Radiation Hardened, High Performance Industry
Standard Single-Ended Current Mode PWM
Controller
ISL78840ASRH, ISL78841ASRH, ISL78843ASRH, ISL78845ASRH
The ISL7884xASRH is a high performance, radiation
hardened drop-in replacement for the popular 28C4x and
18C4x PWM controllers suitable for a wide range of
power conversion applications including boost, flyback,
and isolated output configurations. Its fast signal
propagation and output switching characteristics make
this an ideal product for existing and new designs.
Features include up to 13.2V operation, low operating
current, 90µA typ start-up current, adjustable operating
frequency to 1MHz, and high peak current drive
capability with 50ns rise and fall times.
PART NUMBER
ISL78840ASRH
ISL78841ASRH
ISL78843ASRH
ISL78845ASRH
RISING UVLO
7.0
7.0
8.4V
8.4V
MAX. DUTY CYCLE
100%
50%
100%
50%
ISL78840ASRH, ISL78841ASRH,
ISL78843ASRH, ISL78845ASRH
Features
• Electrically Screened to DSCC SMD # 5962-07249
• QML Qualified Per MIL-PRF-38535 Requirements
• 1A MOSFET Gate Driver
• 90µA Typ Start-up Current, 125µA Max
• 35ns Propagation Delay Current Sense to Output
• Fast Transient Response with Peak Current Mode
Control
• 9V to 13.2V Operation
• Adjustable Switching Frequency to 1MHz
• 50ns Rise and Fall Times with 1nF Output Load
• Trimmed Timing Capacitor Discharge Current for
Accurate Deadtime/Maximum Duty Cycle Control
• 1.5MHz Bandwidth Error Amplifier
• Tight Tolerance Voltage Reference Over Line, Load
and Temperature
• ±3% Current Limit Threshold
• Pb-Free Available
(RoHS Compliant)
Specifications for Rad Hard QML devices are
controlled by the Defense Supply Center in
Columbus (DSCC). The SMD numbers listed in the
ordering information must be used when ordering.
Applications
• Current Mode Switching Power Supplies
• Isolated Buck and Flyback Regulators
• Boost Regulators
• Direction and Speed Control in Motors
• Control of High Current FET Drivers
Pin Configuration
ISL78840ASRH, ISL78841ASRH,
ISL78843ASRH, ISL78845ASRH
(8 LD FLATPACK)
TOP VIEW
COMP
FB
CS
RTCT
1
2
3
4
8
7
6
5
V
REF
V
DD
OUT
GND
December 21, 2009
FN6991.0
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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Copyright Intersil Americas Inc. 2009. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
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