DATASHEET
ISL9440B, ISL9440C
Triple Step-Down PWM and Single Linear Controller with Programmable Soft-Start
The ISL9440B and ISL9440C are quad-output synchronous
buck controllers that integrate three PWM controllers and one
low drop-out linear regulator controller, which are full featured
and designed to provide multi-rail power for use in products
such as cable and satellite set-top boxes, VoIP gateways,
cable modems, and other home connectivity products as well
as a variety of industrial and general purpose applications.
Each output is adjustable down to 0.8V. The PWMs are
synchronized at 180° out-of-phase thus, reducing the RMS
input current and ripple voltage.
The ISL9440B and ISL9440C offer programmable soft-start,
independent enable inputs for ease of supply rail
sequencing, and integrated UV/OV/OC/OT protections in a
space conscious 5mmx5mm QFN package. An early
warning function is offered to output a logic signal to warn
the system to back up data when input voltage falls below a
certain level.
The ISL9440B and ISL9440C utilize internal loop
compensation to keep minimum peripheral components for
compact design and a low total solution cost. These devices
are implemented with current mode control with feed-forward
to cover various applications even with fixed internal
compensations.
Table 1 shows the difference in terms of ISL944xx family
features.
TABLE 1.
PART
NUMBER
ISL9440
ISL9440A
ISL9441
ISL9440B
ISL9440C
(No longer
available or
supported)
EARLY
WARNING
Yes
Yes
No
Yes
Yes
SWITCHING
FREQUENCY
(kHz)
300
600
300
300
600
SOFT-STARTING
TIME (ms)
1.7
1.7
1.7
Programmable
Programmable
FN6799
Rev 4.00
February 18, 2016
Features
• Three Integrated Synchronous Buck PWM Controllers
- Internal Bootstrap Diodes
- Internal Compensation
• Independent Control for each Regulator and
Programmable Output Voltages; Independent
Enable/Shutdown/Soft-start
• Fixed Switching Frequency: 300kHz(B), 600kHz(C)
• Adaptive Shoot-Through Protection on all Synchronous
Buck Controllers
• Pre-biased Output Start-up Capability
• Out-of-Phase Switching to Reduce Input Capacitance
(0°/180°/0°)
• No External Current Sense Resistor
- Uses Lower MOSFET’s r
DS(ON)
• Current Mode Controller with Voltage Feed-Forward
• Complete Protection
- Overcurrent, Overvoltage, Undervoltage Lockout,
Over-Temperature
• Cycle-by-Cycle Current Limiting
• Wide Input Voltage Range
- Input Rail Powers VIN Pin: 5.6V to 24V
- Input Rail Powers VCC_5V Pin (VIN tied to VCC_5V, for
5V input applications): 4.5V to 5.6V
• Early Warning on Input Voltage Failure
• Integrated Reset Function
• Pb-Free (RoHS Compliant)
Applications
• Satellite and Cable Set-Top Boxes
• Cable Modems
• VoX Gateway Devices
• NAS/SAN Devices
• ATX Power Supply
Related Literature
• Technical Brief TB389 “PCB Land Pattern Design and
Surface Mount Guidelines for QFN (MLFP) Packages”
FN6799 Rev 4.00
February 18, 2016
Page 1 of 25
ISL9440B, ISL9440C
Ordering Information
PART NUMBER
(Notes 1, 2, 3)
ISL9440BIRZ
ISL9440CIRZ
(No longer available, recommended replacement:
ISL9440IRZ)
NOTES:
1. Add “-T” for tape and reel. Please refer to
TB347
for details on reel specifications.
2. 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.
3. For Moisture Sensitivity Level (MSL), please see device information page for
ISL9440B, ISL9440C.
For more information on MSL please see
techbrief TB363.
PART
MARKING
9440B IRZ
9440C IRZ
TEMP. RANGE
(°C)
-40 to +85
-40 to +85
PACKAGE
(RoHS Compliant)
32 Ld 5x5 QFN
32 Ld 5x5 QFN
PKG.
DWG. #
L32.5x5B
L32.5x5B
Pinout
ISL9440B, ISL9440C
(32 LD 5x5 QFN)
TOP VIEW
PHASE1
PHASE2
25
24
23
22
21
20
19
18
17
9
G4
10
LDOFB
11
SGND
12
OCSET2
13
FB2
14
EN/SS2
15
OCSET3
16
FB3
ISEN2
PGND
LGATE3
UGATE3
BOOT3
PHASE3
ISEN3
EN/SS3
UGATE1
UGATE2
27
LGATE1
LGATE2
BOOT1
BOOT2
26
32
ISEN1
PGOOD
VCC_5V
VIN
EN/SS1
FB1
OCSET1
RST
1
2
3
4
5
6
7
8
31
30
29
28
FN6799 Rev 4.00
February 18, 2016
Page 2 of 25
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
