ISL6123, ISL6124
TM
ADVANCE INF ORMATION
Data Sheet
February 2001
File Number
9005
USB Port Power Supply Controllers
The ISL6123 and ISL6124 are USB port power controllers.
The ISL6123 is a triple port controller, whereas the
ISL6124 is a quad port controller. Both of these products
have fully independent channels offering overcurrent (OC)
fault protection. Operational over the +2.5V to +5V range,
these devices feature internal current monitoring, accurate
current limiting, integrated power switches and current
limited delay to latch-off for system protection.
The ISL6123/24 current sense and limiting circuitry sets
the current limit to a nominal 1A, making this device well
suited for t USB port power management. The ISL6123/24
provide OC fault notification, accurate current limiting and a
consistent timed latch-off, thus isolating and protecting the
voltage bus in the presence of an OC event or short circuit.
The 12ms time to latch-off is independent of the adjoining
switches electrical or thermal condition and the OC
response time is inversely related to the OC magnitude.
Each ISL6123/24 incorporates in a 16 lead SOIC package
80mΩ N-channel MOSFET power switches for power
control. Each switch is driven by a constant current source
giving a controlled ramp up of the output voltage. This
provides a soft start turn-on eliminating bus voltage
drooping caused by inrush current while charging heavy
load capacitances. Independent enabling inputs and fault
reporting outputs for each channel are compatible with 3V
and 5V logic to allow external control and monitoring.
The ISL6123/24 undervoltage lockout feature prevents
turn-on of the outputs unless the correct ENABLE state and
VIN > 2.5V are present. During initial turn-on the
ISL6123/24 prevents fault reporting by blanking the fault
signal. Rising and falling outputs are current limited voltage
ramps so that both the inrush current and voltage slew rate
are limited, independent of load. This reduces supply droop
due to surge and eliminates the need for external EMI
filters. During operation, once an OC condition is detected
the appropriate output is current limited for 12ms to allow
transient conditions to pass. If still in current limit after the
current limit period has elapsed, the output is then latched
off and the fault is reported by pulling the corresponding
FAULT low. The FAULT signal is latched low until reset by
the ENABLE signal being de-asserted at which time the
FAULT signal will clear.
Features
• 80m
Ω
Integrated Power N-channel MOSFET Switches
• Accurate Current Sensing and 1A Current Limiting
• 12ms Fault Delay to Latch-Off, No Thermal Dependency
• Operating Range 2.5V to 5.5V
• Disabled Output Internally Pulled Low
• Undervoltage Lockout
• Controlled Turn-on Ramp Time
• Channel Independent Fault Output Signals
• Compatible with 3.3V and 5V Logic Families
• Channel Independent Logic Level Enable High Inputs
(ISL6123H, ISL6124H) or Enable Low Inputs (ISL6123L,
ISL6124L)
Applications
• USB Port Power Management
• Electronic Circuit Limiting and Breaker
Ordering Information
PART NUMBER
ISL6123LIB
ISL6123LIB-T
ISL6123HIB
ISL6123HIB-T
ISL6124LIB
ISL6124LIB-T
ISL6124HIB
ISL6124HIB-T
TEMP. RANGE
(
o
C)
-40 to 85
-40 to 85
-40 to 85
-40 to 85
-40 to 85
-40 to 85
-40 to 85
-40 to 85
PACKAGE
16 Ld SOIC
PKG. NO.
M16.15
16 Ld SOIC Tape and Reel
16 Ld SOIC
M16.15
16 Ld SOIC Tape and Reel
16 Ld SOIC
M16.15
16 Ld SOIC Tape and Reel
16 Ld SOIC
M16.15
16 Ld SOIC Tape and Reel
1
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 Inc.
|
Copyright © Intersil Americas Inc. 2001
ISL6123, ISL6124
Pinout
ISL6123
TOP VIEW
GND 1
VIN 2
EN1 3
EN2 4
GND 5
VIN 6
EN3 7
NC 8
16 FLT1
15 OUT1
14 OUT2
13 FLT2
12 FLT3
11 OUT3
10 NC
9 NC
GND 1
VIN 2
EN1 3
EN2 4
GND 5
VIN 6
EN3 7
EN4 8
ISL6124
TOP VIEW
16 FLT1
15 OUT1
14 OUT2
13 FLT2
12 FLT3
11 OUT3
10 OUT4
9 FLT4
Typical Application
OUT_1
ENABLE_1
FAULT_1
V+
USB
PORT_1
ENABLE_2
USB
FAULT_2
OUT_2
V+
USB
PORT_2
+5V
CONTROLLER
VIN
ISL6123
ISL6124
OUT_3
V+
USB
PORT_3
ENABLE_3
FAULT_3
OUT_4
ENABLE_4
FAULT_4
GND
V+
USB
PORT_4
ISL6124 ONLY
2
ISL6123, ISL6124
Simplified Block Diagram Each Channel
VIN
Q-PUMP
POR
CURRENT AND TEMP.
MONITORING, GATE AND
OUTPUT CONTROL
LOGIC
OUT
EN
FAULT
GND
Pin Descriptions
PIN NO.
