Table 15-4 A/D Conversion Time (Single Mode)
CKS = 0
CKS = 1
Symbol
Min
Typ
Max
Min
Typ
Max
Synchronization delay
t
D
10
—
17
6
—
9
Input sampling time
t
SPL
—
63
—
—
31
—
A/D conversion time
t
CONV
259
—
266
131
—
134
Note: Values in the table are numbers of states.
15.4.4 External Trigger Input Timing
A/D conversion can be externally triggered. When the TRGE bit is set to 1 in ADCR, external
trigger input is enabled at the
ADTRG
pin. A high-to-low transition at the
ADTRG
pin sets the
ADST bit to 1 in ADCSR, starting A/D conversion. Other operations, in both single and scan
modes, are the same as if the ADST bit had been set to 1 by software. Figure 15-6 shows the
timing.
Figure 15-6 External Trigger Input Timing
ø
ADTRG
Internal trigger
signal
ADST
A/D conversion
538
www.DataSheet4U.com