AD7195 Analog Devices, AD7195 Datasheet - Page 9

• Manufacturer Part Number: AD7195
• Description: 4.8 kHz, Ultralow Noise, 24-Bit Sigma-Delta ADC with PGA and AC Excitation
• Manufacturer: Analog Devices

Specifications of AD7195

• Resolution (bits): 24bit
• # Chan: 4
• Sample Rate: n/a
• Interface: Ser,SPI
• Analog Input Type: Diff-Bip,Diff-Uni,SE-Bip,SE-Uni
• Ain Range: (2Vref/PGA Gain) p-p
• Adc Architecture: Sigma-Delta
• Pkg Type: CSP

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
Table 5. Pin Function Descriptions
Pin No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Mnemonic
ACX2
ACX2
ACX1
ACX1
AV
AGND
NC
AINCOM
AIN1
AIN2
NC
NC
NC
NC
AIN3
AIN4
REFIN(+)
REFIN(−)
NC
DD
Description
Digital Output. Provides a signal that can be used to control the reversing of the bridge excitation in ac
excited bridge applications. In ac mode, ACX2 toggles in anti-phase with ACX1. If the ACX bit equals zero (ac
excitation turned off), the ACX2 output remains low. When toggling, it is guaranteed to be nonoverlapping
with ACX1. The nonoverlap interval between ACX1 and ACX2 is 1/(master clock) which is equal to 200 ns
when a 4.92 MHz clock is used.
Digital Output. Provides a signal that can be used to control the reversing of the bridge excitation in ac
excited bridge applications. This output is the inverse of ACX2. If the ACX bit equals zero (ac excitation turned
off), the ACX2 output remains high.
Digital Output. Provides a signal that can be used to control the reversing of the bridge excitation in ac
excited bridge applications. When ACX1 is high, the bridge excitation is taken as normal and when ACX1 is
low, the bridge excitation is reversed (chopped). If the Bit ACX equals zero (ac excitation turned off), the ACX1
output remains high.
Digital Output. Provides a signal that can be used to control the reversing of the bridge excitation in ac
excited bridge applications. This output is the inverse of ACX1. When ACX1 is low, the bridge excitation is
taken as normal and when ACX1 is high, the bridge excitation is reversed (chopped). If the ACX bit equals
zero (ac excitation turned off), the ACX1 output remains low.
Analog Supply Voltage, 4.75 V to 5.25 V. AV
Analog Ground Reference Point.
No Connect. This pin should be tied to AGND.
Analog inputs AIN1 to AIN4 are referenced to this input when configured for pseudo differential operation.
Analog Input. This pin can be configured as the positive input of a fully differential input pair when used with
AIN2 or as a pseudo differential input when used with AINCOM.
Analog Input. This pin can be configured as the negative input of a fully differential input pair when used
with AIN1 or as a pseudo differential input when used with AINCOM.
No Connect. This pin should be tied to AGND.
No Connect. This pin should be tied to AGND.
No Connect. This pin should be tied to AGND.
No Connect. This pin should be tied to AGND.
Analog Input. This pin can be configured as the positive input of a fully differential input pair when used with
AIN4 or as a pseudo differential input when used with AINCOM.
Analog Input. This pin can be configured as the negative input of a fully differential input pair when used
with AIN3 or as a pseudo differential input when used with AINCOM.
Positive Reference Input. An external reference can be applied between REFIN(+) and REFIN(−). REFIN(+) can
lie anywhere between AV
but the part functions with a reference from 1 V to AV
Negative Reference Input. This reference input can lie anywhere between AGND and AV
No Connect. This pin should be tied to AGND.
AINCOM
NOTES
1. NC = NO CONNECT.
2. CONNECT EXPOSED PAD TO AGND.
AGND
ACX2
ACX2
ACX1
ACX1
AV
NC
DD
DD
1
2
3
4
5
6
7
8
and AGND + 1 V. The nominal reference voltage, (REFIN(+) − REFIN(−)), is AV
Figure 5.Pin Configuration
Rev. 0 | Page 9 of 44
(Not to Scale)
AD7195
TOP VIEW
DD
is independent of DV
24
23
22
21
20
19
18
17
DV
AV
DGND
AGND
BPDSW
NC
REFIN(–)
REFIN(+)
DD
DD
DD
.
DD
.
DD
− 1 V.
AD7195
DD
,