19-3281; Rev 1; 1/05
-48V Hot-Swap Controllers with V
IN
Step Immunity and No R
SENSE
General Description
The MAX5936/MAX5937 are hot-swap controllers for
-10V to -80V rails. The MAX5936/MAX5937 allow circuit
line cards to be safely hot-plugged into a live back-
plane without causing a glitch on the power supply.
These devices integrate a circuit-breaker function
requiring no R
SENSE
.
The MAX5936/MAX5937 provide a controlled turn-on
for circuit cards, limiting inrush, preventing glitches on
the power-supply rail, and preventing damage to board
connectors and components. Before startup, the
devices perform a Load Probe™ test to detect the
presence of a short-circuit condition. If a short-circuit
condition does not exist, the device limits the inrush
current drawn by the load by gradually turning on the
external MOSFET. Once the external MOSFET is fully
enhanced, the MAX5936/MAX5937 provides overcur-
rent and short-circuit protection by monitoring the volt-
age drop across the R
DS(ON)
of the external power
MOSFET. The MAX5936/MAX5937 integrate a 400mA
fast GATE pulldown to guarantee that the power
MOSFET is rapidly turned off in the event of an overcur-
rent or short-circuit condition.
The MAX5936/MAX5937 protect the system against
input voltage (V
IN
) steps by providing V
IN
step immuni-
ty. The MAX5936/MAX5937 provide an accurate UVLO
voltage. The MAX5936 has an open-drain, active-low
PGOOD
output and the MAX5937 has an open-drain,
active-high PGOOD output.
The MAX5936/MAX5937 are offered with 100mV,
200mV, and 400mV circuit-breaker thresholds, in addi-
tion to a non-circuit-breaker option. These devices are
offered in latched and autoretry fault management, are
available in 8-pin SO packages, and specified for the
extended (-40°C to +85°C) temperature range (see the
Selector Guide).
♦
-10V to -80V Operation
♦
No R
SENSE
Required
♦
Drives Large Power MOSFETS
♦
Programmable Inrush Current Limit During Hot
Plug
♦
100mV, 200mV, 400mV, and No-Circuit-Breaker
Threshold Options
♦
Circuit-Breaker Fault with Transient Rejection
♦
Shorted Load Detection (Load Probe) Before
Power MOSFET Turn-On
♦
±2.4% Accurate Undervoltage Lockout (UVLO)
♦
Autoretry and Latched Fault Management
Available
♦
Low Quiescent Current
Features
MAX5936/MAX5937
Ordering Information
PART
MAX5936_
_ESA
MAX5937_
_ESA
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
8 SO
8 SO
Note:
The first “_” represents A for the autoretry and L for the
latched fault management option.
The second “_” represents the circuit-breaker threshold.
See the Selector Guide for additional information.
Selector Guide and Typical Operating Circuit appear at end
of data sheet.
Applications
Servers
Telecom Line Cards
Network Switches
Solid-State Circuit Breaker
Network Routers
UVLO 2
STEP_MON
3
GND 1
Pin Configuration
TOP VIEW
8
7
PGOOD
(PGOOD)
V
OUT
GATE
LP
MAX5936
MAX5937
6
5
V
EE
4
SO
Load Probe is a trademark of Maxim Integrated Products, Inc.
( ) FOR THE MAX5937.
________________________________________________________________
Maxim Integrated Products
1
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.
-48V Hot-Swap Controllers with V
IN
Step Immunity and No R
SENSE
MAX5936/MAX5937
ABSOLUTE MAXIMUM RATINGS
V
EE
, V
OUT
, PGOOD (PGOOD), LP,
STEP_MON to GND............................................+0.3V to -85V
PGOOD (PGOOD) to V
OUT
....................................-0.3V to +85V
PGOOD (PGOOD), LP, STEP_MON to V
EE
............-0.3V to +85V
GATE to V
EE
...........................................................-0.3V to +20V
UVLO to V
EE
.............................................................-0.3V to +6V
Input Current
LP (internally, duty-cycle limited).........................................1A
PGOOD (PGOOD) (continuous) .....................................80mA
GATE (during 15V clamp, continuous) ...........................30mA
GATE (during 2V clamp, continuous) .............................50mA
GATE (during gate pulldown, continuous)......................50mA
Continuous Power Dissipation (T
A
= +70°C)
8-Pin SO (derate 5.9mW/°C above +70°C)..................471mW
Operating Temperature Range ...........................-40°C to +85°C
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
EE
= -10V to -80V, V
IN
= GND - V
EE
, V
STEP_MON
= V
EE
, R
LP
= 200Ω, UVLO open, T
A
= -40°C to +85°C, unless otherwise noted.
