAX5915 toc12
3.3VAUX_ CURRENT FOLDBACK
vs. DIFFERENTIAL SWITCH VOLTAGE
+12V INTERNAL SWITCH RON (Ω)
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
2ms/div
_______________________________________________________________________________________
Dual PCI 2.2 Hot-Swap Controllers
2.7
2.6
2.5
2.4
2.3
2.2
2.1
1.75
1.50
1.25
1.00
0.75
0.50
MAX5915 toc21
2.00
2.10
0
-15
10
35
60
85
2.05
2.00
1.95
RISING
1.90
FALLING
1.85
1.80
-40
-15
10
35
60
85
-40
10
35
60
TEMPERATURE (°C)
+12V OUTPUT UNDERVOLTAGE
THRESHOLD vs. TEMPERATURE
5V OUTPUT UNDERVOLTAGE
THRESHOLD vs. TEMPERATURE
3.3V OUTPUT UNDERVOLTAGE
THRESHOLD vs. TEMPERATURE
10.6
10.5
10.4
10.3
10.2
4.63
4.58
4.53
4.48
4.43
4.38
-15
10
35
60
85
3.3
3.2
3.1
3.0
2.9
2.8
2.7
2.6
2.5
-40
-15
10
35
60
85
-40
-15
10
35
60
TEMPERATURE (°C)
TEMPERATURE (°C)
3.3V AUXILIARY OUTPUT UNDERVOLTAGE
THRESHOLD vs. TEMPERATURE
3.3V AUXILIARY INPUT UVLO
THRESHOLD vs. TEMPERATURE
+12V INPUT UVLO
THRESHOLD vs. TEMPERATURE
3.1
3.0
2.9
2.8
2.7
3.2
3.1
3.0
2.9
2.8
2.7
2.6
-15
10
35
TEMPERATURE (°C)
60
85
10.4
10.3
10.2
10.1
10.0
9.9
9.8
9.7
9.6
9.5
2.5
-40
10.5
85
MAX5915 toc27
3.3
+12V INPUT UVLO THRESHOLD (V)
MAX5915 toc25
3.2
3.3V AUXILIARY INPUT UVLO THRESHOLD (V)
TEMPERATURE (°C)
3.3
85
MAX5915 toc24
MAX5915 toc23
MAX5915 toc22
10.7
4.68
3.3V OUTPUT UNDERVOLTAGE THRESHOLD (V)
TEMPERATURE (°C)
10.8
-40
-15
TEMPERATURE (°C)
5V OUTPUT UNDERVOLTAGE THRESHOLD (V)
-40
+12V OUTPUT UNDERVOLTAGE THRESHOLD (V)
2.25
0.25
2.0
3.3V AUXILIARY OUTPUT UNDERVOLTAGE THRESHOLD (V)
MAX5915 toc20
2.8
2.50
ON_ AND AUXON_ THRESHOLD
vs. TEMPERATURE
MAX5915 toc26
+12VIN SUPPLY CURRENT (mA)
2.9
3.3VAUXIN SUPPLY CURRENT (mA)
MAX5915 toc19
3.0
3.3VAUXIN SUPPLY CURRENT
vs. TEMPERATURE
ON_ AND AUXON_ THRESHOLD (V)
+12VIN SUPPLY CURRENT
vs. TEMPERATURE
-40
-15
10
35
TEMPERATURE (°C)
60
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
_______________________________________________________________________________________
7
MAX5915/MAX5915A/MAX5916/MAX5916A
Typical Operating Characteristics (continued)
(V+12VIN = +12V, V3.3VAUXIN = +3.3V, V-12VIN = -12V, V5V = +5V, V3.3V = +3.3V, R5VSEN_ = 0.005Ω, R3.3VSEN_ = 0.005Ω, C3.3VO_ =
C5VO_ = 470µF, C+12VO_ = C-12VO_ = C3.3VAUXO_ = 47µF, TA = +25°C, unless otherwise noted. See Typical Application Circuit.)
Typical Operating Characteristics (continued)
(V+12VIN = +12V, V3.3VAUXIN = +3.3V, V-12VIN = -12V, V5V = +5V, V3.3V = +3.3V, R5VSEN_ = 0.005Ω, R3.3VSEN_ = 0.005Ω, C3.3VO_ =
C5VO_ = 470µF, C+12VO_ = C-12VO_ = C3.3VAUXO_ = 47µF, TA = +25°C, unless otherwise noted. See Typical Application Circuit.)
