General Description
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 back-
planes by limiting the inrush current at startup. After
startup, these devices provide protection against short-
circuit, overcurrent, and undervoltage conditions.
The MAX5915/MAX5915A/MAX5916/MAX5916A pro-
vide 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 moni-
tor two PCI card slots.
The MAX5915/MAX5915A offer latched fault protection
and the MAX5916/MAX5916A offer autorestart fault pro-
tection. The devices are available in the low-profile
28-pin TSSOP package.
Features
♦PCI 2.2 Compliant
♦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
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
________________________________________________________________ Maxim Integrated Products 1
19-2420; Rev 2; 9/05
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.
Ordering Information
Applications
PCI 2.2 Server
PCI Server
RAID
PART TEMP RANGE PIN-PACKAGE
MAX5915EUI* -40°C to +85°C 28 TSSOP
MAX5915UUI 0°C to +85°C 28 TSSOP
MAX5915AEUI* -40°C to +85°C 28 TSSOP
MAX5915AUUI 0°C to +85°C 28 TSSOP
MAX5916EUI* -40°C to +85°C 28 TSSOP
MAX5916UUI 0°C to +85°C 28 TSSOP
MAX5916AEUI* -40°C to +85°C 28 TSSOP
MAX5916AUUI 0°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
+12VIN
+3.3V
+5V
-12VIN
3.3VGATE_ 3.3VSEN_ 3.3VO_ 5VGATE_ 5VSEN_
FAIRCHILD
FDS6670A
FAIRCHILD
FDS6670A
0.005Ω
0.005Ω
10kΩ
10kΩ
5VO_
5V
470µF
47µF
3.3VAUXIN 3.3VAUXO_
PGOOD_
GND
ON_
ON
OFF
AUXON_
+12VO_
-12VO_
MAX5915
MAX5915A
MAX5916
MAX5916A
470µF
4.7µF⎥⎥ 0.1µF
ON
OFF
4.7µF⎥⎥ 0.1µF
4.7µF⎥⎥ 0.1µF
47µF
47µF
-12V
+12V
+3.3VAUX
*Contact factory for availabilty.
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
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.
+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
Operating Temperature Ranges:
MAX591_U_ _ ......................................................0°C to +85°C
MAX591_A U_ _ ...................................................0°C to +85°C
MAX591_E_ _....................................................-40°C to +85°C
MAX591_ AE_ _ ................................................-40°C to +85°C
Maximum Junction Temperature .....................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
ELECTRICAL CHARACTERISTICS
(V-12VIN = -12V, V+12VIN = +12V, V3.3VAUXIN = +3.3V, VON_ = VAUXON_ = +5V, TA= TMIN to TMAX, unless otherwise specified.
Typical values are at TA= +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
POWER SUPPLIES
Main Supply Input Voltage
Range V+12VIN 10.8 12 13.2 V
Main Supply Undervoltage
Lockout (UVLO) V+12UVLO V+12VIN rising 9.6 10 10.8 V
Main Supply UVLO Hysteresis VUVLO, HYS 100 mV
Main Input UVLO Delay Time tDEG, UVLO Figures 1 and 2 (Note 1) 1.6 ms
Supply Current IQ2.5 5.0 mA
+3.3V SUPPLY CONTROL
Gate Charge Current I3.3VGATE_
,
CHG V
3 .3 V GAT E _ = + 6V , V
3 .3 V S E N _
= + 3.3V ,
V
3 .3 V O_ = + 3.3V 51530µA
Gate Discharge Current I3.3VGATE_
,
DIS V3.3VGATE _ = +12V, VON_ = 0V 50 150 250 µA
Gate High Voltage V3.3VGATE_
,
HIGH I3.3VGATE _ = 1µA V+12VIN -
0.5 V+12VIN V
Gate Low Voltage V3.3VGATE_
,
LOW I3.3VGATE _ = 1µA, VON_ = 0V 0.1 0.4 V
3.3VO_ Input Bias Current I3.3VO_, BIAS V3.3VO_ = +3.3V 20 µA
3.3VO_ Internal Pulldown RPD VON_ = 0V 1 kΩ
3.3VSEN_ Input Bias Current 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 30 mV
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(V-12VIN = -12V, V+12VIN = +12V, V3.3VAUXIN = +3.3V, VON_ = VAUXON_ = +5V, TA= TMIN to TMAX, unless otherwise specified.