Typical values are at V
EE
= -48V, T
A
= +25°C.) (Notes 1, 2)
PARAMETER
Operating Voltage Range
Operating Supply Current
Default V
EE
Undervoltage Lockout
UVLO Reference Threshold,
V
EE
Rising
UVLO Reference Threshold,
V
EE
Falling
UVLO Input Resistance
UVLO Transient Rejection
Power-Up Delay (Note 3)
V
EE
and UVLO Glitch Rejection
(Note 4)
V
OUT
to V
EE
Leakage Current
LP to V
EE
Leakage Current
External Gate-Drive Voltage
V
GS
t
OVREJ
t
ONDLY
t
REJ
V
EE
= -80V, V
OUT
= GND
V
EE
= -80V, V
LP
= GND
V
GATE
- V
EE
MOSFET fully
enhanced
GATE to V
EE
Clamp Voltage
Power-off,
V
EE
= GND
V
GATE
- V
EE
=
500mV
l dV
OUT
/dt l
V
IN
= 10V
14
≤
V
IN
≤
80V
I
CLAMP
= 9mA
I
CLAMP
= 20mA
I
CLAMP
= 1mA
I
CLAMP
= 10mA
-66
V
IN
> 10V
V
IN
> 14V
2.4
6.5
8.1
13.5
SYMBOL
V
EE
I
CC
V
UVLO,R
V
UVLO,F
V
UVLO_REF,R
V
UVLO_REF,F
lV
EE
l increasing
lV
EE
l decreasing
V
UVLO
increasing
V
UVLO
decreasing
1.219
1.069
20
0.8
80
0.8
1.5
220
1.5
0.01
0.01
6.8
10
16
17
2.1
2.5
-52
9
7.5
9
19.5
2.55
2.9
-35
14.1
12.5
14.8
µA
Ω
V/ms
V
-33.5
CONDITIONS
Referenced to GND
MIN
-80
0.95
-31.0
-28
1.25
1.125
1.281
1.181
50
2.25
380
2.25
1
1
7.2
12.8
TYP
MAX
-10
1.4
-29.5
UNITS
V
mA
V
V
V
kΩ
ms
ms
ms
µA
µA
V
Open-Loop Gate-Charge Current
GATE Pulldown Switch
On-Resistance
Output-Voltage Slew Rate
R
GATE
SR
V
GATE
= V
EE
, V
OUT
= GND
2
_______________________________________________________________________________________
-48V Hot-Swap Controllers with V
IN
Step Immunity and No R
SENSE
ELECTRICAL CHARACTERISTICS (continued)
(V
EE
= -10V to -80V, V
IN
= GND - V
EE
, V
STEP_MON
= V
EE
, R
LP
= 200Ω, UVLO open, T
A
= -40°C to +85°C, unless otherwise noted.
Typical values are at V
EE
= -48V, T
A
= +25°C.) (Notes 1, 2)
PARAMETER
Circuit-Breaker Tempco
Circuit-Breaker Glitch Rejection
t
CB_DLY
MAX5936LA/
MAX5936AA/
MAX5937LA/
MAX5937AA
MAX5936LB/
MAX5936AB/
MAX5937LB/
MAX5937AB
MAX5936LC/
MAX5936AC/
MAX5937LC/
MAX5937AC
MAX5936LA/
MAX5936AA/
MAX5937LA/
MAX5937AA
MAX5936LB/
MAX5936AB/
MAX5937LB/
MAX5937AB
MAX5936LC/
MAX5936AC/
MAX5937LC/
MAX5937AC
Short-Circuit Response Time
(Note 5)
INPUT-VOLTAGE-STEP PROTECTION
Input-Voltage-Step Detection
Threshold
Input-Voltage-Step Threshold
Offset Current
LOAD-PROBE CIRCUIT
Load-Probe Switch On-Resistance
Load-Probe Timeout
Load-Probe Retry Time
Load-Probe Voltage Threshold
t
LP
t
LP_OFF
V
THSC-DET
Referenced to GND
-220
V
LP
- V
EE
= 1V
80
7.5
220
16 x
t
LP
-200
-180
11
380
Ω
ms
s
mV
STEP
TH
I
STEP_OS
1.219
-10.8
1.250
-10.0
1.281
-9.2
V
µA
T
A
= +85°C
T
A
= +25°C
T
A
= -10°C
T
A
= -40°C
T
A
= +85°C
T
A
= +25°C
T
A
= -10°C
T
A
= -40°C
T
A
= +85°C
T
A
= +25°C
T
A
= -10°C
T
A
= -40°C
T
A
= +85°C
T
A
= +25°C
T
A
= -10°C
T
A
= -40°C
T
A
= +85°C
T
A
= +25°C
T
A
= -10°C
T
A
= -40°C
T
A
= +85°C
T
A
= +25°C
T
A
= -10°C
T
A
= -40°C
962
700
510
470
350
255
220
160
111
485
355
270
244
180
135
SYMBOL
CONDITIONS
-40°C < T
A
<+85°C
1.0
118
85
64
MIN
TYP
6000
1.2
140
100
79
62
284
200
158
124
568
400
316
248
280
200
158
124
568
400
316
248
1136
800
632
496
330
500
ns
1310
900
754
667
450
377
mV
340
240
205
651
445
362
324
220
181
mV
1.6
162
115
94
MAX
UNITS
ppm/°C
ms
MAX5936/MAX5937
Circuit-Breaker Threshold
V
CB
Short-Circuit Threshold
V
SC
150mV overdrive, C
LOAD
= 0,
to GATE below 1V
_______________________________________________________________________________________
3
-48V Hot-Swap Controllers with V
IN
Step Immunity and No R
SENSE
MAX5936/MAX5937
ELECTRICAL CHARACTERISTICS (continued)
(V
EE
= -10V to -80V, V
IN
= GND - V
EE
, V
STEP_MON
= V
EE
, R
LP
= 200Ω, UVLO open, T
A
= -40°C to +85°C, unless otherwise noted.
