FN7952 Rev.4.00

Page 1 of 18

Feb 25, 2020

FN7952

Rev.4.00

Feb 25, 2020

ISL78840ASxH, ISL78841ASxH, ISL78843ASxH, ISL78845ASxH, ISL738840ASEH,

ISL738841ASEH, ISL738843ASEH, ISL738845ASEH

Radiation Hardened, High Performance Industry Standard Single-Ended Current Mode PWM Controller

DATASHEET

The ISL78840ASEH, ISL78841ASEH, ISL78843ASEH,

ISL78845ASEH, ISL78840ASRH, ISL78841ASRH,

ISL78843ASRH, ISL78845ASRH, ISL738840ASEH,

ISL738841ASEH, ISL738843ASEH, ISL738845ASEH are high

performance, radiation hardened drop-in replacements for the

popular 28C4x and 18C4x PWM controllers suitable for a wide

range of power conversion applications including boost,

flyback, and isolated output configurations. Fast signal

propagation and output switching characteristics make these

ideal products for existing and new designs.

Features include up to 13.2V operation, low operating current,

90µA typical start-up current, adjustable operating frequency

to 1MHz and high peak current drive capability with 50ns rise

and fall times.

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

Related Literature

For a full list of related documents, visit our website:

• ISL78840ASEH, ISL78841ASEH, ISL78843ASEH,

ISL78845ASEH, ISL78840ASRH, ISL78841ASRH,

ISL78843ASRH, ISL78845ASRH, ISL738840ASEH,

ISL738841ASEH, ISL738843ASEH, and ISL738845ASEH

device pages

Features

• Electrically screened to DLA SMD #5962-07249

• QML qualified per MIL-PRF-38535 requirements

• 1A MOSFET gate driver

• 90µA typical start-up current, 125µA maximum

• 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

dead time/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)

• Radiation acceptance testing - ISL7884xASEH

- HDR (50-300rad(Si)/s): 100krad(Si)

- LDR (0.01rad(Si)/s): 50krad(Si)

• Radiation acceptance testing - ISL7884xASRH

- HDR (50-300rad(Si)/s): 100krad(Si)

• Radiation acceptance testing - ISL73884xASEH

- LDR (0.01rad(Si)/s): 50krad(Si)

TABLE 1. KEY DIFFERENCES BETWEEN FAMILY OF PARTS

PART NUMBER

RISING UVLO

(V)

MAXIMUM DUTY CYCLE

(%)

ISL78840ASxH

7.0

100

ISL78841ASxH

7.0

50

ISL78843ASxH

8.4

100

ISL78845ASxH

8.4

50

ISL738840ASEH

7.0

100

ISL738841ASEH

7.0

50

ISL738843ASEH

8.4

100

ISL738845ASEH

8.4

50