MAX5947BESA+ [MAXIM]
Power Supply Support Circuit, Adjustable, 1 Channel, BICMOS, PDSO8, 0.150 INCH, MS012AA, SOIC-8;
| 型号： | MAX5947BESA+ |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Power Supply Support Circuit, Adjustable, 1 Channel, BICMOS, PDSO8, 0.150 INCH, MS012AA, SOIC-8 控制器 |
| 文件： | 总15页 (文件大小：269K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-3263; Rev 1; 7/04
Positive High-Voltage, Hot-Swap Controllers
General Description
Features
The MAX5933A–MAX5933F/MAX5947A/B/C fully integrat-
ed hot-swap controllers for +9V to +80V positive supply
rails (MAX5947A/B/C), allow for the safe insertion and
removal of circuit cards into live backplanes without caus-
ing glitches on the backplane power-supply rail. The
MAX5947B is pin- and function-compatible with the
LT1641-2. The other devices offer added features such
as a choice of active-high or active-low power-good out-
puts (PWRGD/PWRGD), latched/autoretry fault manage-
ment, and autoretry duty-cycle options of 3.75% or 0.94%
(see the Selector Guide).
♦ Pin- and Function-Compatible with the LT1641-2
(MAX5947B)
♦ Provides Safe Hot Swap for +9V to +80V Power-
Supply Range (MAX5947A/B/C)
♦ Safe Board Insertion and Removal from Live
Backplanes
♦ Latched/Autoretry Management
♦ Active-Low or Active-High Power-Good Output
♦ Programmable Foldback Current Limiting
♦ High-Side Drive for an External N-Channel MOSFET
♦ Built-In Thermal Shutdown
The MAX5933A–MAX5933F are available with a default
undervoltage lockout threshold of +31V and operate over
a supply voltage range of +33V to +80V. The
MAX5947A/B/C are available with a default undervoltage
of +8.3V. All devices feature a programmable analog
foldback current limit. If the device remains in current limit
for more than a programmable time, the external
n-channel MOSFET is either latched off (MAX5933A/
MAX5933C/MAX5947A) or is set to automatically restart
after a timeout delay (MAX5933B/MAX5933D/MAX5933E/
MAX5933F/MAX5947B/MAX5947C).
♦ Undervoltage Lockout (UVLO)
♦ Overvoltage Protection
♦ User-Programmable Supply Voltage
Power-Up Rate
Ordering Information
The MAX5933_ and MAX5947_ operate in the extended
temperature range of -40°C to +85°C. These devices are
available in an 8-pin SO package.
PART
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
8 SO
MAX5933_ESA*
MAX5947_ESA*
8 SO
Applications
Hot Board Insertion
*Insert the desired suffix from the Selector Guide into the blank
to complete the part number.
Electronic Circuit Breakers
Industrial High-Side Switch/Circuit Breakers
Network Routers and Switches
Typical Application Circuit and Pin Configuration appear at
end of data sheet.
24V/48V Industrial/Alarm Systems
Selector Guide
LATCHED
FAULT
PROTECTION
AUTORETRY
FAULT
PROTECTION
SUPPLY
VOLTAGE
RANGE (V)
PWRGD
OUTPUT LOGIC
DUTY CYCLE
(%)
DEFAULT UVLO
(V)