+12V OUTPUT CURRENT
FOLDBACK vs. TEMPERATURE
0.9
0.8
0.7
230
210
190
170
150
-15
10
35
60
85
45
43
41
39
DURING CURRENT LIMIT
35
-40
-15
10
35
60
-40
85
-15
10
35
60
TEMPERATURE (°C)
TEMPERATURE (°C)
3.3V AUXILIARY CURRENT
FOLDBACK vs. TEMPERATURE
5VO_ SENSE RESISTOR VOLTAGE
vs. TEMPERATURE
MAIN SUPPLY
TURN-ON WAVEFORMS
775
700
625
550
475
MAX5915 toc32
850
38
36
ON_
5V/div
34
32
30
5VO_
5V/div
28
26
12VO_
10V/div
24
DURING CURRENT
LIMIT
22
PGOOD_
5V/div
20
-15
10
35
60
85
-40
-15
10
35
60
TEMPERATURE (°C)
TEMPERATURE (°C)
AUXILIARY SUPPLY
TURN-ON WAVEFORMS
TURN-ON DELAY
MAX5915 toc34
AUXON_
5V/div
10ms/div
MAX5915 toc36
ON_
5V/div
5VO_
5V/div
+12VO_
10V/div
3.3VAUXIN_
2V/div
ON_ = 5.0V
10ms/div
MAX5915 toc35
+12VO_
10V/div
PGOOD_
5V/div
85
AUXON_ = 5V
MAIN SUPPLY
TURN-OFF WAVEFORMS
+12VIN
10V/div
3.3VAUXO_
2V/div
85
MAX5915 toc33
40
5V0_ SENSE RESISTOR VOLTAGE (mV)
925
-40
47
TEMPERATURE (°C)
MAX5915 toc31
-40
49
37
130
MAX5915 toc30
MAX5915 toc29
250
3.3V SENSE RESISTOR VOLTAGE (mV)
1.0
-12V OUTPUT CURRENT FOLDBACK (mA)
MAX5915 toc28
+12V OUTPUT CURRENT FOLDBACK (A)
1.1
0.6
8
3.3VO_ SENSE RESISTOR VOLTAGE
vs. TEMPERATURE
-12V OUTPUT CURRENT
FOLDBACK vs. TEMPERATURE
1.2
3.3V AXILIARY CURRENT FOLDBACK (mA)
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
3.3VAUXO_
2V/div
ON_ = 5V
AUXON_ = 5V
200µs/div
PGOOD_
5V/div
40ms/div
_______________________________________________________________________________________
Dual PCI 2.2 Hot-Swap Controllers
AUXILIARY SUPPLY
TURN-OFF WAVEFORMS
tDEG DELAY TIME
MAX5915 toc37
MAIN SUPPLY
LATCHED FAULT MANAGEMENT
ON_
5V/div
ON_
5V/div
MAX5915 toc39
MAX5915 toc38
+12VO_
5V/div
3.3VAUXO_
2V/div
3.3VAUXO_
2V/div
5VO_
2V/div
3.3VAUXO_
5V/div
PGOOD_
5V/div
PGOOD_
5V/div
PGOOD_
5V/div
20ms/div
2µs/div
2ms/div
MAIN SUPPLY
AUTORESTART FAULT MANAGEMENT
AUXILIARY SUPPLY
FAULT MANAGEMENT
+12VO_ IMMEDIATE
SHORT-CIRCUIT RESPONSE
MAX5915 toc40
+12VO_
5V/div
MAX5915 toc41
+12VO_
5V/div
5VO_
2V/div
3.3VAUXO_
5V/div
MAX5915 toc42
+12VO_
5V/div
I+12VO_
10A/div
5VO_
3.3VAUXO_
5V/div
PGOOD_
5V/div
PGOOD_
5V/div
PGOOD_
5V/div
400ms/div
400ms/div
+12VO_ CURRENT FOLDBACK
-12VO_ IMMEDIATE
SHORT-CIRCUIT RESPONSE
MAX5915 toc43
+12VO_
5V/div
I-12VO_
500mA/div
PGOOD_
5V/div
2ms/div
MAX5915 toc45
-12VO_
5V/div
I-12VO_
2A/div
PGOOD_
5V/div
-12VO_ CURRENT FOLDBACK
MAX5915 toc44
-12VO_
5V/div
I+12VO_
5A/div
1µs/div
PGOOD_
5V/div
200ns/div
2ms/div
_______________________________________________________________________________________
9
MAX5915/MAX5915A/MAX5916/MAX5916A
Typical Operating Characteristics (continued)
(V+12VIN = +12V, V3.3VAUXIN = +3.3V, V-12VIN = -12V, V5V = +5V, V3.3V = +3.3V, R5VSEN_ = 0.005Ω, R3.3VSEN_ = 0.005Ω, C3.3VO_ =
C5VO_ = 470µF, C+12VO_ = C-12VO_ = C3.3VAUXO_ = 47µF, TA = +25°C, unless otherwise noted. See Typical Application Circuit.)
