ISL8724IRZ Intersil, ISL8724IRZ Datasheet - Page 12

• Manufacturer Part Number: ISL8724IRZ
• Description: IC POWER SUPPLY SEQUENCER 24QFN
• Manufacturer: Intersil

Specifications of ISL8724IRZ

• Applications: Power Supply Sequencer
• Voltage - Supply: 2.5 V ~ 5 V
• Current - Supply: 270µA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 24-VQFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Input: -

Application Implementations
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 24 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
COMPONENT
DESIGNATOR
Q1, Q2
R11
R12
R10
R13
R14
U1
R6
R1
R2
R3
R4
R5
R9
C5
C9
C2
C8
C3
C7
C4
C6
C1
D1
R9
ISL8723, 4 Supply Sequencer
Voltage Rail Switches
5V to UVLO_A Resistor for Divider String
UVLO_A to GND Resistor for Divider String
3.3V to UVLO_B Resistor for Divider String
UVLO_B to GND Resistor for Divider String
2.5V to UVLO_D Resistor for Divider String
UVLO_D to GND Resistor for Divider String
1.5V to UVLO_C Resistor for Divider String
UVLO_D to GND Resistor for Divider String
RESET LED Current Limiting Resistor
5V turn-on Delay Capacitor A (~10ms)
5V turn-off Delay Capacitor A (~140ms)
3.3V turn-on Delay Capacitor B (~13ms)
3.3V turn-off Delay Capacitor B (~13ms)
2.5V turn-on Delay Capacitor D (~25ms)
2.5V turn-off Delay Capacitor D (0ms)
1.5V turn-on Delay Capacitor C (~100ms)
1.5V turn-off Delay Capacitor C (~60ms)
Decoupling Capacitor
RESET Indicating LED
5V Load Resistor
3.3V Load Resistor
2.5V Load Resistor
1.5V Load Resistor
Test Points Labeled as to Function
12
COMPONENT FUNCTION
TABLE 2. ISL872XSEQEVAL1 BOARD COMPONENT LISTING
ISL8723, ISL8724
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.
Intersil, ISL8723IR 4 Supply Sequencer
FDS6990S or equivalent, Dual N-Channel MOSFET
8.45kΩ 1%, 0402
1.47kΩ 1%, 0402
7.68kΩ 1%, 0402
2.26kΩ 1%, 0402
6.98kΩ 1%, 0402
3.01kΩ 1%, 0402
4.99kΩ 1%, 0402
4.99kΩ 1%, 0402
750Ω 10%, 0805
DNP, 0402
0.1µF 10%, 6.3V, 0402
0.01µF 10%, 6.3V, 0402
0.01µF 10%, 6.3V, 0402
0.022µF 10%, 6.3V, 0402
DNP, 0402
0.068µF 10%, 6.3V, 0402
0.047µF 10%, 6.3V, 0402
1µF, 0805
0805, SMD LEDs Red
10Ω 20%, 3W Carbon
10Ω 20%, 3W Carbon
10Ω 20%, 3W Carbon
10Ω 20%, 3W Carbon
COMPONENT DESCRIPTION
April 22, 2009
FN6413.1