PART
MAX5933A
MAX5933B
MAX5933C
MAX5933D
MAX5933E
MAX5933F
MAX5947A
MAX5947B
MAX5947C
Yes
—
—
High
High
Low
Low
High
Low
Low
High
Low
—
31
31
31
31
31
31
8.3
8.3
8.3
33 to 80
33 to 80
33 to 80
33 to 80
33 to 80
33 to 80
9 to 80
Yes
—
3.75
—
Yes
—
Yes
Yes
Yes
—
3.75
0.94
0.94
—
—
—
Yes
—
Yes
Yes
3.75
3.75
9 to 80
—
9 to 80
________________________________________________________________ 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.
Positive High-Voltage, Hot-Swap Controllers
ABSOLUTE MAXIMUM RATINGS
(Voltages Referenced to GND)
Continuous Power Dissipation (T = +70°C)
A
V
.........................................................................-0.3V to +85V
8-Pin SO (derate 5.9mW/°C above +70°C)..................470mW
Operating Temperature Range ...........................-40°C to +85°C
Maximum Junction Temperature .....................................+150°C
Storage Temperature Range.............................-60°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
ESD Rating (Human Body Model)......................................2000V
CC
SENSE, FB, ON ..........................................-0.3V to (V + 0.3V)
CC
TIMER, PWRGD, PWRGD.......................................-0.3V to +85V
GATE ......................................................................-0.3V to +95V
Maximum GATE Current ....................................-50mA, +150mA
Maximum Current into Any Other Pin................................ 50mA
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
= +24V (MAX5947A/B/C), V
= +48V (MAX5933A–MAX5933F), GND = 0V, T = -40°C to +85°C, unless otherwise noted.
CC
CC A
Typical values are at T = +25°C.) (Note 1)
A
PARAMETER
Supply Voltage Range
Supply Current
SYMBOL
CONDITIONS
MAX5947A/B/C
MAX5933A–MAX5933F
MIN
9
TYP
MAX
UNITS
80
V
V
mA
V
CC
33
80
3.5
8.8
I
V
= 3V, V
= 80V
CC
1.4
8.3
CC
ON
MAX5947A/B/C
MAX5933A–MAX5933F
7.5
V
low-to-high
CC
V
Undervoltage Lockout
V
LKO
CC
transition
29.5
31
32.5
MAX5947A/B/C
0.4
2
V
Undervoltage Lockout
CC
V
V
LKOHYST
Hysteresis
MAX5933A–MAX5933F
FB low-to-high transition
FB High-Voltage Threshold
FB Low-Voltage Threshold
V
1.280
1.221
1.313
1.345
1.245
V
V
FBH
V
FB high-to-low transition
1.233
80
FBL
FB Hysteresis
V
mV
µA
FBHYST
FB Input Bias Current
I
V
V
= 0V
-1
+1
INFB
FB
≤ V
≤ 80V, ON = 0V,
CC(MIN)
CC
FB Threshold Line Regulation
∆V
0.05
mV/V
mV
FB
T
A
= 0°C to +70°C
V
V
= 0V, T = 0°C to +70°C
8
12
47
17
55
FB
FB
A
SENSE Trip Voltage
(V
V
SENSETRIP
- V
)
CC
SENSE
= 1V, T = 0°C to +70°C
39
-5
A
GATE Pullup Current
I
Charge pump on, V
= 7V
-10
70
-20
100
18
µA
GATEUP
GATE
GATE Pulldown Current
I
Any fault condition, V
= 2V
35
10
mA
GATEDN
GATE
MAX5933A–MAX5933F
13.6
V
= 10.8V to 20V,
CC
4.5
6.2
18.0
MAX5947A/B/C
External N-Channel Gate Drive
∆V
V
- V
CC
V
GATE
GATE
V
= 20V to 80V,
CC
10
-24
1.5
13.2
-80
3
18
-120
4.5
MAX5947A/B/C
TIMER Pullup Current
I
V
V
= 0V
= 1V
µA
µA
TIMERUP
TIMER
TIMER
MAX5933A–MAX5933D,
MAX5947A/B/C
TIMER Pulldown Current
I
TIMERON
MAX5933E/MAX5933F
0.37
1.280
1.221
0.75
1.313
1.233
1.12
1.345
1.245
ON Logic-High Threshold
ON Logic-Low Threshold
V
ON low-to-high transition
ON high-to-low transition
V
V
ONH
V
ONL
2
_______________________________________________________________________________________
Positive High-Voltage, Hot-Swap Controllers
ELECTRICAL CHARACTERISTICS (continued)
(V
= +24V (MAX5947A/B/C), V
= +48V (MAX5933A–MAX5933F), GND = 0V, T = -40°C to +85°C, unless otherwise noted.