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
Typical Operating Characteristics (continued)
(V+12VIN = +12V, V3.3VAUXIN = +3.3V, V-12VIN = -12V, V5V = +5V, V3.3V = +3.3V, R5VSEN_ = 0.005Ω, R3.3VSEN_ = 0.005Ω, C3.3VO_ =
C5VO_ = 470µF, C+12VO_ = C-12VO_ = C3.3VAUXO_ = 47µF, TA = +25°C, unless otherwise noted. See Typical Application Circuit.)
5VO_ IMMEDIATE
SHORT-CIRCUIT RESPONSE
MAX5915 toc47
MAX5915 toc46
5VO_
5V/div
5VO_
5V/div
I3.3VO_
10A/div
FAIRCHILD
FDS6670A
PGOOD_
5V/div
40µs/div
2ms/div
3.3VO_ CURRENT LIMIT
3.3VAUXO_ IMMEDIATE
SHORT-CIRCUIT RESPONSE
3.3VAUXO_ CURRENT FOLDBACK
MAX5915 toc51
3.3VAUXO_
2V/div
3.3VAUXO_
2V/div
I3.3VAUXO_
10A/div
I3.3VAUXO_
1A/div
PGOOD_
5V/div
PGOOD_
5V/div
PGOOD_
5V/div
2ms/div
2µs/div
2ms/div
MAX5915A/MAX5916A
12VO_ SHORT CIRCUIT
MAX5915A/MAX5916A
3.3VO_ SHORT CIRCUIT
MAX5915A/MAX5916A
3.3VAUXO_ SHORT CIRCUIT
MAX5915 toc53
MAX5915 toc52
PGOOD_
5V/div
tRESP2
100ns/div
MAX5915 toc54
3.3VAUXO_
1V/div
3.3VO_
1V/div
12VO_
5V/div
10
20µs/div
MAX5915 toc50
MAX5915 toc49
I3.3VO_
10A/div
FAIRCHILD
FDS6670A
PGOOD_
5V/div
PGOOD_
5V/div
3.3VO_
2V/div
MAX5915 toc48
3.3VO_
2V/div
I5VO_
10A/div
I5VO_
10A/div
PGOOD_
5V/div
3.3VO_ IMMEDIATE
SHORT-CIRCUIT RESPONSE
5VO_ CURRENT LIMIT
PGOOD_
5V/div
tRESP2
100ns/div
tRESP2
100ns/div
______________________________________________________________________________________
Dual PCI 2.2 Hot-Swap Controllers
PIN
NAME
FUNCTION
1
+12VOA
2
3.3VGATEA
3
3.3VSENA
4
3.3VOA
5
ONA
Channel A Master ON/OFF Output Control. Drive ONA logic high to enable channel A +3.3V, +5V, and
±12V outputs. V+12VIN must be > UVLO threshold.
6
ONB
Channel B Master ON/OFF Output Control. Drive ONB logic high to enable channel B +3.3V, +5V, and
±12V outputs. V+12VIN must be > UVLO threshold.
7
GND
Ground
8
PGOODA
Channel A Power-Good Output. PGOODA is an open-drain output that pulls low when a fault is detected on
channel A outputs.
9
PGOODB
Channel B Power-Good Output. PGOODB is an open-drain output that pulls low when a fault is detected on
channel B outputs.
10
AUXONA
Channel A 3.3VAUX ON/OFF Control Input. Drive AUXONA logic high to enable channel A +3.3V auxiliary
output.
11
AUXONB
Channel B 3.3VAUX ON/OFF Control Input. Drive AUXONB logic high to enable channel B +3.3V auxiliary
output.
Channel A +12V Output
Channel A +3.3V External N-Channel MOSFET Gate Drive. 3.3VGATEA driven by +12VIN.
Channel A External 3.3V Current-Sense Input
Channel A +3.3V Output Sense
12
3.3VAUXOA Channel A 3.3VAUX Output
13
3.3VAUXIN
14
3.3VAUXOB Channel B 3.3VAUX Output
3.3VAUX Input. Provides power to the +3.3V auxiliary channels.
15
-12VOB
Channel B -12V Output
16
-12VIN
-12V Input
17
-12VOA
Channel A -12V Output
18
5VOB
19
5VSENB
20
5VGATEB
21
5VOA
22
5VSENA
23
5VGATEA
24
3.3VOB
25
3.3VSENB
26
3.3VGATEB
27
+12VOB
Channel B +12V Output
28
+12VIN
+12V Input. +12VIN powers the main supplies of the MAX5915/MAX5915A/MAX5916/MAX5916A.
Channel B +5V Output Sense
Channel B External +5V Current-Sense Input
Channel B +5V External N-Channel MOSFET Gate Drive. 5VGATEB driven by +12VIN.
Channel A +5V Output Sense
Channel A External +5V Current-Sense Input
Channel A +5V External N-Channel MOSFET Gate Drive. 5VGATEA driven by +12VIN.
