DATASHEET

IGNS
NOT RECOMMENDED FOR NEW DES
NT
EME
NO RECOMMENDED REPLAC
ter at
contact our Technical Support Cen
/tsc
com
rsil.
.inte
1-888-INTERSIL or www
Data Sheet
ISL6142, ISL6152
July 2004
Negative Voltage Hot Plug Controller
FN9086.1
Typical Application
The ISL6142/52 are 14 pin, negative voltage hot plug controllers
that allow a board to be safely inserted and removed from a live
backplane. Inrush current is limited to a programmable value by
controlling the gate voltage of an external N-channel pass
transistor. The pass transistor is turned off if the input voltage is
less than the Under-Voltage threshold, or greater than the OverVoltage threshold. The PWRGD/PWRGD outputs can be used to
directly enable a power module. When the Gate and DRAIN
voltages are both considered good the output is latched in the
active state.
GND
Logic
Supply
GND
VDD
FAULT
DIS
PWRGD
PWRGD
ISOUT
R10
R4
ISL6142/ISL6152
UV
R5
OV
R6
CT VEE IS-
IS+ SENSE GATE
DRAIN
LOAD
R9
C3
R7
R8
C1
R3 C2
R2
RL
IntelliTripTM
The
electronic circuit breaker and programmable
current limit features protect the system against short circuits.
When the Over-Current threshold is exceeded, the output current
is limited for a time-out period before the circuit breaker trips and
shuts down the FET. The time-out period is programmable with an
external capacitor connected to the CT pin. If the fault disappears
before the programmed time-out, normal operation resumes. In
addition, the IntelliTripTM electronic circuit breaker has a fast Hard
Fault shutdown, with a threshold set at 4 times the Over-Current
trip point. When activated, the GATE is immediately turned off and
then slowly turned back on for a single retry.
CL
-48V IN
R1 = 0.02 (1%)
R2 = 10 (5%)
R3 = 18K (5%)
R4 = 549K (1%)
R5 = 6.49K (1%)
R1
R6 = 10K (1%)
R7 = R8 = 400 (1%)
R9 = 4.99K (1%)
R10 = 5.1K (10%)
C1 = 150nF (25V)
Q1
-48V OUT
C2 = 3.3nF (100V)
C3 = 1500pF (25V)
Q1 = IRF530
CL = 100uF (100V)
RL = Equivalent load
Features
• Operates from -20V to -80V (-100V Absolute Max Rating)
• Programmable Inrush Current
• Programmable Time-Out
• Programmable Current Limit
The IS+, IS-, and ISOUT pins combine to provide a load current
monitor feature that presents a scaled version of the load current
at the ISOUT pin. Current to voltage conversion is accomplished
by placing a resistor (R9) from ISOUT to the negative input (-48V).
• Programmable Over-Voltage Protection
Related Literature
• IntelliTripTM Electronic Circuit Breaker distinguishes between
severe and moderate faults
- Fast shutdown for short circuit faults with a single retry (fault
current > 4X current limit value).
•
•
•
•
•
•
ISL6142/52EVAL1 Board Set, Document AN1000
ISL6140/50EVAL1 Board Set, Document AN9967
ISL6140/41EVAL1 Board Set, Document AN1020
ISL6141/51 Hot Plug Controller, Document FN9079
ISL6141/51 Hot Plug Controller, Document FN9039
ISL6116 Hot Plug Controller, Document FN4778
NOTE: See www.intersil.com/hotplug for more information.
Pinout
ISL6142 OR ISL6152 (14 LEAD SOIC)
PWRGD/PWRGD 1
14 VDD
Top View
FAULT 2
13 CT
• Programmable Under-Voltage Protection
- 135 mV of hysteresis ~4.7V of hysteresis at the power supply
• VDD Under-Voltage Lock-Out (UVLO) ~ 16.5V
• FAULT pin reports the occurrence of an Over-Current Time-Out
• Disable input controls GATE shutdown and resets Over-Current
fault latch
• Load Current Monitor Function
- ISOUT provides a scaled version of the load current
- A resistor from ISOUT to -VIN provides current to voltage
conversion
• Power Good Control Output
12 ISOUT
DIS
3
OV
4
11 DRAIN
UV
5
10 GATE
IS-
6
9
IS+
VEE
7
8
SENSE
ISL6142/52
- Output latched “good” when DRAIN and GATE voltage
thresholds are met.
- (PWRGD active low: ISL6142 (L version)
- PWRGD active high: ISL6152 (H version)
• Pb-free available
Applications
•
•
•
•
1
VoIP (Voice over Internet Protocol) Servers
Telecom systems at -48V
Negative Power Supply Control
+24V Wireless Base Station Power
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143 | Intersil and Design is a trademark of Intersil Americas LLC.
Intellitrip™ is a trademark of Intersil Americas LLC.
Copyright © Intersil Americas Inc. 2002, 2004, All Rights Reserved
ISL6142, ISL6152
Ordering Information
PART NUMBER TEMP. RANGE (oC)
PACKAGE
PKG.
DWG. #
ISL6142CB
0 to 70
14 Lead SOIC M14.15
ISL6142CBZA
(See Note)
0 to 70
14 Lead SOIC M14.15
(Pb-free)
ISL6152CB
0 to 70
14 Lead SOIC M14.15
ISL6152CBZA
(See Note)
0 to 70
14 Lead SOIC M14.15
(Pb-free)
ISL6142IB
-40 to 85
14 Lead SOIC M14.15
ISL6142IBZA
(See Note)
-40 to 85
14 Lead SOIC M14.15
(Pb-free)
ISL6152IB
-40 to 85
14 Lead SOIC M14.15
ISL6152IBZA
(See Note)
-40 to 85
14 Lead SOIC M14.15
(Pb-free)
*Add “-T” suffix to part number for tape and reel packaging.
NOTE: Intersil Pb-free products employ special Pb-free material
sets; molding compounds/die attach materials and 100% matte tin
plate termination finish, which is compatible with both SnPb and
Pb-free soldering operations. Intersil Pb-free products are MSL
classified at Pb-free peak reflow temperatures that meet or exceed
the Pb-free requirements of IPC/JEDEC J Std-020B.
2
ISL6142, ISL6152
ISL6142, ISL6152 Block Diagram
GND
GND
VDD
-
1.265V +
R4
UVLO
+
-
UV
VEE
REGULATOR,
VEE
REFERENCES
-
1.255V +
R5
UV
13V
+
VEE
OV
+
1.255V
-
+
VEE
-
R6
210mV
+
OV
LOGIC,
TIMING,
GATE
DRIVE
HARD
FAULT
+
VEE
GATE
-
11.1V
-
LOGIC
SUPPLY
R10
50mV +
CURRENT
LIMIT
REGULATOR
(ISL6142)
LATCH,
LOGIC,
OUTPUT
DRIVE
-
1.3V
+
PWRGD
(ISL6152)
+
VEE
FAULT
FAULT
-
VEE
8.0V
DISABLE
LOGIC
INPUT
PWRGD
+
VEE
+
VEE
DIS
+
+
+
VEE
13V
VEE+5V
CT
-
8.5V
C3
TO ADC
VEE
TIMER
+
+
VEE
STOP GATE
CURRENT
SENSE
ISOUT
VEE
R7
IS-
IS+
GATE
SENSE
R8
R9
R3
C1
DRAIN
C2
LOAD
R2
CL
R1
-48V IN
Q1
FIGURE 1. BLOCK DIAGRAM
3
RL
-48V OUT
ISL6142, ISL6152
Pin Descriptions
PWRGD (ISL6142; L Version) Pin 1 - This digital output is
an open-drain pull-down device and can be used to directly
enable an external module. During start-up the DRAIN and
GATE voltages are monitored with two separate comparators.
The first comparator looks at the DRAIN pin voltage compared
to the internal VPG reference (1.3V); this measures the
voltage drop across the external FET and sense resistor.
When the DRAIN to VEE voltage drop is less than 1.3V, the
first of two conditions required for the power to be considered
good are met. In addition, the GATE voltage monitored by the
second comparator must be within approximately 2.5V of its
normal operating voltage (13.6V). When both criteria are met
the PWRGD output will transition low and be latched in the
active state, enabling the external module. When this occurs
the two comparators discussed above no longer control the
output. However a third comparator continues to monitor the
DRAIN voltage, and will drive the PWRGD output inactive if
the DRAIN voltage raises more than 8V above VEE. In
addition, any of the signals that shut off the GATE (OverVoltage, Under-Voltage, Under-Voltage Lock-Out, OverCurrent time-out, pulling the DIS pin high, or powering down)
will reset the latch and drive the PWRGD output high to
disable the module. In this case, the output pull-down device
shuts off, and the pin becomes high impedance. Typically an
external pull-up of some kind is used to pull the pin high
(many brick regulators have a pull-up function built in).