Typical values are at V
EE
= -48V, T
A
= +25°C.) (Notes 1, 2)
PARAMETER
LOGIC AND FAULT MANAGEMENT
Autoretry Delay
t
RETRY
|V
OUT
- V
EE
| falling
Hysteresis
0.67
V
OL
I
L
I
SINK
= 1mA, referenced to V
OUT,
V
OUT
< GND - 5V for PGOOD (PGOOD)
V
EE
= -80V, V
PGOOD(PGOOD)
,
V
PGOOD(PGOOD)
= GND
16 x
t
LP
0.72 x
V
CB
0.26 x
V
CB
1.26
0.05
0.01
1.85
0.4
1
s
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
PGOOD (PGOOD) Assertion
Threshold
PGOOD (PGOOD) Assertion Delay
Time (Note 6)
PGOOD (PGOOD) Low Voltage
PGOOD (PGOOD) Open-Drain
Leakage
mV
ms
V
µA
Note 1:
All currents into pins are positive and all currents out of pins are negative. All voltages referenced to V
EE
, unless otherwise
specified.
Note 2:
All limits are 100% tested at +25°C and +85°C. Limits at -40°C and -10°C are guaranteed by characterization.
Note 3:
Delay time from a valid on-condition until the load probe test begins.
Note 4:
V
EE
or UVLO voltages below V
UVLO,F
or V
UVLO_REF,F
, respectively, are ignored during this time.
Note 5:
The time (V
OUT
- V
EE
) > V
SC
+ overdrive until (V
GATE
- V
EE
) drops to approximately 90% of its initial high value.
Note 6:
The time when the PGOOD (PGOOD) condition is met until the PGOOD (PGOOD) signal is asserted.
4
_______________________________________________________________________________________
-48V Hot-Swap Controllers with V
IN
Step Immunity and No R
SENSE
Typical Operating Characteristics
(V
EE
= -48V, GND = 0V, V
IN
= GND - V
EE
, all voltages are referenced to V
EE
, T
A
= +25°C, unless otherwise noted.)
MAX5936/MAX5937
SUPPLY CURRENT
vs. INPUT VOLTAGE
MAZ5936 toc01
SUPPLY CURRENT
vs. TEMPERATURE
MAX5936 toc02
GATE-DRIVE VOLTAGE
vs. INPUT VOLTAGE
10.0
GATE-DRIVE VOLTAGE (V)
9.5
9.0
8.5
8.0
7.5
7.0
MAX5936 toc03
2.0
1.8
1.6
SUPPLY CURRENT (mA)
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
10
20
30
40
50
60
70
1.2
1.0
SUPPLY CURRENT (mA)
V
IN
= 72V
10.5
V
IN
= 48V
0.8
0.6
0.4
0.2
V
IN
= 12V
6.5
0
80
-40
-15
10
35
60
85
INPUT VOLTAGE (V)
TEMPERATURE (°C)
6.0
10
20
30
40
50
60
70
80
INPUT VOLTAGE (V)
GATE PULLDOWN CURRENT
vs. GATE VOLTAGE
MAX5936 toc04
RETRY TIME
vs. TEMPERATURE
3.9
3.8
RETRY TIME (s)
3.7
3.6
3.5
3.4
3.3
3.2
3.1
3.0
C
GATE
= 0, C
LOAD
= 100µF
MAX5936 toc05
500
450
GATE PULLDOWN CURRENT (mA)
400
350
300
250
200
150
100
50
0
0
1
2
3
4
5
6
7
8
9
4.0
10
-40
-15
10
35
60
85
V
GATE
(V)
TEMPERATURE (°C)
STARTUP WAVEFORM
MAX5936 toc06
MAX5936_A CIRCUIT-BREAKER EVENT
MAX5936 toc07
V
IN
50V/div
V
GATE
10V/div
V
OUT
50V/div
V
PGOOD
50V/div
V
GATE
10V/div
V
OUT
50V/div
V
PGOOD
50V/div
I
IN
2A/div
1ms/div
I
IN
2A/div
40ms/div
_______________________________________________________________________________________
5
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