Channel B +3.3V Output Sense
Channel B External +3.3V Current-Sense Input
Channel B +3.3V External N-Channel MOSFET Gate Drive. 3.3VGATEB driven by +12VIN.
______________________________________________________________________________________
11
MAX5915/MAX5915A/MAX5916/MAX5916A
Pin Description
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
Table 1. PCI Standard Maximum Values
SUPPLY VOLTAGE (V)*
VOLTAGE TOLERANCE (%)
MAX CURRENT (A)
MAX POWER (W)
+5
±5
5
25
+3.3
±0.3V
7.6
25
+12
±5
0.5
6
-12
±10
0.1
1.2
+3.3 aux (enabled)
±10
0.375
1.24
+3.3 aux (disabled)
±10
0.02
0.066
*Supply voltage is referenced to the output of the MAX5915/MAX5916.
Detailed Description
The MAX5915/MAX5915A/MAX5916/MAX5916A are circuit-breaker ICs for hot-swap applications where a PCI
card is inserted into a slot that is connected to a live
backplane. Normally, when a card is plugged into a live
backplane, the card’s discharged capacitors provide a
low-impedance path that can momentarily cause the
main power supply to collapse. Both devices provide
startup current limiting and undervoltage/overcurrent
monitoring of two separate PCI card slots. Current limiting and short-circuit protection are achieved using
external n-channel MOSFETs on the +3.3V and +5V
supply lines and internal MOSFETs on the ±12V and
+3.3V auxiliary supply lines.
External sense resistors monitor the output currents of
the +3.3V and +5V supplies. These external sense
resistors adjust the overcurrent trip threshold. PCI standards dictate maximum values for the supply power
and total power drawn from the backplane. The maximum power that any one PCI board can draw is 25W.
Table 1 lists PCI standard maximum voltage, current,
and power for each supply.
Table 1 illustrates that both the +5V and +3.3V supplies
can draw up to 25W. Total combination of output power
should be limited to 25W based on PCI standard.
Startup Mode
The +12V input powers the internal circuitry of these
devices. The main supply outputs (3.3VO_, 5VO_,
+12VO_, and -12VO_) can become active only after
both of the following events have occurred:
• V+12VIN is above its undervoltage lockout (UVLO)
threshold.
•
ON_ is driven high.
Figure 1 displays typical startup waveforms. The main
supplies can be enabled without using the auxiliary
supply; however, PGOOD_ remains in a low state if the
12
auxiliary supply is not used.
The auxiliary supply (3.3VAUXO_) is available after both
of these events have occurred:
• V3.3VAUXIN is above its UVLO threshold.
•
AUXON_ is driven high.
Normal Operation +3.3V, +5V,
±12V Outputs
The internal circuitry for these devices monitors the output voltage on all channels except the -12V supply. All
outputs are monitored for overcurrent. An undervoltage
condition occurs when any supply’s output voltage falls
below the set undervoltage level. An overcurrent fault
occurs when a monitored output current reaches the
set overcurrent threshold. Each supply has its own
overcurrent and undervoltage thresholds. If any of the
monitored voltages fall below their respective undervoltage level, or if any of the monitored output currents
reach their overcurrent threshold, for a time period,
tDELAY, the controller disables the channel with the fault
condition (see the Fault Management section).
External sense resistors monitor current through the
external MOSFETs of the +3.3V and +5V outputs, while
the current for the ±12V supplies are internally monitored.
A fault condition on one of the main outputs causes all
the channel’s main outputs to shut down after tDELAY
and then either latch off (MAX5915/MAX5915A) or automatically restart after tRESTART (MAX5916/MAX5916A).
A fault on any of the channel’s main outputs does not
affect the channel’s auxiliary outputs.
Normal Operation +3.3V Auxiliary Output
Auxiliary output voltage and current are monitored internally. The +3.3V auxiliary output is independent of the
main outputs but the main outputs are dependent on
the auxiliary outputs. Fault conditions on the main outputs do not affect the auxiliary. A fault on the auxiliary
supply causes the controller to disable all of the affected
______________________________________________________________________________________
Dual PCI 2.2 Hot-Swap Controllers
+12VIN
3.3VAUX UVLO THRESHOLD
3.3VAUXIN
ON_
AUXON_
+12VO_
-12VO_
5VO_
3.3VO_
3.3VAUXO_
PGOOD_
tSTART
TIMING NOT TO SCALE
Figure 1. Startup Waveforms
channel outputs, auxiliary and main. A fault condition
occurs when the output voltage falls below the set
undervoltage threshold or the output current reaches the
overcurrent threshold. When a fault occurs, all supplies
of the affected channel are disabled after a time period
tDELAY. All outputs are automatically restarted after a
time equal to tRESTART. This reset is built into all devices.
