MAXIM MAX5915

19-2420; Rev 0; 4/02
Dual PCI 2.2 Hot-Swap Controllers
Features
♦ PCI 2.2 Compliant
The MAX5915/MAX5916 provide independent power
controls for +3.3V, +5V, ±12V, and +3.3V auxiliary supplies of two PCI cards. The MAX5915/MAX5916 provide
intelligent selective thermal shutdown control that shuts
down the channel with an overcurrent fault. Both the
MAX5915 and MAX5916 include internal power
MOSFETs for the +12V, -12V, and +3.3V auxiliary outputs. The MAX5915/MAX5916 use internal charge
pumps to activate the gates of the internal FETs controlling the +3.3V auxiliary supply. Internal FETs and currentsense circuitry regulate the ±12V and the +3.3V auxiliary
supplies. Channels A and B operate independently,
allowing a single MAX5915/MAX5916 to monitor two PCI
card slots.
♦ Separate ON/OFF Control Input for Each Channel
♦ 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
♦ 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
The MAX5915 offers latched fault protection and the
MAX5916 offers 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.
♦ Intelligent Selective Thermal Shutdown Control
Shuts Down Only the Channel with an Overcurrent
Fault
♦ 28-Pin TSSOP Package
Applications
Ordering Information
PCI 2.2 Server
PCI Server
FAULT
MANAGEMENT
PART
RAID
TEMP
RANGE
PINPACKAGE
MAX5915EUI
Latched
-40°C to +85°C
28 TSSOP
MAX5916EUI
Autorestart
-40°C to +85°C
28 TSSOP
Pin Configuration, Functional Diagram, and Typical Operating
Circuit appear at end of data sheet.
Typical Application Circuit
+3.3V
FAIRCHILD
FDS6670A
0.005Ω
470µF
FAIRCHILD
FDS6670A
+5V
0.005Ω
+12V
4.7µF 0.1µF
-12V
4.7µF 0.1µF
+3.3VAUX
+12VIN
-12VIN
3.3VAUXIN
4.7µF 0.1µF
ON
ON_
OFF
10kΩ
3.3VGATE_
3.3VSEN_
3.3VO_
5VGATE_
5VSEN_
470µF
5VO_
+12VO_
-12VO_
3.3VAUXO_
47µF
47µF
MAX5915
MAX5916
47µF
5V
ON
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/MAX5916
General Description
The MAX5915/MAX5916 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, the
MAX5915/MAX5916 provide protection against shortcircuit, overcurrent, and undervoltage conditions.
MAX5915/MAX5916
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_ = 0
50
150
250
µA
V+12VIN
V
Gate High Voltage
V3.3VGATE_, HIGH
I3.3VGATE _ = 1µA
Gate Low Voltage
V3.3VGATE_, LOW
I3.3VGATE _ = 1µA, VON_ = 0
3.3VO_ Input Bias Current
3.3VO_ Internal Pulldown
3.3VSEN_ Input Bias Current
I3.3VO_, BIAS
RPD
V+12VIN 0.5
0.1
V3.3VO_ = +3.3V
VON_ = 0
V3.3VSEN_ = +3.3V
Current-Limit Threshold
V3.3V, LIM
V3.3VGATE _ = +6V
41
Output Undervoltage Threshold
V3.3VIN, UV
V3.3VGATE _ falling
2.79
2
V
20
µA
1
I3.3VSEN_, BIAS
Output Undervoltage Threshold
Hysteresis
0.4
kΩ
10
µA
46
51
mV
2.89
2.99
V
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_ = 0
Gate High Voltage
V5VGATE_, HIGH
I5VGATE_ = 1µA
Gate Low Voltage
V5VGATE_, LOW
I5VGATE_ = 1µA, VON_ = 0
5VO_ Input Bias Current
I5VO_, BIAS
V5VO_ = +5V
5VO_ Internal Pulldown
R5VO_, PD
VON_ = 0
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
I+12VIN, LIM
