FN9001 Rev.7.01

Page 1 of 4

Feb 16, 2022

© 2003 Renesas Electronics

FN9001

Rev.7.01

Feb 16, 2022

IS-1845ASRH, IS-1845ASEH

Single Event Radiation Hardened High Speed, Current Mode PWM

DATASHEET

The IS-1845ASRH, IS-1845ASEH are designed to be used in

switching power supplies operating in current-mode. Every

other rising edge of the on-chip oscillator turns on the output.

Turn-off is controlled by the current sense comparator and

occurs when the sensed current reaches a peak controlled by

the error amplifier. Turn-off can also be triggered by the end of

the oscillator period. These devices feature a single output

operating from zero to less than 50% duty cycle.

Constructed with Renesas Rad Hard Silicon Gate (RSG)

dielectrically isolated BiCMOS process, these devices are

immune to single event latch-up and have been specifically

designed to provide a high level of immunity to single event

transients. All specified parameters are ensured and tested for

300krad(Si) total dose performance at a high dose rate and

50krad(Si) total dose at a low dose rate.

Detailed Electrical Specifications for these devices are

contained in the SMD 5962-01509.

Features

• Electrically Screened to DSCC SMD # 5962-01509

• QML Qualified per MIL-PRF-38535 Requirements

• Radiation acceptance testing - IS-1845ASRH

- High Dose Rate . . . . . . . . . . . . . . . . . . . . 300krad(SI) (Max)

• Radiation acceptance testing - IS-1845ASEH

- High Dose Rate . . . . . . . . . . . . . . . . . . . . 300krad(SI) (Max)

- Low Dose Rate . . . . . . . . . . . . . . . . . . . . . . 50krad(SI) (Max)

• SEE hardness (see SEE report for details)

- SEL Immune . . . . . . . . . . . . . . . . . . . . Dielectrically Isolated

- SEU Immune. . . . . . . . . . . . . . . . . . . . . . . . 35MeV/mg/cm2

- SEU Cross-Section at 89MeV/mg/cm2. . . . . . . 5x10-6cm2

• Low Start-up Current . . . . . . . . . . . . . . . . . . . . . . . 100µA (Typ)

• Fast Propagation Delay . . . . . . . . . . . . . . . . . . . . . . .80ns (Typ)

• Supply Voltage Range . . . . . . . . . . . . . . . . . . . . . . . 12V to 20V

• High Output Drive. . . . . . . . . . . . . . . . . . . . . . . . 1A (Peak, Typ)

• Undervoltage Lockout . . . . . 8.8V Start (Typ), 8.2V Stop (Typ)

Applications

• Current-Mode Switching Power Supplies

• Control of High Current FET Drivers

•Motor Speed and Direction Control

Pin Configurations

IS7-1845ASRH, IS7-1845ASEH

(8 LD CDIP2-T8 SBDIP)

TOP VIEW

IS9-1845ASRH, IS9-1845ASEH

(18 LD FLATPACK)

TOP VIEW

NOTES:

1. Grounding the COMP pin does not inhibit the output. The output may be inhibited by applying >1.2V to the ISENSE pin.

2. This part is production tested with Ct = 3.3nF and Rt = 10k timing components only.

COMP

VFB

ISENSE

RTCT

1

2

3

4

8

7

6

5

VREF

VCC

OUT

GND

Note 1

Note 2

COMP

VFB

NC

NC

NC

ISENSE

RTCT

NC

3

4

5

6

7

8

9

217

16

15

14

13

12

11

10

VREF

VCC

VC

OUT

NC

GND

OSCGND

NC

NC

1

18

NC

Note 1

Note 2