CC
CC A
Typical values are at T = +25°C.) (Note 1)
A
PARAMETER
ON Hysteresis
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
mV
V
80
ONHYST
ON Input Bias Current
I
V
V
V
= 0V
ON
-1
+1
10
µA
INON
PWRGD Leakage Current
PWRGD Leakage Current
I
= 80V
= 80V
µA
OH
PWRGD
I
10
µA
OL
PWRGD
I
I
= 2mA
= 4mA
SENSE
0.4
2.5
+3
O
PWRGD/PWRGD Output Low
Voltage
V
O
SENSE Input Bias Current
Thermal Shutdown
I
V
= 0V to V
-1
µA
°C
°C
SENSE
CC
Temperature rising
+150
20
Thermal Shutdown Hysteresis
ON Low-to-GATE Low
Propagation Delay
t
C
C
= 0, Figures 1, 2
= 0, Figures 1, 2
6
µs
µs
µs
µs
µs
PHLON
GATE
GATE
ON High-to-GATE High
Propagation Delay
t
1.7
3.2
1.5
PLHON
FB Low-to-PWRGD Low
Propagation Delay
t
Figures 1, 3
Figures 1, 3
PHLFB
PLHFB
FB High-to-PWRGD High
Propagation Delay
t
(V
CC
- V ) High-to-GATE
SENSE
t
T
A
= +25°C, C = 0, Figures 1, 4
GATE
0.5
2
PHLSENSE
Low Propagation Delay
Note 1: All currents into the device are positive and all currents out of the device are negative. All voltages are referenced to
ground, unless otherwise noted.
_______________________________________________________________________________________
3
Positive High-Voltage, Hot-Swap Controllers
Test Circuit and Timing Diagrams
ON
FB
V
CC
24V
SENSE
1.313V
1V
1.233V
FB
MAX5933_
MAX5947_
t
t
PHLFB
PLHFB
V+ = 5V
1V
PWRGD
PWRGD
GATE
5kΩ
10nF
TIMER
GND
Figure 3. FB to PWRGD Timing
Figure 1. Test Circuit
1.313V
1.233V
47mV
V
CC
- SENSE
GATE
ON
t
t
PLHON
PHLON
t
PHLSENSE
5V
V
CC
1V
GATE
Figure 2. ON to GATE Timing
Figure 4. SENSE to GATE Timing
4
_______________________________________________________________________________________
Positive High-Voltage, Hot-Swap Controllers
Typical Operating Characteristics
(V
= +48V, T = +25°C, unless otherwise noted.)
A
CC
FB LOW-VOLTAGE THRESHOLD
vs. TEMPERATURE
I
vs. V
I
vs. TEMPERATURE
CC
CC
CC
2.7
3.0
2.5
2.0
1.5
1.0
0.5
0
1.250
1.245
1.240
1.235
1.230
1.225
1.220
1.215
1.210
1.205
1.200
2.4
2.1
1.8
1.5
1.2
0.9
0.6
0.3
0
T
= +85°C
A
T
= +25°C
A
V
= 48V (MAX5933_/MAX5947_)
CC
T
= -40°C
A
V
= 24V (MAX5947_)
CC
33
40
48
56
64
72
80
-40
-15
10
35
60
85
-40
-15
10
35
60
85
V
(V)
TEMPERATURE (°C)
TEMPERATURE (°C)
CC
FB HIGH-VOLTAGE THRESHOLD
vs. TEMPERATURE
I
PULLUP CURRENT
vs. TEMPERATURE
GATE
FB HYSTERESIS vs. TEMPERATURE
0.11
0.10
0.09
0.08
0.07
0.06
0.05
0.04
1.335
1.330
1.325
1.320
1.315
1.310
1.305
1.300
1.295
1.290
1.285
1.280
-5
-6
-7
-8
-9
-10
-11
-12
-13
-40
-15
10
35
60
85
-40
-15
10
35
60
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
MAX5947_
GATE DRIVE vs. V
GATE DRIVE vs. TEMPERATURE
CC
15
14
13
12
11
10
9
16
14
12
10
8
V
= 48V (MAX5933_/MAX5947_)
CC
6
8
4
V
= 10.8V (MAX5947_)
CC
7
2
6
5
0
-40
-15
10
35
60
85
0
10 20 30 40 50 60 70 80
(V)
TEMPERATURE (°C)
V
CC
_______________________________________________________________________________________
5
Positive High-Voltage, Hot-Swap Controllers
Typical Operating Characteristics (continued)
(V
= +48V, T = +25°C, unless otherwise noted.)