Current-Foldback Threshold
TA = +25°C, ID = 0.5A
0.32
TA = +85°C, ID = 0.5A
V+12VO_ = 0
0.5
0.68
Output current rising (Note 2)
Output Undervoltage Threshold
V+12VO_, UV
Output falling
+12VO_ Internal Pulldown
R+12VO_, PD
VON_ = 0
0.38
1
1.36
1.4
10.00
10.4
Ω
A
A
10.82
1
V
kΩ
-12V SUPPLY CONTROL
On-Resistance of Internal Switch
Foldback Current Limit
RDS(ON), -12V
TA = +25°C, ID = 0.1A
I-12VIN, LIM
V-12VO_ = 0
-12VO_ Internal Pullup
R-12VO_, PU
VON_ = 0
+3.3VAUX SUPPLY CONTROL
Input Voltage Range
V3.3VAUXIN
Current-Foldback Threshold
3.3VAUXIN Undervoltage
Lockout
Hysteresis
Supply Current
0.58
TA = +85°C, ID = 0.1A
136
Output current rising (Note 2)
VUVLO, AUX
Input rising
0.9
1.3
205
273
Ω
mA
240
mA
1
kΩ
3.0
3.3
3.6
V
2.65
2.75
2.85
V
2
mA
VUVLO-AUX, HYS
30
IQ, 3.3VAUX
1
mV
_______________________________________________________________________________________
3
MAX5915/MAX5916
ELECTRICAL CHARACTERISTICS (continued)
MAX5915/MAX5916
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
MIN
TYP
0.24
TA = +85°C, ID = 0.4A
V3.3VAUXO_ = 0
MAX
0.4
0.6
0.5
0.75
2.76
2.89
Output current rising (Note 2)
1.0
1.2
UNITS
Ω
A
A
Output Undervoltage Threshold
V3.3VAUXIN, UV
2.99
Auxiliary Input UVLO Delay Time
tDEG, UVLO
(Note 1)
1.6
ms
V
3.3VAUXO_ Internal Pulldown
R3.3VAUXO_
ON_ = 0
1
kΩ
ON AND AUXON COMPARATORS
Threshold Voltage
Hysteresis
Input Bias Current
ON_ and AUXON_ Deglitch
Time
1.0
VHYS
2.1
25
IB, COMP
tDEG
mV
20
Figures 5–8 (Note 3)
V
µA
µs
4
FAULT RESPONSE, PGOOD_ STATUS OUTPUT
PGOOD_ Output Overcurrent
and Undervoltage Response
Time
tRESP
Figures 5–8
Output Overcurrent and
Undervoltage Deglitch Time
tDELAY
Figures 3–7
16 ✕
tRESP
ms
PGOOD_ Startup Time Out
tSTART
See Figures 1, 2, 5, 6, 7, and 8
4✕
tDELAY
ms
Delay time to restart after OC and/or
UV shutdown
64 ✕
tSTART
ms
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
ISINK = 2mA, ON_ = 0
0.5
1.5
0.5
0.7
V
1
µA
VPGOOD_ = +5.5V
(Note 4)
(Note 5)
ms
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
4.84
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
50
-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/MAX5916
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
650
600
550
23.5
21.5
19.5
17.5
15.5
13.5
3.3VGATE_
11.5
175
CGATE = 1nF
9.5
500
3.0
-40
MAX5915 toc13
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0
3.3V AUXILIARY INTERNAL SWITCH RON (Ω)
+12V INTERNAL SWITCH RON
vs. TEMPERATURE
-15
10
35
60
-15
10
35
60
145
0.20
0.15
0.10
0.05
-40
35
60
85
0.7
0.6
0.5
0.4
0.3
0.2
0
-15
10
35
60
85
-40
TEMPERATURE (°C)
TIME-TO-CHARGE GATE
(CGATE = 1nF)
10
35
60
TIME-TO-CHARGE GATE
(CGATE = 10nF)
MAX5915 toc17
85
MAX5915 toc18
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
-15
TEMPERATURE (°C)
ON_,
5V/div
6
10
0.8
ON_,
5V/div
100µs/div
-15
0.1
-40
MAX5915 toc16
CGATE = 1nF
-12V INTERNAL SWITCH RON
vs. TEMPERATURE
0.25
TIME-TO-CHARGE GATE
(CGATE = 0.1nF)
5VGATE_
140
3.3V AUXILIARY INTERNAL SWITCH RON
vs. TEMPERATURE
0.30
TEMPERATURE (°C)
150