PWRGD (ISL6152; H Version) Pin 1 - This digital output is
used to provide an active high signal to enable an external
module. The Power Good comparators are the same as
described above, but the active state of the output is
reversed (reference figure 37).
When power is considered good (both DRAIN and GATE are
normal) the output is latched in the active high state, the
DMOS device (Q3) turns on and sinks current to VEE through
a 6.2K resistor. The base of Q2 is clamped to VEE to turn it
off. If the external pull-up current is high enough (>1mA, for
example), the voltage drop across the resistor will be large
enough to produce a logic high output and enable the external
module (in this example, 1mA x 6.2K = 6.2V).
Note that for all H versions, although this is a digital pin
functionally, the logic high level is determined by the external
pull-up device, and the power supply to which it is
connected; the IC will not clamp it below the VDD voltage.
Therefore, if the external device does not have its own
clamp, or if it would be damaged by a high voltage, an
external clamp might be necessary.
If the power good latch is reset (GATE turns off), the internal
DMOS device (Q3) is turned off, and Q2 (NPN) turns on to
clamp the output one diode drop above the DRAIN voltage
to produce a logic low, indicating power is no longer good.
4
FAULT Pin 2- This digital output is an open-drain, pull-down
device, referenced to VEE. It is pulled active low whenever
the Over-Current latch is set. It goes to a high impedance
state when the fault latch is reset by toggling the UV or DIS
pins. An external pull-up resistor to a logic supply (5V or
less) is required; the fault outputs of multiple IC’s can be
wire-OR’d together. If the pin is not used it should be left
open.
DIS Pin 3 - This digital input disables the FET when driven to
a logic high state. It has a weak internal pull-up device to an
internal 5V rail (10A), so an open pin will also act as a logic
high. The input has a nominal trip point of 1.6 V while rising,
and a hysteresis of 1.0V. The threshold voltage is referenced
to VEE, and is compatible with CMOS logic levels. A logic
low will allow the GATE to turn on (assuming the 4 other
conditions described in the GATE section are also true). The
DIS pin can also be used to reset the Over-Current latch
when toggled high to low. If not used the pin should be tied
to the negative supply rail (-VIN).
OV (Over-Voltage) Pin 4 - This analog input compares the
voltage on the pin to an internal voltage reference of 1.255 V
(nominal). When the input goes above the reference the
GATE pin is immediately pulled low to shut off the external
FET. The built in 25mV hysteresis will keep the GATE off
until the OV pin drops below 1.230V (the nominal high to low
threshold). A typical application will use an external resistor
divider from VDD to -VIN to set the OV trip level. A threeresistor divider can be used to set both OV and UV trip
points to reduce component count.
UV (Under-Voltage) Pin 5 - This analog input compares the
voltage on the pin to an internal comparator with a built in
hysteresis of 135mv. When the UV input goes below the
nominal reference voltage of 1.120V, the GATE pin is
immediately pulled low to shut off the external FET. The
GATE will remain off until the UV pin rises above a 1.255V
low to high threshold. A typical application will use an
external resistor divider from VDD to -VIN to set the UV level
as desired. A three-resistor divider can be used to set both
OV and UV trip points to reduce component count.
The UV pin is also used to reset the Over-Current latch. The
pin must be cycled below 1.120V (nominal) and then above
1.255V (nominal) to clear the latch and initiate a normal
start-up sequence.
IS- Pin 6 - This analog pin is the negative input of the current
sense circuit. A sensing resistor (R7) is connected between
this pin and the VEE side of resistor R1. The ratio of R1/R7
defines the ISENSE to ISOUT current scaling factor. If current
sensing is not used in the application, the IS- pin should be
tied directly to the IS+ pin and the node should be left
floating.
ISL6142, ISL6152
VEE Pin 7 - This is the most Negative Supply Voltage, such
as in a -48V system. Most of the other signals are
referenced relative to this pin, even though it may be far
away from what is considered a GND reference.
SENSE Pin 8 - This analog input monitors the voltage drop
across the external sense resistor to determine if the current
flowing through it exceeds the programmed Over-Current
trip point (50mV / Rsense). If the Over-Current threshold is
exceeded, the circuit will regulate the current to maintain a
nominal voltage drop of 50mV across the R1 sense resistor,
also referred to as Rsense. If current is limited for more than
the programmed time-out period the IntelliTripTM electronic
circuit breaker will trip and turn off the FET.
A second comparator is employed to detect and respond
quickly to hard faults. The threshold of this comparator is set
approximately four times higher (210mV) than the OverCurrent trip point. When the hard fault comparator threshold
is exceeded the GATE is immediately (10s typical) shut off
(VGATE = VEE), the timer is reset, and a single retry (soft
start) is initiated.
IS+ Pin 9 - This analog pin is the positive input of the current
sense circuit. A sensing resistor (R8) is connected between
this pin and the output side of R1, which is also connected to
the SENSE pin. It should match the IS- resistor (R7) as
closely as possible (1%) to minimize output current error
(ISOUT). If current sensing is not used in the application, the
IS+ pin should be tied directly to the IS- pin and the node
should be left floating.
GATE Pin 10 - This analog output drives the gate of the
external FET used as a pass transistor. The GATE pin is
high (FET is on) when the following conditions are met:
•
•
•
•
•
VDD UVLO is above its trip point (~16.5V)
Voltage on the UV pin is above its trip point (1.255V)
Voltage on the OV pin is below its trip point (1.255V)
No Over-Current conditions are present.
The Disable pin is low.
If any of the 5 conditions are violated, the GATE pin will be
pulled low to shut off or regulate current through the FET.
The GATE is latched off only when an Over-Current event
exceeds the programmed time-out period.
The GATE is driven high by a weak (-50A nominal) pull-up
current source, in order to slowly turn on the FET. It is driven
low by a 70mA (nominal) pull-down device for three of the
above shut-off conditions. A larger (350mA nominal) pulldown current shuts off the FET very quickly in the event of a
hard fault where the sense pin voltage exceeds
approximately 210mV.
DRAIN Pin 11 - This analog input monitors the voltage of the
FET drain for the Power Good function. The DRAIN input is
tied to two comparators with internal reference voltages of
5
1.3v and 8.0V. At initial start-up the DRAIN to VEE voltage
differential must be less than 1.3V, and the GATE voltage
must be within 2.5V of its normal operating voltage (13.6V)
for power to be considered good. When both conditions are
met, the PWRGD/PWRGD output is latched into the active
state. At this point only the 8V DRAIN comparator can
control the PWRGD/PWRGD output, and will drive it inactive
if the DRAIN voltage exceeds VEE by more than 8.0V.
ISOUT Pin 12 - This analog pin is the output of the current
sense circuit. The current flowing out of this pin (ISOUT) is
proportional to the current flowing through the R1 sense
resistor (ISENSE). The scaling factor, ISOUT/ISENSE is
defined by the resistor ratio of R1/R7. Current to voltage
conversion is accomplished by placing a resistor from this
pin to -VIN. The current flowing out of the pin is supplied by
the internal 13V regulator and should not exceed 600A.
The output voltage will clamp at approximately 8V. If current
sensing is not used in the application the pin should be left
open.
CT Pin 13 - This analog I/O pin is used to program the OverCurrent Time-Out period with a capacitor connected to the
negative supply rail (-VIN which is equal to VEE). During
normal operation, the pin is pulled down to VEE. During
current limiting, the capacitor is charged with a 20A
(nominal) current source. When the CT pin charges to 8.5V,
it times out and the GATE is latched off. If the short circuit
goes away prior to the time-out, the GATE will remain on. If
no capacitor is connected, the time-out will be much quicker,
with only the package pin capacitance (~ 5 to 10 pF) to
charge. If no external capacitor is connected to the CT pin
the time-out will occur in a few sec. To set the desired timeout period use:
dt = (C * dV) / I = (C * 8.5) / 20 A = 0.425*106 * C
NOTE: The printed circuit board’s parasitic capacitance (CT pin to
the negative input, -VIN) should be taken into consideration when
calculating the value of C3 needed for the desired time-out.
VDD Pin 14 - This is the most positive Power Supply pin. It
can range from the Under-Voltage lockout threshold (16.5V)
to +80V (Relative to VEE). The pin can tolerate up to 100V
without damage to the IC.
ISL6142, ISL6152
.