Current Limits
All supplies are protected against output overcurrent or
short-circuit conditions. The MAX5915/MAX5915A and
MAX5916/MAX5916A employ a “brickwall” current limit
on the +3.3V and +5V supplies and a current-foldback
scheme on the ±12V and +3.3V auxiliary supplies.
Brickwall
A brickwall current limit protects the +3.3V and +5V
main supplies by limiting the load current. The external
sense resistors and the current-limit threshold set the
brickwall current limits. A fault occurs when the load
current reaches the brickwall limit. The main outputs
shut down after tDELAY if the fault remains. The brickwall feature limits inrush current caused by positive
supply voltage steps.
Foldback
The ±12V and +3.3V auxiliary supplies employ an
internal current-foldback scheme. The MAX5915/
MAX5915A/MAX5916/MAX5916A gradually limit the load
current once the current-foldback threshold is reached. If
the overcurrent condition lasts longer than a fast transient, the output current is reduced to the foldback current limit and remains at that level for tDELAY unless the
overcurrent condition is cleared. See the Typical
Operating Characteristics.
______________________________________________________________________________________
13
MAX5915/MAX5915A/MAX5916/MAX5916A
+12V
UVLO THRESHOLD
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
+12VIN
+12V UVLO THRESHOLD
3.3VAUX UVLO THRESHOLD
3.3VAUXIN
ON_
AUXON_
+12VO_
5VO_
3.3VO_
-12VO_
3.3VAUXO_
PGOOD_
tDEG.UVLO
TIMING NOT TO SCALE
tSTART
tDEG.UVLO
tSTART
Figure 2. Input UVLO Fault Management in the MAX5915/MAX5915A/MAX5916/MAX5916A
Input Undervoltage Lockout
UVLO prevents these devices from turning on
internal/external MOSFETs until the input voltage exceeds
the lockout threshold. The UVLO protects the MOSFETs
from insufficient gate-drive voltage. Figure 2 shows that if
an input undervoltage condition exists for more than
tDEG,UVLO, the outputs are disabled and PGOOD_ goes
low immediately. The time delay tDEG,UVLO is negative
edge delayed and acts as a deglitch.
Fault Management
When a fault is detected on one of the main outputs, the
MAX5915/MAX5915A/MAX5916/MAX5916A disable the
channel outputs after tDELAY. A fault occurs when any of
the output voltages fall below their output undervoltage
threshold or any of the output currents exceed their output overcurrent threshold. PGOOD_ pulls low if a fault
persists for more than tRESP. The channel with the fault is
disabled after tDELAY. The MAX5915/MAX5916 are available with a response time of 1.5ms (t RESP ). The
MAX5915A/MAX5916A offer a response time of 100ns
(tRESP2). If the fault is removed before tDELAY, the channel remains on and PGOOD_ pulls high immediately.
14
Latched Fault Protection
The MAX5915/MAX5915A latch off the appropriate
channel’s main outputs. Toggling +12VIN or ON_
restarts the main outputs. Figure 3 outlines the logic for
the main and auxiliary shutdown control of the
MAX5915, while fault handling is shown in Figures 5
and 6.
Autoretry Fault Protection
The MAX5916/MAX5916A automatically restart the outputs after t RESTART . The MAX5915/MAX5915A/
MAX5916/MAX5916A handle faults on the auxiliary outputs by automatically restarting the appropriate channel. Figure 4 outlines the logic for the main and auxiliary
shutdown control of the MAX5916, while fault handling
is shown in Figures 6 and 7.
Output Overcurrent
External sense resistors monitor the current on the +5V
and +3.3V outputs, while the +3.3V auxiliary and ±12V
output currents are monitored internally. Figures 5, 6,
and 7 show overcurrent fault management for the
MAX5915/MAX5915A/MAX5916/MAX5916A.
______________________________________________________________________________________
Dual PCI 2.2 Hot-Swap Controllers
MAIN ON
HIGH = MAIN SUPPLIES
ARE TURNED OFF
STARTUP_+12VIN
AUX OFF
ENABLE_3.3VAUXIN
HIGH = AUX SUPPLY
TURNED OFF
V
D
STARTUP_3.3VAUXIN
tRESTART
Q
RESET
Q
OC_3.3VAUXO_
tDELAY
tRESTART
POSITIVE EDGE
TRIGGERED D FLIP-FLOP,
RESET IS ACTIVE LOW
RESET
UV_3.3VAUXO_
V = INTERNAL SUPPLY LOGIC
GENERATED BY THE 12VIN OR THE
3.3VAUXIN, WHICHEVER IS HIGHER
OC_3.3VO_
OC_5VO_
V
tDELAY
OC_+12VO_
OC_-12VO_
UV_3.3VO_
D
Q
RESET
Q
tDELAY
POSITIVE EDGE TRIGGERED D FLIP-FLOP,
RESET IS ACTIVE LOW
UV_5VO_
UV_+12VO_
SEE TABLE 2 FOR EXPLANATION OF SIGNALS.
