Техническая Спецификация для Freescale Semiconductor Accelerometer Cube Demo MMA9559LKUBE MMA9559LKUBE
Модели
MMA9559LKUBE
MMA955xL
Sensors
18
Freescale Semiconductor, Inc.
4.11
AC Electrical Characteristics
Tests are conducted using the input levels specified in
Table 5 on page 15
. Unless otherwise specified, propagation delays are
measured from the 50-percent to 50-percent point. Rise and fall times are measured between the 10-percent and 90-percent
points, as shown in the following figure.
points, as shown in the following figure.
Figure 7. Input signal measurement references
The subsequent figure shows the definitions of the following signal states:
• Active state, when a bus or signal is driven and enters a low-impedance state
• Three-stated, when a bus or signal is placed in a high-impedance state
• Data Valid state, when a signal level has reached V
• Three-stated, when a bus or signal is placed in a high-impedance state
• Data Valid state, when a signal level has reached V
OL
or V
OH
• Data Invalid state, when a signal level is in transition between V
OL
and V
OH
Figure 8. Signal states
4.12
General Timing Control
Table 11. General timing characteristics
(1)
1.
All conditions at nominal supply: V
DD
= V
DDA
= 1.8 V
Characteristic
Symbol
Condition(s)
Min
Typ
Max
Unit
V
DD
rise time
T
rvdd
10% to 90%
—
—
1
ms
POR release delay
(2)
2.
This is the time measured from V
DD
= V
POR
until the internal reset signal is released.
T
POR
Power-up
0.35
1.5
ms
Warm-up time
T
WU
From STOP
NC
—
7
—
sample
periods
periods
Frequency of operation
F
OPH
Full Speed Clock
—
8
—
MHz
F
OPL
Slow Clock
—
62.5
—
KHz
System clock period
t
CYCH
Full Speed Clock
—
125
—
ns
t
CYCL
Slow Clock
—
16
—
s
Full/Slow clock ratio
—
—
—
128
—
Oscillator frequency absolute accuracy @ 25°C
—
Full Speed Clock
-5
—
+5
%
Oscillator frequency variation over temperature
(-40°C to 85°C vs. ambient)
(-40°C to 85°C vs. ambient)
—
Slow Clock
-6
—
+6
%
Minimum RESET assertion duration
t
RA
—
4T
(3)
3.
In the formulas, T = 1 system clock cycle. In full speed mode, T is nominally 125 ns. In slow speed mode, T is nominally 16
s.
—
—
—
V
IH
V
IL
Fall Time
Input Signal
Note: The midpoint is V
IL
+ (V
IH
– V
IL
)/2.
Midpoint1
Low
High
90%
50%
10%
Rise Time
Data Invalid State
Data1
Data
3-stated
Data3 Valid
Data2
Data3
Data1 Valid
Data Active
Data Active
Data1 Valid