Absolute Maximum Ratings
Thermal Information
Supply Voltage (VDD to VEE). . . . . . . . . . . . . . . . . . . . -0.3V to 100V
DRAIN, PWRGD, PWRGD Voltage . . . . . . . . . . . . . . . -0.3V to 100V
UV, OV Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 60V
SENSE, GATE Voltage . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 20V
FAULT, DIS, IS+, IS-, ISOUT, CT . . . . . . . . . . . . . . . . . -0.3V to 8.0V
ESD Rating
Human Body Model (Per MIL-STD-883 Method 3015.7) . . .2000V
Thermal Resistance (Typical, Note 1)
JA (oC/W)
14 Lead SOIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Maximum Junction Temperature (Plastic Package) . . . . . . . .150oC
Maximum Storage Temperature Range . . . . . . . . . . -65oC to 150oC
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . .300oC
Operating Conditions
Temperature Range (Industrial) . . . . . . . . . . . . . . . . . -40oC to 85oC
Temperature Range (Commercial). . . . . . . . . . . . . . . . . 0oC to 70oC
Supply Voltage Range (Typical). . . . . . . . . . . . . . . . . . . 36V to 72V
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTES:
1. JA is measured with the component mounted on a high effective thermal conductivity test board in free air. See Tech Brief TB379 for details.
2. PWRGD is referenced to DRAIN; VPWRGD-VDRAIN = 0V.
Electrical Specifications
VDD = +48V, VEE = +0V Unless Otherwise Specified. All tests are over the full temperature range; either
Commercial (0oC to 70oC) or Industrial (-40oC to 85oC). Typical specs are at 25oC.
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
20
-
80
V
2.6
4.0
mA
DC PARAMETRIC
VDD PIN
Supply Operating Range
VDD
Supply Current
IDD
UV = 3V; OV = VEE; SENSE = VEE; VDD =
80V
UVLO High
VUVLOH
VDD Low to High transition
15
16.7
19
V
UVLO Low
VUVLOL
VDD High to Low transition
13
15.0
17
V
UVLO hysteresis
1.9
V
GATE PIN
A
GATE Pin Pull-Up Current
IPU
GATE Drive on, VGATE = VEE
GATE Pin Pull-Down Current
IPD1
GATE Drive off, UV or OV false
70
mA
GATE Pin Pull-Down Current
IPD2
GATE Drive off, Over-Current Time-Out
70
mA
GATE Pin Pull-Down Current
IPD3
GATE Drive off; Hard Fault, Vsense > 210mv
350
mA
External Gate Drive (at 20V, at 80V)
GATE High Threshold (PWRGD/PWRGD active)
VGATE
(VGATE - VEE), 20V <=VDD <=80V
VGH
VGATE - VGATE
VCL
VCL = (VSENSE - VEE)
-30
12
-50
13.6
-60
15
2.5
V
V
SENSE PIN
Current Limit Trip Voltage
Hard Fault Trip Voltage
HFTV
SENSE Pin Current
ISENSE
40
HFTV = (VSENSE - VEE)
VSENSE = 50mV
50
60
210
mV
mV
-
0
-0.5
A
UV PIN
UV Pin High Threshold Voltage
VUVH
UV Low to High Transition
1.240
1.255
1.270
V
UV Pin Low Threshold Voltage
VUVL
UV High to Low Transition
1.105
1.120
1.145
V
UV Pin Hysteresis
VUVHY
6
135
mV
ISL6142, ISL6152
Electrical Specifications
VDD = +48V, VEE = +0V Unless Otherwise Specified. All tests are over the full temperature range; either
Commercial (0oC to 70oC) or Industrial (-40oC to 85oC). Typical specs are at 25oC. (Continued)
PARAMETER
SYMBOL
UV Pin Input Current
TEST CONDITIONS
MIN
TYP
MAX
UNITS
-
-0.05
-0.5
A
IINUV
VUV = VEE
OV Pin High Threshold Voltage
VOVH
OV Low to High Transition
1.235
1.255
1.275
V
OV Pin Low Threshold Voltage
VOVL
OV High to Low Transition
1.215
1.230
1.255
V
OV pin
OV Pin Hysteresis
VOVHY
OV Pin Input Current
25
mV
-
-0.05
-0.5
A
VDRAIN - VEE
0.80
1.30
2.00
V
VDRAIN = 48V
10
38
60
A
VDH
VDRAIN - VEE > 8.0V
7.0
8.0V
9.0
V
VOL1
VOL5
(VDRAIN - VEE) < VPG; IOUT = 1mA
-
0.3
0.8
V
(VDRAIN - VEE) < VPG; IOUT = 5mA
-
1.50
3.0
V
IOH
VDRAIN = 48V, V PWRGD = 80V
-
0.05
10
A
VOL
VDRAIN = 5V, IOUT = 1mA
-
0.80
1.0
V
IINOV
VOV = VEE
VPG
IDRAIN
DRAIN Pin
Power Good Threshold (Enable PWRGD/PWRGD
Output)
Drain Input Bias Current
DRAIN Pin Comparator Trip Point
(PWRGD/PWRGD Inactive)
ISL6142 (PWRGD Pin: L Version)
PWRGD Output Low Voltage
Output Leakage
ISL6152 (PWRGD Pin: H Version)
PWRGD Output Low Voltage (PWRGD-DRAIN)
PWRGD Output Impedance
ROUT
(VDRAIN - VEE) < VPG
4.5
6.2
7.5
k
DIS Pin High Threshold Voltage
VDISH
DIS Low to High Transition
1.60
2.20
3.00
V
DIS Pin Low Threshold Voltage
VDISL
DIS High to Low Transition
1.1
1.50
V
DIS PIN
DIS Pin Hysteresis
VDISHY
DIS Hysteresis
1.0
DIS Pin Input High Leakage
IDISINH
Input Voltage = 5V
0.1
DIS Pin Input Low Current
IDISINL
Input Voltage = 0V
10
A
FAULT Output Voltage
VFVOL
I = 1.6 mA
0.4
V
FAULT Output Leakage
IFIOH
V = 5.0V
ICTINL
VCT = 0V
V
1.0
A
FAULT PIN
10
A
CT PIN
CT Pin Charging Current
CT Pin Input Threshold
VCT
A
20
7.5
8.5
9.5
V
IS PINS (IS-, IS+, ISOUT)
ISOUT Error
VSENSE = 50mV, R7 = 400, R8 = 404
2.0
%
ISOUT Error
VSENSE = 200mV, R7 = 400, R8 = 404
1.0
%
ISOUT Offset Current
VSENSE = 0.0mV, R7 = 400, R8 = 404
4.5
A
Output Voltage Range (ISOUT Pin)
7
0
5
8
V
ISL6142, ISL6152
Electrical Specifications
VDD = +48V, VEE = +0V Unless Otherwise Specified. All tests are over the full temperature range; either
Commercial (0oC to 70oC) or Industrial (-40oC to 85oC). Typical specs are at 25oC. (Continued)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
AC TIMING
OV High to GATE Low
tPHLOV
Figures 2A, 3A
0.6
1.6
3.0
s
OV Low to GATE High
tPLHOV
Figures 2A, 3A
1.0
7.8
12.0
s
UV Low to GATE Low
tPHLUV
Figures 2A, 3B
0.6
1.3
3.0
s
UV High to GATE High
tPLHUV
Figures 2A, 3B
1.0
8.4
12.0
s
DIS Low to GATE Low
tPHLDIS
Figure 2A, 7
0.6
s
DIS High to GATE High
tPLHDIS
Figure 2A, 7
2.5
s
GATE Low (Over-Current) to FAULT Low
tPHLGF
Figure 2A, 8
0.5
s
ISOUT Rise Time
tR
Figure 2A, 12
1.2
s
ISOUT Fall Time
tF
Figure 2A, 12
4.0
s
SENSE High to GATE Low
tPHLSENSE Figures 2A, 9
1
3
s
Current Limit to GATE Low
tPHLCB
Figures 2B, 11, Effective Capacitance During
Test = 2550pF
1200
s
Hard Fault to GATE Low (200mV comparator)
Typical GATE shutdown based on application ckt.
Guaranteed by design.
tPHLHF
Figures 10, 20, 33
10.0
s
DRAIN Low to PWRGD Low (Active)
tPHLDL
Figures 2A, 4A
DRAIN High to PWRGD High (Inactive)
tPLHDH
Figure 2A, 6A
0.2
s
GATE High to PWRGD Low (Active)
tPHLGH
Figures 2A, 5A
1.0
s
DRAIN Low to (PWRGD-DRAIN) High (Active)
tPLHDL
Figures 2A, 4B
DRAIN High to (PWRGD -DRAIN) Low (Inactive)
tPHLDH
Figure 2A, 6B
0.5
s
GATE High to (PWRGD-DRAIN) High (Active)
tPLHGH
Figures 2A, 5B
0.4
s
ISL6142 (L Version)
0.1
3.1
5.0
s
ISL6152 (H Version)
8
0.1
0.2
5.0
s
ISL6142, ISL6152
?