Figure 3. Main and Auxiliary Supply Shutdown Control Logic for MAX5915/MAX5915A
Output Undervoltage
PGOOD_ Operation
The output voltages on all supplies, except the -12V
supply, are monitored for undervoltage. Output undervoltage fault management is identical to the output
overcurrent fault management. Figures 5, 6, and 7 can
be used to illustrate undervoltage faults on the
MAX5915/MAX5915A/MAX5916/MAX5916A.
The MAX5915/MAX5915A/MAX5916/MAX5916A incorporate a PGOOD_ output to report when power is good
to a microprocessor or controller. PGOOD_ remains low
if the auxiliary outputs are not powered, for PCI and
compact PCI systems where the 3.3VAUX is not available. Connect 3.3VAUXIN to 3.3VIN and connect
AUXON_ to ON_ to allow PGOOD_ to transition high
when the main supplies are available. The open-drain
structure of PGOOD_ requires an external pullup resistor (see the Functional Diagram). Figure 8 shows the
internal logic of the PGOOD_ output.
Thermal Shutdown Control
The MAX5915/MAX5915A/MAX5916/MAX5916A feature
internal thermal protection. Two thresholds detect when
the device is overheated. If the first threshold is reached,
the channel that is in overcurrent shuts down. If the second thermal threshold is reached, the entire device shuts
down. The device cannot be restarted until the thermal
condition is cleared. For the MAX5915, the main channels turn back on after +12VIN or ON_ is toggled. For the
MAX5916, the main channels turn back on after
t RESTART . The auxiliary channels for the MAX5915/
MAX5915A/MAX5916/MAX5916A restart after tRESTART.
______________________________________________________________________________________
15
MAX5915/MAX5915A/MAX5916/MAX5916A
ENABLE_+12VIN
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
ENABLE_+12VIN
MAIN OFF
HIGH = MAIN SUPPLIES
ARE TURNED OFF
STARTUP_+12VIN
AUX OFF
ENABLE_3.3VAUXIN
HIGH = AUX SUPPLY
TURNED ON
V
D
STARTUP_3.3VAUXIN
Q
tRESTART
RESET
Q
OC_3.3VAUXO_
tDELAY
POSITIVE EDGE
TRIGGERED D FLIP-FLOP,
RESET IS ACTIVE LOW
RESET
UV_3.3VAUXO_
V = INTERNAL SUPPLY LOGIC
GENERATED BY THE 12VIN OR THE
3.3VAUXIN, WHICHEVER IS HIGHER
V
OC_3.3VO_
OC_5VO_
D
tDELAY
OC_+12VO_
OC_-12VO_
UV_3.3VO_
Q
tRESTART
RESET
Q
tDELAY
RESET
POSITIVE EDGE TRIGGERED D FLIP-FLOP,
RESET IS ACTIVE LOW
UV_5VO_
UV_+12VO_
SEE TABLE 2 FOR EXPLANATION OF SIGNALS.
tRESTART
Figure 4. Main and Auxiliary Supply Shutdown Control Logic for MAX5916/MAX5916A
Applications Information
Component Selection
External MOSFETs
Select the external n-channel MOSFETs according to
the application’s current requirement. Limit switch power
dissipation by choosing a MOSFET with an RDS(ON) low
enough to have a minimum voltage drop at full load.
High RDS(ON) causes output ripple if the board has
pulsing loads. High RDS(ON) can trigger an external
undervoltage fault at full load. Determine the MOSFET’s
power rating requirement to accommodate a short-circuit condition on the board during startup (see the
External MOSFET Thermal Considerations section).
Table 3 lists MOSFET and sense resistor manufacturers.
16
Sense Resistors
The overcurrent sense voltage threshold on the +3.3V
output is 46mV and 31mV on the +5V output. Choose a
sense resistor using the following equation:
RSENSE = (V-ILIM / ILOAD)
where ILOAD is the brickwall current limit for the output.
Choose the sense resistors’ power rating to accommodate the overload current:
PSENSE = (ILOAD)2 x RSENSE
Additional External Gate Capacitance
Connecting an external capacitance from the gates of
the external MOSFETs to GND slows the turn on of the
+5V and +3.3V supplies.
______________________________________________________________________________________
Dual PCI 2.2 Hot-Swap Controllers
SIGNAL NAME
DESCRIPTION
Enable_+12VIN
Signal is HIGH:
1. +12VIN > VUVLO, +12V
2. ON_ = HIGH
3. Thermal shutdown NOT active
Startup_+12VIN
Signal is HIGH:
1. +12VIN > VUVLO, +12V
2. ON_ = HIGH
3. tSTART has elapsed
Enable_3.3VAUXIN
Signal is HIGH
1. 3.3VAUXIN > VUVLO, AUX
2. AUXON_ = HIGH
3. Thermal shutdown NOT active
Startup_3.3VAUXIN
Signal is HIGH:
1. 3.3VAUXIN > VUVLO, AUX
2. AUXON_ = HIGH
3. tSTART has elapsed
OC_
Signal is HIGH when an overcurrent condition exists on the output of the supply.
