LTC6804 datasheet(80/90 Pages) AD

80 / 90 page

LTC6810-1/LTC6810-2

Rev. A

For more information www.analog.com

APPLICATIONS INFORMATION

Both t5 and t6 must be lengthened as the number of

LTC6810 devices in the daisy chain increase. The equa-

tions for these times are below:

t5 > (#devices • 70ns) + 900ns

t6 > (#devices • 70ns) + 950ns

Connecting Multiple LTC6810-1s on the Same PCB

When connecting multiple LTC6810-1 devices on the

same PCB, only a single transformer is required between

the LTC6810-1 isoSPI ports. The absence of the cable also

reduces the noise levels on the communication lines and

often only a split termination is required. Figure 47 shows

an example application that has multiple LTC6810-1s

on the same PCB, communicating to the bottom MCU

through a LTC6820 isoSPI driver. If a transformer with

a center tap is used, a capacitor can be added for better

noise rejection. Additional noise filtering is provided with

discrete common mode chokes (CMC) placed to both

sides of the single transformer as shown in Figure 47.

On single board designs with lower noise requirements,

it is possible for a simplified capacitor-isolated coupling

as shown in Figure 48 to replace the transformer. In this

circuit the transformer is directly replaced with two 10nF

capacitors. An optional common mode choke (CMC)

helps provides noise rejection similar to application cir-

cuits using transformers. The circuit is designed to use

IBIAS/ICMP settings identical to the transformer circuit.

Figure 48.

10nF

GNDB

VREG

10nF

GNDB

VREG

10nF

GNDA

VREG

10nF

GNDA

VREG

68101 F48

10nF

C13

10nF

IPA

IBIAS

ICMP

LTC6810

IMA

49.9

IPB

IMB

V–

IPA

IBIAS

ICMP

LTC6810

IMA

49.9

IPB

IMB

V–

ACT45B-101-2P-TL003

Capacitive Isolation Coupling for LTC6810-1s on the Same PCB

LTC6804 Datasheet(PDF) 80 Page - Analog Devices

LTC6804 Datasheet(HTML) 80 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90

Datasheet Download

Link URL