AD7927BRUZ Analog Devices Inc, AD7927BRUZ Datasheet - Page 12

• Manufacturer Part Number: AD7927BRUZ
• Description: IC ADC 12BIT 8CH 200KSPS 20TSSOP
• Manufacturer: Analog Devices Inc

Specifications of AD7927BRUZ

• Data Interface: DSP, MICROWIRE™, QSPI™, Serial, SPI™
• Number Of Bits: 12
• Sampling Rate (per Second): 200k
• Number Of Converters: 1
• Power Dissipation (max): 7.5mW
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-TSSOP (0.173", 4.40mm Width)
• Resolution (bits): 12bit
• Sampling Rate: 200kSPS
• Input Channel Type: Single Ended
• Supply Voltage Range - Analog: 2.7V To 5.25V
• Supply Current: 1.5mA
• Number Of Elements: 1
• Resolution: 12Bit
• Architecture: SAR
• Sample Rate: 200KSPS
• Input Polarity: Unipolar
• Input Type: Voltage
• Rated Input Volt: 2.5/5V
• Differential Input: No
• Power Supply Requirement: Analog and Digital
• Single Supply Voltage (typ): 3/5V
• Single Supply Voltage (min): 2.7V
• Single Supply Voltage (max): 5.25V
• Dual Supply Voltage (typ): Not RequiredV
• Dual Supply Voltage (min): Not RequiredV
• Dual Supply Voltage (max): Not RequiredV
• Power Dissipation: 7.5mW
• Differential Linearity Error: -0.9LSB/1.5LSB
• Integral Nonlinearity Error: ±1LSB
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 20
• Package Type: TSSOP
• Input Signal Type: Single-Ended
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: EVAL-AD7927CBZ - BOARD EVALUATION FOR AD7927
• Lead Free Status / Rohs Status: Compliant

AD7927
CONTROL REGISTER
The control register on the AD7927 is a 12-bit, write-only register. Data is loaded from the DIN pin of the AD7927 on the falling edge of
SCLK. The data is transferred on the DIN line at the same time that the conversion result is read from the part. The data transferred on
the DIN line corresponds to the AD7927 configuration for the next conversion. This requires 16 serial clocks for every data transfer. Only
the information provided on the first 12 falling clock edges (after CS falling edge) is loaded to the control register. MSB denotes the first
bit in the data stream. The bit functions are outlined in Table 5.
Table 5. Control Register Bit Functions
Table 6. Control Register Bit Function Description
Bit
11
10
9
8 to
6
5, 4
3
2
1
0
Table 7. Channel Selection
ADD2
0
0
0
0
1
1
1
1
Table 8. Power Mode Selection
PM1
1
1
0
0
WRITE
MSB
PM0
1
0
1
0
Mnemonic
WRITE
SEQ
DONTC
ADD2 to
ADD0
PM1, PM0
SHADOW
DONTC
RANGE
CODING
SEQ
Mode
Normal Operation. In this mode, the AD7927 remains in full power mode, regardless of the status of any of the logic inputs.
This mode allows the fastest possible throughput rate from the AD7927.
Full Shutdown. In this mode, the AD7927 is in full shutdown mode with all circuitry on the AD7927 powering down. The
AD7927 retains the information in the control register while in full shutdown. The part remains in full shutdown until these
bits are changed.
Auto Shutdown. In this mode, the AD7927 automatically enters full shutdown mode at the end of each conversion when the
control register is updated. Wake-up time from full shutdown is 1 μs and the user should ensure that 1 μs has elapsed before
attempting to perform a valid conversion on the part in this mode.
Invalid Selection. This configuration is not allowed.
DONTC
ADD1
0
0
1
1
0
0
1
1
Description
The value written to this bit of the control register determines whether the following 11 bits are loaded to
the control register. If this bit is a 1, the following 11 bits are written to the control register; if it is a 0, then the
remaining 11 bits are not loaded to the control register and it remains unchanged.
The SEQ bit in the control register is used in conjunction with the SHADOW bit to control the use of the sequencer
function and access the shadow register (see Table 10).
Don’t care.
These three address bits are loaded at the end of the present conversion and select which analog input channel
is to be converted in the next serial transfer, or they may select the final channel in a consecutive sequence as
described in Table 9. The selected input channel is decoded as shown in Table 7. The address bits corresponding
to the conversion result are also output on DOUT prior to the 12 bits of data (see the Serial Interface section). The
next channel to be converted on is selected by the mux on the 14
Power Management Bits. These two bits decode the mode of operation of the AD7927 as shown in Table 8.
The SHADOW bit in the control register is used in conjunction with the SEQ bit to control the use of the sequencer
function and access the shadow register (see Table 10).
Don’t care.
This bit selects the analog input range to be used on the AD7927. If it is set to 0, the analog input range extends
from 0 V to 2 × REF
the 0 V to 2 × REF
This bit selects the type of output coding the AD7927 uses for the conversion result. If this bit is set to 0, the
output coding for the part is twos complement. If this bit is set to 1, the output coding from the part is straight
binary (for the next conversion).
ADD2
IN
IN
range, AV
. If it is set to 1, the analog input range extends from 0 V to REF
ADD1
ADD0
0
1
0
1
0
1
0
1
DD
= 4.75 V to 5.25 V.
ADD0
Rev. A | Page 12 of 28
PM1
Analog Input Channel
V
V
V
V
V
V
V
V
IN
IN
IN
IN
IN
IN
IN
IN
0
1
2
3
4
5
6
7
PM0
SHADOW
th
SCLK falling edge.
DONTC
IN
(for the next conversion). For
RANGE
CODING
LSB