Typical values are at TA= +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
+5V SUPPLY CONTROL
Gate Charge Current I5VGATE_
,
CHG V5VGATE_ = +6V, V5VSEN_ = +5V,
V5VO_ = +5V 51530µA
Gate Discharge Current I5VGATE_, DIS V5VGATE_ = +12V, VON_ = 0V 50 150 250 µA
Gate High Voltage V5VGATE_
,
HIGH I5VGATE_ = 1µA V+12VIN -
0.5V V+12VIN V
Gate Low Voltage V5VGATE_
,
LOW I5VGATE_ = 1µA, VON_ = 0V 0.1 0.4 V
5VO_ Input Bias Current I5VO_, BIAS V5VO_ = +5V 20 µA
5VO_ Internal Pulldown R5VO_, PD VON_ = 0V 1 kΩ
5VSEN_ Input Bias Current I5VSEN_, BIAS V5VSEN_ = +5V 10 µA
Current-Limit Threshold V5VO_, LIM V5VGATE_ falling 27 31 35 mV
Output Undervoltage Threshold V5VO_, UV Output falling 4.34 4.50 4.70 V
Output Undervoltage Threshold
Hysteresis 45 mV
+12V SUPPLY CONTROL
TA = +25°C, ID = 0.5A 0.32 0.38
On-Resistance of Internal Switch RDS(ON), +12V TA = +85°C, ID = 0.5A 0.5 Ω
Foldback Current Limit I+12VIN, LIM V+12VO_ = 0V 0.68 1 1.36 A
Current-Foldback Threshold Output current rising (Note 2) 1.4 A
Output Undervoltage Threshold V+12VO_, UV Output falling 10.00 10.4 10.82 V
+12VO_ Internal Pulldown R+12VO_, PD VON_ = 0V 1 kΩ
-12V SUPPLY CONTROL
TA = +25°C, ID = 0.1A 0.58 0.9
On-Resistance of Internal Switch RDS(ON), -12V TA = +85°C, ID = 0.1A 1.3 Ω
Foldback Current Limit I-12VIN, LIM V-12VO_ = 0V 136 205 273 mA
Current-Foldback Threshold Output current rising (Note 2) 240 mA
-12VO_ Internal Pullup R-12VO_, PU VON_ = 0V 1 kΩ
+3.3VAUX SUPPLY CONTROL
Input Voltage Range V3.3VAUXIN 3.0 3.3 3.6 V
3.3VAUXIN Undervoltage
Lockout VUVLO, AUX Input rising 2.65 2.75 2.85 V
Hysteresis VUVLO-AUX
,
HYS 30 mV
Supply Current IQ, 3.3VAUX 12mA
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(V-12VIN = -12V, V+12VIN = +12V, V3.3VAUXIN = +3.3V, VON_ = VAUXON_ = +5V, TA= TMIN to TMAX, unless otherwise specified.
Typical values are at TA= +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
TA = +25°C, ID = 0.4A 0.24 0.4
On-Resistance of Internal Switch RDS
(
ON
),
3.3VAUX TA = +85°C, ID = 0.4A 0.6 Ω
Foldback Current Limit I3.3VAUXIN
,
LIM V3.3VAUXO_ = 0V 0.5 0.75 1.0 A
Current-Foldback Threshold Output current rising (Note 2) 1.2 A
Output Undervoltage Threshold V3.3VAUXIN
,
UV 2.76 2.89 2.99 V
Auxiliary Input UVLO Delay Time tDEG, UVLO (Note 1) 1.6 ms
3.3VAUXO_ Internal Pulldown R3.3VAUXO_ ON_ = 0V 1 kΩ
ON AND AUXON COMPARATORS
Threshold Voltage 1.0 2.1 V
Hysteresis VHYS 25 mV
Input Bias Current IB, COMP 20 µA
ON_ and AUXON_ Deglitch
Time tDEG Figures 5–8 (Note 3) 4 µs
FAULT RESPONSE, PGOOD_ STATUS OUTPUT COMPARATORS
tRESP Figures 5–8 MAX5915/MAX5916 0.5 1.5 ms
PGOOD_ Output Overcurrent
and Undervoltage Response
Time tRESP2 Figures 5–8 MAX5915A/MAX5916A 100 ns
Output Overcurrent and
Undervoltage Deglitch Time tDELAY Figures 3–7 16 x
tRESP ms
PGOOD_ Startup Timeout tSTART See Figures 1, 2, 5, 6, 7, and 8 4 x
tDELAY ms
Autorestart Delay tRESTART Delay time to restart after OC and/or
UV shutdown
64 x
tSTART ms
PGOOD_ Output Low Voltage VOL ISINK = 2mA, ON_ = 0V 0.5 0.7 V
PGOOD_ Output High Leakage
Current ILEAK VPGOOD_ = +5.5V 1 µA
Thermal Shutdown Threshold TSD (Note 4) 125 °C
Thermal Shutdown Hysteresis THYS 5°C
Full Thermal Shutdown
Threshold TSD, FULL (Note 5) TSD +
20 °C
Full Thermal Shutdown
Hysteresis THYS, FULL 5°C
Note 1: tDEG, UVLO is negative edge triggered. There is no time delay when the inputs rise above the UVLO threshold.
Note 2: The current threshold when the output current starts to fold back. See the Typical Operating Characteristics.
