1
FN9196.1
ISL6455, ISL6455A
Triple Output Regulator with Single
Synchronous Buck and Dual LDO
The ISL6455 is a highly integrated triple output regulator
which provides a single chip solution for FPGAs and wireless
chipset power management. The device integrates an
adjustable high efficiency synchronous buck regulator with
two adjustable ultra low noise LDO regulators. Either the
ISL6455 or ISL6455A can be selected based on whether
3.3V ±10% or 5V ±10% is required as an input voltage.
The synchronous current mode control PWM regulator with
integrated N- Channel and P-Channel power MOSFET
provides adjustable voltages based on external resistor
setting. Synchronous rectification with internal MOSFETs is
used to achieve higher efficiency and reduced number of
external components. Operating frequency is typically
750kHz, allowing the use of smaller inductor and capacitor
values. The device can be synchronized to an external clock
signal in the range of 500kHz to 1MHz. The PG_PWM
output indicates loss of regulation on PWM output.
The ISL6455 also has two LDO adjustable regulators using
internal PMOS transistors as pass devices. LDO2 features
ultra low noise typically below 30µV
RMS
to aid VCO stability.
The EN_LDO pin controls LDO1 and LDO2 outputs. The
ISL6455 also integrates a RESET
function, which eliminates
the need for additional RESET IC required in WLAN and
other applications. The IC asserts a RESET
signal whenever
the V
IN
supply voltage drops below a preset threshold,
keeping it asserted for at least 25ms after V
IN
has risen
above the reset threshold. The PG_LDO output indicates
loss of regulation on either of the two LDO outputs. Other
features include overcurrent protection and thermal
shutdown for all of the three outputs. High integration and
the thin Quad Flat No-lead (QFN) package makes ISL6455
an ideal choice for powering FPGAs and small form factor
wireless cards such as PCMCIA, mini-PCI and Cardbus-32.
Features
• Fully integrated synchronous buck regulator + dual LDO
• PWM output voltage adjustable.
- 0.8V to 2.5V with ISL6455 (VIN = 3.3V)
- 0.8V to 3.3V with ISL6455A (VIN = 5.0V)
• High output current. . . . . . . . . . . . . . . . . . . . . . . . . 600mA
• Dual LDO adjustable options
- LDO1, 1.2V to Vin - 0.3V (3.3Vmax). . . . . . . . . . 300mA
- LDO2, 1.2V to Vin - 0.3V (3.3Vmax). . . . . . . . . . 300mA
• Ultra-compact DC/DC converter design
• Stable with small ceramic output capacitors and no load
• High conversion efficiency
• Low shutdown supply current
• Low dropout voltage for LDOs
- LDO1 . . . . . . . . . . . . . . . . . . 150mV (typical) at 300mA
- LDO2 . . . . . . . . . . . . . . . . . . 150mV (typical) at 300mA
• Low output voltage noise
- <30µV
RMS
(typical) for LDO2 (VCO supply)
• PG_LDO and PG_PWM (PWM and LDO) outputs
• Extensive circuit protection and monitoring features
- PWM overvoltage protection
- Overcurrent protection
- Shutdown
- Thermal shutdown
• Integrated RESET
output for microprocessor reset
• Proven reference design for total WLAN system solution
• QFN package
- Compliant to JEDEC PUB95 MO-220 QFN - Quad Flat
No Leads - Product Outline
- Near Chip-Scale package footprint Improves PCB
efficiency and is thinner in Profile
• Pb-free (RoHS compliant)
Applications
• WLAN cards
- PCMCIA, Cardbus32, MiniPCI cards
- Compact flash cards
• Hand-held instruments
Related Literature
• TB363 - Guidelines for Handling and Processing Moisture
Sensitive Surface Mount Devices (SMDs)
• TB389 - PCB Land Pattern Design and Surface Mount
Guidelines for QFN Packages
Ordering Information
PART NUMBER*
(Note)
PART
MARKING
TEMP.
RANGE (°C)
PACKAGE
(Pb-Free)
PKG.
DWG. #
ISL6455IRZ 64 55IRZ -40 to +85 24 Ld QFN L24.4x4B
ISL6455AIRZ 64 55AIRZ -40 to +85 24 Ld QFN L24.4x4B
Add “-TK” or T5K 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.
Data Sheet February 19, 2014
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Copyright Intersil Americas LLC 2005, 2014. All Rights Reserved
Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries.
All other trademarks mentioned are the property of their respective owners.
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