ISL6142CBZA [INTERSIL]
Negative Voltage Hot Plug Controller; 负电压热插拔控制器型号: | ISL6142CBZA |
厂家: | Intersil |
描述: | Negative Voltage Hot Plug Controller |
文件: | 总23页 (文件大小:451K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
ISL6142, ISL6152
®
Data Sheet
July 2004
FN9086.1
Negative Voltage Hot Plug Controller
Typical Application
GND
GND
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 Over-
Voltage 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.
Logic
Supply
FAULT
V
DD
PWRGD
PWRGD
DIS
IS
R10
OUT
R4
R5
R6
ISL6142/ISL6152
UV
OV
CT
IS+ SENSE
V
GATE DRAIN
IS-
EE
LOAD
R3
C2
C1
R7
CL
RL
R8
R9
C3
R2
The IntelliTripTM 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.
-48V IN
R1
Q1
-48V OUT
C2 = 3.3nF (100V)
C3 = 1500pF (25V)
Q1 = IRF530
R1 = 0.02
Ω
(5%)
(1%)
R6 = 10K
Ω
(1%)
R2 = 10
Ω
R7 = R8 = 400
Ω
(1%)
R3 = 18K
Ω
(5%)
(1%)
(1%)
R9 = 4.99K
Ω
Ω
(1%)
CL = 100uF (100V)
RL = Equivalent load
R4 = 549K
Ω
R10 = 5.1K
(10%)
R5 = 6.49K
Ω
C1 = 150nF (25V)
Features
• Operates from -20V to -80V (-100V Absolute Max Rating)
• Programmable Inrush Current
• Programmable Time-Out
• Programmable Current Limit
The IS+, IS-, and IS
OUT
pins combine to provide a load current
• Programmable Over-Voltage Protection
• Programmable Under-Voltage Protection
- 135 mV of hysteresis ~4.7V of hysteresis at the power supply
monitor feature that presents a scaled version of the load current
at the IS pin. Current to voltage conversion is accomplished
OUT
by placing a resistor (R9) from IS
to the negative input (-48V).
OUT
• V
DD
Under-Voltage Lock-Out (UVLO) ~ 16.5V
Related Literature
• IntelliTripTM Electronic Circuit Breaker distinguishes between
severe and moderate faults
• 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.
- Fast shutdown for short circuit faults with a single retry (fault
current > 4X current limit value).
• 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
Pinout
- IS
OUT
provides a scaled version of the load current
ISL6142 OR ISL6152 (14 LEAD SOIC)
- A resistor from IS
conversion
to -V provides current to voltage
IN
OUT
14
13
12
11
10
9
PWRGD/PWRGD
1
2
V
DD
Top View
FAULT
DIS
CT
IS
• Power Good Control Output
3
4
5
OUT
ISL6142/52
OV
- Output latched “good” when DRAIN and GATE voltage
thresholds are met.
DRAIN
GATE
IS+
UV
IS-
6
7
- (PWRGD active low: ISL6142 (L version)
- PWRGD active high: ISL6152 (H version)
8
V
SENSE
EE
• Pb-free available
Applications
• 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 registered trademark of Intersil Americas Inc.
Intellitrip™ is a trademark of Intersil Americas Inc.
1
Copyright © Intersil Americas Inc. 2002, 2004, All Rights Reserved
ISL6142, ISL6152
Ordering Information
PKG.
DWG. #
o
PART NUMBER TEMP. RANGE ( C) PACKAGE
ISL6142CB
0 to 70
0 to 70
14 Lead SOIC M14.15
ISL6142CBZA
(See Note)
14 Lead SOIC M14.15
(Pb-free)
ISL6152CB
0 to 70
0 to 70
14 Lead SOIC M14.15
ISL6152CBZA
(See Note)
14 Lead SOIC M14.15
(Pb-free)
ISL6142IB
-40 to 85
-40 to 85
14 Lead SOIC M14.15
ISL6142IBZA
(See Note)
14 Lead SOIC M14.15
(Pb-free)
ISL6152IB
-40 to 85
-40 to 85
14 Lead SOIC M14.15
ISL6152IBZA
(See Note)
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
V
DD
-
UVLO
1.265V
R4
R5
+
+
REGULATOR,
REFERENCES
-
V
V
EE
EE
UV
OV
-
UV
OV
1.255V
+
13V
+
-
V
EE
+
-
1.255V
LOGIC,
+
-
TIMING,
V
EE
GATE
DRIVE
-
HARD
FAULT
R6
210mV
+
+
-
V
EE
-
GATE
11.1V
+
+
PWRGD
(ISL6142)
-
V
EE
LATCH,
LOGIC,
OUTPUT
DRIVE
CURRENT
LIMIT
-
-
LOGIC
PWRGD
50mV
REGULATOR
+
1.3V
(ISL6152)
SUPPLY
+
+
-
+
-
V
EE
V
EE
R10
FAULT
DIS
FAULT
-
V
8.0V
EE
+
DISABLE
+
-
LOGIC
INPUT
V
EE
13V
V
EE+5V
CT
-
TIMER
8.5V
+
+
-
V
C3
V
EE
EE
GATE
STOP
CURRENT
SENSE
IS
OUT
TO ADC
V
GATE
DRAIN
EE IS-
R8
IS+
SENSE
LOAD
CL
R7
R3 C2
R9
R2
C1
RL
Q1
FIGURE 1. BLOCK DIAGRAM
-48V OUT
R1
-48V IN
3
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
FAULT Pin 2- This digital output is an open-drain, pull-down
device, referenced to V . It is pulled active low whenever
EE
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.
to the internal V
reference (1.3V); this measures the
voltage drop across the external FET and sense resistor.