1, 5
2, 6
DESIGNATOR
GND
VIN
FUNCTION
IC Reference
Chip Bias, Controlled
VIN provides chip bias voltage. At VIN < 2.5V chip functionality is disabled,
Supply Input,
FAULT_X latch is cleared and floating and VOUT_X is held low.
Undervoltage Lock-Out
Channel Enable Inputs Enables / Disables Switch.
Channel 2, 1 Over
Current Fault Indicator
Channel overcurrent fault indicator. FAULT floats and is disabled until VIN >2.5V.
This output is pulled low after the OC time-out period has expired and stays latched
until ENABLE is deasserted.
Channel voltage output, connect to load to protect. Upon an OC condition I
OUT
is
current limited to 1A. Current limit response time is within 200µS. This output will
remain in current limit for a nominal 12ms before being latched off.
DESCRIPTION
3, 4, 7, 8
16, 13, 12, 9
ENABLE 1, 2, 3,4
FAULT _1, 2, 3, 4
15, 14, 11, 10
VOUT1, 2, 3, 4
Channel 2, 1
Controlled Supply
Output
3
ISL6123, ISL6124
Absolute Maximum Ratings
Supply Voltage (VIN to GND). . . . . . . . . . . . . . . . . . . . . . . . . . . 6.0V
EN, FAULT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6V
OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GND-0.3V to VIN + 0.3V
Output Current . . . . . . . . . . . . . . . . . . . . . . .Short Circuit Protected
ESD Rating
Human Body Model (Per MIL-STD-883 Method 3015.7) . . . . 3KV
Thermal Information
Thermal Resistance (Typical, Note 1)
θ
JA
(
o
C/W)
16 Lead SOIC Package . . . . . . . . . . . . . . . . . . . . . .
70
Maximum Junction Temperature . . . . . . . . . . . . . . . . . . . . . . .150
o
C
Maximum Storage Temperature Range . . . . . . . . . . -65
o
C to 150
o
C
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . .300
o
C
Operating Conditions
Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . -40
o
C to 85
o
C
Supply Voltage Range (Typical) . . . . . . . . . . . . . . . . . . 2.7V to 5.5V
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.
NOTE:
1.
θ
JA
is measured with the component mounted on a high effective thermal conductivity test board in free air. See Tech Brief TB379 for details.
Electrical Specifications
PARAMETER
POWER SWITCH
ISL6123, ISL6124 On Resistance
Supply Voltages = 5V, T
A
= T
J
= -40 to 85
o
C, Unless Otherwise Specified
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
r
DS(ON)_27
VIN = 2.7V, IOUT = 0.7A, T
A
= T
J
= 25
o
C
T
A
= T
J
= 85
o
C
-
-
-
-
-
-
-
-
-
-
90
115
80
115
80
115
300
10
10
4
105
130
100
130
95
130
450
-
-
-
mΩ
mΩ
mΩ
mΩ
mΩ
mΩ
mV
V/ms
V/ms
V/µs
ISL6123, ISL6124 On Resistance
r
DS(ON)_33
VIN = 3.3V, IOUT = 0.7A, T
A
= T
J
= 25
o
C
T
A
= T
J
= 85
o
C
ISL6123, ISL6124 On Resistance
r
DS(ON)_50
VIN = 5V, IOUT = 0.7A, T
A
= T
J
= 25
o
C
T
A
= T
J
= 85
o
C
Disabled Output Voltage
VOUT Rising Rate
Slow VOUT Turn-off Rate
Fast VOUT Turn-off Rate
CURRENT CONTROL
Current Limit, VIN = 3.3V - 5V
OC Regulation Settling Time
Severe OC Regulation Settling Time
Over Current Latch-off Time
I/O PARAMETERS
Fault Output Voltage
ENABLE High Threshold
ENABLE Low Threshold
ENABLE Input Current
BIAS PARAMETERS
Enabled VIN Current
Disabled VIN Current
Undervoltage Lockout Threshold
UV Hysteresis
Over Temperature Disable
V
OUT_DIS
t_vout_rt
t_svout_offt
t_fvout_offt
VIN = 5V, Switch Disabled, 50µA Load
R
L
= 10Ω, C
L
= 0.1µF, 10% - 90%
R
L
= 10Ω, C
L
= 0.1µF, 90% - 10%
R
L
= 1Ω, C
L
= 0.1µF, 90%-10%
Ilim
tsett
Ilim
tsett
Ilim_sev
t
OC_loff
VOUT = 0.8V
R
L
= 5Ω, C
L
= 0.1µF to Within 10% of CR
R
L
< 1Ω, C
L
= 0.1µF to Within 10% of CR
ISL6123, ISL6124X, T
J
= 25
o
C
0.75
-
-
-
1
2
100
10
1.25
-
-
-
A
ms
µs
ms
Vfault_hi
Ven_vih
Ven_vil
Ien_i
Fault IOUT = 10mA
VIN = 5.5V
VIN = 2.7V
ENABLE = 0V to 5V, VIN = 5V, T
J
>25
o
C
-
2.0
-
-0.5
-
-
-
-
0.4
-
0.6
0.5
V
V
V
µA
I
VDD
I
VDD
V
UVLO
UV
HYS
Temp_dis
Switches Closed, OUTPUT = OPEN, T
J
>0
o
C
Switches Open, OUTPUT = OPEN
VIN Rising, Switch Enabled
-
-
1.7
50
-
120
-
2.25
100
150
200
5
2.5
-
-
µA
µA
V
mV
o
C
4
ISL6123, ISL6124
Introduction
The ISL6123 and ISL6124 are fully independent triple and
quad channel overcurrent (OC) fault protection ICs respectively
for the +2.5V to +5V environment. Each ISL6123/24
incorporates in a 16 lead SOIC package, 80mΩ N-channel
MOSFET power switches for power control. See Figure 1 for
switch resistance performance curves. Independent enabling
inputs and fault reporting outputs compatible with 3V and 5V
logic allows for external control and monitoring. This device
features internal current monitoring, accurate current limiting,
integrated power switches and current limited timed delay to
latch-off for system protection. See Figure 7 for operational
waveforms.
