AAT2550_08 ANALOGICTECH [Advanced Analogic Technologies], AAT2550_08 Datasheet - Page 20

• Manufacturer Part Number: AAT2550_08
• Description: Total Power Solution for Portable Applications
• Manufacturer: ANALOGICTECH [Advanced Analogic Technologies]

Timing Diagram
The DATA pin function is active low and should normally
be pulled high to V
high to the same level as the high state for the logic I/O
port on the system microcontroller. In order for the DATA
pin control circuit to generate clean, sharp edges for the
data output and to maintain the integrity of the data tim-
ing for the system, the pull-up resistor on the data line
should be low enough in value so that the DATA signal
returns to the high state without delay. If too small a
pull-up resistor is used, the strobe pulse from the system
microcontroller could exceed the maximum pulse time
and the DATA output control could issue false status
reports. A 1.5kΩ resistor is recommended when pulling
the DATA pin high to 5.0V. If the data line is pulled high
to a voltage level less than 5.0V, the pull-up resistor can
20
SystemPower
AAT2550
Control
Status
SQ
CK
Data
OUT
IN
TM
ADP
. This data line may also be pulled
T
T
DATA(RPT)
OFF
> 2 P
= T
DATA
T
System Reset
System Start
S
SYNC
SYNC
QPULSE
+ T
DATA Pin
Figure 3: Data Pin Application Circuit.
LAT
< 2.5 P
T
LAT
w w w . a n a l o g i c t e c h . c o m
DATA
1.8V to 5.0V
Total Power Solution for Portable Applications
P
DATA
R
N=1
PULL_UP
be calculated based on a recommended minimum pull-up
current of 3mA. Use the following formula:
Data Timing
The system microcontroller should assert an active low
data request pulse for minimum duration of 200ns; this is
specified by the S
end of the data request pulse, the AAT2550 status data
control will reply the data word back to the system micro-
controller after a delay defined by the data report time
specification T
data pulses will be defined by the T
N=2
DATA(RPT)
QPULSE
N=3
R
. The period of the following group of
PRODUCT DATASHEET
PULL-UP
. Upon sensing the rising edge of the
T
OFF
GPIO
≤
V
AAT2550178
3mA
PULL-UP
DATA
μP GPIO
specification.
IN
Port
2550.2008.02.1.3
OUT