PG
When the DRAIN to V voltage drop is less than 1.3V, the
EE
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
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 (10µA), 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 V , and is compatible with CMOS logic levels. A logic
EE
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 DRAIN voltage raises more than 8V above V . In
EE
addition, any of the signals that shut off the GATE (Over-
Voltage, Under-Voltage, Under-Voltage Lock-Out, Over-
Current 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).
the negative supply rail (-V ).
IN
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
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).
divider from V
to -V to set the OV trip level. A three-
DD
IN
resistor 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 V
as desired. A three-resistor divider can be used to set both
OV and UV trip points to reduce component count.
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 V through
EE
a 6.2KΩ resistor. The base of Q2 is clamped to V to turn it
EE
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 6.2KΩ = 6.2V).
to -V to set the UV level
DD
IN
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
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.
connected; the IC will not clamp it below the V
voltage.
DD
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.
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 V side of resistor R1. The ratio of R1/R7
EE
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.
defines the I
SENSE
to IS
current scaling factor. If current
OUT
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.
4
ISL6142, ISL6152
V
Pin 7 - This is the most Negative Supply Voltage, such
1.3v and 8.0V. At initial start-up the DRAIN to V voltage
EE
EE
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.
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
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.
if the DRAIN voltage exceeds V by more than 8.0V.
EE
IS
OUT
Pin 12 - This analog pin is the output of the current
) is
sense circuit. The current flowing out of this pin (IS
OUT
proportional to the current flowing through the R1 sense
resistor (I ). The scaling factor, IS /I is
SENSE OUT SENSE
defined by the resistor ratio of R1/R7. Current to voltage
conversion is accomplished by placing a resistor from this
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 Over-
Current trip point. When the hard fault comparator threshold
is exceeded the GATE is immediately (10µs typical) shut off
pin to -V . The current flowing out of the pin is supplied by
IN
the internal 13V regulator and should not exceed 600µA.
The output voltage will clamp at approximately 8V. If current
sensing is not used in the application the pin should be left
open.
(V
= V ), the timer is reset, and a single retry (soft
GATE
EE
start) is initiated.
CT Pin 13 - This analog I/O pin is used to program the Over-
Current Time-Out period with a capacitor connected to the
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
negative supply rail (-V which is equal to V ). During
IN EE
normal operation, the pin is pulled down to V . During
EE
current limiting, the capacitor is charged with a 20µA
(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 µsec. To set the desired time-
out period use:
(IS
). If current sensing is not used in the application, the
OUT
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:
6
• V
DD
UVLO is above its trip point (~16.5V)
dt = (C * dV) / I = (C * 8.5) / 20 µA = 0.425*10 * C
• 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.
NOTE: The printed circuit board’s parasitic capacitance (CT pin to
the negative input, -V ) should be taken into consideration when
IN
calculating the value of C3 needed for the desired time-out.
V
Pin 14 - This is the most positive Power Supply pin. It
DD
can range from the Under-Voltage lockout threshold (16.5V)
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.
to +80V (Relative to V ). The pin can tolerate up to 100V
EE
without damage to the IC.
The GATE is driven high by a weak (-50µA 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) pull-
down 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
ISL6142, ISL6152
.
Absolute Maximum Ratings
Thermal Information
o
Supply Voltage (V
to V ). . . . . . . . . . . . . . . . . . . . -0.3V to 100V
EE
Thermal Resistance (Typical, Note 1)
θ
( C/W)
DD
JA
DRAIN, PWRGD, PWRGD Voltage . . . . . . . . . . . . . . .-0.3V to 100V
UV, OV Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 60V
SENSE, GATE Voltage . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 20V
14 Lead SOIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
o
Maximum Junction Temperature (Plastic Package) . . . . . . . .150 C
o
o
Maximum Storage Temperature Range. . . . . . . . . . -65 C to 150 C
o
FAULT, DIS, IS+, IS-, IS
ESD Rating
, CT . . . . . . . . . . . . . . . . . -0.3V to 8.0V
OUT
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . .300 C
Human Body Model (Per MIL-STD-883 Method 3015.7) . . .2000V
Operating Conditions
o
o
Temperature Range (Industrial) . . . . . . . . . . . . . . . . . -40 C to 85 C
Temperature Range (Commercial). . . . . . . . . . . . . . . . . 0 C to 70 C
Supply Voltage Range (Typical). . . . . . . . . . . . . . . . . . . 36V to 72V
o
o
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. θ is measured with the component mounted on a high effective thermal conductivity test board in free air. See Tech Brief TB379 for details.
