AD7934BRUZ Analog Devices Inc, AD7934BRUZ Datasheet - Page 15

• Manufacturer Part Number: AD7934BRUZ
• Description: IC ADC 12BIT 4CH 1.5MSPS 28TSSOP
• Manufacturer: Analog Devices Inc

Specifications of AD7934BRUZ

• Data Interface: Parallel
• Number Of Bits: 12
• Sampling Rate (per Second): 1.5M
• 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: 28-TSSOP (0.173", 4.40mm Width)
• Resolution (bits): 12bit
• Input Channel Type: Differential, Single Ended
• Supply Voltage Range - Analogue: 2.7V To 5.25V
• Supply Voltage Range - Digital: 2.7V To 5.25V
• Supply: RoHS Compliant
• Sampling Rate: 1.5MSPS
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

CONTROL REGISTER
The control register on the AD7933/AD7934 is a 12-bit, write-
only register. Data is written to this register using the CS and
WR pins. The functions of the control register bits are described
in Table 8. At power-up, the default bit settings in the control
Table 7. Control Register Bits
MSB
DB11
PM1
Table 8. Control Register Bit Function Description
Bit No.
11, 10
9
8
7
6, 5
4, 3
2
1
0
Table 9. Power Mode Selection Using the Power Management Bits in the Control Register
PM1
0
0
1
1
PM0
0
1
0
1
Mnemonic
PM1, PM0
CODING
REF
ZERO
ADD1,
ADD0
MODE1,
MODE0
SEQ1
SEQ0
RANGE
DB10
PM0
Mode
Normal Mode
Autoshutdown
Autostandby
Full Shutdown
DB9
CODING
Description
Power Management Bits. Use these two bits to select the power mode of operation. The user can choose between
normal mode or various power-down modes of operation as shown in Table 9.
This bit selects the output coding of the conversion result. If the CODING bit is set to 0, the output coding is
straight (natural) binary. If the CODING bit is set to 1, the output coding is twos complement.
This bit selects whether the internal or external reference is used to perform the conversion. If the REF bit is
Logic 0, an external reference should be applied to the V
selected. See the Reference section.
This bit is not used; therefore, it should always be set to Logic 0.
Use these two address bits to select which analog input channel is to be converted in the next conversion, if the
sequencer is not being used, or to select the final channel in a consecutive sequence when the sequencer is being
used (see Table 11 for more information). The selected input channel is decoded as shown in Table 10.
The two mode pins select the type of analog input on the four V
single-ended inputs, two fully differential inputs, or two pseudo differential inputs (see Table 10).
The SEQ1 bit in the control register is used in conjunction with the SEQ0 bit to control the sequencer function
(see Table 11).
The SEQ0 bit in the control register is used in conjunction with the SEQ1 bit to control the sequencer function
(see Table 11).
This bit selects the analog input range of the AD7933/AD7934. If RANGE is set to 0, the analog input range
extends from 0 V to V
is selected, V
the analog input remains within the supply rails. See the Analog Inputs section for more information.
Description
When operating in normal mode, all circuitry is fully powered up at all times.
When operating in autoshutdown mode, the AD7933/AD7934 enters full shutdown mode at the end of
each conversion. In this mode, all circuitry is powered down.
When the AD7933/AD7934 enters this mode, the reference remains fully powered, the reference buffer is
partially powered down, and all other circuitry is fully powered down. This mode is similar to
autoshutdown mode, but it allows the part to power up in 7 μs (or 600 ns if an external reference is used).
See the Power Modes of Operation section for more information.
When the AD7933/AD7934 enters this mode, all circuitry is powered down. The information in the control
register is retained.
DB8
REF
DD
must be 4.75 V to 5.25 V if a 2.5 V reference is used; otherwise, care must be taken to ensure that
ZERO
DB7
REF
. If RANGE is set to 1, the analog input range extends from 0 V to 2 × V
DB6
ADD1
Rev. B | Page 15 of 32
DB5
ADD0
register are all 0s. When writing to the control register between
conversions, ensure that CONVST returns high before
performing the write.
DB4
MODE1
REF
pin, and if it is Logic 1, the internal reference is
IN
pins. The AD7933/AD7934 have either four
DB3
MODE0
DB2
SEQ1
AD7933/AD7934
REF
DB1
SEQ0
. When this range
LSB
DB0
RANGE