Test Circuit and Timing Diagrams
5K
5V
+
-
5K
PWRGD
FAULT
VDIS
1
14
2
13
3
VOV
OV
VUV
UV
400
VEE
.
10 GATE
404
9
DRAIN
1
14
2
13
3
OV
VUV
5
8
FAULT
VOV
4.99K
11
7
PWRGD
5K
4
6
+
-
5K
5V
VDD
12
ISL6142
48V
UV
VDRAIN
VEE
ISL6142
48V
VDD
CT
12
DRAIN
4
11
5
10 GATE
6
9
7
8
VDRAIN
9.0K
SENSE
0.90K
SENSE
0.1K
VSENSE
FIGURE 2B. TEST CIRCUIT FOR TIMEOUT
FIGURE 2A. TYPICAL TEST CIRCUIT
2V
2V
1.255V
0V
tPLHOV
tPLHUV
tPHLUV
13.6V
1V
1.255V
UV Pin
0V
tPHLOV
13.6V
GATE
0V
1.125V
1.230V
1V
1V
0V
1V
GATE
FIGURE 3B. UV TO GATE TIMING
FIGURE 3A. OV TO GATE TIMING
FIGURE 3. OV AND UV TO GATE TIMING
DRAIN
DRAIN
1.3V
1.3V
VPG
tPHLDL
PWRGD
VPG
VEE
tPLHDL
1.0V
1.0V
PWRGD
FIGURE 4A. DRAIN TO PWRGD ACTIVE TIMING (ISL6142)
FIGURE 4B. DRAIN TO PWRGD ACTIVE TIMING (ISL6152)
FIGURE 4. DRAIN TO PWRGD/PWRGD TIMING
VGATE - VGATE = 0V
13.6V
2.5V
VGATE - VGATE = 0V
2.5V
VGH
GATE
GATE
13.6V
VGH
tPLHGH
tPHLGH
PWRGD
1.0V
FIGURE 5A. GATE TO PWRGD ACTIVE (ISL6142)
9
PWRGD
1.0V
VPWRGD - VDRAIN = 0V
FIGURE 5B. GATE TO PWRGD ACTIVE (ISL6152)
ISL6142, ISL6152
Test Circuit and Timing Diagrams (Continued)
VDRAIN - VEE = 8.0V
VDRAIN - VEE = 8.0V
VDH
8.0V
VDH
VEE - VDRAIN = 0V
VEE - VDRAIN = 0V
tPLHDH
DRAIN
8.0V
DRAIN
tPHLDH
PWRGD
1.0V
1.0V
PWRGD
VPWRGD - VDRAIN = 0V
FIGURE 6A. DRAIN HIGH TO PWRGD (INACTIVE) HIGH
(ISL6142)
FIGURE 6B. DRAIN HIGH TO PWRGD (INACTIVE) LOW
(ISL6152)
FIGURE 6. DRAIN TO PWRGD/PWRGD INACTIVE TIMING
VGATE - VGATE = 0V
3V
DIS
1.50V
GATE
0V
2.2V
tPHLDIS tPLHDIS
13.6V
1.4V
GATE
tPHLF
FAULT
1V
1V
1.0V
0V
FIGURE 7. DISABLE TO GATE TIMING (ISL6142/52)
FIGURE 8. FAULT TO GATE TIMING (ISL6142/52)
50mV
210mV
SENSE
0V
13.6V
tPHLSENSE
0V
13.6V
GATE
SENSE
tPHLHF
GATE
VEE
~4V (depends on FET threshold)
FIGURE 9. SENSE TO GATE (CURRENT LIMIT) TIMING
FIGURE 10. SENSE TO GATE (HARD FAULT) TIMING
VSENSE
UV
tR
tPHLCB
90%
GATE
1.0V
1.0V
VOUT
10%
tF
90%
10%
Over-Current Time-Out
FIGURE 11. CURRENT LIMIT TO GATE TIMING
10
FIGURE 12. OUTPUT CURRENT RISE AND FALL TIME
ISL6142, ISL6152
16
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
14
Gate Voltage (V)
IDD (mA)
Typical Performance Curves
12
10
8
6
4
2
0
10
20
30
40
50
60
70
80
90
100
10
20
Supply Voltage (VDD)
40
60
70
80
100
FIGURE 14. GATE VOLTAGE VS SUPPLY VOLTAGE (25oC)
14
2.75
2.7
2.65
2.6
2.55
2.5
2.45
2.4
2.35
2.3
2.25
Gate Voltage (V)
13.9
13.8
13.7
13.6
13.5
13.4
13.3
-40
-20
0
20
40
60
80
100
-40
-20
0
Temperature (C)
Gate Current (uA)
13.9
VDD = 80V
13.7
VDD = 20V
13.6
13.5
13.4
-40 -20
0
20
40
60
80
Temperature (C)
FIGURE 17. GATE VOLTAGE VS TEMPERATURE
11
40
60
80
100
FIGURE 16. GATE VOLTAGE VS TEMPERATURE VDD = 48V
14
13.8
20
Temperature (C)
FIGURE 15. SUPPLY CURRENT VS TEMPERATURE, VDD = 80V
Gate Voltage (V)
50
Supply Voltage (VDD)
FIGURE 13. SUPPLY CURRENT VS. SUPPLY VOLTAGE (25oC)
IDD (mA)
30
100
50
49
48
47
46
45
44
43
42
41
-40
-20
0
20
40
60
80
Temperature (C)
FIGURE 18. GATE PULL-UP CURRENT VS TEMPERATURE
100
90
80
70
60
50
40
30
20
10
0
-40
-20
0
20
40
60
80
100
Gate Pull Down Current (mA)
Gate Pull Down Current (mA)
ISL6142, ISL6152
450
400
350
300
250
200
150
100
50
0
-40
-20
0
Temperature (C)
1.6
Output Low Voltage (V)
Trip Voltage (mv)
52
50
48
46
44
42
40
0
20
40
80
100
60
80
5mA
1.4
1.2
1
0.8
0.6
0.4
1mA
0.2
0
-40
100
-20
0
20
40
60
80
100
Temperature (C)
Temperature (C)
FIGURE 21. OVER-CURRENT TRIP VOLTAGE VS
TEMPERATURE
FIGURE 22. PWRGD (ISL6142) VOL VS TEMPERATURE
2
(1 ma)
6.8
Impedance (KOhms)
Trip Voltage (V)
60
FIGURE 20. HARD FAULT GATE PULL-DOWN CURRENT VS
TEMPERATURE
54
-20
40
Temperature (C)
FIGURE 19. GATE PULL-DOWN CURRENT
(UV/OV/TIME-OUT) VS TEMPERATURE
-40
20
1.5
1
0.5
0
6.7
6.6
6.5
6.4
6.3
6.2
6.1
-40
-20
0
20
40
60
80
100
Temperature (C)
FIGURE 23. DRAIN to PWRGD / PWRGD TRIP VOLTAGE (VPG)
VS TEMPERATURE
12
-40
-20
0
20
40
60
80
Temperature (C)
FIGURE 24. PWRGD (ISL6152) OUTPUT IMPEDANCE VS
TEMPERATURE
100
ISL6142, ISL6152
2.5
o
-40 C
5
4
3
o
85 C
2
o
-40 C
ISOUT Error (%)
ISOUT Error (uA)
6
1
0
2
1.5
1
o
85 C
0.5
0
50
100
150
0
200
50
FIGURE 25. ISOUT ERROR VS SENSE PIN VOLTAGE
FIGURE 26. ISOUT ERROR VS SENSE PIN VOLTAGE
VSENSE = 0V
20.5
CT Charging Current (uA)
ISOUT Offset Current (uA)
150
SENSE pin Voltage (mV)
SENSE Pin Voltage (mV)
4.475
100
4.47
4.465
4.46
4.455
4.45
4.445
4.44
4.435
20
19.5
19
18.5
18
17.5
17
-40
-20
0
20
40
60
80
100
Temperature (C)
FIGURE 27. ISOUT OFFSET CURRENT VS TEMPERATURE
13
-40
-20
0
20
40
60
80
100
Temperature (C)
FIGURE 28. CT CHARGING CURRENT VS TEMPERATURE
ISL6142, ISL6152
Applications Information
GND
GND
VDD
FAULT
PWRGD
DIS
ISOUT
Logic
Supply
R4
ISL6142
UV
R10
R5
OV
R6
CT VEE IS-
IS+ SENSE GATE
DRAIN
ADC
Q2
R9
C3
C1
R7
R8
-48V IN
R1
R2
R3 C2
CL
RL
Q1
-48V OUT
FIGURE 29. TYPICAL APPLICATION WITH MINIMUM COMPONENTS
Typical Values for a representative
system; which assumes:
Quick Guide to Choosing Component
Values
43V to 71V supply range; 48 nominal; UV = 43V; OV = 71V
(See fig 29 for reference)
1A of typical current draw; 2.5 Amp Over-Current
This section will describe the minimum components needed
for a typical application, and will show how to select
component values. Note that “typical” values may only be
good for this application; the user may have to select
alternate component values to optimize performance for
other applications. Each block will then have more detailed
explanation of how the device works, and alternatives.