JA
2. PWRGD is referenced to DRAIN; V = 0V.
-V
PWRGD DRAIN
Electrical Specifications
V
= +48V, V = +0V Unless Otherwise Specified. All tests are over the full temperature range; either
EE
DD
Commercial (0 C to 70 C) or Industrial (-40 C to 85 C). Typical specs are at 25 C.
o
o
o
o
o
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX UNITS
DC PARAMETRIC
V
PIN
DD
Supply Operating Range
Supply Current
V
20
-
80
V
DD
I
UV = 3V; OV = V ; SENSE = V ; V
=
2.6
4.0
mA
DD
EE
EE DD
80V
UVLO High
V
V
V
Low to High transition
High to Low transition
15
13
16.7
15.0
1.9
19
17
V
V
V
UVLOH
DD
DD
UVLO Low
V
UVLOL
UVLO hysteresis
GATE PIN
GATE Pin Pull-Up Current
GATE Pin Pull-Down Current
GATE Pin Pull-Down Current
GATE Pin Pull-Down Current
External Gate Drive (at 20V, at 80V)
GATE High Threshold (PWRGD/PWRGD active)
SENSE PIN
I
GATE Drive on, V
V
GATE = EE
-30
12
-50
70
-60
15
µA
mA
mA
mA
V
PU
I
GATE Drive off, UV or OV false
PD1
PD2
PD3
I
I
GATE Drive off, Over-Current Time-Out
70
GATE Drive off; Hard Fault, Vsense > 210mv
350
13.6
2.5
∆V
(V
V
, 20V <=V
<=80V
DD
GATE
GATE - EE)
∆V - V
GATE
V
V
GH
GATE
Current Limit Trip Voltage
Hard Fault Trip Voltage
SENSE Pin Current
V
V
= (V
- V
)
40
-
50
210
0
60
mV
mV
µA
CL
CL
SENSE
EE
HFTV
HFTV = (V
- V
)
SENSE
= 50mV
SENSE
EE
I
V
-0.5
SENSE
UV PIN
UV Pin High Threshold Voltage
UV Pin Low Threshold Voltage
UV Pin Hysteresis
V
UV Low to High Transition
UV High to Low Transition
1.240
1.105
1.255 1.270
1.120 1.145
135
V
V
UVH
V
UVL
V
mV
UVHY
6
ISL6142, ISL6152
Electrical Specifications
V
= +48V, V = +0V Unless Otherwise Specified. All tests are over the full temperature range; either
EE
DD
o
o
o
o
o
Commercial (0 C to 70 C) or Industrial (-40 C to 85 C). Typical specs are at 25 C. (Continued)
PARAMETER
UV Pin Input Current
OV pin
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX UNITS
I
V
= V
EE
-
-0.05
-0.5
µA
INUV
UV
OV Pin High Threshold Voltage
OV Pin Low Threshold Voltage
OV Pin Hysteresis
V
OV Low to High Transition
OV High to Low Transition
1.235
1.215
1.255 1.275
1.230 1.255
25
V
V
OVH
V
OVL
V
mV
µA
OVHY
INOV
OV Pin Input Current
DRAIN Pin
I
V
V
= V
-
-0.05
-0.5
OV
EE
Power Good Threshold (Enable PWRGD/PWRGD
Output)
V
- V
0.80
1.30
2.00
V
PG
DRAIN
EE
Drain Input Bias Current
I
V
V
= 48V
10
38
60
µA
DRAIN
VDH
DRAIN
DRAIN
DRAIN Pin Comparator Trip Point
(PWRGD/PWRGD Inactive)
- V > 8.0V
EE
7.0
8.0V
9.0
V
ISL6142 (PWRGD Pin: L Version)
PWRGD Output Low Voltage
V
V
(V
(V
- V
- V
< V
< V
I
PG; OUT
= 1mA
= 5mA
-
-
-
0.3
0.8
3.0
10
V
V
OL1
OL5
DRAIN
DRAIN
DRAIN
EE)
EE)
I
1.50
0.05
PG; OUT
Output Leakage
I
V
= 48V, V
= 80V
PWRGD
µA
OH
ISL6152 (PWRGD Pin: H Version)
PWRGD Output Low Voltage (PWRGD-DRAIN)
PWRGD Output Impedance
DIS PIN
V
V
= 5V, I
= 1mA
PG
-
0.80
6.2
