Rainbow Electronics MAX149 - Manual (Page 16)

MAX148/MAX149
+2.7V to +5.25V, Low-Power, 8-Channel,
Serial 10-Bit ADCs
16 ______________________________________________________________________________________
Table 6. Hard-Wired Power-Down
and Internal Clock Frequency
PD1 PD0 DEVICE MODE
0 0 Full Power-Down
0 1 Fast Power-Down
1 0 Internal Clock
1 1 External Clock
Table 5. Software Power-Down
and Clock Mode
Figure 13. Average Supply Current vs. Conversion Rate with
External Reference
1000
10,000
0.1
0.1
AVERAGE SUPPLY CURRENT
vs. CONVERSION RATE
WITH EXTERNAL REFERENCE
100
10
1
CONVERSION RATE (Hz)
AVERAGE SUPPLY CURRENT (µA)
1 100 10 1k 10k 1M 100k
MAX148/9-13
VREF = V DD = 3.0V
R LOAD = ∞
CODE = 1010101000
1 CHANNEL
8 CHANNELS
Figure 14a. MAX149 Supply Current vs. Conversion Rate,
FULLPD
100
1
0.01 0.1 1
AVERAGE SUPPLY CURRENT
vs. CONVERSION RATE
(USING FULLPD)
10
CONVERSION RATE (Hz)
AVERAGE SUPPLY CURRENT (
µ A)
100 10 1k
MAX148/9-F14A
R LOAD = ∞
CODE = 1010101000
8 CHANNELS
1 CHANNEL
POWER-DOWN
POWERED UP
POWERED UP
DATA VALID DATA VALID
INTERNAL
S X X X X X 1 0 S 0 0 X X X X X S
MODE
DOUT
DIN
CLOCK
MODE
SETS INTERNAL
CLOCK MODE SETS
POWER-DOWN
CONVERSION CONVERSION SSTRB
Figure 12b. Timing Diagram Power-Down Modes, Internal Clock
N/A N/A Power-Down 0
1.8MHz External Enabled Floating
225kHz Internal Enabled 1
INTERNAL
CLOCK
FREQUENCY
REFERENCE-
BUFFER
COMPENSATION
DEVICE
MODE
SHDN
STATE