100F of load capacitance (CL); equivalent RL of 48
(R = V/I = 48V/1A)
R1: 0.02 (1%)
R2: 10 (5%)
R3: 18k (5%)
R4, R5, R6 - together set the Under-Voltage (UV) and OverVoltage (OV) trip points. When the power supply ramps up
and down, these trip points (and their hysteresis) will
determine when the GATE is allowed to turn on and off (UV
and OV do not control the PWRGD / PWRGD output). The
input power supply is divided down such that when the
voltage on the OV pin is below its threshold and the UV pin is
above its threshold their comparator outputs will be in the
proper state signaling the supply is within its desired
operating range, allowing the GATE to turn on. The
equations below define the comparator thresholds for an
increasing (in magnitude) supply voltage.
R4: 549k (1%)
R5: 6.49k (1%)
R6: 10k (1%)
R7/R8: 400 (1%)
R9: 4.99K (1%)
R10: 5.10K (10%)
C1: 150nF (25V)
C2: 3.3nF (100V)
C3: 1500pF (25V)
Q1: IRF530 (100V, 17A, 0.11)
Q2: N-Channel logic FET
14
 R 4 + R 5 + R 6
V UV = -----------------------------------------  1.255
 R5 + R6 
(EQ. 1)
 R 4 + R 5 + R 6
V OV = -----------------------------------------  1.255
 R6 
(EQ. 2)
ISL6142, ISL6152
The values of R4 = 549K, R5 = 6.49K, and R6 = 10K shown
in figure 29 set the Under-Voltage threshold at 43V, and the
Over-Voltage, turn off threshold to 71V. The Under-Voltage
(UV) comparator has a hysteresis of 135mv’s (4.6V of
hysteresis on the supply) which correlates to a 38.4V turn off
voltage. The Over-Voltage comparator has a 25mv
hysteresis (1.4V of hysteresis on the supply) which
translates to a turn on voltage (supply decreasing) of
approximately 69.6V.
Q1 - is the FET that connects the input supply voltage to the
output load, when properly enabled. It needs to be selected
based on several criteria:
R1 resistor, and the VEE and SENSE pins should be direct
and as short as possible with zero current in the sense lines.
Note that in figure 30 the traces from each side of the R1
resistor also connect to the R8 (IS+), and R7 (IS-) current
sensing resistors.
CORRECT
INCORRECT
To VEE
and R7
• Maximum voltage expected on the input supply (including
transients) as well as transients on the output side.
• Maximum current and power dissipation expected during
normal operation, usually at a level just below the current
limit threshold.
To SENSE
and R8
• Power dissipation and/or safe-operating-area
considerations during current limiting and single retry
events.
FIGURE 30. SENSE RESISTOR LAYOUT GUIDELINES
• Other considerations include the GATE voltage threshold
which affects the rDS(ON) (which in turn, affects the
voltage drop across the FET during normal operation),
and the maximum gate voltage allowed (the IC’s GATE
output is clamped to ~14V).
R1 - is the Over-Current sense resistor also referred to as
RSENSE. If the input current is high enough, such that the
voltage drop across R1 exceeds the SENSE comparator trip
point (50mV nominal), the GATE pin will be pulled lower (to
~4V) and current will be regulated to 50mV/Rsense for the
programmed time-out period which is set by C3. The OverCurrent threshold is defined in Equation 3 below. If the timeout period is exceeded the Over-Current latch will be set and
the FET will be turned off to protect the load from excessive
current. A typical value for R1 is 0.02which sets an OverCurrent trip point of; IOC = V/R = 0.05/0.02 = 2.5 Amps. To
select the appropriate value for R1, the user must first
determine at what level of current it should trip, take into
account worst case variations for the trip point (50mV
10mV = 20%), and the tolerances of the resistor (typically
1% or 5%). Note that the Over-Current threshold should be
set above the inrush current level plus the expected load
current to avoid activating the current limit and time-out
circuitry during start-up. If the power good output
(PWRGD/PWRGD) is used to enable an external module,
the desired inrush current only needs to be considered. One
rule of thumb is to set the Over-Current threshold 2-3 times
higher than the normal operating current.
50mv
I OC = -------------------R sense
(EQ. 3)
CURRENT
SENSE RESISTOR
CL - is the sum of all load capacitances, including the load’s
input capacitance itself. Its value is usually determined by
the needs of the load circuitry, and not the hot plug (although
there can be interaction). For example, if the load is a
regulator, then the capacitance may be chosen based on the
input requirements of that circuit (holding regulation under
current spikes or loading, filtering noise, etc.) The value
chosen will affect the peak inrush current. Note that in the
case of a regulator, there may be capacitors on the output of
that circuit as well; these need to be added into the
capacitance calculation during inrush (unless the regulator is
delayed from operation by the PWRGD/PWRGD signal).
RL - is the equivalent resistive value of the load and
determines the normal operating current delivered through
the FET. It also affects some dynamic conditions (such as
the discharge time of the load capacitors during a powerdown). A typical value might be 48 (I=V/R = 48/48 = 1A).
R2, C1, R3, C2 - are related to the GATE driver, as it
controls the inrush current.
R2 prevents high frequency oscillations; 10 is a typical
value. R2 = 10.
R3 and C2 act as a feedback network to control the inrush
current as shown in equation 4, where CL is the load
capacitance (including module input capacitance), and IPU is
the GATE pin charging current, nominally 50A.
CL
I inrush = I PU  ------C
(EQ. 4)
2
The physical layout of the R1 sense resistor is critical to
avoid the possibility of false over current events. Since it is in
the main input-to-output path, the traces should be wide
enough to support both the normal current, and currents up
to the over-current trip point. The trace routing between the
15
Begin by choosing a value of acceptable inrush current for
the system, and then solve for C2.
ISL6142, ISL6152
C1 and R3 prevent Q1 from turning on momentarily when
power is first applied. Without them, C2 would pull the gate
of Q1 up to a voltage roughly equal to VEE*C2/Cgs(Q1)
(where Cgs is the FET gate-source capacitance) before the
ISL6142/52 could power up and actively pull the gate low.
Place C1 in parallel with the gate capacitance of Q1; isolate
them from C2 by R3.
C1 =[(Vinmax - Vth)/Vth] * (C2+Cgd) - where Vth is the
FET’s minimum gate threshold, Vinmax is the maximum
operating input voltage, and Cgd is the FET gate-drain
capacitance.
R3 - its value is not critical, a typical value of 18k is
recommended but values down to 1K can be used. Lower
values of R3 will add delay to gate turn-on for hot insertion
and the single retry event following a hard fault.
R7/R8/R9 - are used to sense the load current (R7/R8) and
convert the scaled output current (ISOUT) to a voltage (R9)
that would typically be the input signal to an A to D converter.
R7 is connected between -IS and the R1 sense resistor.
These two resistors set the ISENSE (current through the
Rsense resistor) to ISOUT scaling factor based on equation 5
below. R8 does not effect the scaling factor but should match
R7 to minimize ISOUT error. Their tolerance should be +/-1%,
which will typically result in an output current error of less than
5% for a full scale condition. The trace layout is also critical to
obtain optimum performance. The traces connecting these
resistors to the device pins (IS+ and IS-) and to the R1 sense
resistor should be kept as short as possible, match in length,
and be isolated from the main current flow as illustrated in
figure 30.
R9 is used to convert the ISOUT current to voltage and is
connected between the ISOUT pin and -VIN. The current
flowing through the resistor (EQ. 5) should not exceed 600A
and the voltage on the CT pin will clamp at approximately 8V.
R SENSE
IS OUT = I SENSE  ----------------------R7
(EQ. 5)
To select the appropriate resistor values for the application
the user must first define the R1 sense resistor value and the
maximum load current to be detected/measured. The value
of R7 should then be selected such that the maximum ISOUT
current is in the 400-500A range. For example, if the user
wanted to detect and measure fault currents up to the hard
fault comparator trip point (10A); the maximum ISOUT
current using the application components in figure 23 would
be [10A x (.02/400] = 500A. The value of R9 should be set
to accommodate the dynamic range of the A to D converter.