A
CC
MAX5947_
TIMER PULLUP CURRENT vs. V
TIMER PULLUP CURRENT
vs. TEMPERATURE
MAX5933_
TIMER PULLUP CURRENT vs. V
CC
CC
-73
-74
-75
-76
-77
-78
-79
-60
-65
-73
-74
-75
-76
-77
-78
-79
T
= +85°C
A
T
= +85°C
A
T
= +25°C
A
T
= +25°C
A
-70
-75
-80
-85
-90
T
= 0°C
T
= 0°C
A
T = -40°C
A
A
T
= -40°C
A
0
10 20 30 40 50 60 70 80
(V)
-40
-15
10
35
60
85
30
40
50
60
70
80
V
CC
TEMPERATURE (°C)
V
(V)
CC
ON HIGH-VOLTAGE THRESHOLD
vs. TEMPERATURE
ON LOW-VOLTAGE THRESHOLD
vs. TEMPERATURE
ON HYSTERESIS vs. TEMPERATURE
0.083
0.081
0.079
0.077
0.075
0.073
1.343
1.333
1.323
1.313
1.303
1.293
1.283
1.265
1.255
1.245
1.235
1.225
1.215
1.205
-40
-15
10
35
60
85
-40
-15
10
35
60
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
PWRGD V
LOW vs. I
SENSE REGULATION VOLTAGE vs. V
FB
OUT
LOAD
20
18
16
14
12
10
8
50
45
40
35
30
25
20
15
10
5
6
4
T = +25°C
A
T
= -40°C
T
= +85°C
A
A
2
0
0
10
30
50
70
90
0
0.2
0.4
0.6
(V)
0.8
1.0
I
(mA)
V
FB
LOAD
6
_______________________________________________________________________________________
Positive High-Voltage, Hot-Swap Controllers
Pin Description
PIN
NAME
FUNCTION
ON/OFF Control Input. ON is used to implement the undervoltage lockout threshold and resets the part
after a fault condition for the latched-off version (MAX5933A/MAX5933C/MAX5947A, see the Detailed
Description section).
1
ON
Power-Good Comparator Input. Connect a resistive divider from output to FB to GND to monitor the output
voltage (see the Power-Good Detection section). FB is also used as a feedback for the current-limit
foldback function.
2
FB
PWRGD/ Open-Drain Power-Good Output. PWRGD is high (PWRGD is low) when V is higher than V
. PWRGD
FB
FBH
3
4
5
6
7
PWRGD is low (PWRGD is high) when V is lower than V
.
FB
FBL
GND
TIMER
GATE
SENSE
Ground
Timing Input. Connect a capacitor from TIMER to GND to program the maximum time the part is allowed to
remain in current limit (see the TIMER section).
Gate-Drive Output. The high-side gate drive for the external N-channel MOSFET (see the GATE Voltage section).
Current-Sense Input. Connect a sense resistor from V to SENSE and the drain of the external n-channel
CC
MOSFET.