Note 3: tDEG is negative edge triggered. ON_ or AUXON_ transition from low to high has no delay.
Note 4: Temperature threshold at which the outputs of the channel with overcurrent shut down.
Note 5: The temperature threshold at which both channels shut down.
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
_______________________________________________________________________________________ 5
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_ =
MAX5915 toc09
OUTPUT CURRENT (A)
3.3VAUX_ VOLTAGE (V)
1.050.900.60 0.750.30 0.450.15
2.6
2.7
2.8
2.9
3.0
3.1
3.2
3.3
3.4
3.5
2.5
0 1.20
3.3VAUX_ VOLTAGE
vs. OUTPUT CURRENT
3.3VO_ SENSE RESISTOR VOLTAGE
vs. DIFFERENTIAL SWITCH VOLTAGE
MAX5915 toc08
VIN - V3.3VSEN_ (V)
3.3VO_ CURRENT-LIMIT THRESHOLD (mV)
30
34
32
36
38
42
46
44
48
40
3.02.51.5 2.01.0 3.5
DURING CURRENT LIMIT
FAIRCHILD
FDS6670A
3.3VO_ VOLTAGE
vs. OUTPUT CURRENT
MAX5915 toc07
OUTPUT CURRENT (A)
3.3VO_ VOLTAGE (V)
2
3.18
3.20
3.22
3.28
3.30
3.32
3.16
08
46
3.24
3.26
FAIRCHILD
FDS6670A
20
24
22
28
26
30
34
38
36
40
1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
5VO_ SENSE RESISTOR VOLTAGE
vs. DIFFERENTIAL SWITCH VOLTAGE
MAX5915 toc06
VIN - V5VSEN_ (V)
5VO_ CURRENT-LIMIT THRESHOLD (mV)
32
DURING CURRENT LIMIT
FAIRCHILD
FDS6670A
5VO_ VOLTAGE
vs. OUTPUT CURRENT
MAX5915 toc05
OUTPUT CURRENT (A)
5VO_ VOLTAGE (V)
1
4.82
4.84
4.86
4.88
4.90
4.92
4.80
05
234
4.94
4.96
4.98
5.00
5.02
FAIRCHILD
FDS6670A
-12VO_ CURRENT FOLDBACK
vs. DIFFERENTIAL SWITCH VOLTAGE
MAX5915 toc04
V-12VIN - V-12VO_ (V)
-12VO_ CURRENT FOLDBACK (mA)
2
50
100
150
200
250
0
04
6 8 10 12
-12VO_ VOLTAGE
vs. OUTPUT CURRENT
MAX5915 toc03
OUTPUT CURRENT (mA)
-12VO_ VOLTAGE (V)
50
-12.0
-11.9
-11.8
-11.7
-11.6
-11.5
-12.1
0250
100 150 200
+12VO_ CURRENT FOLDBACK
vs. DIFFERENTIAL SWITCH VOLTAGE
MAX5915 toc02
V+12VIN - V+12VO_ (V)
+12VO_ CURRENT FOLDBACK (A)
2
0.1
0.3
0.5
0.7
0.9
1.1
-0.1
046810 12
+12VO_ VOLTAGE
vs. OUTPUT CURRENT
MAX5915 toc01
OUTPUT CURRENT (A)
+12VO_ VOLTAGE (V)
1.00.5
11.5
11.6
11.7
11.8
11.9
12.0
12.1
11.4
0 1.5
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
6 _______________________________________________________________________________________
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_ =
2ms/div
TIME-TO-CHARGE GATE
(CGATE = 10nF)
ON_
5V/div
3.3VGATE_
5V/div
MAX5915 toc18
5VGATE_
5V/div
200µs/div
TIME-TO-CHARGE GATE
(CGATE = 1nF)
ON_
5V/div
3.3VGATE_
5V/div
MAX5915 toc17
5VGATE_
5V/div
100µs/div
TIME-TO-CHARGE GATE
(CGATE = 0.1nF)
ON_
5V/div
3.3VGATE_
5V/div
MAX5915 toc16
5VGATE_
5V/div
MAX5915 toc15
TEMPERATURE (°C)
-12V INTERNAL SWITCH RON (Ω)
6035-15 10
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0
-40 85
-12V INTERNAL SWITCH RON
vs. TEMPERATURE
MAX5915 toc14
TEMPERATURE (°C)
3.3V AUXILIARY INTERNAL SWITCH RON (Ω)
603510-15
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0
-40 85
3.3V AUXILIARY INTERNAL SWITCH RON
vs. TEMPERATURE
MAX5915 toc13
TEMPERATURE (°C)
+12V INTERNAL SWITCH RON (Ω)
603510-15
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0
-40 85
+12V INTERNAL SWITCH RON
vs. TEMPERATURE
5VGATE_ AND 3.3VGATE_
