19-3473; Rev 1; 8/11
-48V Hot-Swap Controllers
with External R
SENSE
General Description
The MAX5948A/MAX5948B are hot-swap controllers
that allow a circuit card to be safely hot plugged into a
live backplane. The MAX5948A/MAX5948B operate
from -20V to -80V and are well-suited for -48V power
systems. The MAX5948A is pin- and function-compati-
ble with both the LT1640AL and LT1640L. The
MAX5948B is pin- and function-compatible with both
the LT1640AH and LT1640H.
The MAX5948A/MAX5948B provide a controlled turn-on
to circuit cards preventing glitches on the power-supply
rail and damage to board connectors and components.
The MAX5948A/MAX5948B provide undervoltage, over-
voltage, and overcurrent protection. These devices
ensure the input voltage is stable and within tolerance
before applying power to the load.
Both the MAX5948A and MAX5948B protect a system
against overcurrent and short-circuit conditions by turning
off the external MOSFET in the event of a fault condition.
Both devices feature an open-drain power-good status
output,
PWRGD
for MAX5948A or PWRGD for
MAX5948B, that can be used to enable downstream
converters.
The MAX5948A/MAX5948B are available in an 8-pin SO
package. Both devices are specified for the extended
-40°C to +85°C temperature range.
o
Pin- and Function-Compatible with
LT1640AL/LT1640L (MAX5948A)
o
Pin- and Function-Compatible with
LT1640AH/LT1640H (MAX5948B)
o
Withstand -100V Input Transients with No
External Components
o
Operate from -20V to -80V
o
Programmable Inrush and Short-Circuit Current
Limits
o
Programmable Overvoltage Protection
o
Programmable Undervoltage Lockout
o
Power Up into a Shorted Load
o
Power-Good Control Output
Features
o
Allow Safe Board Insertion and Removal from a
Live -48V Backplane
MAX5948A/MAX5948B
Ordering Information
PART
MAX5948AESA+
MAX5948BESA+
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
8 SO
8 SO
+Denotes
a lead(Pb)-free/RoHS-compliant package.
Applications
Central-Office Switching
Network Switches/Routers
Server Line Cards
Base-Station Line Cards
PART
MAX5948AESA
MAX5948BESA
Selector Guide
PWRGD POLARITY
Active Low (PWRGD)
Active High (PWRGD)
Pin Configuration
TOP VIEW
PWRGD
(PWRGD) 1
OV 2
UV
3
8
7
V
DD
DRAIN
GATE
SENSE
MAX5948A
MAX5948B
6
5
V
EE
4
SO
( ) FOR MAX5948B.
Typical Operating Circuit appears at end of data sheet.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
-48V Hot-Swap Controllers
with External R
SENSE
MAX5948A/MAX5948B
ABSOLUTE MAXIMUM RATINGS
(All voltages are referenced to V
EE
, unless otherwise noted.)
Supply Voltage (V
DD
- V
EE
) .................................-0.3V to +100V
PWRGD,
PWRGD
.................................................-0.3V to +100V
DRAIN (Note 1)........................................................-2V to +100V
SENSE ....................................................................-0.3V to +20V
GATE (internally clamped) .....................................-0.3V to +18V
UV and OV..............................................................-0.3V to +60V
Current through SENSE ....................................................±20mA
Current into GATE...........................................................±300mA
Current into Any Other Pin................................................±20mA
Current into Drain............................................-100mA to +20mA
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
Soldering Temperature (reflow) .......................................+260°C
Note 1:
Test condition per Figure 1. DRAIN current must be limited to the specified 100mA maximum.
