ATA6826-DK Atmel, ATA6826-DK Datasheet - Page 12

• Manufacturer Part Number: ATA6826-DK
• Description: BOARD EVALUATION FOR ATA6826
• Manufacturer: Atmel

Specifications of ATA6826-DK

• Main Purpose: Power Management, Half H-Bridge Driver (Internal FET)
• Embedded: No
• Utilized Ic / Part: ATA6826
• Primary Attributes: 3 Half H-Bridge Drivers, 1A, 2 kV ESD Protection
• Secondary Attributes: Short-Circuit, Thermal & Undervoltage Protection
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

4.3
12
Daisy Chaining of Several ATA6826s
ATA6826
In applications with a larger number of loads, there's a second option for connecting several
ATA6826s to the microcontroller. The daisy-chain arrangement requires only one CS line; the
data signal is handed over step-by-step from one ATA6826 to the next as long as the CS signal
stays low. It should be evident that this advantage is traded for slower reaction times, as several
programming cycles are needed to load the desired setting into each ATA6826.
The DI pin of the first IC acts as input for all ICs while the DO of the last IC represents the output
for the whole chain. The data word intended for the last IC has to be put in first, followed by the
word for the previous IC, and so on. Only n shifts total will be needed for a number n of ICs, as
any DI information is transferred immediately to the output register.
Table 4-2
numbers 1, 2 and 3, while the initial contents of the registers are termed as X to Z. It can be seen
that the desired status of the input registers DI is reached after n = 3 shift operations.
Figure 4-3.
Table 4-2.
IC number
I/O Cycle
DO
DI
controller
WATCHDOG
clarifies the above method: the n = 3 data words A, B, C are shifted into the driver ICs
Micro-
U5021M
V
CC
Daisy Chain Operation With Microcontroller and Watchdog
Principal Method of Shifting Data Words Through Daisy-chained ICs
V
CC
Enable
1
A
Z
CS
DI
DO
CLK
CS
ATA6826
0
2
Y
DI
INH
DO
CLK
3
X
CS
ATA6826
B
A
1
DI
INH
DO
CLK
A
1
2
Z
CS
ATA6826
Y
3
DI
INH
DO
CLK
C
B
1
4981A–AUTO–02/07
CS
ATA6826
B
A
2
2
DI
INH
DO
CLK
A
Z
3