For this example, a 5K resistor would produce a full scale
input voltage to the converter of 2.5V (500A x 5K).
Figures 32 and 33 illustrate the typical output voltage
16
response of the current sense circuit for the Over-Current
Time-out and hard fault single retry events.
R10 - is a pull-up resistor for the open drain FAULT output
pin which goes active low when the Over-Current latch is set
(Over-Current Time-Out). The output signal is referenced to
VEE and the resistor is connected to a positive voltage, 5V or
less, with respect to VEE. A typical value of 5K is
recommended. A fault indicator LED can be placed in series
with the pull-up resistor if desired. The resistor value should
be selected such that it will allow enough current to drive the
LED adequately (brightness).
C3 - is the capacitor used to program the current limit timeout period. When the Over-Current threshold is exceeded a
20A (nominal) current source will charge the C3 capacitor
from VEE to approximately 8.5V. When the voltage on the CT
pin exceeds the 8.5V threshold, the GATE pin will
immediately be pulled low with a 70ma pull down device, the
Over-Current latch will be set, and the FET will be turned off.
If the Over-Current condition goes away before the time-out
period expires, the CT pin will be pulled back down to VEE,
and normal operation will resume. Note that any parasitic
capacitance from the CT pin to -VIN will effectively add to
C3. This additional capacitance should be taken into account
when calculating the C3 value needed for the desired timeout period.
The value of C3 can be calculated using equation 6 where dt
is the time-out period, dv is the CT pin threshold, and ICT is
the capacitor charging current.
–6
dt
timeout
C3 = ------  I CT = ----------------------  20 10
dv
8.5V
(EQ. 6
Q2- is an N-channel logic FET used to drive the disable pin
(DIS). The DIS pin is used to enable/disable the external
pass transistor (Q1) by turning the GATE drive voltage on or
off. The DIS pin can also be used to reset the Over-Current
latch by toggling the pin high and then low. When Q2 is off,
the DIS pin is pulled high with an internal 500K resistor,
connected to an internal +5V (VEE + 5V) supply rail (10A).
In this condition the GATE pin is low, and Q1 is turned off.
When Q2 is on, the DIS pin is pulled low to VEE allowing the
GATE pin to pull up and turn on Q1. The gate of Q2 will
typically be driven low (<1.5V) or High (>3.0V) with external
logic circuitry referenced to the negative input (-VIN).
Low-side Application
Although this IC was designed for -48V systems, it can also
be used as a low-side switch for positive 48V systems; the
operation and components are usually similar. One possible
difference is the kind of level shifting that may be needed to
interface logic signals to the IC. For example, many of the IC
functions are referenced to the IC substrate, connected to the
VEE pin, but this pin may be considered -48V or GND,
depending upon the polarity of the system. Also, the input or
output logic (running at 5V or 3.3V or even lower) might be
ISL6142, ISL6152
After the contact bounce subsides the UVLO and UV criteria
are quickly met and the GATE begins to ramp up. As the
GATE reaches approximately 4V with respect to the source,
the FET begins to turn on allowing current to charge the
100F load capacitor. As the drain to source voltage begins to
drop, the feedback network of C2 and R3 hold the GATE
constant, in this case limiting the current to approximately
1.5A. When the DRAIN voltage completes its ramp down, the
load current remains constant at approximately 1.0A as the
GATE voltage increases to its final value.
excessive supply or fault currents. The IntelliTripTM electronic
circuit breaker is capable of detecting both hard faults, and
less severe Over-Current conditions.
The Over-Current trip point is determined by R1 (EQ. 3) also
referred to as Rsense. When the voltage across this resistor
exceeds 50mV, the current limit regulator will turn on, and the
GATE will be pulled lower (to ~4V) to regulate current through
the FET at 50mV/Rsense. If the fault persists and current
limiting exceeds the programmed time-out period, the FET will
be turned off by discharging the GATE pin to VEE. This will set
the Over-Current latch and the PWRGD/PWRGD output will
transition to the inactive state, indicating power is no longer
good. To clear the latch and initiate a normal start-up
sequence, the user must either power down the system
(below the UVLO voltage), toggle the UV pin below and above
its threshold (usually with an external transistor), or toggle the
DIS pin high to low. Figure 32 shows the Over-Current shut
down and current limiting response for a 10 short to ground
on the output. Prior to the short circuit the output load is 110
producing an operating current of about 0.44A (48V/110). A
10 short is then applied to the output causing an initial fault
current of 4.8A. This produces a voltage drop across the
0.02 sense resistor of approximately 95mV, roughly two
times the Over-Current threshold of 50mV. The GATE is
quickly pulled low to limit the current to 2.5A (50mV/Rsense)
and the timer is enabled. The fault condition persists for the
duration of the programmed time-out period (C3 = 1500pF)
and the GATE is latched off in about 740s. There is a short
filter (3s nominal) on the comparator, so current transients
shorter than this will be ignored. Longer transients will initiate
the GATE pull down, current limiting, and the timer. If the fault
current goes away before the time-out period expires the
device will exit the current limiting mode and resume normal
operation.
FIGURE 31. HOT INSERTION INRUSH CURRENT LIMITING,
DISABLE PIN TIED TO VEE
FIGURE 32. CURRENT LIMITING AND TIME-OUT
externally referenced to either VDD or VEE of the IC, instead
of GND.
Inrush Current Control
The primary function of the ISL6142/52 hot plug controller is
to control the inrush current. When a board is plugged into a
live backplane, the input capacitors of the board’s power
supply circuit can produce large current transients as they
charge up. This can cause glitches on the system power
supply (which can affect other boards!), as well as possibly
cause some permanent damage to the power supply.
The key to allowing boards to be inserted into a live backplane
is to turn on the power to the board in a controlled manner,
usually by limiting the current allowed to flow through a FET
switch, until the input capacitors are fully charged. At that
point, the FET is fully on, for the smallest voltage drop across
it. Figure 31 illustrates the typical inrush current response for a
hot insertion under the following conditions:
VIN = -48V, Rsense = 0.02W
Current limit = 50mV / 0.02 = 2.5A
C1 = 150nF, C2 = 3.3nF, R3 = 18k
CL = 100F, RL = 50, I LOAD = 48V / 50 ~1.0A
Iinrush = 50A (100F / 3.3nF) = 1.5A
Electronic Circuit Breaker/Current Limit
The ISL6142/52 allows the user to program both the current
limit and the time-out period to protect the system against
17
In addition to current limiting and programmable time-out,
there is a hard fault comparator to respond to short circuits
with an immediate GATE shutdown (typically 10s) and a
single retry. The trip point of this comparator is set ~4 times
ISL6142, ISL6152
(210mV) higher than the Over-Current threshold of 50mV. If
the hard fault comparator trip point is exceeded, a hard pull
down current (350mA) is enabled to quickly pull down the
GATE and momentarily turn off the FET. The fast shutdown
resets the timer and is followed by a soft start, single retry
event. If the fault is still present after the GATE is slowly
turned on, the current limit regulator will trip (sense pin
voltage > 50mV), turn on the timer, and limit the current to
50mV/Rsense. If the fault remains and the time-out period is
exceeded the GATE pin will be latched low. Note: Since the
timer starts when the SENSE pin exceeds the 50mV
threshold, then depending on the speed of the current
transient exceeding 200mV; it’s possible that the current limit
time-out and shutdown can occur before the hard fault
comparator trips (and thus no retry). Figure 33 illustrates the
hard fault response with a zero ohm short circuit at the output.
threshold, the supply is within its expected operating range
and the GATE will be allowed to turn on, or remain on. If the
UV pin voltage drops below its high to low threshold, or the
OV pin voltage increases above its low to high threshold, the
GATE pin will be pulled low, turning off the FET until the
supply is back within tolerance.
The OV and UV inputs are high impedance, so the value of
the external resistor divider is not critical with respect to input
current. Therefore, the next consideration is total current; the
resistors will always draw current, equal to the supply
voltage divided by the total resistance of the divider
(R4+R5+R6) so the values should be chosen high enough to
get an acceptable current. However, to the extent that the
noise on the power supply can be transmitted to the pins, the
resistor values might be chosen to be lower. A filter capacitor
from UV to -VIN or OV to -VIN is a possibility, if certain
transients need to be filtered. (Note that even some
transients which could momentarily shut off the GATE might
recover fast enough such that the GATE or the output
current does not even see the interruption).
Finally, take into account whether the resistor values are
readily available, or need to be custom ordered. Tolerances
of 1% are recommended for accuracy. Note that for a typical
48V system (with a 43V to 72V range), the 43V or 72V is
being divided down to 1.255V, a significant scaling factor.