DISCHARGE CURRENT vs. TEMPERATURE
MAX5915 toc12
TEMPERATURE (°C)
GATE DISCHARGE CURRENT (µA)
603510-15
135
140
145
150
155
160
165
170
175
180
130
-40 85
3.3VGATE_
CGATE = 1nF
5VGATE_
5VGATE_ AND 3.3VGATE_
CHARGE CURRENT vs. TEMPERATURE
MAX5915 toc11
TEMPERATURE (°C)
GATE CHARGE CURRENT (µA)
603510-15
9.5
11.5
13.5
15.5
17.5
19.5
21.5
23.5
25.5
27.5
7.5
-40 85
3.3VGATE_
CGATE = 1nF
5VGATE_
3.3VAUX_ CURRENT FOLDBACK
vs. DIFFERENTIAL SWITCH VOLTAGE
MAX5915 toc10
V3.3VAUXIN - V3.3VAUXO_ (V)
3.3VAUX_ CURRENT FOLDBACK (mA)
0.5
550
600
650
700
750
800
500
01.0 2.0 2.5 3.0
1.5 3.5
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
_______________________________________________________________________________________ 7
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_ =
MAX5915 toc27
TEMPERATURE (°C)
+12V INPUT UVLO THRESHOLD (V)
603510-15
9.6
9.7
9.8
9.9
10.0
10.1
10.2
10.3
10.4
10.5
9.5
-40 85
+12V INPUT UVLO
THRESHOLD vs. TEMPERATURE
3.3V AUXILIARY INPUT UVLO
THRESHOLD vs. TEMPERATURE
MAX5915 toc26
TEMPERATURE (°C)
3.3V AUXILIARY INPUT UVLO THRESHOLD (V)
6035-15 10
2.6
2.7
2.8
2.9
3.0
3.1
3.2
3.3
2.5
-40 85
3.3V AUXILIARY OUTPUT UNDERVOLTAGE
THRESHOLD vs. TEMPERATURE
MAX5915 toc25
TEMPERATURE (°C)
3.3V AUXILIARY OUTPUT UNDERVOLTAGE THRESHOLD (V)
603510-15
2.8
2.9
3.0
3.1
3.2
3.3
2.7
-40 85
3.3V OUTPUT UNDERVOLTAGE
THRESHOLD vs. TEMPERATURE
MAX5915 toc24
TEMPERATURE (°C)
3.3V OUTPUT UNDERVOLTAGE THRESHOLD (V)
6035-15 10
2.6
2.7
2.8
2.9
3.0
3.1
3.2
3.3
2.5
-40 85
5V OUTPUT UNDERVOLTAGE
THRESHOLD vs. TEMPERATURE
MAX5915 toc23
TEMPERATURE (°C)
5V OUTPUT UNDERVOLTAGE THRESHOLD (V)
603510-15
4.43
4.48
4.53
4.58
4.63
4.68
4.38
-40 85
+12V OUTPUT UNDERVOLTAGE
THRESHOLD vs. TEMPERATURE
MAX5915 toc22
TEMPERATURE (°C)
+12V OUTPUT UNDERVOLTAGE THRESHOLD (V)
603510-15
10.3
10.4
10.5
10.6
10.7
10.8
10.2
-40 85
ON_ AND AUXON_ THRESHOLD
vs. TEMPERATURE
MAX5915 toc21
TEMPERATURE (°C)
ON_ AND AUXON_ THRESHOLD (V)
603510-15
1.85
1.90
1.95
2.00
RISING
FALLING
2.05
2.10
1.80
-40 85
3.3VAUXIN SUPPLY CURRENT
vs. TEMPERATURE
MAX5915 toc20
TEMPERATURE (°C)
3.3VAUXIN SUPPLY CURRENT (mA)
603510-15
0.25
0.50
0.75
1.00
1.25
1.50
1.75
2.00
2.25
2.50
0
-40 85
+12VIN SUPPLY CURRENT
vs. TEMPERATURE
MAX5915 toc19
TEMPERATURE (°C)
+12VIN SUPPLY CURRENT (mA)
603510-15
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3.0
2.0
-40 85
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
8 _______________________________________________________________________________________
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_ =
200µs/div
TURN-ON DELAY
+12VIN
10V/div
3.3VAUXIN_
2V/div
MAX5915 toc35
3.3VAUXO_
2V/div
+12VO_
10V/div
ON_ = 5V
AUXON_ = 5V
10ms/div
AUXILIARY SUPPLY
TURN-ON WAVEFORMS
AUXON_
5V/div
3.3VAUXO_
2V/div
MAX5915 toc34
PGOOD_
5V/div ON_ = 5.0V
10ms/div
MAIN SUPPLY
TURN-ON WAVEFORMS
ON_
5V/div
12VO_
10V/div
MAX5915 toc33
PGOOD_
5V/div
5VO_
5V/div
AUXON_ = 5V
5VO_ SENSE RESISTOR VOLTAGE
vs. TEMPERATURE
MAX5915 toc32
TEMPERATURE (°C)
5V0_ SENSE RESISTOR VOLTAGE (mV)
6035-15 10
24
22
20
26
28
34
36
38
40
-40 85
32
30
DURING CURRENT
LIMIT
3.3V AUXILIARY CURRENT
FOLDBACK vs. TEMPERATURE
MAX5915 toc31
