AD7924BRUZ-REEL7 Analog Devices Inc, AD7924BRUZ-REEL7 Datasheet - Page 20

• Manufacturer Part Number: AD7924BRUZ-REEL7
• Description: IC,Data Acquisition System,4-CHANNEL,12-BIT,TSSOP,16PIN,PLASTIC
• Manufacturer: Analog Devices Inc

Specifications of AD7924BRUZ-REEL7

• Number Of Bits: 12
• Sampling Rate (per Second): 1M
• Data Interface: DSP, MICROWIRE™, QSPI™, Serial, SPI™
• Number Of Converters: 1
• Power Dissipation (max): 13.5mW
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-TSSOP (0.173", 4.40mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: EVAL-AD79X4CBZ - BOARD EVALUATION FOR AD79X4CBZ
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AD7904/AD7914/AD7924
POWER VERSUS THROUGHPUT RATE
By operating in Auto Shutdown mode on the AD7904/AD7914/
AD7924, the average power consumption of the ADC decreases
at lower throughput rates. Figure 15 shows how as the through-
put rate is reduced, the part remains in its shutdown state longer
and the average power consumption over time drops accordingly.
For example, if the AD7924 is operated in a continuous sam-
pling mode, with a throughput rate of 100 kSPS and an SCLK
of 20 MHz (V
down mode, i.e., if PM1 = 0 and PM0 = 1, then the power
consumption is calculated as follows:
DOUT
DOUT
SCLK
SCLK
DIN
DIN
CS
CS
PART IS IN
UNKNOWN MODE
AFTER POWER-ON
PART IS IN
UNKNOWN MODE
AFTER POWER-ON
Figure 14c. To Place AD7904/AD7914/AD7924 into Auto Shutdown Mode after Supplies are First Applied
Figure 14b. To Place AD7904/AD7914/AD7924 into Full Shutdown Mode after Supplies are First Applied
Figure 14a. To Place AD7904/AD7914/AD7924 into Normal Mode after Supplies are First Applied
DD
= 5 V), and the device is placed in Auto Shut-
1
1
DIN LINE HIGH FOR FIRST DUMMY CONVERSION
DIN LINE HIGH FOR FIRST DUMMY CONVERSION
INVALID DATA
INVALID DATA
DOUT
SCLK
DIN
CS
PART IS IN
UNKNOWN MODE
AFTER POWER-ON
IF IN SHUTDOWN AT POWER-ON,
PART BEGINS TO POWER UP ON
CS RISING EDGE AS PM1 = PM0 = 1
1
CONTROL REGISTER IS LOADED ON
THE FIRST 12 CLOCKS. PM1 = 1, PM0 = 0
14
14
DATA IN TO CONTROL REGISTER
16
16
INVALID DATA
–20–
t
The maximum power dissipation during normal operation is
13.5 mW (V
is one dummy cycle, i.e., 1 µs, and the remaining conversion time is
another cycle, i.e., 1 µs, then the AD7924 can be said to dissipate
13.5 mW for 2 µs during each conversion cycle. For the remainder
of the conversion cycle, 8 µs, the part remains in shutdown.
The AD7924 can be said to dissipate 2.5 µW for the remaining 8 µs of
the conversion cycle. If the throughput rate is 100 kSPS, the cycle
time is 10 µs and the average power dissipated during each cycle is
(2/10) × (13.5 mW) + (8/10) × (2.5 µW) = 2.702 mW.
12
PART ENTERS SHUTDOWN ON
CS RISING EDGE AS PM1 = PM0 = 0
ALLOW
TO KEEP THE PART IN NORMAL MODE, LOAD
PM1 = PM0 = 1 IN CONTROL REGISTER
CONTROL REGISTER IS LOADED ON THE
FIRST 12 CLOCKS. PM1 = 0, PM0 = 1
1
1
t
POWER
CHANNEL IDENTIFIER BITS + CONVERSION RESULT
DD
14
= 5 V). If the power-up time from Auto Shutdown
TO ELAPSE
16
DATA IN TO CONTROL REGISTER
DATA IN TO CONTROL REGISTER
INVALID DATA
PART ENTERS AUTO SHUTDOWN ON
CS RISING EDGE AS PM1 = 0, PM0 = 1
14
14
16
16
REV. 0