1.0
7.5
V
OL
DRAIN
OUT
< V
R
(V
- V
EE)
4.5
kΩ
OUT
DRAIN
DIS Pin High Threshold Voltage
DIS Pin Low Threshold Voltage
DIS Pin Hysteresis
V
DIS Low to High Transition
DIS High to Low Transition
DIS Hysteresis
1.60
2.20
1.1
1.0
0.1
10
3.00
1.50
V
V
DISH
V
DISL
V
V
DISHY
DIS Pin Input High Leakage
DIS Pin Input Low Current
FAULT PIN
I
Input Voltage = 5V
1.0
µA
µA
DISINH
I
Input Voltage = 0V
DISINL
FAULT Output Voltage
FAULT Output Leakage
CT PIN
VF
I = 1.6 mA
V = 5.0V
0.4
V
VOL
IF
10
µA
IOH
CT Pin Charging Current
CT Pin Input Threshold
I
V
= 0V
CT
20
µA
CTINL
V
7.5
8.5
9.5
V
CT
IS PINS (IS-, IS+, IS
)
OUT
IS
IS
Error
Error
VSENSE = 50mV, R7 = 400Ω, R8 = 404Ω
VSENSE = 200mV, R7 = 400Ω, R8 = 404Ω
VSENSE = 0.0mV, R7 = 400Ω, R8 = 404Ω
2.0
1.0
4.5
5
%
%
µA
V
OUT
OUT
ISOUT Offset Current
Output Voltage Range (IS
Pin)
0
8
OUT
7
ISL6142, ISL6152
Electrical Specifications
V
= +48V, V = +0V Unless Otherwise Specified. All tests are over the full temperature range; either
EE
DD
o
o
o
o
o
Commercial (0 C to 70 C) or Industrial (-40 C to 85 C). Typical specs are at 25 C. (Continued)
PARAMETER
AC TIMING
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX UNITS
OV High to GATE Low
OV Low to GATE High
UV Low to GATE Low
t
t
Figures 2A, 3A
0.6
1.0
0.6
1.0
1.6
7.8
1.3
8.4
0.6
2.5
0.5
1.2
4.0
1
3.0
12.0
3.0
µs
µs
µs
µs
µs
µs
µs
µs
µs
µs
µs
PHLOV
PLHOV
Figures 2A, 3A
Figures 2A, 3B
Figures 2A, 3B
Figure 2A, 7
t
t
PHLUV
PLHUV
UV High to GATE High
DIS Low to GATE Low
DIS High to GATE High
GATE Low (Over-Current) to FAULT Low
12.0
t
t
PHLDIS
PLHDIS
Figure 2A, 7
t
Figure 2A, 8
PHLGF
IS
IS
Rise Time
Fall Time
t
Figure 2A, 12
Figure 2A, 12
Figures 2A, 9
OUT
OUT
R
t
F
SENSE High to GATE Low
Current Limit to GATE Low
t
3
PHLSENSE
t
Figures 2B, 11, Effective Capacitance During
Test = 2550pF
1200
PHLCB
Hard Fault to GATE Low (200mV comparator)
Typical GATE shutdown based on application ckt.
Guaranteed by design.
t
Figures 10, 20, 33
10.0
µs
PHLHF
ISL6142 (L Version)
DRAIN Low to PWRGD Low (Active)
DRAIN High to PWRGD High (Inactive)
GATE High to PWRGD Low (Active)
ISL6152 (H Version)
t
Figures 2A, 4A
Figure 2A, 6A
Figures 2A, 5A
0.1
0.1
3.1
0.2
1.0
5.0
5.0
µs
µs
µs
PHLDL
t
PLHDH
t
PHLGH
DRAIN Low to (PWRGD-DRAIN) High (Active)
DRAIN High to (PWRGD -DRAIN) Low (Inactive)
GATE High to (PWRGD-DRAIN) High (Active)
t
Figures 2A, 4B
Figure 2A, 6B
Figures 2A, 5B
0.2
0.5
0.4
µs
µs
µs
PLHDL
PHLDH
PLHGH
t
t
8
ISL6142, ISL6152
?
Test Circuit and Timing Diagrams
5K
+
-
48V
5K
5V
5V
+
48V
5K
-
PWRGD
FAULT
V
DD
14
13
12
11
10
1
2
3
V
DD
PWRGD
FAULT
5K
CT
14
13
12
11
10
1
2
3
V
DIS
V
OV
ISL6142
4.99K
OV
UV
DRAIN
GATE
4
ISL6142
V
V
OV
V
UV
DRAIN
OV
UV
4
V
5
6
7
DRAIN
UV
V
DRAIN
9.0K
5
6
7
GATE
9
8
400Ω
404Ω
V
EE
SENSE
9
8
V
0.90K
EE
SENSE
.