TEMPERATURE (°C)
3.3V AXILIARY CURRENT FOLDBACK (mA)
6035-15 10
475
550
625
700
775
850
925
-40 85
3.3VO_ SENSE RESISTOR VOLTAGE
vs. TEMPERATURE
MAX5915 toc30
TEMPERATURE (°C)
3.3V SENSE RESISTOR VOLTAGE (mV)
603510-15
37
39
41
43
45
35
-40 85
47
49
DURING CURRENT LIMIT
-12V OUTPUT CURRENT
FOLDBACK vs. TEMPERATURE
MAX5915 toc29
TEMPERATURE (°C)
-12V OUTPUT CURRENT FOLDBACK (mA)
6035-15 10
130
150
170
190
210
230
250
-40 85
MAX5915 toc28
TEMPERATURE (°C)
+12V OUTPUT CURRENT FOLDBACK (A)
603510-15
0.7
0.8
0.9
1.0
1.1
1.2
0.6
-40 85
+12V OUTPUT CURRENT
FOLDBACK vs. TEMPERATURE
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
_______________________________________________________________________________________ 9
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_ =
-12VO_ CURRENT FOLDBACK
MAX5915 toc45
2ms/div
I-12VO_
500mA/div
PGOOD_
5V/div
-12VO_
5V/div
-12VO_ IMMEDIATE
SHORT-CIRCUIT RESPONSE
MAX5915 toc44
200ns/div
I-12VO_
2A/div
PGOOD_
5V/div
-12VO_
5V/div
+12VO_ CURRENT FOLDBACK
MAX5915 toc43
2ms/div
I+12VO_
5A/div
PGOOD_
5V/div
+12VO_
5V/div
+12VO_ IMMEDIATE
SHORT-CIRCUIT RESPONSE
MAX5915 toc42
1µs/div
I+12VO_
10A/div
PGOOD_
5V/div
+12VO_
5V/div
AUXILIARY SUPPLY
FAULT MANAGEMENT
MAX5915 toc41
400ms/div
5VO_
+12VO_
5V/div
3.3VAUXO_
5V/div
PGOOD_
5V/div
400ms/div
MAIN SUPPLY
AUTORESTART FAULT MANAGEMENT
+12VO_
5V/div
5VO_
2V/div
MAX5915 toc40
3.3VAUXO_
5V/div
PGOOD_
5V/div
2ms/div
MAIN SUPPLY
LATCHED FAULT MANAGEMENT
+12VO_
5V/div
5VO_
2V/div
MAX5915 toc39
3.3VAUXO_
5V/div
PGOOD_
5V/div
2µs/div
tDEG DELAY TIME
ON_
5V/div
3.3VAUXO_
2V/div
MAX5915 toc38
PGOOD_
5V/div
20ms/div
AUXILIARY SUPPLY
TURN-OFF WAVEFORMS
ON_
5V/div
3.3VAUXO_
2V/div
MAX5915 toc37
PGOOD_
5V/div
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
10 ______________________________________________________________________________________
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_ =
3.3VAUXO_ CURRENT FOLDBACK
MAX5915 toc51
2ms/div
I3.3VAUXO_
1A/div
PGOOD_
5V/div
3.3VAUXO_
2V/div
3.3VAUXO_ IMMEDIATE
SHORT-CIRCUIT RESPONSE
MAX5915 toc50
2µs/div
I3.3VAUXO_
10A/div
PGOOD_
5V/div
3.3VAUXO_
2V/div
3.3VO_ CURRENT LIMIT
MAX5915 toc49
2ms/div
I3.3VO_
10A/div
PGOOD_
5V/div
3.3VO_
2V/div
3.3VO_ IMMEDIATE
SHORT-CIRCUIT RESPONSE
MAX5915 toc48
20µs/div
I3.3VO_
10A/div
PGOOD_
5V/div
3.3VO_
2V/div
FAIRCHILD
FDS6670A
5VO_ CURRENT LIMIT
MAX5915 toc47
2ms/div
I5VO_
10A/div
PGOOD_
5V/div
5VO_
5V/div
5VO_ IMMEDIATE
SHORT-CIRCUIT RESPONSE
MAX5915 toc46
40µs/div
I5VO_
10A/div
PGOOD_
5V/div
5VO_
5V/div
FAIRCHILD
FDS6670A
MAX5915A/MAX5916A
3.3VAUXO_ SHORT CIRCUIT
MAX5915 toc54
100ns/div
PGOOD_
5V/div
3.3VAUXO_
1V/div
tRESP2
MAX5915A/MAX5916A
3.3VO_ SHORT CIRCUIT
MAX5915 toc53
100ns/div
PGOOD_
5V/div
3.3VO_
1V/div
tRESP2
MAX5915A/MAX5916A
12VO_ SHORT CIRCUIT
MAX5915 toc52
100ns/div
PGOOD_
5V/div
12VO_
5V/div
tRESP2
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
______________________________________________________________________________________ 11
PIN NAME FUNCTION
1 +12VOA Channel A +12V Output
2 3.3VGATEA Channel A +3.3V External N-Channel MOSFET Gate Drive. 3.3VGATEA driven by +12VIN.