Power-Supply Input. Bypass V
for the MAX5947A/B/C. Input voltage range is from +33V to +80V for the MAX5933A–MAX5933F.
to GND with a 0.1µF capacitor. Input voltage range is from +9V to +80V
CC
8
V
CC
_______________________________________________________________________________________
7
Positive High-Voltage, Hot-Swap Controllers
Functional Diagram
FB
V
SENSE
CC
MAX5933_
MAX5947_
V GEN
P
CHARGE
PUMP
AND
REF
GEN
GATE
0.5V
GATE
DRIVER
OPEN
DRAIN
12mV TO 47mV
PWRGD
(PWRGD)
1.233V
ON
UNDERVOLTAGE
LOCKOUT
V
CC
V
UVLO
LOGIC
V
P
0.5V
80µA
1.233V
TIMER
3µA
*0.75µA
GND
( ) FOR THE MAX5933C/D/F AND THE MAX5947A/C.
*FOR THE MAX5933E/MAX5933F.
8
_______________________________________________________________________________________
Positive High-Voltage, Hot-Swap Controllers
The MAX5933_ and MAX5947_ monitor the input volt-
Detailed Description
age, the output voltage, the output current, and the die
The MAX5933_ and MAX5947_ are fully integrated hot-
temperature. These devices feature power-good outputs
swap controllers for positive supply rails. The devices
(PWRGD/PWRGD) to indicate the status of the output
allow for the safe insertion and removal of circuit cards
voltage by monitoring the voltage at FB (see the Power-
into live backplanes without causing glitches on the
Good Detection section).
backplane power-supply rail. During startup, the
As shown in Figure 5, a sense resistor is connected
between V and SENSE to regulate the voltage
MAX5933_ and MAX5947_ act as current regulators
using an external sense resistor and a MOSFET to limit
the amount of current drawn by the load.
CC
across the sense resistor (V - V
) to 47mV when
IN
SENSE
the voltage at FB ≥ 0.5V. The current-limit threshold
The MAX5933_ operate from a +33V to +80V supply
voltage range and have a default undervoltage lockout
(UVLO) set to +31V. The MAX5947_ operate from a
+9V to +80V supply voltage range and have a default
UVLO set to +8.3V. The UVLO threshold is adjustable
(V
) decreases linearly from 47mV to 12mV as
SENSETRIP
FB decreases from 0.5V to 0V.
An undervoltage fault is detected when ON goes below
the threshold (V
= 1.233V) and the voltage at GATE
ONL
goes low as a result to turn off the MOSFET. ON must
pass the V = 1.313V threshold to turn on the
using a resistive divider connected from V
GND (see Figure 5).
to ON to
CC
ONH
MOSFET again.
R
SENSE
Q1
IRF530
0.025Ω
V
IN
24V
C
L
D1
R5
10Ω
5%
CMPZ5248B
R6
1kΩ
5%
R1
49.9kΩ
1%
R3
59kΩ
1%
0.1µF
R7
24kΩ
5%
8
7
6
C1
10nF
V
SENSE
GATE
CC
2
3
1
FB
ON
R4
3.57kΩ
1%
R2
3.4kΩ
1%
MAX5933A
5
TIMER
PWRGD
PWRGD
C2
0.68µF
GND
4
GND
Figure 5. Application Circuit
_______________________________________________________________________________________
9
Positive High-Voltage, Hot-Swap Controllers
Short-Circuit Protection
Applications Information
The MAX5933_/MAX5947_ feature a programmable fold-
back current limit with an electronic circuit breaker that
protects against short circuits or excessive supply cur-
rents. The current limit is set by placing a sense resistor
Hot-Circuit Insertion
When circuit boards are inserted into a live backplane,
the supply bypass capacitors on the boards draw high
peak currents from the backplane power bus as they
charge up. The transient currents can permanently
damage the connector pins and glitch the system sup-
ply, causing other boards in the system to reset.
between V (pin 8) and SENSE (pin 7).
CC
To prevent excessive power dissipation in the pass
transistor and to prevent voltage spikes on the input
supply during short-circuit conditions at the output, the
current folds back as a function of the output voltage
that is sensed at FB (Figure 7).