0.1K
V
SENSE
FIGURE 2B. TEST CIRCUIT FOR TIMEOUT
FIGURE 2A. TYPICAL TEST CIRCUIT
2V
2V
0V
1.125V
1.255V
1V
1.255V
1.230V
1V
UV Pin
GATE
0V
13.6V
t
t
PLHUV
t
PHLUV
t
PHLOV
PLHOV
13.6V
GATE
1V
1V
0V
0V
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
V
PG
V
PG
V
EE
t
t
PHLDL
PLHDL
PWRGD
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
13.6V
GH
∆V
- V
= 0V
GATE
GATE
∆V
- V = 0V
GATE
13.6V
GATE
V
2.5V
V
2.5V
GH
GATE
t
PLHGH
GATE
t
PHLGH
PWRGD
1.0V
= 0V
PWRGD
1.0V
V
- V
DRAIN
PWRGD
FIGURE 5A. GATE TO PWRGD ACTIVE (ISL6142)
FIGURE 5B. GATE TO PWRGD ACTIVE (ISL6152)
9
ISL6142, ISL6152
Test Circuit and Timing Diagrams (Continued)
V
- V = 8.0V
EE
DRAIN
V
- V = 8.0V
EE
DRAIN
V
DH
8.0V
8.0V
V
DH
DRAIN
PWRGD
V
- V = 0V
DRAIN
t
EE
PHLDH
V
- V = 0V
DRAIN
EE
t
PLHDH
DRAIN
1.0V
1.0V
PWRGD
V
- V
= 0V
DRAIN
PWRGD
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
3V
∆V
- V
= 0V
GATE
GATE
DIS
1.50V
1.4V
GATE
2.2V
1V
t
0V
PHLF
t
t
PLHDIS
PHLDIS
GATE
FAULT
13.6V
1V
1.0V
0V
FIGURE 7. DISABLE TO GATE TIMING (ISL6142/52)
FIGURE 8. FAULT TO GATE TIMING (ISL6142/52)
50mV
210mV
SENSE
0V
SENSE
0V
13.6V
t
PHLHF
t
13.6V
PHLSENSE
GATE
GATE
V
EE
~4V (depends on FET threshold)
FIGURE 9. SENSE TO GATE (CURRENT LIMIT) TIMING
FIGURE 10. SENSE TO GATE (HARD FAULT) TIMING
V
SENSE
UV
t
R
t
PHLCB
t
F
90%
90%
V
GATE
OUT
10%
1.0V
1.0V
10%
Over-Current Time-Out
FIGURE 11. CURRENT LIMIT TO GATE TIMING
FIGURE 12. OUTPUT CURRENT RISE AND FALL TIME
10
ISL6142, ISL6152
Typical Performance Curves
16
14
12
10
8
6
4
2
0
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
10 20 30 40 50 60 70 80 90 100
10
20
30
40
50
60
70
80 100
Supply Voltage (VDD)
o
o
FIGURE 13. SUPPLY CURRENT VS. SUPPLY VOLTAGE (25 C)
FIGURE 14. GATE VOLTAGE VS SUPPLY VOLTAGE (25 C)
14
13.9
13.8
13.7
13.6
13.5
13.4
13.3
2.75
2.7
2.65
2.6
2.55
2.5
2.45
2.4
2.35
2.3
2.25
-40 -20
0
20
40
60
80
100
-40
-20
0
20
40
60
80
100
Temperature (C)
Temperature (C)
FIGURE 16. GATE VOLTAGE VS TEMPERATURE V
= 48V
FIGURE 15. SUPPLY CURRENT VS TEMPERATURE, V
= 80V
DD
DD
50
49
48
47
46
45
44
43
42
41
14
13.9
V
= 80V
DD
13.8
13.7
13.6
13.5
13.4
V
= 20V
DD
-40
-20
0
20
40
60
80
100
-40 -20
0
20 40 60 80 100
Temperature (C)
Temperature (C)
FIGURE 17. GATE VOLTAGE VS TEMPERATURE
FIGURE 18. GATE PULL-UP CURRENT VS TEMPERATURE
11
ISL6142, ISL6152
450
400
350
300
250
200
150
100
50
90
80
70
60
50
40
30
20
10
0
0
-40
-20
0
20
40
60
80
100
-40
-20
0
20
40
60
80
100
Temperature (C)
Temperature (C)
FIGURE 20. HARD FAULT GATE PULL-DOWN CURRENT VS
TEMPERATURE
FIGURE 19. GATE PULL-DOWN CURRENT
(UV/OV/TIME-OUT) VS TEMPERATURE
54
52
50
48
46
44
42
40
1.6
5mA
1.4
1.2
1
0.8
0.6
0.4
0.2
0
1mA
-40
-20
0
20
40
60
80
100
-40
-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
1.5
1
6.8
6.7
6.6
6.5
6.4
6.3
6.2
6.1
0.5
0
-40
-20
0
20
40
60
80
100
-40
-20
0
20
40
60
80
100
Temperature (C)
Temperature (C)
FIGURE 23. DRAIN to PWRGD / PWRGD TRIP VOLTAGE (V
VS TEMPERATURE
)
FIGURE 24. PWRGD (ISL6152) OUTPUT IMPEDANCE VS
TEMPERATURE
PG
12
ISL6142, ISL6152
6
5
4
3
2
1
0
2.5
-40oC
-40oC
2
1.5
1
85oC
85oC
0.5
0
50
100
150
200
0
50
100
150
SENSE Pin Voltage (mV)
SENSE pin Voltage (mV)
FIGURE 25. IS
OUT
ERROR VS SENSE PIN VOLTAGE
VSENSE = 0V
FIGURE 26. IS
ERROR VS SENSE PIN VOLTAGE
OUT
20.5
4.475
4.47
4.465
4.46
4.455
4.45
4.445
4.44
20
19.5
19
18.5
18
17.5
17
4.435
-40 -20
0
20
40
60
80
100
-40
-20
0
20
40
60
80
100
Temperature (C)
Temperature (C)
FIGURE 27. ISOUT OFFSET CURRENT VS TEMPERATURE
FIGURE 28. CT CHARGING CURRENT VS TEMPERATURE
13
ISL6142, ISL6152
Applications Information
GND
GND
V
FAULT
PWRGD
DD
DIS
IS
Logic
OUT
Supply
R4
R5
ISL6142
UV
R10
OV
CT
V
IS-
R7
IS+ SENSE GATE
DRAIN
C2
R6
R9
EE
ADC
Q2
R3
C1
R2
C3
CL
R8
RL
-48V IN
R1
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.