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
= 0V, V
DD
= 48V, T
A
= -40°C to +85°C. Typical values are at T
A
= +25°C, unless otherwise noted.) (Notes 2, 3)
PARAMETER
POWER SUPPLIES
Operating Input Voltage Range
Supply Current
Gate Pin Pullup Current
Gate Pin Pulldown Current
External Gate Drive
GATE to V
EE
Clamp Voltage
CIRCUIT BREAKER
Current-Limit Trip Voltage
SENSE Input Bias Current
UV PIN
UV High Threshold
UV Low Threshold
UV Hysteresis
UV Input Bias Current
OV PIN
OV High Threshold
OV Low Threshold
OV Hysteresis
OV Input Bias Current
DRAIN Input Bias Current
Power-Good Threshold
Power-Good Threshold Hysteresis
V
OVH
V
OVL
V
OVHY
I
INOV
I
DRAIN
V
PG
V
PGHY
V
OV
= V
EE
V
DRAIN
= 48V
V
DRAIN
- V
EE
, high to low transition
0
10
1.1
80
1.4
0.4
OV low to high transition
OV high to low transition
1.198
1.165
1.223
1.203
20
-0.5
250
2.0
1.247
1.232
V
V
mV
µA
µA
V
V
V
UVH
V
UVL
V
UVHY
I
INUV
V
UV
= V
EE
0
UV low to high transition
UV high to low transition
1.213
1.198
1.243
1.223
20
-0.5
1.272
1.247
V
V
mV
µA
V
CB
I
SENSE
V
CB
= V
SENSE
- V
EE
V
SENSE
= 50mV
40
0
50
-0.03
60
-1
mV
µA
V
DD
I
DD
I
PU
I
PD
∆V
GATE
V
GSCLMP
V
UV
= 3V, OV = V
EE
, SENSE = V
EE
GATE drive on, V
GATE
= V
EE
Any fault condition, V
GATE
= 2V
V
GATE
- V
EE
, 20V
≤
V
DD
≤
80V
V
GATE
- V
EE
, current into GATE = 30mA
-30
24
10
15
20
0.7
-45
50
13.5
16.4
80
2
-60
70
18
18
V
mA
µA
mA
V
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
GATE DRIVER AND CLAMPING CIRCUITS
PWRGD OUTPUT SIGNAL REFERENCED TO DRAIN
2
_______________________________________________________________________________________
-48V Hot-Swap Controllers
with External R
SENSE
ELECTRICAL CHARACTERISTICS (continued)
(V
EE
= 0V, V
DD
= 48V, T
A
= -40°C to +85°C. Typical values are at T
A
= +25°C, unless otherwise noted.) (Notes 2, 3)
PARAMETER
PWRGD,
PWRGD
Output
Leakage
Power-Good Output Impedance
(PWRGD to DRAIN)
PWRGD
Output Low Voltage
PWRGD Output Low Voltage
AC PARAMETERS
OV High to GATE Low
UV Low to GATE Low
OV Low to GATE High
UV High to GATE High
SENSE High to GATE Low
DRAIN Low to
PWRGD
Low
DRAIN Low to (PWRGD - DRAIN)
High
DRAIN High to
PWRGD
High
DRAIN High to (PWRGD -
DRAIN) Low
t
PHLOV
t
PHLUV
t
PLHOV
t
PLHVL
t
PHLSENSE
t
PHLPG
MAX5948B, Figures 2, 6
MAX5948A, Figures 2, 6
t
PLHPG
MAX5948B, Figures 2, 6
0.5
0.5
0.5
µs
Figures 2, 3
Figures 2, 4
Figures 2, 3
Figures 2, 4
Figures 2, 5
MAX5948A, Figures 2, 6
2
0.5
0.4
3.3
3.4
3
0.5
µs
4
µs
µs
µs
µs
µs
SYMBOL
I
OH
R
OUT
V
OL
V
OL
CONDITIONS
V
PWRGD
(MAX5948A) = 80V, V
DRAIN
= 48V,
V
PWRGD
(MAX5948B) = 80V, V
DRAIN
= 0V
V
PWRGD
(MAX5948B) (V
DRAIN
- V
EE
) < V
PG
V
PWRGD
- V
EE;
V
DRAIN
- V
EE
< V
PG
,
I
OUT
= 1mA (MAX5948A)
V
PWRGD
- V
DRAIN
; V
DRAIN
= 5V,
I
OUT
= 1mA (MAX5948B)
500 x
10
3
0.11
0.11
0.4
0.4
MIN
TYP
MAX
10
UNITS
µA
MΩ
V
V
MAX5948A/MAX5948B
Note 2:
All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to V
EE
,
unless otherwise specified.