For UV, the ratio is roughly 35 times; every 3mV change on
the UV pin represents roughly 0.1V change of power supply
voltage. Conversely, an error of 3mV (due to the resistors,
for example) results in an error of 0.1V for the supply trip
point. The OV ratio is around 60. So the accuracy of the
resistors comes into play.
FIGURE 33. HARD FAULT SHUTDOWN AND RETRY
As in the Over-Current Time-Out response discussed
previously, the supply is set at -48V and the current limit is
set at 2.5A. After the initial gate shutdown (10s) a soft start
is initiated with the short circuit still present. As the GATE
slowly turns on the current ramps up and exceeds the OverCurrent threshold (50mV) enabling the timer and current
limiting (2.5A). The fault remains for the duration of the timeout period and the GATE pin is quickly pulled low and
latched off.
Applications: OV and UV
The UV and OV pins can be used to detect Over-Voltage
and Under-Voltage conditions on the input supply and
quickly shut down the external FET to protect the system.
Each pin is tied to an internal comparator with a nominal
reference of 1.255V. A resistor divider between the VDD
(gnd) and -VIN is typically used to set the trip points on the
UV and OV pins. If the voltage on the UV pin is above its
threshold and the voltage on the OV pin is below its
18
The hysteresis of the comparators is also multiplied by the
scale factor of 35 for the UV pin (35 * 135mV = 4.7V of
hysteresis at the power supply) and 60 for the OV pin (60 *
25mV = 1.5V of hysteresis at the power supply).
With the three resistors, the UV equation is based on the
simple resistor divider:
1.255 = VUV [(R5 + R6)/(R4 + R5 + R6)] or
VUV = 1.255 [(R4 + R5 + R6)/(R5 + R6)]
Similarly, for OV:
1.255 = VOV [(R6)/(R4 + R5 + R6)] or
VOV = 1.255 [(R4 + R5 + R6)/(R6)]
Note that there are two equations, but 3 unknowns. Because
of the scale factor, R4 has to be much bigger than the other
two; chose its value first, to set the current (for example, 50V /
500k draws 100A), and then the other two will be in the
10k range. Solve the two equations for two unknowns. Note
that some iteration may be necessary to select values that
meet the requirement, and are also readily available standard
values.
The three resistor divider (R4, R5, R6) is the recommended
approach for most applications, but if acceptable values
ISL6142, ISL6152
Applications: PWRGD/PWRGD
The PWRGD/PWRGD outputs are typically used to directly
enable a power module, such as a DC/DC converter. The
PWRGD (ISL6142) is used for modules with active low
enable (L version), and PWRGD (ISL6152) for those with an
active high enable (H version). The modules usually have a
pull-up device built-in, as well as an internal clamp. If not, an
external pull-up resistor may be needed. If the pin is not
used, it can be left open.
For both versions at initial start-up, when the DRAIN to VEE
voltage differential is less than 1.3V and the GATE voltage is
within 2.5V (VGH) of its normal operating voltage (13.6V),
power is considered good and the PWRGD/PWRGD pins
will go active. At this point the output is latched and the
comparators above no longer control the output. However a
second DRAIN comparator remains active and will drive the
PWRGD/PWRGD output inactive if the DRAIN voltage
exceeds VEE by more than 8V. The latch is reset by any of
the signals that shut off the GATE (Over-Voltage, UnderVoltage; Under-Voltage-Lock-Out; Over-Current Time-Out,
disable pin high, or powering down). In this case the
PWRGD/PWRGD output will go inactive, indicating power is
no longer good.
ISL6142 (L version; Figure 34): Under normal conditions
(DRAIN voltage - VEE < VPG, and VGATE - VGATE < VGH)
the Q2 DMOS will turn on, pulling PWRGD low, enabling the
module.
When any of the 5 conditions occur that turn off the GATE
(OV, UV, UVLO, Over-Current Time-Out, disable pin high)
the PWRGD latch is reset and the Q2 DMOS device will shut
off (high impedance). The pin will quickly be pulled high by
the external module (or an optional pull-up resistor or
equivalent) which in turn will disable it. If a pull-up resistor is
used, it can be connected to any supply voltage that doesn’t
exceed the IC pin maximum ratings on the high end, but is
high enough to give acceptable logic levels to whatever
19
signal it is driving. An external clamp may be used to limit the
voltage range.
VDD
VIN+ VOUT+
 VGATE
+
-
can’t be found, then consider 2 separate resistor dividers
(one for each pin, both from VDD to -VIN). This also allows
the user to adjust or trim either trip point independently.
Some applications employ a short pin ground on the
connector tied to R4 to ensure the hot plug device is fully
powered up before the UV and OV pins (tied to the short pin
ground) are biased. This ensures proper control of the GATE
is maintained during power up. This is not a requirement for
the ISL6142/52 however the circuit will perform properly if a
short pin scheme is implemented (reference Figure 38).
VGH
GATE
VPG
+
-
(SECTION OF) ISL6142
(L VERSION)
+
-
VEE
VDH
+
-
PWRGD
+
+
-
+
CL
LATCH Q2
LOGIC
VEE
ON/OFF
ACTIVE LOW
ENABLE
MODULE
VIN-
VOUT-
VEE
DRAIN
FIGURE 34. ACTIVE LOW ENABLE MODULE
The PWRGD can also drive an opto-coupler (such as a
4N25), as shown in Figure 35 or LED (Figure 36). In both
cases, they are on (active) when power is good. Resistors
R13 or R14 are chosen based on the supply voltage, and the
amount of current needed by the loads.
VDD
(SECTION OF) ISL6142
(L VERSION)
LOGIC
PWRGD
R13
PWRGD
Q2
OPTO
LATCH
COMPARATORS
VEE
DRAIN
FIGURE 35. ACTIVE LOW ENABLE OPTO-ISOLATOR
VDD
(SECTION OF) ISL6142
(L VERSION)
LOGIC
PWRGD
R14
Q2
LED (GREEN)
LATCH
COMPARATORS
VEE
DRAIN
FIGURE 36. ACTIVE LOW ENABLE LED
ISL6152 (H version; Figure 37): Under normal conditions
(DRAIN voltage - VEE < VPG, and VGATE - VGATE < VGH),
the Q3 DMOS will be on, shorting the bottom of the internal
resistor to VEE, turning Q2 off. If the pull-up current from the
external module is high enough, the voltage drop across the
6.2k resistor will look like a logic high (relative to DRAIN).
Note that the module is only referenced to DRAIN, not VEE
ISL6142, ISL6152
(but under normal conditions, the FET is on, and the DRAIN
and VEE are almost the same voltage).
When any of the 5 conditions occur that turn off the GATE, the
Q3 DMOS turns off, and the resistor and Q2 clamp the
PWRGD pin to one diode drop (~0.7V) above the DRAIN pin.
This should be able to pull low against the module pull-up
current, and disable the module.
VDD
VIN+ VOUT+
+
-
 VGATE
VGH
GATE
VPG
+
-
+
+
-
VEE
VDH
+
-
PWRGD
(SECTION OF) ISL6152
(H VERSION)
+
-
ON/OFF
6.2K
Q2
+
CL
LATCH Q3
LOGIC
VEE
ACTIVE HIGH
ENABLE
MODULE
VIN-
VOUT-
VEE
DRAIN
FIGURE 37. ACTIVE HIGH ENABLE MODULE
Applications: GATE Pin
To help protect the external FET, the output of the GATE pin
is internally clamped; up to an 80V supply and will not be any
higher than 15V. Under normal operation when the supply
voltage is above 20V, the GATE voltage will be regulated to a
nominal 13.6V above VEE.
a high enough input voltage (remember that current through
the RPG 6.2k resistor generates the high voltage level; see
Figure 34).
The input capacitance of the brick is chosen to match its
system requirements, such as filtering noise, and
maintaining regulation under varying loads. Note that this
input capacitance appears as the load capacitance of the
ISL6142/52.
The brick’s output capacitance is also determined by the
system, including load regulation considerations. However, it
can affect the ISL6142/52, depending upon how it is
enabled. For example, if the PWRGD/PWRGD signal is not
used to enable the brick, the following could occur.
Sometime during the inrush current time, as the main power
supply starts charging the brick input capacitors, the brick
itself will start working, and start charging its output
capacitors and load; that current has to be added to the
inrush current. In some cases, the sum could exceed the
Over-Current threshold, which could shut down the system if
the time-out period is exceeded! Therefore, whenever
practical, it is advantageous to use the PWRGD/PWRGD
output to keep the brick off at least until the input caps are
charged up, and then start-up the brick to charge its output
caps.