100µF of load capacitance (CL); equivalent RL of 48Ω
(R = V/I = 48V/1A)
R1: 0.02Ω (1%)
R2: 10Ω (5%)
R3: 18kΩ (5%)
R4, R5, R6 - together set the Under-Voltage (UV) and Over-
Voltage (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: 549kΩ (1%)
R5: 6.49kΩ (1%)
R6: 10kΩ (1%)
R7/R8: 400Ω (1%)
R9: 4.99KΩ (1%)
R10: 5.10KΩ (10%)
C1: 150nF (25V)
C2: 3.3nF (100V)
C3: 1500pF (25V)
Q1: IRF530 (100V, 17A, 0.11Ω)
Q2: N-Channel logic FET
〈 R + R + R 〉
4
5
6
(EQ. 1)
----------------------------------------
V
=
× 1.255
UV
(R + R )
5
6
〈 R + R + R 〉
4
5
6
(EQ. 2)
----------------------------------------
V
=
× 1.255
OV
(R )
6
14
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.
R1 resistor, and the V and SENSE pins should be direct
EE
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 V
EE
and R7
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:
• 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
CURRENT
SENSE RESISTOR
• 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
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
which affects the r
(which in turn, affects the
DS(ON)
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
R
. If the input current is high enough, such that the
SENSE
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 Over-
Current threshold is defined in Equation 3 below. If the time-
out 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 0.02Ω, which sets an Over-
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 power-
down). A typical value might be 48Ω (I=V/R = 48/48 = 1A).
Current trip point of; I
= V/R = 0.05/0.02 = 2.5 Amps. To
OC
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
R2, C1, R3, C2 - are related to the GATE driver, as it
controls the inrush current.
R2 prevents high frequency oscillations; 10Ω is a typical
value. R2 = 10Ω.
(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.
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 I is
PU
the GATE pin charging current, nominally 50µA.
50mv
I
= -------------------
C
L
C
2
OC
(EQ. 3)
R
------
sense
(EQ. 4)
I
= I
×
PU
inrush
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
Begin by choosing a value of acceptable inrush current for
the system, and then solve for C2.
15
ISL6142, ISL6152
C1 and R3 prevent Q1 from turning on momentarily when
power is first applied. Without them, C2 would pull the gate
response of the current sense circuit for the Over-Current
Time-out and hard fault single retry events.
of Q1 up to a voltage roughly equal to V *C2/Cgs(Q1)
EE
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
(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.
V
and the resistor is connected to a positive voltage, 5V or
EE
less, with respect to V . A typical value of 5KΩ is
EE
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.
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).
R3 - its value is not critical, a typical value of 18kΩ is
recommended but values down to 1KΩ 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.
C3 - is the capacitor used to program the current limit time-
out period. When the Over-Current threshold is exceeded a
20µA (nominal) current source will charge the C3 capacitor
from V to approximately 8.5V. When the voltage on the CT
EE
pin exceeds the 8.5V threshold, the GATE pin will
R7/R8/R9 - are used to sense the load current (R7/R8) and
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
convert the scaled output current (IS
) to a voltage (R9)
OUT
that would typically be the input signal to an A to D converter.
R7 is connected between -IS and the R1 sense resistor.
period expires, the CT pin will be pulled back down to V
,
EE
and normal operation will resume. Note that any parasitic
capacitance from the CT pin to -V will effectively add to
These two resistors set the I
(current through the
scaling factor based on equation 5
SENSE
Rsense resistor) to IS
OUT
IN
below. R8 does not effect the scaling factor but should match
R7 to minimize IS error. Their tolerance should be +/-1%,
C3. This additional capacitance should be taken into account
when calculating the C3 value needed for the desired time-
out period.
OUT
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.
The value of C3 can be calculated using equation 6 where dt
is the time-out period, dv is the CT pin threshold, and I is
CT
the capacitor charging current.
–6
dt
dv
timeout
8.5V
(EQ. 6
------
---------------------
× 20×10
C3 =
× I
=
CT
R9 is used to convert the IS
OUT
current to voltage and is
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 500KΩ resistor,
connected between the IS
pin and -V . The current
OUT
IN
flowing through the resistor (EQ. 5) should not exceed 600µA
and the voltage on the CT pin will clamp at approximately 8V.
R
SENSE
R7
connected to an internal +5V (V + 5V) supply rail (10µA).
-----------------------
IS
= I
×
SENSE
EE
(EQ. 5)
OUT
In this condition the GATE pin is low, and Q1 is turned off.
When Q2 is on, the DIS pin is pulled low to V allowing the
EE
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 (-V ).
IN
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 IS
current is in the 400-500µA range. For example, if the user
OUT
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
wanted to detect and measure fault currents up to the hard
fault comparator trip point (10A); the maximum IS
OUT
current using the application components in figure 23 would
be [10A x (.02/400] = 500µA. The value of R9 should be set
to accommodate the dynamic range of the A to D converter.
For this example, a 5KΩ resistor would produce a full scale
input voltage to the converter of 2.5V (500µA x 5KΩ).