Latch-Off Time Delay
The primary function of any OC protection device is to
quickly isolate the voltage bus from a faulty load. Many other
IC products sense the IC thermal condition (the monitored
IC junction temperature depends on a number of factors the
most important of which are power dissipation of the faulted
and adjacent switches and package temp) to isolate a faulty
load. The ISL6123/24 uses an internal 12ms timer that starts
upon OC detection. Once an OC condition is detected the
appropriate output is current limited for 12ms to allow
transient conditions to pass before latch-off. The time to
latch-off is independent of device thermal or adjacent switch
condition. See Figure 16 for waveforms illustrating
independent latch-off.
If, after the ISL6123/24 has latched off, and the fault has
asserted and, the enable is not deasserted but the OC
condition still exists, the ISL6123/24 unlike other IC devices
does not send to the controller a continuous string of fault
pulses. The ISL6123/24’s single fault signal is sent at the
time of latch-off unlike other devices, see Figure 10.
Key Feature Description and Operation
UV Lockout
The ISL6123/24 undervoltage lockout feature prevents
functionality of the device unless the correct ENABLE state
and VIN > 2.5V are present.
Soft Start
A constant 500nA current source ramps up the switch’s gate
causing a voltage follower effect on the output voltage. This
provides a soft start turn-on eliminating bus voltage drooping
caused by in-rush current charging heavy load capacitances.
Rising and falling outputs are current limited voltage ramps
so that both the inrush current and voltage slew rate are
limited, independent of load. This reduces supply droop due
to surge and also eliminates the need for EMI filters
necessary on other IC products. See Figure 2 for turn on
waveforms.
Slow and Fast Shutdown
The ISL6123/24 has two shutdown modes. When disabled
with a load current less than the Current Regulation (CR)
level the ISL6123/24 shuts down in a controlled manner
using a 500nA constant current source controlled ramp.
When latched off due to CR and the timer has expired the
ISL6123/24 quickly pulls down the output thereby quickly
removing the faulted load from the voltage bus. See Figures
8 and 9 for waveforms of each mode.
Temperature Shutdown
Although the ISL6123/24 has a thermal shutdown feature,
because of the 12ms timed shutdown this will only be
invoked in extremely high ambient temperatures.
Fault Blanking On Start-up
During initial turn-on the ISL6123/24 prevent nuisance faults
being reported to the system controller by blanking the fault
signal for 12ms. This blanking eliminates the need for
external RC filters necessary for other vendor products that
assert a fault signal upon initial turn-on into a temporary high
current condition. See Figures 10 through 12 for waveform
examples.
Active Output Pulldown
Another unique ISL6123/24 feature is the active pull down
on the outputs to 300mV above GND when the device is
disabled. Competitors’ parts’ switch leakage causes the
output voltage to drift up to VIN voltage even when the part
is supposed to be disabled.
Current Regulation
The ISL6123/24 have integrated current sensing on the
power MOSFET that allows for rapid control of OC events.
Once an OC is detected the ISL6123/24 goes into its
Current Regulation (CR) control mode. The ISL6123/24 CR
level is set to a nominal 1A for each channel. This current
regulation is
±25%
over the full operating temperature and
voltage bias range. See Figures 3 and 4 for illustrative
curves.
The speed of this control is inversely related to the
magnitude of the OC fault. Thus a hard over current is more
quickly controlled than a marginal OC condition. See Figure
5 for waveforms illustrating this and Figure 6 for an
accompanying graph.
Instantaneous Protection Compared to PPTC
Devices
The ISL6123/24 provide a more consistent level of protection
versus the PPTC alternative. PPTC, or poly fuses which are
thermal sensing devices, increasing in resistance as their
internal temperature increases to a level where current flow
is slowly restricted. See Figure 13 for a comparison of the
ISL6123/24 voltage loss (efficiency) to a PPTC device. The
ISL6123 and ISL6124 with their independent of temperature
12ms time to latch off is contrasted to a suitably sized PPTC
device for time to shutdown in an OC condition for both in
Figures 14 and 15.
5
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