INTERSIL ISL8723IRZ

ISL8723, ISL8724
®
Data Sheet
December 21, 2006
FN6413.0
Power Sequencing Controllers
Features
The Intersil ISL8723 and ISL8724 are 4 channel sequencers
controlling the on and off sequence of voltages with under
voltage supply fault protection and a “sequence completed”
signal (RESET#). For larger systems, more than 4 voltages
can be sequenced by a simple connection of multiple IC's.
These sequencers use an integrated charge pump to drive 4
external low-cost N-channel MOSFET switch gates above
the IC bias voltage by 5.3V. These IC's can be biased from
and control any supply from 2.5V to 5V and additionally
monitor any voltage above 0.7V. Individual product
descriptions are below.
• Enables arbitrary turn-on and turn-off sequencing of up to
four power supplies (0.7V to 5V)
The four channel ISL8723 (ENABLE input), ISL8724
(ENABLE# input) offer the designer 4 voltage control when it
is required that all four rails are in minimal compliance prior
to turn on and that compliance must be maintained during
operation. The ISL8723 has a low power standby mode
when it is disabled suitable for battery powered applications.
• 30µA Sleep State (ISL8723)
External resistors provide flexible voltage threshold
programming of monitored voltages. Delay and sequencing
timing are programmable by external capacitors for both
ramp up and ramp down.
TEMP.
RANGE
PART
(°C)
MARKING
• Active high (ISL8723) or low (ISL8724) ENABLE# input
• Pb-free plus anneal available (RoHS compliant) QFN
Package
Applications
• Graphics cards
• FPGA/ASIC/microprocessor/PowerPC supply sequencing
• Network Routers
Pinout
PACKAGE
PKG.
DWG. #
ISL8723, ISL8724
(24 LD QFN)
TOP VIEW
1
UVLO_A
NC
23
22
21
20
19
1
18 DLY_OFF_A
GATE_A
2
17 UVLO_C
DLY_OFF_C
3
16 DLY_ON_C
4mmx4mm
4
15 DLY_ON_D
GATE_B
5
14 UVLO_D
GATE_C
6
13 DLY_OFF_B
7
8
9
10
11
12
UVLO_B
DLY_OFF_D
NC
NOTE: Intersil Pb-free plus anneal products employ special Pb-free
material sets; molding compounds/die attach materials and 100% matte
tin plate termination finish, which are RoHS compliant and 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-020.
24
ENABLE/
ENABLE#
GND
Evaluation Platform
DLY_ON_A
-40 to +85 24 Ld 4x4 QFN L24.4x4
(Pb-free)
L24.4x4
Tape & Reel
SYSRST#
-40 to +85 24 Ld 4x4 QFN L24.4x4
(Pb-free)
L24.4x4
NC
ISL8723EVAL1
• Under voltage lockout for each monitored supply voltage
VDD
ISL8723IRZ-T (Note) 8723IRZ
ISL8724IRZ-T (Note) 8724IRZ
• Glitch immunity
DLY_ON_B
8724IRZ
• Multiple sequencers can be easily daisy-chained to
sequence an infinite number of independent voltages
RESET#
8723IRZ
• Adjustable voltage slew rate for each rail
GATE_D
ISL8723IRZ (Note)
ISL8724IRZ (Note)
• Supplies VDD +5.3V of charge pumped gate drive
• Telecommunications Systems
Ordering Information
PART NUMBER
• Operates from 2.5V to 5V supply voltage
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2006. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
ISL8723, ISL8724
AIN
AOUT
BIN
BOUT
CIN
COUT
DIN
VDD
ENABLE
AIN
BIN
CIN
DLY_OFF_D
DLY_OFF_C
DLY_ON_C
DLY_ON_B
DLY_OFF_A
DLY_ON_A
DLY_OFF_B
RESET#
DLY_ON_D
UVLO_A
UVLO_B
UVLO_C
UVLO_D
SYSRST#
GROUND
DIN
GATE A
GATE B
GATE C
GATE D
DOUT
FIGURE 1. TYPICAL ISL8723 APPLICATION USAGE
Pin Descriptions
PIN
#
PIN NAME
23
VDD
Chip Bias
Bias IC from nominal 2.5V to 5V
10
GND
Bias Return
IC ground
1
ENABLE/
ENABLE#
Input to start on/off
sequencing.