3 3.3VSENA Channel A External 3.3V Current-Sense Input
4 3.3VOA Channel A +3.3V Output Sense
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.
12 3.3VAUXOA Channel A 3.3VAUX Output
13 3.3VAUXIN 3.3VAUX Input. Provides power to the +3.3V auxiliary channels.
14 3.3VAUXOB Channel B 3.3VAUX Output
15 -12VOB Channel B -12V Output
16 -12VIN -12V Input
17 -12VOA Channel A -12V Output
18 5VOB Channel B +5V Output Sense
19 5VSENB Channel B External +5V Current-Sense Input
20 5VGATEB Channel B +5V External N-Channel MOSFET Gate Drive. 5VGATEB driven by +12VIN.
21 5VOA Channel A +5V Output Sense
22 5VSENA Channel A External +5V Current-Sense Input
23 5VGATEA Channel A +5V External N-Channel MOSFET Gate Drive. 5VGATEA driven by +12VIN.
24 3.3VOB Channel B +3.3V Output Sense
25 3.3VSENB Channel B External +3.3V Current-Sense Input
26 3.3VGATEB Channel B +3.3V External N-Channel MOSFET Gate Drive. 3.3VGATEB driven by +12VIN.
27 +12VOB Channel B +12V Output
28 +12VIN +12V Input. +12VIN powers the main supplies of the MAX5915/MAX5915A/MAX5916/MAX5916A.
Pin Description
MAX5915/MAX5915A/MAX5916/MAX5916A
Detailed Description
The MAX5915/MAX5915A/MAX5916/MAX5916A are cir-
cuit-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 limit-
ing 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 stan-
dards dictate maximum values for the supply power
and total power drawn from the backplane. The maxi-
mum 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
auxiliary supply is not used.
The auxiliary supply (3.3VAUXO_) is available after both
of these events have occurred:
•V
3.3VAUXIN is above its UVLO threshold.
• AUXON_ is driven high.
Normal Operation +3.3V, +5V,
±12V Outputs
The internal circuitry for these devices monitors the out-
put 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 under-
voltage 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 auto-
matically 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 inter-
nally. 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 out-
puts 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
12 ______________________________________________________________________________________
Table 1. PCI Standard Maximum Values
SUPPLY VOLTAGE (V)* VOLTAGE TOLERANCE (%) MAX CURRENT (A) MAX POWER (W)
+5 ±5525
+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.
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 brick-
wall 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 tran-
sient, the output current is reduced to the foldback cur-
rent limit and remains at that level for tDELAY unless the
overcurrent condition is cleared. See the Typical
Operating Characteristics.
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
______________________________________________________________________________________ 13
tSTART
ON_
+12VIN
3.3VAUXIN
PGOOD_
TIMING NOT TO SCALE
AUXON_
+12V
UVLO THRESHOLD
3.3VAUX UVLO THRESHOLD
+12VO_
5VO_
3.3VO_
3.3VAUXO_
-12VO_
Figure 1. Startup Waveforms
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 out-
put 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 avail-
able with a response time of 1.5ms (tRESP). The
MAX5915A/MAX5916A offer a response time of 100ns
(tRESP2). If the fault is removed before tDELAY, the chan-
nel remains on and PGOOD_ pulls high immediately.
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 out-
puts after tRESTART. The MAX5915/MAX5915A/
MAX5916/MAX5916A handle faults on the auxiliary out-
puts by automatically restarting the appropriate chan-
nel. 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
14 ______________________________________________________________________________________
ON_
+12VIN
3.3VAUXIN
PGOOD_
AUXON_
+12V UVLO THRESHOLD
3.3VAUX UVLO THRESHOLD
tSTART
tSTART
tDEG.UVLO tDEG.UVLO
+12VO_
5VO_
3.3VO_
3.3VAUXO_
-12VO_
TIMING NOT TO SCALE
Figure 2. Input UVLO Fault Management in the MAX5915/MAX5915A/MAX5916/MAX5916A
Output Undervoltage
The output voltages on all supplies, except the -12V
supply, are monitored for undervoltage. Output under-
voltage 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.