Figures 32 and 33 illustrate the typical output voltage
V
pin, but this pin may be considered -48V or GND,
EE
depending upon the polarity of the system. Also, the input or
output logic (running at 5V or 3.3V or even lower) might be
16
ISL6142, ISL6152
TM
excessive supply or fault currents. The IntelliTrip 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
externally referenced to either V
of GND.
or V of the IC, instead
EE
DD
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.
be turned off by discharging the GATE pin to V . This will set
EE
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 10Ω short to ground
on the output. Prior to the short circuit the output load is 110Ω
producing an operating current of about 0.44A (48V/110Ω). A
10Ω short is then applied to the output causing an initial fault
current of 4.8A. This produces a voltage drop across the
0.02Ω 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 740µs. There is a short
filter (3µs 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.
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:
V
= -48V, Rsense = 0.02W
IN
Current limit = 50mV / 0.02Ω = 2.5A
C1 = 150nF, C2 = 3.3nF, R3 = 18kΩ
CL = 100µF, RL = 50Ω, I
= 48V / 50Ω ~1.0A
LOAD
= 50µA (100µF / 3.3nF) = 1.5A
I
inrush
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
100µF 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.
FIGURE 31. HOT INSERTION INRUSH CURRENT LIMITING,
FIGURE 32. CURRENT LIMITING AND TIME-OUT
DISABLE PIN TIED TO V
EE
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 10µs) and a
single retry. The trip point of this comparator is set ~4 times
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
ISL6142, ISL6152
(210mV) higher than the Over-Current threshold of 50mV. If
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 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.
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 -V or OV to -V is a possibility, if certain
IN IN
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.
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).
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 (10µs) a soft start
is initiated with the short circuit still present. As the GATE
slowly turns on the current ramps up and exceeds the Over-
Current threshold (50mV) enabling the timer and current
limiting (2.5A). The fault remains for the duration of the time-
out period and the GATE pin is quickly pulled low and
latched off.
With the three resistors, the UV equation is based on the
simple resistor divider:
1.255 = V
[(R5 + R6)/(R4 + R5 + R6)] or
= 1.255 [(R4 + R5 + R6)/(R5 + R6)]
UV
V
UV
Similarly, for OV:
1.255 = V [(R6)/(R4 + R5 + R6)] or
OV
V
= 1.255 [(R4 + R5 + R6)/(R6)]
OV
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 /
500kΩ draws 100µA), and then the other two will be in the
10kΩ 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.
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 V
(gnd) and -V is
DD
IN
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 threshold, the supply is
The three resistor divider (R4, R5, R6) is the recommended
approach for most applications, but if acceptable values can’t
18
ISL6142, ISL6152
be found, then consider 2 separate resistor dividers (one for
each pin, both from V to -V ). This also allows the user to
signal it is driving. An external clamp may be used to limit the
voltage range.
DD
IN
adjust or trim either trip point independently. Some
VDD
VIN+
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).
VOUT+
∆ V
(SECTION OF) ISL6142
(L VERSION)
-
GATE
V
PWRGD
GH
ON/OFF
GATE
+
V
PG
+
ACTIVE LOW
ENABLE
+
CL
+
-
-
LATCH
LOGIC
Q2
MODULE
V
EE
Applications: PWRGD/PWRGD
V
EE
V
DH
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.
+
-
VIN- VOUT-
+
-
V
EE
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.
For both versions at initial start-up, when the DRAIN to V
EE
voltage differential is less than 1.3V and the GATE voltage is
within 2.5V (V ) of its normal operating voltage (13.6V),
GH
V
DD
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
(SECTION OF) ISL6142
(L VERSION)
PWRGD
R13
PWRGD
LOGIC
Q2
OPTO
LATCH
exceeds V by more than 8V. The latch is reset by any of
EE
COMPARATORS
the signals that shut off the GATE (Over-Voltage, Under-
Voltage; 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.
V
EE
DRAIN
FIGURE 35. ACTIVE LOW ENABLE OPTO-ISOLATOR
V
DD
ISL6142 (L version; Figure 34): Under normal conditions
(DRAIN voltage - V < V , and ∆V
the Q2 DMOS will turn on, pulling PWRGD low, enabling the
module.
- V
< V )
EE PG GATE
GATE
GH
(SECTION OF) ISL6142
(L VERSION)
PWRGD
R14
LOGIC
Q2
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
LED (GREEN)
LATCH
COMPARATORS
V
EE
DRAIN
FIGURE 36. ACTIVE LOW ENABLE LED
ISL6152 (H version; Figure 37): Under normal conditions
(DRAIN voltage - V < V , and ∆V
- V
< V ),
EE PG GATE
GATE
GH
the Q3 DMOS will be on, shorting the bottom of the internal
resistor to V , turning Q2 off. If the pull-up current from the
EE
external module is high enough, the voltage drop across the
6.2kΩ resistor will look like a logic high (relative to DRAIN).
Note that the module is only referenced to DRAIN, not V
EE
19
ISL6142, ISL6152
(but under normal conditions, the FET is on, and the DRAIN
and V are almost the same voltage).
EE
a high enough input voltage (remember that current through
the RPG 6.2kΩ resistor generates the high voltage level; see
Figure 34).
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
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.
current, and disable the module.
VDD
VIN+
VOUT+
∆ V
GATE
PWRGD
(SECTION OF) ISL6152
(H VERSION)
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.
