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AS1532/AS1533
Data Sheet
- Detailed Description
Reduced Power Mode
Reduced power mode is activated using bits PD1 and PD0
(see Table 12)
. When reduced power mode is asserted, the
AS1532/AS1533 completes any conversion in progress and enters reduced power mode.
The next start of conversion puts the AS1532/AS1533 into normal operation mode. The 8-bit control byte shifted into
the control register determines the next power mode. For example, if the 8-bit control byte contains PD1 = 0 and PD0
= 1, reduced power mode starts immediately after the conversion (see
Figure 28
)
.
The reduced-power mode achieves the lowest power consumption at speeds close to the maximum sample rate.
Figure 29
shows the AS1533 power consumption in reduced-power mode and normal operating mode
(see Table 12
on page 19)
with the internal reference and maximum clock speed.
Figure 28. Reduced-Power Mode Timing Waveforms (AS1533)
Note:
The clock speed in reduced-power mode should be limited to 4.8MHz. Full power-down mode may provide
increased power savings in applications where the devices are inactive for long periods of time, where intermit-
tent bursts of high-speed conversions are required.
Figure 29. Normal Operation and Reduced Power Mode using Internal Reference (AS1533)
Full Power-Down Mode
Full power-down is activated using bits PD1 and PD0
(see Table 12)
. Full power-down mode offers the lowest power
consumption at up to 1000 conversions per-channel per-second. When full power-down is asserted, the AS1532/
AS1533 completes any conversion in progress and powers down into specified low-quiescent current state.
The start of the next conversion puts the AS1532/AS1533 into normal operation mode. The 8-bit control byte shifted
into the control register determines the next power mode. For example, if the 8-bit control byte contains PD1 = 0 and
PD0 = 0, full power-down mode starts immediately after the conversion (see
Figure 30 on page 21
)
DIN
1
V
DD1
+V
DD2
+V
DD3
1
1
1
1
1
0
0
0
Reduced-
Power Mode
Reduced-
Power Mode
Reduced-
Power Mode
2.50V (Always On)
2.2mA
2.2mA
2.2mA
0.4mA
Reduced
Power Mode
0.4mA
Reduced
Power Mode
0.4mA
Reduced
Power Mode
REF
Normal Mode
Conversion
Normal Mode
Conversion
Normal Mode
Conversion
0
0.001
500
1000
1500
2000
2500
3000
0.1
10
1000
Sampling Rate (ksps)
S
.
Reduced Power Mode
Normal Operation