Typical brick regulators include models such as Lucent
JW050A1-E or Vicor VI-J30-CY. These are nominal -48V
input, and 5V outputs, with some isolation between the input
and output.
Applications: “Brick” Regulators
Applications: Optional Components
One of the typical loads used are DC/DC regulators, some
commonly known as “brick” regulators, (partly due to their
shape, and because it can be considered a “building block”
of a system). For a given input voltage range, there are
usually whole families of different output voltages and
current ranges. There are also various standardized sizes
and pinouts, starting with the original “full” brick, and since
getting smaller (half-bricks and quarter-bricks are now
common).
In addition to the typical application, and the variations
already mentioned, there are a few other possible
components that might be used in specific cases. See Figure
38 for some possibilities.
Other common features may include: all components
(except some filter capacitors) are self-contained in a
molded plastic package; external pins for connections; and
often an ENABLE input pin to turn it on or off. A hot plug IC,
such as the ISL6142 is often used to gate power to a brick,
as well as turn it on.
Many bricks have both logic polarities available (Enable high
or low input); select the ISL6142 (L-version) or ISL6152 (Hversion) to match. There is little difference between them,
although the L-version output is usually simpler to interface.
The Enable input often has a pull-up resistor or current
source, or equivalent built in; care must be taken in the
ISL6152 (H version) output that the given current will create
20
If the input power supply exceeds the 100V absolute
maximum rating, even for a short transient, that could cause
permanent damage to the IC, as well as other components
on the board. If this cannot be guaranteed, a voltage
suppressor (such as the SMAT70A, D1) is recommended.
When placed from VDD to -VIN on the board, it will clamp the
voltage.
If transients on the input power supply occur when the
supply is near either the OV or UV trip points, the GATE
could turn on or off momentarily. One possible solution is to
add a filter cap C4 to the VDD pin, through isolation resistor
R11. A large value of R11 is better for the filtering, but be
aware of the voltage drop across it. For example, a 1k
resistor, with 2.4mA of IDD would have 2.4V across it and
dissipate 2.4mW. Since the UV and OV comparators are
referenced with respect to VEE, they should not be affected,
but the GATE clamp voltage could be offset by the voltage
across the extra resistor.
ISL6142, ISL6152
R12 is a pull-up resistor for PWRGD, if there is no other
component acting as a pull-up device. The value of R12 is
determined by how much current is needed when the pin is
pulled low (also affected by the VDD voltage); and it should
be pulled low enough for a good logic low level. An LED can
also be placed in series with R12, if desired. In that case, the
criteria is the LED brightness versus current.
The switch SW1 is shown as a simple push button. It can be
replaced by an active switch, such as an NPN or NFET; the
principle is the same; pull the UV node below its trip point,
and then release it (toggle low). To connect an NFET, for
example, the DRAIN goes to UV; the source to -VIN, and the
GATE is the input; if it goes high (relative to -VIN), it turns the
NFET on, and UV is pulled low. Just make sure the NFET
resistance is low compared to the resistor divider, so that it
has no problem pulling down against it.
GND
(SHORT PIN)
GND
GND
Logic
Supply
(VEE+5V)
R10
R11*
R12*
VDD
FAULT
DIS
ISOUT
PWRGD
R4
ISL6142
UV
R5
TO
ADC R6
SW1*
D1* Logic
Input
Q2
R9
OV
CT VEE ISC3
IS+ SENSE GATE
R7
C1
R8
R2
DRAIN
R3 C2
C4*
CL
RL
-48V IN
R1
Q1
-48V OUT
FIGURE 38. ISL6142/52 OPTIONAL COMPONENTS (SHOWN WITH *)
Applications: Layout Considerations
For the minimum application, there are 10 resistors, 3
capacitors, one IC and 2 FETs. A sample layout is shown in
Figure 39. It assumes the IC is 8-SOIC; Q1 is in a D2PAK (or
similar SMD-220 package).
Although GND planes are common with multi-level PCBs, for
a -48V system, the -48V rails (both input and output) act
more like a GND than the top 0V rail (mainly because the IC
signals are mostly referenced to the lower rail). So if
separate planes for each voltage are not an option, consider
prioritizing the bottom rails first.
Note that with the placement shown, most of the signal lines
are short, and there should be minimal interaction between
them.
Although decoupling capacitors across the IC supply pins
are often recommended in general, this application may not
need one, nor even tolerate one. For one thing, a decoupling
cap would add to (or be swamped out by) any other input
capacitance; it also needs to be charged up when power is
applied. But more importantly, there are no high speed (or
any) input signals to the IC that need to be conditioned. If still
21
desired, consider the isolation resistor R10, as shown in
figure 38.
NOTE:
1. Layout scale is approximate; routing lines are just for illustration
purposes; they do not necessarily conform to normal PCB
design rules. High current buses are wider, shown with parallel
lines.
2. Approximate size of the above layout is 0.8 x 0.8 inches,
excluding Q1 (D2PAK or similar SMD-220 package).
3. R1 sense resistor is size 2512; all other R’s and C’s shown are
0805; they can all potentially use smaller footprints, if desired.
4. The RL and CL are not shown on the layout.
5. Vias are needed to connect R4 and VDD to GND on the bottom
of the board, and R8 to pin 9; all other routing can be on the top
level.
6. PWRGD signal is not used here.
ISL6142, ISL6152
BOM (Bill Of Materials)
R9 = 4.99K (1%)
R1 = 0.02 (5%)
R10 = 5.10K (10%)
R2 =10.0 (5%)
C1 = 150nF (25V)
R3 = 18.0K (10%)
C2 = 3.3nF (100V)
R4 = 549K (1%)
C3 = 1500pF (25V)
R5 = 6.49K (1%)
Q1 = IRF530 (100V, 17A, 0.11)
R6 = 10.0K (1%)
Q2 = N-channel Logic FEFT
R7 = R8 = 400(1%)
GND
GND
TO
VDD
R9
-48VIN
C3
+5V
LOGIC IN
-48VIN
R10
G
D
S
1 PG
VDD 14
2 FLT
CT 13
3 DIS
ISO 12
4 OV
R5
GND
GATE
NFET
R3
R6
-48VIN
C2
R4
ISL6142
D 11
5 UV
G 10
6 IS-
IS+ 9
7 VEE
S8
R7
-48V IN
DRAIN
R2
C1
R8
SOURCE
TO
PIN 9
R1
FIGURE 39. ISL6142 SAMPLE LAYOUT (NOT TO SCALE)
22
-48V OUT
ISL6142, ISL6152
Small Outline Plastic Packages (SOIC)
M14.15 (JEDEC MS-012-AB ISSUE C)
N
INDEX
AREA
0.25(0.010) M
H
14 LEAD NARROW BODY SMALL OUTLINE PLASTIC
PACKAGE
B M
E
INCHES
-B1
2
SYMBOL
3
L
SEATING PLANE
-A-
h x 45o
A
D
-C-
µ
e
A1
B
0.10(0.004)
0.25(0.010) M
C A M
B S
NOTES:
1. Symbols are defined in the “MO Series Symbol List” in Section
2.2 of Publication Number 95.
MAX
MILLIMETERS
MIN
MAX
NOTES
A
0.0532
0.0688
1.35
1.75
-
A1
0.0040
0.0098
0.10
0.25
-
B
0.013
0.020
0.33
0.51
9
C
0.0075
0.0098
0.19
0.25
-
D
0.1890
0.1968
4.80
5.00
3
E
0.1497
0.1574
3.80
4.00
4
e
C
MIN
0.050 BSC
1.27 BSC
-
H
0.2284
0.2440
5.80
6.20
-
h
0.0099
0.0196
0.25
0.50
5
L
0.016
0.050
0.40
1.27
6
8o
0o
N

8
0o
8
7
8o
2. Dimensioning and tolerancing per ANSI Y14.5M-1982.
Rev. 0 12/93
3. Dimension “D” does not include mold flash, protrusions or gate
burrs. Mold flash, protrusion and gate burrs shall not exceed
0.15mm (0.006 inch) per side.
4. Dimension “E” does not include interlead flash or protrusions.
Interlead flash and protrusions shall not exceed 0.25mm
(0.010 inch) per side.
5. The chamfer on the body is optional. If it is not present, a visual
index feature must be located within the crosshatched area.
6. “L” is the length of terminal for soldering to a substrate.
7. “N” is the number of terminal positions.
8. Terminal numbers are shown for reference only.
9. The lead width “B”, as measured 0.36mm (0.014 inch) or greater above the seating plane, shall not exceed a maximum value
of 0.61mm (0.024 inch).
10. Controlling dimension: MILLIMETER. Converted inch dimensions are not necessarily exact.
All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9001 quality systems.
Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see www.intersil.com
23
Similar pages