TEMPERATURE (°C)
0.35
85
155
85
0
-40
3.3VGATE_
160
TEMPERATURE (°C)
-12V INTERNAL SWITCH RON (Ω)
1.0 1.5
2.0 2.5
V3.3VAUXIN - V3.3VAUXO_ (V)
165
130
MAX5915 toc14
0.5
170
135
5VGATE_
7.5
0
MAX5915 toc12
25.5
180
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 toc15
3.3VAUX_ CURRENT FOLDBACK
vs. DIFFERENTIAL SWITCH VOLTAGE
+12V INTERNAL SWITCH RON (Ω)
MAX5915/MAX5916
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
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
2.10
0.25
2.0
3.3V AUXILIARY OUTPUT UNDERVOLTAGE THRESHOLD (V)
MAX5915 toc20
2.8
ON_ AND AUXON_ THRESHOLD
vs. TEMPERATURE
MAX5915 toc26
+12VIN SUPPLY CURRENT (mA)
2.9
2.50
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/MAX5916
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
TEMPERATURE (°C)
-15
10
35
60
10ms/div
85
AUXON_
5V/div
MAIN SUPPLY
TURN-OFF WAVEFORMS
TURN-ON DELAY
MAX5915 toc34
ON_
5V/div
5VO_
5V/div
+12VO_
10V/div
3.3VAUXO_
2V/div
MAX5915 toc36
MAX5915 toc35
+12VIN
10V/div
+12VO_
10V/div
3.3VAUXIN_
2V/div
ON_ = 5V
AUXON_ = 5V
ON_ = 5.0V
10ms/div
AUXON_ = 5V
TEMPERATURE (°C)
AUXILIARY SUPPLY
TURN-ON WAVEFORMS
PGOOD_
5V/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/MAX5916
Dual PCI 2.2 Hot-Swap Controllers
3.3VAUXO_
2V/div
200µs/div
PGOOD_
5V/div
40ms/div
_______________________________________________________________________________________
Dual PCI 2.2 Hot-Swap Controllers
AUXILIARY SUPPLY
TURN-OFF WAVEFORMS
tDEG DELAY TIME
MAX5915 toc37
ON_
5V/div
MAIN SUPPLY
LATCHED FAULT MANAGEMENT
MAX5915 toc39
MAX5915 toc38
ON_
5V/div
+12VO_
5V/div
3.3VAUXO_
2V/div
5VO_
2V/div
3.3VAUXO_
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
5VO_
2V/div
MAX5915 toc41
+12VO_
5V/div
+12VO_
5V/div
5VO_
I+12VO_
10A/div
3.3VAUXO_
5V/div
3.3VAUXO_
5V/div
PGOOD_
5V/div
PGOOD_
5V/div
PGOOD_
5V/div
400ms/div
400ms/div
1µs/div
-12VO_ IMMEDIATE
SHORT-CIRCUIT RESPONSE
+12VO_ CURRENT FOLDBACK
MAX5915 toc43
+12VO_
5V/div
MAX5915 toc42
-12VO_ CURRENT FOLDBACK
MAX5915 toc45
MAX5915 toc44
-12VO_
5V/div
-12VO_
5V/div
I-12VO_
2A/div
I-12VO_
500mA/div
I+12VO_
5A/div
PGOOD_
5V/div
2ms/div
PGOOD_
5V/div
200ns/div
PGOOD_
5V/div
2ms/div
_______________________________________________________________________________________
9
MAX5915/MAX5916
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/MAX5916
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
I5VO_
10A/div
PGOOD_
5V/div
FAIRCHILD
FDS6670A
MAX5915 toc48
5VO_
5V/div
3.3VO_
2V/div
I5VO_
10A/div
I3.3VO_
10A/div
PGOOD_
5V/div
40µs/div
3.3VO_ IMMEDIATE
SHORT-CIRCUIT RESPONSE
5VO_ CURRENT LIMIT
PGOOD_
5V/div
2ms/div
3.3VAUXO_ IMMEDIATE
SHORT-CIRCUIT RESPONSE
3.3VO_ CURRENT LIMIT
3.3VAUXO_ CURRENT FOLDBACK
MAX5915 toc51
3.3VO_
2V/div
3.3VAUXO_
2V/div
3.3VAUXO_
2V/div
I3.3VO_
10A/div
I3.3VAUXO_
10A/div
I3.3VAUXO_
1A/div
10
2ms/div
20µs/div
MAX5915 toc50
MAX5915 toc49
PGOOD_
5V/div
FAIRCHILD
FDS6670A
PGOOD_
5V/div
2µs/div
PGOOD_
5V/div
2ms/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/MAX5916.
