15

9, 16

11

10

12

13

14

IN-

IN+

RDY

RST

10k

10k

FLT

0.1F

GND1

2.25V-5.5V

10R

ISO5452



C

ISO5452

SLLSEQ4A – AUGUST 2015 – REVISED SEPTEMBER 2015

www.ti.com

10.2.2.2 FLT and RDY Pin Circuitry

There is 50-k

Ω pull-up resistor internally on FLT and RDY pins. The FLT and RDY pin is an open-drain output. A

10-k

Ω pull-up resistor can be used to make it faster rise and to provide logic high when FLT and RDY is inactive,

as shown in Figure 50.

Fast common mode transients can inject noise and glitches on FLT and RDY pins due to parasitic coupling. This

is dependent on board layout. If required, additional capacitance (100 pF to 300 pF) can be included on the FLT

and RDY pins.

Figure 50. FLT and RDY Pin Circuitry for High CMTI

10.2.2.3 Driving the Control Inputs

The amount of common-mode transient immunity (CMTI) can be curtailed by the capacitive coupling from the

high-voltage output circuit to the low-voltage input side of the ISO5452. For maximum CMTI performance, the

digital control inputs, IN+ and IN-, must be actively driven by standard CMOS, push-pull drive circuits. This type

of low-impedance signal source provides active drive signals that prevent unwanted switching of the ISO5452

output under extreme common-mode transient conditions. Passive drive circuits, such as open-drain

configurations using pull-up resistors, must be avoided. There is a 20 ns glitch filter which can filter a glitch up to

20 ns on IN+ or IN-.

24

Submit Documentation Feedback

Copyright © 2015, Texas Instruments Incorporated

Product Folder Links: ISO5452