Power-Up Sequence
The power supply on a board is controlled by placing
an external n-channel MOSFET (Q1) in the power path
When the voltage at FB is 0V, the current-limit circuit
drives GATE to force a constant 12mV drop across the
sense resistor. As the output voltage at FB increases,
the voltage across the sense resistor increases until FB
reaches 0.5V. At this point, the voltage across the
sense resistor is held constant at 47mV.
(Figure 5). Resistor R
provides current detection
SENSE
and capacitor C1 provides control of the GATE slew
rate. Resistor R6 provides current control-loop compen-
sation, while R5 prevents high-frequency oscillations in
Q1. Resistors R1 and R2 provide undervoltage sensing.
After the power pins first make contact, transistor Q1 is
turned off. When the voltage at ON exceeds the turn-on
The maximum current limit is calculated as:
I
= 47mV / R
SENSE
LIMIT
threshold voltage, the voltage on V
exceeds the
CC
undervoltage lockout threshold, and when the voltage
on TIMER is less than 1.233V, transistor Q1 turns on
(Figure 6).
For a 0.025Ω sense resistor, the current limit is set at
1.88A and folds back to 480mA when the output is
shorted to ground.
The voltage at GATE rises with a slope equal to
10µA/C1 and the supply inrush current is set at:
The MAX5933_/MAX5947_ also feature a variable over-
current response time. The time required to regulate
Q1’s drain current depends on:
I
= C x 10µA/C1
L
INRUSH
1) Q1’s input capacitance
When the voltage across the current-sense resistor
reaches V , the inrush current is limit-
ed by the internal current-limit circuitry that adjusts the
voltage on GATE to maintain a constant voltage across
the sense resistor.
R
2) GATE capacitor C1 and compensation resistor R6
3) The internal delay from SENSE to GATE
SENSE
SENSETRIP
Figure 8 shows the delay from a voltage step at SENSE
until GATE voltage starts falling, as a function of
overdrive.
Once the voltage at the output has reached its final value,
as sensed by resistors R3 and R4, PWRGD goes high or
PWRGD goes low.
POWER-UP WAVEFORMS
V
CC
- V
SENSE
GATE
50V/div
47mV
I
SENSE
2A/div
OUTPUT
50V/div
12mV
PWRGD
50V/div
V
FB
0V
0.5V
20ms/div
Figure 7. Current-Limit Sense Voltage vs. Feedback Voltage
Figure 6. Power-Up Waveforms
10 ______________________________________________________________________________________
Positive High-Voltage, Hot-Swap Controllers
RESPONSE TIME TO OVERCURRENT
SHORT-CIRCUIT WAVEFORMS
14
OUTPUT
12
10
8
50V/div
I
SENSE
1A/div
GATE
50V/div
6
4
TIMER
1V/div
2
0
0
100
200
(mV)
300
10ms/div
V
- V
SENSE
CC
Figure 8. Response Time to Overcurrent
Figure 9. Short-Circuit Waveforms
Figure 10 shows an overvoltage detection circuit. When
the input voltage exceeds the Zener diode’s breakdown
voltage, D1 turns on and starts to pull TIMER high. After
TIMER is pulled higher than 1.233V, the fault latch is set
and GATE is pulled to GND immediately, turning off
transistor Q1 (see Figure 11). Operation is restored
either by interrupting power or by pulsing ON low.
TIMER
TIMER provides a method for programming the maxi-
mum time the device is allowed to operate in current
limit. When the current-limit circuitry is not active,
TIMER is pulled to GND by a 3µA current source. After
the current-limit circuit becomes active, an 80µA pullup
current source is connected to TIMER, and the voltage
rises with a slope equal to 77µA/C
, as long as the
TIMER
Power-Good Detection
The MAX5933_/MAX5947_ include a comparator for mon-
itoring the output voltage. The noninverting input (FB) is
compared against an internal 1.233V precision reference
and exhibits 80mV hysteresis. The comparator’s output
(PWRGD) is open drain and capable of operating from a
pullup as high as 80V. The PWRGD is similar to PWRGD
with an opposite polarity (active low) output.
current-limit circuit remains active. Once the desired
maximum current-limit time is chosen, the capacitor
value is:
C(nF) = 65 x t(ms)
or
T
LIMIT
= (C
/80µA) x 1.233V
TIMER
When the current-limit circuit turns off, TIMER is dis-
charged to GND by the 3µA current source.