Input to initiate the start of the programmed sequencing of supplies on or off. Enable functionality is
disabled for 10ms after UVLO is satisfied. ISL8723 has ENABLE. ISL8724 has ENABLE#.
24
RESET#
RESET# Output
RESET# provides a high signal ~160ms after all GATEs are fully enhanced. This delay is for stabilization
of output voltages. RESET# will assert low upon any UVLO not being satisfied or ENABLE/ENABLE#
being deasserted. The RESET# output is an open drain N-channel FET and is guaranteed to be in the
correct state for VDD down to 1V and is filtered to ignore fast transients on VDD and UVLO_X.
20
UVLO_A
12
UVLO_B
Under Voltage Lock
Out/Monitoring
Input
These inputs provide for a programmable UV lockout referenced to an internal 0.631V reference and
are filtered to ignore short (<7µs) transients below programmed UVLO level.
17
UVLO_C
14
UVLO_D
21
DLY_ON_A
8
DLY_ON_B
Gate On Delay
Timer Output
Allows for programming the delay and sequence for VOUT turn-on using a capacitor to ground. Each
cap is charged with 1µA, 10ms after turn-on initiated by ENABLE/ENABLE# with an internal current
source providing delayed enhancement of the associated FETs GATE to turn-on.
16
DLY_ON_C
15
DLY_ON_D
18
13
DLY_OFF_A Gate Off Delay
Timer Output
DLY_OFF_B
Allows for programming the delay and sequence for VOUT turn-off through ENABLE/ENABLE# via a
capacitor to ground. Each cap is charged with a 1µA internal current source to an internal reference
voltage causing the corresponding gate to be pulled down thus turning-off the FET.
3
DLY_OFF_C
4
DLY_OFF_D
2
GATE_A
5
GATE_B
6
GATE_C
7
GATE_D
FUNCTION
FET Gate Drive
Output
2
DESCRIPTION
Drives the external FETs with a 10µA current source to soft start ramp into the load. During sequence
off, 10µA is sunk from this pin to control the FET turn-off. During a turn-off due to a fault, the gate will
sink ~75mA to ensure a rapid turn-off.
FN6413.0
December 21, 2006
ISL8723, ISL8724
Pin Descriptions
PIN
#
PIN NAME
22
SYSRST#
(Continued)
FUNCTION
System Reset I/O
DESCRIPTION
As an input, allows for immediate and unconditional latch-off of all GATE outputs when driven low. This pin
can also be used to initiate the programmed sequence with ‘zero’ wait (no 10ms stabilization delay) from
input signal on this pin being driven high to first GATE.
As an output when there is a UV condition this pin pulls low. If common to other SYSRST# pins in a multiple
IC configuration it will cause immediate and unconditional latch-off of all other GATEs on all other ISL872x
sequencers.
This pin is released to go high once all UVLO and enable conditions are satisfied and is pulled low
concurrent with the last GATE being turned off after EN disabled.
9,11,
19
No Connect
No Connect
3
No Connect
FN6413.0
December 21, 2006
ISL8723, ISL8724
Absolute Maximum Ratings
Thermal Information
VDD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +6.0V
GATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to VDD+6V
UVLO, ENABLE, ENABLE#, SYSRST# . . . . . . -0.3V to VDD +0.3V
RESET#, DLY_ON, DLYOFF . . . . . . . . . . . . . . . -0.3V to VDD +0.3V
Thermal Resistance (Typical, Notes 1, 2)
θJA (°C/W)
θJC (°C/W)
4 x 4 QFN Package . . . . . . . . . . . . . . .
48
9
Maximum Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . +125°C
Maximum Storage Temperature Range . . . . . . . . . .-65°C to +150°C
Operating Conditions
VDD Supply Voltage Range . . . . . . . . . . . . . . . . . . . . +2.5V to +5.0V
Temperature Range (TA) . . . . . . . . . . . . . . . . . . . . . .-40°C to +85°C
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. θJA is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. See
Tech Brief TB379.