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/MAX5916
Pin Description
MAX5915/MAX5916
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/MAX5916 are circuit-breaker ICs for hotswap 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 the
MAX5915/MAX5916. 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 the MAX5915/MAX5916 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 t DELAY and then either latch off (MAX5915) or
automatically restart after tRESTART (MAX5916). 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 dis-
______________________________________________________________________________________
Dual PCI 2.2 Hot-Swap Controllers
MAX5915/MAX5916
+12V
UVLO THRESHOLD
+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
able all of the affected 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 both the MAX5915/MAX5916.
Current Limits
All supplies are protected against output overcurrent or
short-circuit conditions. The MAX5915 and MAX5916
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/MAX5916
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/MAX5916
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/MAX5916
Input Undervoltage Lockout
UVLO prevents the MAX5915/MAX5916 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
t DEG,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/MAX5916 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. If the fault is removed before
tDELAY, the channel remains on and PGOOD_ pulls high
immediately.
14
Latched Fault Protection
The MAX5915 latches 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 automatically restarts the outputs after
tRESTART. Both the MAX5915 and the MAX5916 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/MAX5916.
______________________________________________________________________________________
Dual PCI 2.2 Hot-Swap Controllers
MAX5915/MAX5916
ENABLE_+12VIN
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
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 both the
MAX5915/MAX5916.
Both the MAX5915/MAX5916 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/MAX5916 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 tRESTART. The
auxiliary channels for both the MAX5915/MAX5916
restart after tRESTART.
______________________________________________________________________________________
15
MAX5915/MAX5916
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
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
MAX5915/MAX5916
Table 2. Logic Diagram Signal Descriptions
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.
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/MAX5916 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.
The MAX5915/MAX5916 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:
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/MAX5916
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/MAX5916
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
tDELAY
tSTART
OUTPUT UNDERVOLTAGE FAULT HANDLING RESULTS IN SIMILAR RESPONSE. TIMING NOT TO SCALE.
Figure 5. Main Outputs Overcurrent Fault Management in the MAX5915
18
______________________________________________________________________________________
Dual PCI 2.2 Hot-Swap Controllers
MAX5915/MAX5916
+12VIN
+12V UVLO THRESHOLD
OVERCURRENT
UVLO THRESHOLD
IOUT
(3.3VAUXO_)
ON_
+12VO_
5VO_
3.3VO_
tDEG
-12VO_
3.3VAUXO_
PGOOD_
tRESP
tDELAY
tRESTART
tSTART
OUTPUT UNDERVOLTAGE FAULT HANDLING RESULTS IN SIMILAR RESPONSE. TIMING NOT TO SCALE.
Figure 6. Auxiliary Outputs Overcurrent Fault Management in the MAX5915/MAX5916
______________________________________________________________________________________
19
MAX5915/MAX5916
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
tDELAY
tRESTART
tSTART
OUTPUT UNDERVOLTAGE FAULT HANDLING RESULTS IN SIMILAR RESPONSE. TIMING NOT TO SCALE.
Figure 7. Main Outputs Overcurrent Fault Handling in the MAX5916
20
______________________________________________________________________________________
Dual PCI 2.2 Hot-Swap Controllers
MAX5915/MAX5916
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
OC_3.3VAUXO_
UV_3.3VAUXO_
Figure 8. PGOOD_ Logic Diagram
______________________________________________________________________________________
21
MAX5915/MAX5916
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
MAX5916
Figure 9. Kelvin Connections for Sense Resistors
24 3.3VOB
MAX5915
MAX5916
GND 7
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
22
______________________________________________________________________________________
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
MAX5915
MAX5916
5VGATEA
5VSENB
5VGATEB
ON
OFF
3.3VAUX
5VOB
ON
ONA
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/MAX5916
Typical Operating Circuit
Dual PCI 2.2 Hot-Swap Controllers
MAX5915/MAX5916
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
5VOA
RSENSE
MAX5915
MAX5916
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
TSSOP,NO PADS.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
© 2002 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
MAX5915/MAX5916
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.)