The PWRGD (PWRGD) can be used to directly
enable/disable a power module with an active-high
enable input. Figure 12 shows how to use PWRGD to
control an active-low enable-input power module. Signal
inversion is accomplished by transistor Q2 and R7.
Whenever TIMER reaches 1.233V, the internal fault
latch is set. GATE is immediately pulled to GND and
TIMER is pulled back to GND by the 3µA current
source. When TIMER falls below 0.5V, ON is pulsed low
to reset the internal fault latch.
Supply Transient Protection
The MAX5933_/MAX5947_ are 100% tested and guar-
anteed to be safe from damage with supply voltages
up to 80V. However, spikes above 85V may damage
the device. During a short-circuit condition, the large
change in currents flowing through the power-supply
traces can cause inductive voltage spikes which could
exceed 85V. To minimize the spikes, the power-trace
parasitic inductance should be minimized by using
wider traces or heavier trace plating and a 0.1µF
The waveform in Figure 9 shows how the output latches
off following a short circuit. The drop across the sense
resistor is held at 12mV as the timer ramps up. Since
the output did not rise, FB remains below 0.5V and the
circuit latches off. For Figure 9, C = 100nF.
T
Undervoltage and Overvoltage Detection
ON can be used to detect an undervoltage condition at
the power-supply input. ON is internally connected to
an analog comparator with 80mV of hysteresis. If ON
falls below its threshold voltage (1.233V), GATE is
pulled low and is held low until ON is high again.
bypass capacitor placed between V
and GND. A
CC
transient voltage suppressor (TVS) at the input can also
prevent damage from voltage surges.
______________________________________________________________________________________ 11
Positive High-Voltage, Hot-Swap Controllers
R
SENSE
Q1
IRF530
0.025Ω
V
IN
C
L
SHORT
PIN
D2
R5
10Ω
5%
CMPZ5248B
R6
1kΩ
5%
R1
49.9kΩ
1%
R3
59kΩ
1%
D1
30V
1N5256B
0.1µF
R7
24kΩ
5%
8
7
6
C1
V
SENSE
GATE
CC
10nF
2
3
1
FB
ON
R4
3.57kΩ
1%
MAX5933B
MAX5947B
R2
3.4kΩ
1%
5
TIMER
PWRGD
PWRGD
C2
0.68µF
GND
4
GND
Figure 10. Overvoltage Detection
GATE Voltage
is shown in Figure 13.
A curve of Gate Drive vs. V
CC
OVERVOLTAGE WAVEFORMS
GATE is clamped to a maximum voltage of 18V above the
input voltage. At a minimum input-supply voltage of 33V,
the minimum gate drive voltage is 10V. When the input
supply voltage is higher than 20V, the gate-drive voltage
is at least 10V and a standard n-channel MOSFET can be
used. Using the MAX5947 in applications over a 9V to
20V range, a logic-level N-FET must be used with a prop-
er protection Zener diode between its gate and source
(see D1 in Figure 5).
IN
50V/div
I
SENSE
5A/div
GATE
50V/div
Thermal Shutdown
If the MAX5933_/MAX5947_ die temperature reaches
+150°C, an overtemperature fault is generated. As a
result, GATE goes low and turns the external MOSFET off.
The MAX5933_/MAX5947_ die temperature must cool
down below +130°C before the overtemperature fault
condition is removed.