2. For θJC, the “case temp” location is the center of the exposed metal pad on the package underside.
3. All voltages are relative to GND, unless otherwise specified.
Electrical Specifications
VDD = 3.3V to +5V, TA = TJ = -40°C to +85°C, Unless Otherwise Specified.
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
619
631
647
mV
UVLO
Undervoltage Lockout Falling Threshold
VUVLOvth
Undervoltage Lockout Falling Threshold
VUVLOvth
604
631
656
mV
Undervoltage Lockout Hysteresis
VUVLOhys
-
9
-
mV
Undervoltage Lockout Threshold Range
RUVLOvth
Max VUVLOvth- Min VUVLOvth
-
6
18
mV
Undervoltage Lockout Delay
TUVLOdel
ENABLE satisfied
-
10
-
ms
VDD, UVLO, ENABLE glitch filter
-
7
-
μs
0.9
1
1.115
μA
-
0.01
0.05
μA
1.21
1.273
1.32
V
-
1.28
1.35
V
-
0.5 VDD
-
V
Transient Filter Duration
tFIL
TA = TJ = +25°C
DELAY ON/OFF
Delay Charging Current
DLY_ichg
Delay Charging Current Range
DLY_ichg_r
Delay Threshold Voltage
VDLY = 0V
DLY_ichg(max) - DLY_ichg(min)
DLY_Vth
ENABLE/ENABLE#, RESET# AND SYSRST# I/O
ENABLE Threshold
VENh
ENABLE# Threshold
VENh
Measured at VDD = 5V
ENABLE/ENABLE# Hysteresis
VENh -VENl
Measured at VDD = 5V
-
0.1
0.2
V
ENABLE/ENABLE# Lockout Delay
TdelEN_LO
UVLO satisfied, EN to DLY_ON
-
10
-
ms
ENABLE/ENABLE# Input Capacitance
Cin_en
-
5
-
pF
RESET# Pull-up Voltage
Vpu_rst
-
VDD
-
V
RESET# Pull-Down Current
IRSTpd5
VDD = 5V, RST = 0.1V
-
13
-
mA
RESET# Delay after GATE High
TRSTdel
GATE = VDD+5V
-
160
-
ms
Measured at VDD = 5V, 1mA
sourcing current
-
-
0.1
V
RESET# Output Low
VRSTl
RESET Output Capacitance
Cout_rst
-
10
-
pF
SYSRST# Pull-up Voltage
Vpu_srst
-
VDD-0.5V
-
V
SYSRST# Pull-up Current
Ipu_srst
VDD = 3.3V, SYSRST# = 0.5V
-
12
-
μA
VDD = 5V
-
2.7
-
μA
VDD = 5V, IOUT = 100μA
-
0.1
V
SYSRST# Pull Down Current
Ipu_5
SYSRST# Low Output Voltage
Vol_srst
4
FN6413.0
December 21, 2006
ISL8723, ISL8724
Electrical Specifications
VDD = 3.3V to +5V, TA = TJ = -40°C to +85°C, Unless Otherwise Specified. (Continued)
PARAMETER
SYMBOL
SYSRST# Output Capacitance
TEST CONDITIONS
Cout_srst
MIN
TYP
MAX
UNIT
-
10
-
pF
SYSRST# Low to GATE Turn-off
TdelSYS_G_1
GATE = 80% of VDD+5V
-
40
-
ns
SYSRST# High to GATE Turn-on
TdelSYS_G_2
GATE = 50% of VDD+5V
-
0.4
-
ms
8.3
10.2
12.5
μA
-12.5
-10.2
-8.3
μA
GATE
GATE Turn-On Current
IGATEon
GATE Turn-Off Current
IGATEoff_l
GATE = 0V
GATE = VDD, Disabled
IGATE_range
Within IC IGATE max-min
-
0.6
3
μA
GATE Pull-Down High Current
IGATEoff_h
GATE = VDD, UVLO = 0V
-
75
-
mA
GATE High Voltage
VGATEh5
VDD = 5V
VDD+5.3V
VDD+5.6V
-
V
GATE Low Voltage
VGATEl
Gate Low Voltage, VDD = 1V
-
0.01
0.1
V
IC Supply Current
IVDD_5V
VDD = 5V, Enabled and static
-
0.27
0.31
mA
ISL8723 Stand By IC Supply Current
IVDD_sb
VDD = 5V, ENABLE = 0V
-
30
40
μA
VDD rising
-
2.2
2.41
V
GATE Current Range
BIAS
VDD Power On Reset
VDD_POR
ISL8723, ISL8724 Descriptions and
Operation
The ISL8723 and ISL8724 sequencers are quad voltage
sequencing controllers designed for use in multiple-voltage
systems requiring power sequencing of various supply
voltages. Individual voltage rails are gated on and off by
external N-Channel MOSFETs, the gates of which are
driven by an internal charge pump to ~VDD +5.6V (VQP) in
a user programmed sequence.
