1
®
FN6413.1
ISL8723, ISL8724
Power Sequencing Controllers
The Intersil ISL8723 and ISL8724 are 4 channel sequencers
controlling the on and off sequence of voltages with
undervoltage 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 follow.
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.
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.
Features
• Enables arbitrary turn-on and turn-off sequencing of up to
four power supplies (0.7V to 5V)
• Operates from 2.5V to 5V supply voltage
• Supplies V
DD
+5.3V of charge pumped gate drive
• Adjustable voltage slew rate for each rail
• Multiple sequencers can be easily daisy-chained to
sequence an infinite number of independent voltages
• Glitch immunity
• Undervoltage lockout for each monitored supply voltage
• 30µA Sleep State (ISL8723)
• Active high (ISL8723) or low (ISL8724) ENABLE
input
• Pb-free (RoHS compliant)
Applications
• Graphics cards
• FPGA/ASIC/microprocessor/PowerPC supply sequencing
• Network Routers
• Telecommunications Systems
Pinout
ISL8723, ISL8724
(24 LD QFN)
TOP VIEW
Ordering Information
PART NUMBER
(Note)
PART
MARKING
TEMP.
RANGE
(°C)
PACKAGE
(Pb-free)
PKG.
DWG. #
ISL8723IRZ* 87 23IRZ -40 to +85 24 Ld 4x4 QFN L24.4x4
ISL8724IRZ* 87 24IRZ -40 to +85 24 Ld 4x4 QFN L24.4x4
ISL8723EVAL1 Evaluation Platform
*Add “-T” suffix for tape and reel. Please refer to TB347 for details on
reel specifications.
NOTE: These Intersil Pb-free plastic packaged products employ
special Pb-free material sets, molding compounds/die attach
materials, and 100% matte tin plate plus anneal (e3 termination finish,
which is 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.
1
2
3
4
5
6
18
17
16
15
14
13
24 23 22 21 20 19
7 8 9 10 11 12
4mmx4mm
ENABLE/
ENABLE
GATE_A
DLY_OFF_C
DLY_OFF_D
GATE_B
GATE_C
GATE_D
DLY_ON_B
NC
GND
NC
UVLO_B
DLY_OFF_B
UVLO_D
DLY_ON_D
DLY_ON_C
UVLO_C
DLY_OFF_A
GND
UVLO_A
DLY_ON_A
SYSRST
VDD
RESET
Data Sheet April 22, 2009
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, 2009. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
