1
®
FN6538.2
ISL6341, ISL6341A, ISL6341B, ISL6341C
5V or 12V Single Synchronous Buck
Pulse-Width Modulation (PWM) Controller
The ISL6341, ISL6341A, ISL6341B, ISL6341C makes
simple work out of implementing a complete control and
protection scheme for a DC/DC stepdown converter driving
N-Channel MOSFETs in a synchronous buck topology. Since
it can work with either 5V or 12V supplies, this one family of
IC’s can be used in a wide variety of applications within a
system. It integrates the control, gate drivers, output
adjustment, monitoring and protection functions into a single
10 Ld Thin DFN package.
The ISL6341, ISL6341A, ISL6341B, ISL6341C (hereafter
referred to as “ISL6341x”, except as needed) provides single
feedback loop, voltage-mode control with fast transient
response. The output voltage can be precisely regulated to as
low as 0.8V, with a maximum tolerance of ±0.8%
over-temperature and line voltage variations. A fixed frequency
oscillator and wide duty cycle range reduces design complexity,
while balancing typical application cost and efficiency. The
frequency, duty cycle and OCP response are the only
differences among the ISL6341x versions. See Table 1.
Protection from overcurrent conditions is provided by
monitoring the r
DS(ON)
of the lower MOSFET to inhibit PWM
operation appropriately (see “Overcurrent Protection (OCP)”
on page 8 for details). This approach simplifies the
implementation and improves efficiency by eliminating the
need for a current sense resistor. The output voltage is also
monitored for undervoltage and overvoltage protection, in
addition to monitoring for a PGOOD output.
Features
• Operates from +4.5V to 14.4V Supply Voltage (for Bias)
- 1.5V to 12V V
IN
Input Range (Up to 20V is Possible with
Restrictions; see “Input Voltage Considerations” on
page 12)
- 0.8V to ~V
IN
Output Range (Duty Cycle Limited)
- Integrated Gate Drivers; LGATE Uses V
CC
(5V to 12V);
UGATE Uses External Boot Diode to (5V to 12V)
- 0.8V Internal Reference; ±0.8% Tolerance
• Simple Single-Loop Control Design
- Traditional Dual Edge Modulator
- Voltage-Mode PWM Control
- Drives N-Channel MOSFETs
• Fast Transient Response
- High-Bandwidth Error Amplifier
- 0% to 85% Max Duty Cycle for ISL6341, ISL6341C
- 0% to 75% Max Duty Cycle for ISL6341A, ISL6341B
• Lossless, Programmable Overcurrent Protection
- Uses Lower MOSFET’s r
DS(ON)
- Latch off mode (ISL6341, ISL6341B)
- Infinite Retry (Hiccup) Mode (ISL6341A)
- Infinite Retry (Hiccup) Mode; no UVP (ISL6341C)
• Output Voltage Monitoring
- Undervoltage and Overvoltage Shutdown
- PGOOD Output
• Small Converter Size in 10 Ld 3x3 Thin DFN
- 300kHz Fixed Oscillator (ISL6341, ISL6341C)
- 600kHz Fixed Oscillator (ISL6341A, ISL6341B)
- Fixed Internal Soft-Start, Capable into a Pre-biased
Load
- Enable/Shutdown Function on COMP/EN Pin
• Pb-Free (RoHS Compliant)
Applications
• Power Supplies for Microprocessors or Peripherals
- PCs, Servers, Memory Supplies
- DSP and Core Communications Processor Supplies
• Subsystem Power Supplies
- PCI, AGP; Graphics Cards; Digital TV
- SSTL-2 and DDR/DDR2/DDR3 SDRAM Bus
Termination Supply
• Cable Modems, Set-Top Boxes, and DSL Modems
• Industrial Power Supplies; General Purpose Supplies
• 5V or 12V-Input DC/DC Regulators
• Low-Voltage Distributed Power Supplies; Point of Load
Ordering Information
PART NUMBER
(Note)
PART
MARKING
TEMP.
RANGE (°C)
PACKAGE
(Pb-free)
PKG.
DWG. #
ISL6341ACRZ* 41AC 0 to +70 10 Ld 3x3 TDFN L10.3x3B
ISL6341BCRZ* 41BC 0 to +70 10 Ld 3x3 TDFN L10.3x3B
ISL6341CCRZ* 41CC 0 to +70 10 Ld 3x3 TDFN L10.3x3B
ISL6341CRZ* 341C 0 to +70 10 Ld 3x3 TDFN L10.3x3B
ISL6341AIRZ* 41AI -40 to +85 10 Ld 3x3 TDFN L10.3x3B
ISL6341BIRZ* 41BI -40 to +85 10 Ld 3x3 TDFN L10.3x3B
ISL6341CIRZ* 41CI -40 to +85 10 Ld 3x3 TDFN L10.3x3B
ISL6341IRZ* 6341 -40 to +85 10 Ld 3x3 TDFN L10.3x3B
ISL6341EVAL1Z Evaluation Board
*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.
Data Sheet December 2, 2008
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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