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 sec-
ond 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 chan-
nels turn back on after +12VIN or ON_ is toggled. For the
MAX5916, the main channels turn back on after
tRESTART. The auxiliary channels for the MAX5915/
MAX5915A/MAX5916/MAX5916A restart after tRESTART.
PGOOD_ Operation
The MAX5915/MAX5915A/MAX5916/MAX5916A incor-
porate 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 avail-
able. 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 resis-
tor (see the Functional Diagram). Figure 8 shows the
internal logic of the PGOOD_ output.
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
______________________________________________________________________________________ 15
tDELAY
tDELAY
tDELAY
tRESTART
tRESTART
ENABLE_+12VIN
STARTUP_+12VIN
OC_3.3VAUXO_
UV_3.3VAUXO_ RESET
RESET
DQ
V
Q
POSITIVE EDGE
TRIGGERED D FLIP-FLOP,
RESET IS ACTIVE LOW
OC_3.3VO_
OC_5VO_
OC_+12VO_
OC_-12VO_
UV_3.3VO_
UV_5VO_
UV_+12VO_
POSITIVE EDGE TRIGGERED D FLIP-FLOP,
RESET IS ACTIVE LOW
HIGH = MAIN SUPPLIES
ARE TURNED OFF
MAIN ON
AUX OFF
HIGH = AUX SUPPLY
TURNED OFF
ENABLE_3.3VAUXIN
STARTUP_3.3VAUXIN
V = INTERNAL SUPPLY LOGIC
GENERATED BY THE 12VIN OR THE
3.3VAUXIN, WHICHEVER IS HIGHER
RESET
DQ
V
Q
SEE TABLE 2 FOR EXPLANATION OF SIGNALS.
Figure 3. Main and Auxiliary Supply Shutdown Control Logic for MAX5915/MAX5915A
MAX5915/MAX5915A/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-cir-
cuit condition on the board during startup (see the
External MOSFET Thermal Considerations section).
Table 3 lists MOSFET and sense resistor manufacturers.
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 accommo-
date 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
16 ______________________________________________________________________________________
tDELAY
tDELAY
tDELAY
tRESTART
tRESTART
tRESTART
ENABLE_+12VIN
STARTUP_+12VIN
OC_3.3VAUXO_
UV_3.3VAUXO_ RESET
RESET
RESET
DQ
V
Q
POSITIVE EDGE
TRIGGERED D FLIP-FLOP,
RESET IS ACTIVE LOW
OC_3.3VO_
OC_5VO_
OC_+12VO_
OC_-12VO_
UV_3.3VO_
UV_5VO_
UV_+12VO_
POSITIVE EDGE TRIGGERED D FLIP-FLOP,
RESET IS ACTIVE LOW
HIGH = MAIN SUPPLIES
ARE TURNED OFF
MAIN OFF
AUX OFF
HIGH = AUX SUPPLY
TURNED ON
ENABLE_3.3VAUXIN
STARTUP_3.3VAUXIN
V = INTERNAL SUPPLY LOGIC
GENERATED BY THE 12VIN OR THE
3.3VAUXIN, WHICHEVER IS HIGHER
RESET
DQ
V
Q
SEE TABLE 2 FOR EXPLANATION OF SIGNALS.
Figure 4. Main and Auxiliary Supply Shutdown Control Logic for MAX5916/MAX5916A
Maximum Load Capacitance
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 start-
up 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/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= ILOAD2x RDS(ON). A considerable
amount of power is dissipated during startup and con-
tinuous short-circuit conditions. The design must take
into consideration the worst-case scenario.
Layout Considerations
To take full advantage of the switch response time to an
output fault condition, keep all traces as short as possi-
ble 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 tempera-
ture 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.
Chip Information
TRANSISTOR COUNT: 1021
PROCESS: BiCMOS
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
______________________________________________________________________________________ 17
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.