TIMER
10V/div
OUTPUT
50V/div
10µs/div
Figure 11. Overvoltage Waveforms
12 ______________________________________________________________________________________
Positive High-Voltage, Hot-Swap Controllers
R
SENSE
Q1
IRF530
0.01Ω
V
IN
SHORT
PIN
D1
R5
10Ω
5%
CMPZ5248B
R6
1kΩ
5%
R1
294kΩ
1%
R3
143kΩ
1%
0.1µF
V
V
OUT+
IN+
C
L
220µF
V
OUT
R7
47kΩ
5%
ON/OFF
8
7
6
C1
10nF
V
SENSE
GATE
V
IN-
V
OUT-
CC
2
3
1
FB
ON
R4
4.22kΩ
1%
MAX5933A
R2
10.2kΩ
1%
5
TIMER
PWRGD
C2
0.68µF
GND
4
GND
Figure 12. Active-Low Enable Module
Layout Considerations
GATE DRIVE vs. V
CC
To achieve accurate current sensing, a Kelvin connec-
tion is recommended. The minimum trace width for 1oz
copper foil is 0.02in per amplifier to ensure the trace
stays at a reasonable temperature. However, 0.03in.
per amplifier or wider is recommended. Note that 1oz
copper exhibits a sheet resistance of approximately
530µΩ/square. Small resistances add up quickly in
high-current applications. To improve noise immunity,
connect the resistor-divider to ON close to the device,
16
14
12
10
8
6
and keep traces to V
and GND short. A 0.1µF
CC
4
capacitor from ON to GND also helps reject induced
noise. Figure 14 shows a layout that addresses these
issues. It is recommended that 2oz copper is used,
particularly as the external MOSFET must be thermally
coupled to the MAX5933_/MAX5947_ to ensure proper
thermal-shutdown operation.
2
0
0
20
40
(V)
60
80
V
CC
Figure 13. Gate Drive vs. Supply Voltage
______________________________________________________________________________________ 13
Positive High-Voltage, Hot-Swap Controllers
Chip Information
TRANSISTOR COUNT: 1573
PROCESS: BiCMOS
Pin Configuration
MAX5933_
MAX5947_
TOP VIEW
IRF530
ON
1
2
3
4
8
7
6
5
V
CC
FB
PWRGD (PWRGD)
GND
SENSE
GATE
MAX5933_
MAX5947_
TIMER
SO
( ) ONLY FOR THE MAX5933C/D/F/MAX5947A/MAX5947C.
Figure 14. Recommended Layout for R1, R2, and R
SENSE
Typical Application Circuit
R
SENSE
Q1
IRF530
0.01Ω
V
IN
C
L
D1
R5
10Ω
5%
CMPZ5248B
R6
1kΩ
5%
R1
49.9kΩ
1%
R3
59kΩ
1%
0.1µF
*SMBJ51A
R7
24kΩ
5%
8
7
6
C1
10nF
V
SENSE
GATE
CC
2
3
1
5
FB
ON
R2
3.4kΩ
1%
R4
3.57kΩ
1%
MAX5933A
TIMER
PWRGD
PWRGD
C2
0.68µF
GND
4
GND
*DIODES, INC.
14 ______________________________________________________________________________________
Positive High-Voltage, Hot-Swap Controllers
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.)
INCHES
MILLIMETERS
DIM
A
MIN
MAX
0.069
0.010
0.019
0.010
MIN
1.35
0.10
0.35
0.19
MAX
1.75
0.25
0.49
0.25
0.053
0.004
0.014
0.007
N
A1
B
C
e
0.050 BSC
1.27 BSC
E
0.150
0.228
0.016
0.157
0.244
0.050
3.80
5.80
0.40
4.00
6.20
1.27
E
H
H
L
VARIATIONS:
INCHES
1
MILLIMETERS
DIM
D
MIN
MAX
0.197
0.344
0.394
MIN
4.80
8.55
9.80
MAX
5.00
N
8
MS012
AA
TOP VIEW
0.189
0.337
0.386
D
8.75 14
10.00 16
AB
D
AC
D
C
A
B
0∞-8∞
e
A1
L
FRONT VIEW
SIDE VIEW
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, .150" SOIC
APPROVAL
DOCUMENT CONTROL NO.
REV.
1
21-0041
B
1
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 ____________________ 15
© 2004 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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