With the ISL8723 the ENABLE must be asserted high and
all four voltages to be sequenced must be above their
respective user programmed Under Voltage Lock Out
(UVLO) levels before programmed output turn on
sequencing can begin. Sequencing and delay
determination is accomplished by the choice of external
cap values on the DLY_ON and DLY_OFF pins. The
SYSRST# goes high once all 4 UVLO inputs and ENABLE
are satisfied. Once all 4 UVLO inputs and ENABLE are
satisfied for 10ms, the four DLY_ON caps are
simultaneously charged with 1μA current sources to the
DLY_Vth level of 1.28V. As each DLY_ON pin reaches the
DLY_Vth level its associated GATE will then turn-on with a
10μA source current to the VQP voltage of VDD+5.6V.
Thus all four GATEs will sequentially turn on. Once at
DLY_Vth the DLY_ON pins will discharge to be ready when
next needed. After the entire turn on sequence has been
completed and all GATEs have reached the charge
pumped voltage (VQP), a 160ms delay is started to ensure
stability after which the RESET# output will be released to
go high. Subsequent to turn-on, if any input falls below its
UVLO point for longer than the glitch filter period, TFIL
(~7μs) this is considered a fault. RESET#, SYSRST# and
all GATEs are simultaneously pulled low. In this mode the
5
GATEs are pulled low with ~75mA. Normal shutdown mode
is entered when no UVLO is violated and the ENABLE is
deasserted. When ENABLE is deasserted, RESET# is
asserted and pulled low. Next, all four shutdown ramp caps
on the DLY_OFF pins are charged with a 1μA source and
when any ramp-cap reaches DLY_Vth, a latch is set and a
10μA current is sunk on the respective GATE pin to turn off
its external MOSFET. When the falling GATE voltage is
approximately 1.5V, the GATE is pulled down the rest of the
way at a higher current level to ensure a hard turn-off. Each
individual external FET is thus turned off removing the
voltages from the load in the programmed sequence. The
SYSRST# will pull low concurrent with the last GATE being
pulled low.
The ISL8723 and ISL8724 have the same functionality
except for the complimentary ENABLE active polarity with
the ISL8724 having an ENABLE# input. Additionally the
ISL8723 also has a low power sleep state when disabled.
Upon bias the SYSRST# and RESET# pins are held low
before bias voltage = 1V.
The SYSRST# has both an input and output function. As an
output the SYSRST# pin is useful when implementing
multiple sequencers in a design needing simultaneous
shutdown as with a kill switch across all sequencers. Once
any UVLO is unsatisfied for longer than TFIL the related
SYSRST# will pull low and pull all other SYSRST# pins low
that are on a common connection thus unconditionally
shutting down all outputs across multiple sequencers. As
an input, if it is pulled low all GATEs will be unconditionally
shut off and RESET# pulled low, see Figure 17. This pin
can also be used as a ‘no wait’ enabling input, if all inputs
(ENABLE and UVLO) are satisfied it does not wait through
FN6413.0
December 21, 2006
ISL8723, ISL8724
the ~10ms enable delay to initiate DLY_ON cap charging
when released to go high. This feature can be used where
4 voltages can be monitored in addition to a on-off switch
position or, in the case of the ISL8724 a present pin pull
down.
Restart of the turn on sequence is automatic once all
requirements are met. This allows for no interaction
between the sequencer and a controller IC if so desired.
If no capacitors are connected between DLY_ON or
DLY_OFF pins and ground then all such related GATEs
start to turn on immediately after the 10ms (TUVLOdel)
ENABLE stabilization time out has expired and the GATEs
start to immediately turn off when ENABLE is deasserted.
