AD4695BCPZ datasheet(27/96 Pages) AD

27 / 96 page

Data Sheet

AD4695/AD4696

Rev. 0 | Page 27 of 96

Table 8. Output Codes and Ideal Input Voltages, VREF = 5 V, OSR = 4

Description

Input Voltage in

Unipolar Mode

Digital Output Code

(Straight Binary)

Input Voltage in Pseudo

Bipolar Mode

Digital Output Code (Twos

Complement)

FSR − 1 LSB

4.999962 V

0x1FFFF

2.499962 V

0x0FFFF

Midscale + 1 LSB

2.500038 V

0x10001

38.1 μV

0x00001

Midscale

2.5 V

0x10000

0 V

0x00000

Midscale − 1 LSB

2.499962 V

0x0FFFF

−38.1 μV

0x1FFFF

−FSR + 1 LSB

38.1 μV

0x00001

−2.499962 V

0x10001

−FSR

0 V

0x00000

−2.5 V

0x10000

Table 9. Output Codes and Ideal Input Voltages, VREF = 5 V, OSR = 16

Description

Input Voltage in

Unipolar Mode

Digital Output Code

(Straight Binary)

Input Voltage in Pseudo

Bipolar Mode

Digital Output Code (Twos

Complement)

FSR − 1 LSB

4.999981 V

0x3FFFF3

2.499981 V

0x1FFFF

Midscale + 1 LSB

2.500019 V

0x20001

19.1 μV

0x00001

Midscale

2.5 V

0x20000

0 V

0x00000

Midscale − 1 LSB

2.499981 V

0x1FFFF

−19.1 μV

0x3FFFF

−FSR + 1 LSB

19.1 μV

0x00001

−2.499981 V

0x20001

−FSR

0 V

0x000004

−2.5 V

0x20000

Table 10. Output Codes and Ideal Input Voltages, VREF = 5 V, OSR = 64

Description

Input Voltage in

Unipolar Mode

Digital Output Code

(Straight Binary)

Input Voltage in Pseudo

Bipolar Mode

Digital Output Code (Twos

Complement)

FSR − 1 LSB

4.999910 V

0x7FFFF3

2.499990 V

0x3FFFF

Midscale + 1 LSB

2.500010 V

0x40001

9.54 μV

0x00001

Midscale

2.5 V

0x40000

0 V

0x00000

Midscale − 1 LSB

2.499990 V

0x3FFFF

−9.54 μV

0x7FFFF

−FSR + 1 LSB

9.54 μV

0x00001

−2.499990 V

0x40001

−FSR

0 V

0x000004

−2.5 V

0x40000

ANALOG INPUTS

Figure 64 shows an equivalent circuit of the AD4695/AD4696

analog inputs (IN0 to IN15 and COM).

CEXT

REXT

VIN

REF

IN0 TO IN15,

COM

REFGND

CLAMP

RIN

CDAC

CPIN

Figure 64. Equivalent Analog Input Circuit

A low crosstalk analog multiplexer routes the signals from the

analog input pins to the ADC core inputs. The impedance of the

analog inputs are modeled as the parallel combination of the

pin capacitance (CPIN) and the network formed by the series

connection of RIN and CDAC. RIN represents the ADC input series

resistance and the multiplexer switch resistance and is typically

240 Ω. CDAC represents the ADC sampling capacitive DAC shown

in Figure 61, and is typically 60 pF.

Each analog input has a unique overvoltage protection clamp

circuit, represented by OV clamp in Figure 64. The clamps

protect the analog inputs from dc overvoltage conditions and

eliminate the need for additional external protection diodes. See

the Input Overvoltage Protection Clamps section for a detailed

description of the overvoltage protection clamps.

REXT and CEXT in Figure 64 represent an external, RC low-pass

filter, which is included in the system design to limit the bandwidth

of the input signal. REXT can also be used to improve overvoltage

protection of the analog inputs. See the External RC Filter section

for detailed descriptions of the REXT and CEXT functions.

AD4695BCPZ Datasheet(PDF) 27 Page - Analog Devices

AD4695BCPZ Datasheet(HTML) 27 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96

Datasheet Download

Link URL