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
18 ______________________________________________________________________________________
+12V UVLO THRESHOLD
ON_
+12VIN
PGOOD_
IOUT
(+12VO_, 5VO_, 3.3VO-, OR -12VO_)
OVERCURRENT THRESHOLD
tSTART
tDELAY
tDEG
tRESP
(tRESP2)
+12VO_
5VO_
3.3VO_
3.3VAUXO_
-12VO_
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
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
______________________________________________________________________________________ 19
+12V UVLO THRESHOLD
ON_
PGOOD_
IOUT
(3.3VAUXO_)
OVERCURRENT
UVLO THRESHOLD
tSTART
tRESTART
tDEG
+12VO_
+12VIN
5VO_
3.3VO_
3.3VAUXO_
-12VO_
tDELAY
tRESP
(tRESP2)
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
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
20 ______________________________________________________________________________________
+12V UVLO THRESHOLD
ON_
PGOOD_
IOUT
(+12VO_, 5VO_, 3.3VO_, OR- 12VO_)
OVERCURRENT THRESHOLD
tSTART
tRESTART
+12VO_
+12VIN
5VO_
3.3VO_
3.3VAUXO_
-12VO_
tDELAY
tRESP
(tRESP2)
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
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
______________________________________________________________________________________ 21
GND
PGOOD_
tSTART
tSTART
ON_
UVLO_+12VIN
AUXON_
UVLO_3.3VAUXIN
OC_MAIN_OUTPUTS
UV_MAIN_OUTPUTS
OC_3.3VAUXO_
UV_3.3VAUXO_
tDEG
tDEG
tDEG
tDEG, UVLO
tDEG, UVLO
tDEG, UVLO
tRESP
tRESP
(tRESP2)
( ) FOR MAX5915A/MAX5916A.
Figure 8. PGOOD_ Logic Diagram
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
22 ______________________________________________________________________________________
Table 3. Component Manufacturers
COMPONENT MANUFACTURER PHONE WEBSITE
Dale-Vishay 402-564-3131 www.vishay.com
Sense Resistors
IRC 704-264-8861 www.irctt.com
Fairchild 888-522-5372 www.fairchildsemi.com
International Rectifier 310-322-3331 www.irf.comMOSFETs
Motorola 602-244-3576 www.mot-sps.com/ppd/
SENSE RESISTOR
HIGH-CURRENT PATH
MAX5915
MAX5915A
MAX5916
MAX5916A
Figure 9. Kelvin Connections for Sense Resistors
28
27
26
25
24
23
22
21
20
19
18
17
16
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
+12VIN
+12VOB
3.3VGATEB
3.3VSENB
3.3VOB
5VGATEA
-12VOB
5VSENA
5VOA
5VGATEB
5VSENB
5VOB
-12VOA
-12VIN
3.3VAUXOB
3.3VAUXIN
3.3VAUXOA
AUXONB
AUXONA
PGOODB
PGOODA
GND
ONB
ONA
3.3VOA
3.3VSENA
3.3VGATEA
+12VOA
TSSOP
TOP VIEW
MAX5915
MAX5915A
MAX5916
MAX5916A
Pin Configuration
Selector Guide
PART FAULT
MANAGEMENT
PGOOD_ FAULT
RESPONSE TIME (S)
MAX5915EUI Latched 1.5m
MAX5915AEUI Latched 100n
MAX5916EUI Autorestart 1.5m
MAX5916AEUI Autorestart 100n
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
______________________________________________________________________________________ 23
ON
OFF
ON
OFF
ON
OFF
ON
OFF
MAX5915
MAX5915A
MAX5916
MAX5916A
PCI SLOT BPCI SLOT A
GND
GND GND
3.3VAUXOA 3.3VAUXOB
5VGATEA
5VSENA
5VOA
5VGATEB
5VSENB
5VOB
3.3VGATEA
3.3VSENA
3.3VOA
3.3VGATEB
3.3VSENB
3.3VOB
+12VOA
-12VOA
+12VOB
-12VOB
+12VIN -12VIN3.3VAUXIN
+12V 3.3VAUX -12V
+5V
+5V
+3.3V +3.3V
BACKPLANE
+12V
-12V
3.3VAUX
+5V
+3.3V
+12V
-12V
3.3VAUX
+5V
+3.3V
ONA ONB
PGOODA PGOODB
AUXONA AUXONB
PCI CARD BPCI CARD A
Typical Operating Circuit
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
24 ______________________________________________________________________________________
-12VIN+12VIN
-12VOB
+12VOB
3.3VAUXOB
5V
5VSENB
5VOB
5VGATEB
3.3V
3.3VGATEB
RSENSE
RSENSE
3.3VSENB
3.3VOB
GND
-12VOA
+12VOA
3.3VAUXOA
3.3V
3.3VGATEA
3.3VSENA
5V
5VSENA
RSENSE
RSENSE
3.3VOA
5VOA
5VGATEA
3.3VAUXIN
ONA
AUXONA
PGOODA
VPULLUP
CHANNEL B
CONTROL
CHANNEL A
CONTROL
CHARGE PUMP
AND GATE
CONTROL
TEMPERATURE
SENSOR
BIAS, BANDGAP
REFERENCE, AND
UVLO
PGOODB
ONB
VPULLUP
AUXONB
MAX5915
MAX5915A
MAX5916
MAX5916A
Functional Diagram
MAX5915/MAX5915A/MAX5916/MAX5916A
Dual PCI 2.2 Hot-Swap Controllers
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
© 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
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.)
TSSOP4.40mm.EPS
PACKAGE OUTLINE, TSSOP 4.40mm BODY
21-0066 1
1
G
Mouser Electronics
Authorized Distributor
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