V
GH
ON/OFF
-
6.2K
GATE
+
V
PG
+
ACTIVE HIGH
ENABLE
+
Q2
CL
+
-
-
LATCH
LOGIC
Q3
MODULE
V
EE
V
EE
V
DH
+
-
VIN- VOUT-
+
-
V
EE
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
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.
nominal 13.6V above V
.
EE
Applications: Optional Components
Applications: “Brick” Regulators
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.
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).
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 V
voltage.
to -V on the board, it will clamp the
IN
DD
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.
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 V
pin, through isolation resistor
DD
R11. A large value of R11 is better for the filtering, but be
aware of the voltage drop across it. For example, a 1kΩ
Many bricks have both logic polarities available (Enable high
or low input); select the ISL6142 (L-version) or ISL6152 (H-
version) to match. There is little difference between them,
although the L-version output is usually simpler to interface.
resistor, with 2.4mA of I
would have 2.4V across it and
DD
dissipate 2.4mW. Since the UV and OV comparators are
referenced with respect to V they should not be affected,
EE,
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
but the GATE clamp voltage could be offset by the voltage
across the extra resistor.
20
ISL6142, ISL6152
The switch SW1 is shown as a simple push button. It can be
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
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
pulled low (also affected by the V
voltage); and it should
DD
example, the DRAIN goes to UV; the source to -V , and the
GATE is the input; if it goes high (relative to -V ), it turns the
IN
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.
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.
IN
GND
(SHORT PIN)
GND
GND
Logic
R11*
Supply
(V +5V)
EE
R10
R12*
V
FAULT
DIS
DD
PWRGD
IS
OUT
R4
ISL6142
UV
R5
R6
OV
CT
TO
SW1*
V
IS-
R7
IS+ SENSE GATE
DRAIN
C2
EE
ADC
D1*
Logic
Input
R3
C1
R2
Q2
C3
CL
R9
R8
C4*
RL
-48V IN
R1
Q1
-48V OUT
FIGURE 38. ISL6142/52 OPTIONAL COMPONENTS (SHOWN WITH *)
desired, consider the isolation resistor R10, as shown in
figure 38.
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).
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.
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.
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 V
to GND on the bottom
DD
Note that with the placement shown, most of the signal lines
are short, and there should be minimal interaction between
them.
of the board, and R8 to pin 9; all other routing can be on the top
level.
6. PWRGD signal is not used here.
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
ISL6142, ISL6152
R9 = 4.99KΩ (1%)
BOM (Bill Of Materials)
R1 = 0.02Ω (5%)
R10 = 5.10KΩ (10%)
C1 = 150nF (25V)
R2 =10.0Ω (5%)
R3 = 18.0KΩ (10%)
R4 = 549KΩ (1%)
R5 = 6.49KΩ (1%)
R6 = 10.0KΩ (1%)
R7 = R8 = 400Ω (1%)
C2 = 3.3nF (100V)
C3 = 1500pF (25V)
Q1 = IRF530 (100V, 17A, 0.11)
Q2 = N-channel Logic FEFT
GND
GND
TO
V
DD
R9
C3
-48V
IN
+5V
R10
1 PG
2 FLT
3 DIS
VDD 14
CT 13
C2
R3
LOGIC IN
G
S
D
-48V
IN
GATE
NFET
IS
O 12
R6
-48V
IN
ISL6142
4 OV
5 UV
D 11
DRAIN
G 10
IS+ 9
R5
R4
R2
6 IS-
GND
SOURCE
7 VEE
S 8
C1
-48V OUT
TO
PIN 9
R7
R8
-48V IN
R1
FIGURE 39. ISL6142 SAMPLE LAYOUT (NOT TO SCALE)
22
ISL6142, ISL6152
Small Outline Plastic Packages (SOIC)
N
M14.15 (JEDEC MS-012-AB ISSUE C)
14 LEAD NARROW BODY SMALL OUTLINE PLASTIC
PACKAGE
INDEX
AREA
0.25(0.010)
M
B M
H
E
INCHES
MILLIMETERS
-B-
SYMBOL
MIN
MAX
MIN
1.35
0.10
0.33
0.19
4.80
3.80
MAX
1.75
0.25
0.51
0.25
5.00
4.00
NOTES
A
A1
B
C
D
E
e
0.0532
0.0040
0.013
0.0688
0.0098
0.020
-
1
2
3
L
-
SEATING PLANE
A
9
-A-
o
0.0075
0.1890
0.1497
0.0098
0.1968
0.1574
-
h x 45
D
3
-C-
4
α
µ
0.050 BSC
1.27 BSC
-
e
A1
C
H
h
0.2284
0.0099
0.016
0.2440
0.0196
0.050
5.80
0.25
0.40
6.20
0.50
1.27
-
B
0.10(0.004)
5
0.25(0.010) M
C
A M B S
L
6
NOTES:
N
α
8
8
7
1. Symbols are defined in the “MO Series Symbol List” in Section
2.2 of Publication Number 95.
o
o
o
o
0
8
0
8
-
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 great-
er above the seating plane, shall not exceed a maximum value
of 0.61mm (0.024 inch).
10. Controlling dimension: MILLIMETER. Converted inch dimen-
sions are not necessarily exact.
All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 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
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