LTC6802-1_1 LINER [Linear Technology], LTC6802-1_1 Datasheet - Page 33

• Manufacturer Part Number: LTC6802-1_1
• Description: Multicell Battery Stack Monitor
• Manufacturer: LINER [Linear Technology]

APPLICATIONS INFORMATION
PROVIDING HIGH-SPEED OPTO-ISOLATION
OF THE SPI DATA-PORT
Isolation techniques that are capable of supporting the
1Mbps data rate of the LTC6802-1 require more power
on the isolated (battery) side than can be furnished by
the V
minimal, this means that a DC/DC function must be imple-
mented along with a suitable data isolation circuit, such as
shown in Figure 19. Here an optimal Avago 4-channel (3/1
bidirectional) opto-coupler is used, with a simple isolated
REG
LTC6802-1
output of the LTC6802-1. To keep battery drain
V
CSBI
SCKI
SDO
SDI
REG
V
−
249Ω
3.57k
1μF
ISOLATED V
3.57k
100nF
Figure 19. Providing an Isolated High-Speed Data Interface
BAT54S
3.57k
LOGIC
BAT54S
6
4
PE68386
•
ACSL-6410
•
1
3
supply generated by an LTC1693-2 configured as a 200kHz
oscillator. The DC/DC function provides an unregulated
logic voltage (~4V) to the opto-coupler isolated side,
from energy provided by host-furnished 5V. This circuit
provides totally galvanic isolation between the batteries
and the host processor, with an insulation rating of 560V
continuous, 2500V transient.
33nF
330Ω
TP0610K
100k
4.99k
V
OUT1
V
OUT2
CC1
CC2
LTC1693-2
330Ω
1μF
GND1
GND2
IN1
IN2
TP0610K
100k
330Ω
68021 F19
LTC6802-1
10k
TP0610K
100k
470pF
20k
+5V_HOST
CSBI
SDI
SCKI
SDO
GND_HOST
33
68021fa