Table 1 illustrates the nominal time delay from the start of
charging to the 1.27V reference for various capacitor
values on the DLY_X pins. This table does not include the
10ms of enable lock out delay during a start up sequence
but represents the time from the end of the enable lock out
delay to the start of GATE transition. There is no enable
lock out delay for a sequence off, so this table illustrates
the delay to GATE transition from a disable signal.
TABLE 1.
NOMINAL DELAY TO SEQUENCING THRESHOLD
DLY PIN CAPACITANCE
TIME (ms)
Open
0.02
100pF
0.135
1000pF
1.35
0.01μF
13.5
0.1μF
135
1μF
1350
NOTE: Nom. TDEL_SEQ = dly_cap (µF) X 1.35MΩ
Figure 2 illustrates the turn-on and Figure 3 the nominal turnoff
timing diagrams of the ISL8723 and ISL8724 product.
Note the delay and flexible sequencing possibilities. Multiple
series, parallel or adjustable capacitors can be used to easily
fine tune timing between that offered by standard value
capacitors.
6
FN6413.0
December 21, 2006
ISL8723, ISL8724
l
VUVLOVth
<tFIL
UVLO_A
VUVLOVth
UVLO_B
VUVLOVth
UVLO_C
VUVLOVth
UVLO_D
ENABLE# (ISL8724)
TUVLOdel
VEN
ENABLE (ISL8723)
DLY_Vth
DLYON_B
DLY_Vth
DLYON_D
DLY_Vth
DLYON_A
DLY_Vth
DLYON_C
VQPUMP
VQPUMP
VQPUMP
GATE_B
VQPUMP
GATE_D
VQPUMP-1V
GATE_C
TRSTdel
GATE_A
RESET#
SYSRST#
FIGURE 2. ISL8723, ISL8724 TURN-ON AND GLITCH RESPONSE TIMING DIAGRAM
UVLO_X>VUVLOVth
ENABLE(ISL8723)
ENABLE# (ISL8724)
VEN
DLY_Vth
DLYOFF_A
DLY_Vth
DLYOFF_B
DLY_Vth
DLYOFF_C
DLY_Vth
DLYOFF_D
GATE_C
GATE_D
GATE_A
GATE_B
RESET#
SYSRST#
FIGURE 3. ISL8723, ISL8724 TURN-OFF TIMING DIAGRAM
7
FN6413.0
December 21, 2006
ISL8723, ISL8724
Typical Performance Curves
650
VDD = 5V
0.25
645
640
0.20
VDD = 3.3V
UVLO (mV)
BIAS CURRENT (mA)
0.30
0.15
0.10
ISL8723 DISABLED
635
630
625
620
0.05
615
0.00
-40
-20
0
25
45
75
85
100
610
-40
125
-20
0
25
TEMPERATURE (°C)
FIGURE 4. BIAS CURRENT
DLY_ON/OFF CURRENT (µA)
DLY_OFF Vth
DLY VTH (V)
1.28
1.27
1.26
DLY_ON Vth
1.25
1.24
-20
0
25
45
75
75
85
100
125
FIGURE 5. UVLO THRESHOLD VOLTAGE
1.29
1.23
-40
45
TEMPERATURE (°C)
85
100
125
1.020
1.000
DLY_ON
0.980
DLY_OFF
0.960
0.940
0.920
-40
-20
0
TEMPERATURE (°C)
25
45
75
85
100
125
100
125
TEMPERATURE (°C)
FIGURE 6. DLY THRESHOLD VOLTAGE
FIGURE 7. DLY CHARGE CURRENT
1.29
6.0
Q-PUMP VOLTAGE (V)
DLY_OFF Vth
DLY VTH (V)
1.28
1.27
1.26
DLY_ON Vth
1.25
1.24
1.23
-40
5.8
VDD = 5V
5.6
5.4
5.2
VDD = 2.5V
5.0
4.8
-20
0
25
45
75
85
TEMPERATURE (°C)
FIGURE 8. BIAS POWER ON RESET
8
100
125
-40
-20
0
25
45
75
85
TEMPERATURE (°C)
FIGURE 9. CHARGE PUMP VOLTAGE
FN6413.0
December 21, 2006
ISL8723, ISL8724
Typical Performance Curves
(Continued)
FAULT GATE CURRENT (mA)
10.3
GATE CURRENT (µA)
10.2
10.1
I_GATE_ON
10.0
9.9
I_GATE_OFF
9.8
9.7
9.6
9.5
9.4
-40
-20
0
25
45
75
85
100
125
TEMPERATURE (°C)
FIGURE 10. GATE TURN-OFF/ON (DIS)CHARGE CURRENT
Using the ISL8723EVAL1 Platform
The ISL8723EVAL1 platform allows evaluation of the
ISL8723, easily providing access to the critical nodes, see
Figure 21 for schematic and Figure 22 for a photograph of
the evaluation platform.