UV_
Signal is HIGH when an undervoltage condition exists on the output of the supply.
Maximum Load Capacitance
Layout Considerations
Large capacitive loads can cause a problem when
inserting discharged PCI cards into the live backplane.
If the time needed to charge the capacitance of the
board is greater than the typical startup time, 50ms, a
fault can occur after startup.
The MAX5915/MAX5915A/MAX5916/MAX5916A are able
to withstand large capacitive loads due to their long startup time. Each supply has its own current-limit threshold.
Calculate the maximum load capacitance as follows:
To take full advantage of the switch response time to an
output fault condition, keep all traces as short as possible and maximize the high-current trace dimensions to
reduce the effect of undesirable parasitic inductance.
Place the MAX5915/MAX5915A/MAX5916/MAX5916A
close to the PCI card’s connector. Use a ground plane
to minimize impedance and inductance. Minimize the
current-sense resistor trace length and ensure accurate
current sensing with Kelvin connections (Figure 9).
When an output is short circuited, the voltage drop
across the external MOSFET becomes large. Hence the
power dissipation across the switch and die temperature both increase. An efficient way to achieve good
power dissipation on a surface-mount package is to lay
out two copper pads directly under the package on
both sides of the board. Connect the two pads to the
ground plane through vias, and use enlarged copper
mounting pads on the topside of the board.
CBOARD < 50ms x I_, LIM / VSUPPLY
Input Transients
The +12V and +3.3VAUX supplies must be above their
respective UVLO thresholds before startup can occur.
Input transients can cause the input voltage to sag
below the UVLO threshold. The MAX5915/MAX5915A/
MAX5916/MAX5916A reject input transients that are
shorter than tDEG, UVLO.
External MOSFET Thermal
Considerations
The power dissipation of the external MOSFET is low
when it is on, PD = ILOAD2 x RDS(ON). A considerable
amount of power is dissipated during startup and continuous short-circuit conditions. The design must take
into consideration the worst-case scenario.
Chip Information
TRANSISTOR COUNT: 1021
PROCESS: BiCMOS
______________________________________________________________________________________
17
MAX5915/MAX5915A/MAX5916/MAX5916A
Table 2. Logic Diagram Signal Descriptions
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
+12VIN
+12V UVLO THRESHOLD
OVERCURRENT THRESHOLD
IOUT
(+12VO_, 5VO_, 3.3VO-, OR -12VO_)
ON_
+12VO_
5VO_
3.3VO_
tDEG
-12VO_
3.3VAUXO_
PGOOD_
tRESP
(tRESP2)
tDELAY
tSTART
OUTPUT UNDERVOLTAGE FAULT HANDLING RESULTS IN SIMILAR RESPONSE. TIMING NOT TO SCALE.
( ) FOR MAX5915A.
Figure 5. Main Outputs Overcurrent Fault Management in the MAX5915/MAX5915A
18
______________________________________________________________________________________
Dual PCI 2.2 Hot-Swap Controllers
MAX5915/MAX5915A/MAX5916/MAX5916A
+12VIN
+12V UVLO THRESHOLD
OVERCURRENT
UVLO THRESHOLD
IOUT
(3.3VAUXO_)
ON_
+12VO_
5VO_
3.3VO_
tDEG
-12VO_
3.3VAUXO_
PGOOD_
tRESP
(tRESP2)
tDELAY
tRESTART
tSTART
OUTPUT UNDERVOLTAGE FAULT HANDLING RESULTS IN SIMILAR RESPONSE. TIMING NOT TO SCALE.
( ) FOR MAX5915A/MAX5916A.
Figure 6. Auxiliary Outputs Overcurrent Fault Management in the MAX5915/MAX5915A/MAX5916/MAX5916A
______________________________________________________________________________________
19
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
+12VIN
+12V UVLO THRESHOLD
OVERCURRENT THRESHOLD
IOUT
(+12VO_, 5VO_, 3.3VO_, OR- 12VO_)
ON_
+12VO_
5VO_
3.3VO_
-12VO_
3.3VAUXO_
PGOOD_
tRESP
(tRESP2)
tDELAY
tRESTART
tSTART
OUTPUT UNDERVOLTAGE FAULT HANDLING RESULTS IN SIMILAR RESPONSE. TIMING NOT TO SCALE.
( ) FOR MAX5916A.
