AD7324 Analog Devices, AD7324 Datasheet - Page 23

• Manufacturer Part Number: AD7324
• Description: Software Selectable True Bipolar Input, 4-Channel, 12-Bit Plus Sign A/D Converter
• Manufacturer: Analog Devices

Specifications of AD7324

• Resolution (bits): 13bit
• # Chan: 4
• Sample Rate: 1MSPS
• Interface: Ser,SPI
• Analog Input Type: Diff-Bip,Diff-Uni,SE-Uni
• Ain Range: Bip (Vref),Bip (Vref) x 2,Bip (Vref) x 4,Bip 10V,Bip 2.5V,Bip 5.0V,Uni (Vref) x 4,Uni 10V
• Adc Architecture: SAR
• Pkg Type: SOP

The four analog input channels can be configured as three pseudo differential analog inputs, two pseudo differential inputs, two true
differential input pairs, or four single-ended analog inputs.
Table 10. Analog Input Configuration Selection
Channel Address Bits
ADD1
0
0
1
1
Table 11. Power Mode Selection
PM1
1
1
0
0
Table 12. Sequencer Selection
Seq1
0
0
1
1
SEQUENCE REGISTER
The sequence register on the AD7324 is a 4-bit, write-only register. Each of the four analog input channels has one corresponding bit in
the sequence register. To select a channel for inclusion in the sequence, set the corresponding channel bit to 1 in the sequence register.
MSB
16
Write
PM0
1
0
1
0
Seq2
0
1
0
1
15
Register Select 1
ADD0
0
1
0
1
Description
Full Shutdown Mode. In this mode, all internal circuitry on the AD7324 is powered down. Information in the control register
is retained when the AD7324 is in full shutdown mode.
Autoshutdown Mode. The AD7324 enters autoshutdown on the 15
All internal circuitry is powered down in autoshutdown.
Autostandby Mode. In this mode, all internal circuitry is powered down excluding the internal reference. The AD7324 enters
autostandby mode on the 15
Normal Mode. All internal circuitry is powered up at all times.
Sequence Type
The channel sequencer is not used. The analog channel, selected by programming the ADD1 bit and ADD0 bit in the
control register, selects the next channel for conversion.
Uses sequence of channels that were previously programmed in the sequence register for conversion. The AD7324 starts
converting on the lowest channel in the sequence. The channels are converted in ascending order. If uninterrupted, the
AD7324 keeps converting the sequence. The range for each channel defaults to the range previously written into the
range register.
Used in conjunction with the channel address bits in the control register. This allows continuous conversions on a
consecutive sequence of channels, from Channel 0 up to and including a final channel selected by the channel address bits
in the control register. The range for each channel defaults to the range previously written into the range register.
The channel sequencer is not used. The analog channel, selected by programming the ADD1 bit and ADD0 bit in the
control register, selects the next channel for conversion.
Mode 1 = 1, Mode 0 = 1
3 Pseudo Differential Inputs
V
V
V
V
Not a valid selection
IN
IN
IN
IN
0
1
2
+
14
Register Select 2
V
V
V
V
IN
IN
IN
IN
3
3
3
−
th
SCLK rising edge after the control register is updated.
13
V
IN
0
Mode 1 = 1, Mode 0 = 0
2 Fully Differential Inputs
V
V
V
V
V
IN
IN
IN
IN
IN
0
0
2
2
+
12
V
Rev. A | Page 23 of 36
IN
1
11
V
V
V
V
V
V
IN
IN
IN
IN
IN
IN
2
1
1
3
3
−
10
V
IN
3
th
SCLK rising edge when the control register is updated.
Mode 1 = 0, Mode 0 =1
V
V
V
V
V
2 Pseudo Differential Inputs
9
0
IN
IN
IN
IN
IN
0
0
2
2
+
8
0
V
V
V
V
V
7
0
IN
IN
IN
IN
IN
1
1
3
3
−
6
0
Mode 1 = 0, Mode 0 = 0
4 Single-Ended Inputs
V
V
V
V
V
5
0
IN
IN
IN
IN
IN
0
1
2
3
+
4
0
3
0
AD7324
V
AGND
AGND
AGND
AGND
IN
2
0
−
LSB
1
0