The board has a SMD layout with a ISL8723 illustrating the
possible small implementation size for a typical four rail
sequencing application. There are bias and function labeled
test points to give access to the IC pins for evaluation.
Remember that significant current or capacitive loading of
particular I/O pins will affect functionality and performance.
The default configuration of the ISL8723EVAL1 circuit was
built around the following design assumptions:
1. Using the ISL8723IR
2. The four supplies being sequenced are 5V (IN_A), 3.3V
(IN_B), 2.5V (IN_D) and 1.5V (IN_C), the UVLO levels
are ~80% of nominal voltages. Resistors chosen such
that the total resistance of each divider is ~ 10k using
standard value resistors to approximate 80% of
nominal voltage supply = 0.63V on UVLO input.
100
90
80
70
60
50
40
-40
-20
0
25
45
75
85
100
125
TEMPERATURE (°C)
FIGURE 11. FAULT GATE TURN-OFF SINK CURRENT
VOUT voltage for a single channel being turned on and off
respectively.
RESET# and SYSRST# functionality and relationships are
shown in Figures 16 through 20.
Figure 16 illustrates that with a rising VDD, EN tied to VDD,
and all UVLO configured to be satisfied, both the RESET#
and SYSRST# are held low before VDD = 1V. SYSRST# is
released to go high once the last UVLO is satisfied and
RESET# is released to go high at TRSTdel after the last GATE
is high.
Figure 17 shows GATE and RESET# response to SYSRST#
being pulled low.
Figure 18 shows EN high to SYSRST# delay with all UVLO
inputs satisfied.
Figure 19 shows RESET# and SYSRST# delay to EN pulled
low.
Figure 20 shows ~8µs of glitch filter duration, tFIL during
which the RESET# and SYSRST# do not react.
3. The desired order turn-on sequence is 5V first, then 3.3V
about 12ms later then the 2.5V supply about 19ms later
and lastly the 1.5V supply about 40ms later.
4. The desired turn-off sequence is first the 2.5V, the 3.3V
12ms later, then the 1.5V supply about 36ms later and
lastly the 5V supply about 72ms after that.
5. LED off indicates sequence has completed and RESET
has released and pulled high.
All scope shots are taken from ISL8723EVAL1 board.
Figures 12 and 13 illustrate the desired turn-on and turn-off
sequences respectively. The sequencing order and delay
between voltages sequencing is set by external capacitance
values so other than that illustrated can be accomplished.