Figure 7. Main Outputs Overcurrent Fault Handling in the MAX5916/MAX5916A
20
______________________________________________________________________________________
Dual PCI 2.2 Hot-Swap Controllers
MAX5915/MAX5915A/MAX5916/MAX5916A
tDEG
tDEG, UVLO
tDEG
ON_
tSTART
UVLO_+12VIN
tDEG, UVLO
tSTART
UVLO_3.3VAUXIN
PGOOD_
tDEG
AUXON_
tDEG, UVLO
GND
OC_MAIN_OUTPUTS
UV_MAIN_OUTPUTS
tRESP
tRESP
(tRESP2)
OC_3.3VAUXO_
( ) FOR MAX5915A/MAX5916A.
UV_3.3VAUXO_
Figure 8. PGOOD_ Logic Diagram
______________________________________________________________________________________
21
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
Table 3. Component Manufacturers
COMPONENT
MANUFACTURER
PHONE
WEBSITE
Dale-Vishay
402-564-3131
www.vishay.com
IRC
704-264-8861
www.irctt.com
Fairchild
888-522-5372
www.fairchildsemi.com
International Rectifier
310-322-3331
www.irf.com
Motorola
602-244-3576
www.mot-sps.com/ppd/
Sense Resistors
MOSFETs
Pin Configuration
HIGH-CURRENT PATH
TOP VIEW
SENSE RESISTOR
+12VOA 1
28 +12VIN
3.3VGATEA 2
27 +12VOB
3.3VSENA 3
26 3.3VGATEB
3.3VOA 4
25 3.3VSENB
ONA 5
ONB 6
MAX5915
MAX5915A
MAX5916
MAX5916A
GND 7
Figure 9. Kelvin Connections for Sense Resistors
Selector Guide
PART
MAX5915EUI
FAULT
MANAGEMENT
PGOOD_ FAULT
RESPONSE TIME (S)
Latched
1.5m
Latched
100n
MAX5916EUI
Autorestart
1.5m
MAX5916AEUI
Autorestart
100n
MAX5915AEUI
22
24 3.3VOB
MAX5915
MAX5915A
MAX5916
MAX5916A
23 5VGATEA
22 5VSENA
PGOODA 8
21 5VOA
PGOODB 9
20 5VGATEB
AUXONA 10
19 5VSENB
AUXONB 11
18 5VOB
3.3VAUXOA 12
17 -12VOA
3.3VAUXIN 13
16 -12VIN
3.3VAUXOB 14
15 -12VOB
TSSOP
______________________________________________________________________________________
Dual PCI 2.2 Hot-Swap Controllers
PCI CARD A
+12V
3.3VAUX
-12V
+12VIN
3.3VAUXIN
-12VIN
PCI SLOT A
BACKPLANE
PCI SLOT B
PCI CARD B
+12V
+12VOA
+12VOB
+12V
-12V
-12VOA
-12VOB
-12V
3.3VAUX
3.3VAUXOA
3.3VAUXOB
5VOA
5VSENA
5VGATEA
ON
OFF
3.3VAUX
5VOB
MAX5915
MAX5915A
MAX5916
MAX5916A
ONA
5VSENB
5VGATEB
ON
OFF
ONB
+5V
+5V
+5V
+5V
+3.3V
+3.3V
GND
GND
+3.3V
ON
OFF
PGOODA
PGOODB
AUXONA
AUXONB
3.3VGATEA
3.3VGATEB
3.3VSENA
3.3VSENB
3.3VOA
+3.3V
ON
OFF
3.3VOB
GND
______________________________________________________________________________________
23
MAX5915/MAX5915A/MAX5916/MAX5916A
Typical Operating Circuit
Dual PCI 2.2 Hot-Swap Controllers
MAX5915/MAX5915A/MAX5916/MAX5916A
Functional Diagram
+12VIN
-12VIN
3.3V
3.3V
-12VOA
-12VOB
+12VOA
+12VOB
3.3VGATEB
3.3VGATEA
3.3VSENA
CHANNEL B
CONTROL
CHANNEL A
CONTROL
3.3VSENB
RSENSE
RSENSE
3.3VOA
3.3VOB
5V
5VGATEA
5VSENA
RSENSE
5V
BIAS, BANDGAP
REFERENCE, AND
UVLO
5VGATEB
5VSENB
TEMPERATURE
SENSOR
RSENSE
MAX5915
MAX5915A
MAX5916
MAX5916A
5VOA
VPULLUP
5VOB
CHARGE PUMP
AND GATE
CONTROL
ONA
ONB
PGOODA
PGOODB
AUXONA
3.3VAUXIN
3.3VAUXOA
AUXONB
3.3VAUXOB
GND
24
______________________________________________________________________________________
VPULLUP
Dual PCI 2.2 Hot-Swap Controllers
TSSOP4.40mm.EPS
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 25
© 2004 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
MAX5915/MAX5915A/MAX5916/MAX5916A
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)