Note 3:
Limits are 100% tested at T
A
= +25°C and +85°C. Limits at -40°C are guaranteed by design.
V
DD
UV
PWRGD/PWRGD
OV
V
EE
MAX5948
SENSE
GATE
DRAIN
100mA MAX
TEST VOLTAGE
2V
Figure 1. -2V DRAIN Voltage Test Circuit
_______________________________________________________________________________________
3
-48V Hot-Swap Controllers
with External R
SENSE
MAX5948A/MAX5948B
Typical Operating Characteristics
(V
DD
= 48V, V
EE
= 0V, T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX5948 toc01
SUPPLY CURRENT vs. TEMPERATURE
0.9
0.8
SUPPLY CURRENT (mA)
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
MAX5948 toc02
900
800
SUPPLY CURRENT (µA)
700
600
500
400
300
200
100
0
0 10
20 30 40
1.0
50 60 70 80 90 100
-50
-25
0
25
50
75
100
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
GATE VOLTAGE vs. SUPPLY VOLTAGE
MAX5948 toc03
GATE VOLTAGE vs. TEMPERATURE
MAX5948 toc04
16
14
12
GATE VOLTAGE (V)
15.0
14.5
GATE VOLTAGE (V)
14.0
13.5
13.0
12.5
12.0
10
8
6
4
2
0
0
10 20 30 40 50 60 70 80 90 100
SUPPLY VOLTAGE (V)
-50
-25
0
25
50
75
100
TEMPERATURE (°C)
CIRCUIT-BREAKER TRIP VOLTAGE
vs. TEMPERATURE
MAX5948 toc05
GATE PULLUP CURRENT vs. TEMPERATURE
V
GATE
= 0V
47
GATE PULLUP CURRENT (µA)
46
45
44
43
42
41
40
-50
-25
0
25
50
75
100
MAX5948 toc06
55
54
TRIP VOLTAGE (mV)
53
52
51
50
49
48
-50
-25
0
25
50
75
48
100
TEMPERATURE (°C)
TEMPERATURE (°C)
4
_______________________________________________________________________________________
-48V Hot-Swap Controllers
with External R
SENSE
Typical Operating Characteristics (continued)
(V
DD
= 48V, V
EE
= 0V, T
A
= +25°C, unless otherwise noted.)
MAX5948A/MAX5948B
GATE PULLDOWN CURRENT
vs. TEMPERATURE
MAX5948 toc07
PWRGD OUTPUT LOW VOLTAGE
vs. TEMPERATURE (MAX5948A)
I
OUT
= 1mA
PWRGD OUTPUT LOW VOLTAGE (mV)
35
30
25
20
15
10
5
0
1
-50
-25
0
25
50
75
100
-50
MAX5948 toc08
PWRGD OUTPUT IMPEDANCE
vs. TEMPERATURE (MAX5948B)
MAX5948 toc09
60
V
GATE
= 2V
GATE PULLDOWN CURRENT (mA)
55
50
45
40
35
30
-50
-25
0
25
50
75
40
10,000
OUTPUT IMPEDANCE (GΩ)
1000
100
10
100
-25
0
25
50
75
100
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
V+
5V
R
5kΩ
PWRGD/PWRGD
OV
V
OV
V
DD
DRAIN
V
DRAIN
V
S
48V
MAX5948A
MAX5948B
UV
V
UV
GATE
V
EE
SENSE
V
SENSE
Figure 2. Test Circuit 1
_______________________________________________________________________________________
5
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