Figures 14 and 15 illustrate the timing relationships between
the EN input, RESET#, DLY and GATE outputs and the
9
FN6413.0
December 21, 2006
ISL8723, ISL8724
Typical Performance Waveforms
ENABLE
ENABLE
RESET#
RESET#
SYSRST#
I/O = 5V/DIV
SYSRST#
I/O = 5V/DIV
5VOUT
5VOUT
3.3VOUT
3.3VOUT
2.5VOUT
1.5VOUT
1.5VOUT
2.5VOUT
VOUT = 2V/DIV
40ms/DIV
VOUT = 2V/DIV
20ms/DIV
FIGURE 13. ISL8723 SEQUENCED TURN-OFF
FIGURE 12. ISL8723 SEQUENCED TURN-ON
EN 5V/DIV
EN 5V/DIV
GATE 2V/DIV
TdelENLO
DLY_Vth
DLY_Vth
DLY_ON 0.5V/DIV
DLY_OFF 0.5V/DIV
GATE 2V/DIV
3.3VO 2V/DIV
3.3VO 2V/DIV
4ms/DIV
10ms/DIV
FIGURE 14. ISL8723 3.3V TURN-ON
FIGURE 15. ISL8723 3.3V TURN-OFF
GATE
VDD
SYSRST#
SYSRST#
RESET#
RESET#
FIGURE 16. SYSRST# and RESET# vs VDD (EN = VDD, 4
UVLO > UVLO Vth)
10
FIGURE 17. SYSRST# LOW to GATE and RESET# LOW
FN6413.0
December 21, 2006
ISL8723, ISL8724
Typical Performance Waveforms
(Continued)
SYSRST#
SYSRST#
RESET#
ENABLE
FIGURE 18. 4 UVLOs VALID, ENABLE HIGH to SYSRST HIGH
ENABLE
FIGURE 19. ENABLE LOW to RESET# and SYSRST LOW
UVLO
RESET#
SYSRST#
FIGURE 20. UVLO INVALID to RESET# and SYSRST$# LOW
11
FN6413.0
December 21, 2006
ISL8723, ISL8724
+3.3V
1.5V
+2.5V
+5V
C1
1
EN
23
VDD
DLY_ON_B
ENABLE
DLY_ON_D
R1
7.681K
R4
4.99K
R2
6.98K
R6
8.45K
17
14
20
SYSRST
R5
4.99K
R3
3.01K
UVLO_B
DLY_OFF_C
UVLO_C
DLY_OFF_D
UVLO_D
DLY_OFF_B
UVLO_A
DLY_OFF_A
GATE_A
GATE_B
GATE_D
9,11
19
GATE_C
SYSRST
0.068μF
3
C6
4
13
0.047μF
C8
18
0.01μF
0.022μF
C5
C7
OPEN
C9
2
5 6 FDS6990S
4
5
Q1A
3
7
7 8 FDS6990S
2
6
NC
RESET 24
GND
C3
0.01μF
C4
0.1μF
ISL8723IR
22
C2
OPEN
U1
R11
1.47K
1
15
DLY_ON_C 16
21
DLY_ON_A
12
R12
2.26K
1μF
8
Q1B
1
D1
5 6
4
FDS6990S
Q2A
FDS6990S
3
R9
7 8
2
750
10
Q2B
1
R9
10
R10
10
R13
10
R14
10
FIGURE 21. ISL8723EVAL1 BOARD SCHEMATIC
FIGURE 22. EVAL BOARD PHOTOGRAPH
12
FN6413.0
December 21, 2006
ISL8723, ISL8724
TABLE 2. ISL872XSEQEVAL1 BOARD COMPONENT LISTING
COMPONENT
DESIGNATOR
U1
COMPONENT FUNCTION
COMPONENT DESCRIPTION
ISL8723, 4 Supply Sequencer
Intersil, ISL8723IR 4 Supply Sequencer
Voltage Rail Switches
FDS6990S or equiv, Dual N-Channel MOSFET
R6
5V to UVLO_A Resistor for Divider String
8.45kΩ 1%, 0402
R11
UVLO_A to GND Resistor for Divider String
1.47kΩ 1%, 0402
R1
3.3V to UVLO_B Resistor for Divider String
7.68kΩ 1%, 0402
R12
UVLO_B to GND Resistor for Divider String
2.26kΩ 1%, 0402
R2
2.5V to UVLO_D Resistor for Divider String
6.98kΩ 1%, 0402
R3
UVLO_D to GND Resistor for Divider String
3.01kΩ 1%, 0402
R4
1.5V to UVLO_C Resistor for Divider String
4.99kΩ 1%, 0402
R5
UVLO_D to GND Resistor for Divider String
4.99kΩ 1%, 0402
R9
RESET LED Current Limiting Resistor
750Ω 10%, 0805
C5
5V turn-on Delay Cap. A (~10ms)
DNP, 0402
C9
5V turn-off Delay Cap. A (~140ms)
0.1μF 10%, 6.3V, 0402
C2
3.3V turn-on Delay Cap.B (~13ms)
0.01μF 10%, 6.3V, 0402
C8
3.3V turn-off Delay Cap. B (~13ms)
0.01μF 10%, 6.3V, 0402
C3
2.5V turn-on Delay Cap.D (~25ms)
0.022μF 10%, 6.3V, 0402
C7
2.5V turn-off Delay Cap. D (0ms)
DNP, 0402
C4
1.5V turn-on Delay Cap. C (~100ms)
0.068μF 10%, 6.3V, 0402
C6
1.5V turn-off Delay Cap. C (~60ms)
0.047μF 10%, 6.3V, 0402
C1
Decoupling Capacitor
1μF, 0805
D1
RESET Indicating LED
0805, SMD LEDs Red
R9
5V Load Resistor
10Ω 20%, 3W Carbon
R10
3.3V Load Resistor
10Ω 20%, 3W Carbon
R13
2.5V Load Resistor
10Ω 20%, 3W Carbon
R14
1.5V Load Resistor
10Ω 20%, 3W Carbon
Q1, Q2
Test Points Labeled as to Function
13
FN6413.0
December 21, 2006
ISL8723, ISL8724
Application Implementations
HIGH = POWER GOOD
Multiple Sequencer Implementations
In order to control the sequencing of more than 4 voltages in
applications where the integrity of these critical voltages
must be assured prior to sequencing, several of the ISL8723
or ISL8724 devices can configured together to accomplish
this.
Figure 23 shows a typical multi sequencer implementation,
note the common SYSRST# signal that asserts once all
monitored voltages are valid allowing the sequence to
initiate. The sequencing is straight forward across multiple
sequencers as all DLY_ON capacitors will simultaneously
start charging once all monitored voltages area valid and
~10ms after the common ENABLE input signal is delivered.
This allows the choice of capacitors to be related to each
other no different than using a single sequencer. When the
common enabling signal is deasserted this configuration will
then execute the turn-off sequence across all sequencers as
programmed by the DLY_OFF capacitor values.
With all the SYSRST# pins bused together once the on
sequence is complete simultaneous shutdown upon any
UVLO input failure is assured as the SYSRST# output will
pull low, simultaneously turning off all GATE outputs.
SYSRST#
ISL872X
UVLO
ENABLE
ENABLE#
G
A
T
E
RESET#
SYSRST#
ISL872X
POWER
SUPPLY
UVLO
ENABLE#
G
A
T
E
RESET#
HIGH = SEQUENCE COMPLETED
FIGURE 23. MULTIPLE ISL872X CONFIGURATION
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
14
FN6413.0
December 21, 2006
ISL8723, ISL8724
Package Outline Drawing
L24.4x4
24 LEAD QUAD FLAT NO-LEAD PLASTIC PACKAGE
Rev 4, 10/06
4X 2.5
4.00
A
20X 0.50
B
PIN 1
INDEX AREA
PIN #1 CORNER
(C 0 . 25)
24
19
1
4.00
18
2 . 10 ± 0 . 15
13
0.15
(4X)
12
7
0.10 M C A B
0 . 07
24X 0 . 23 +- 0
. 05 4
24X 0 . 4 ± 0 . 1
TOP VIEW
BOTTOM VIEW
SEE DETAIL "X"
0.10 C
C
0 . 90 ± 0 . 1
BASE PLANE
( 3 . 8 TYP )
SEATING PLANE
0.08 C
SIDE VIEW
(
2 . 10 )
( 20X 0 . 5 )
C
0 . 2 REF
5
( 24X 0 . 25 )
0 . 00 MIN.
0 . 05 MAX.
( 24X 0 . 6 )
DETAIL "X"
TYPICAL RECOMMENDED LAND PATTERN
NOTES:
1. Dimensions are in millimeters.
Dimensions in ( ) for Reference Only.
2. Dimensioning and tolerancing conform to AMSE Y14.5m-1994.
3. Unless otherwise specified, tolerance : Decimal ± 0.05
4. Dimension b applies to the metallized terminal and is measured
between 0.15mm and 0.30mm from the terminal tip.
5. Tiebar shown (if present) is a non-functional feature.
6. The configuration of the pin #1 identifier is optional, but must be
located within the zone indicated. The pin #1 indentifier may be
either a mold or mark feature.
15
FN6413.0
December 21, 2006