MS1100

Hangzhou Ruimeng Technology Co.,Ltd

VERSION : V1.10

2023.05.22

http://www.relmon.com

- PAGE 6 -

FUNCTION DESCRIPTION

The MS1100 is a 16-bit, fully differential, delta-sigma analog-to-digital converter. The MS1100 consists of a

delta-sigma A/D converter with adjustable gain, a 2.048V voltage reference, a clock oscillator, a digital filter

and an I2C interface. It has easy design and configuration, so users can easily achieve accurate measurement

Analog-to-Digital Converter

The MS1100 A/D converter core consists of a differential switched-capacitor delta-sigma modulator

and a digital filter. The modulator measures the voltage difference between the positive and negative

analog inputs and compares it to reference voltage, which is 2.048V in the MS1100. The digital filter

receives a high-speed bit stream from the modulator and outputs digital signal, which is proportional to

the input voltage.

Voltage Reference

The MS1100 has a 2.048V on-board voltage reference without need for external reference.

Output Code Calculation

The number of bits for the MS1100 depends on update rate, as shown in Table 1.

Table 1. Minimum and Maximum Codes

Update Rate

Number Of Bits

Minimum Code

Maximum Code

15SPS

16

-32768

32767

30SPS

15

-16384

16383

60SPS

14

-8192

8191

240SPS

12

-2048

2047

The output code of the MS1100 is in binary two’s complement format, right-justified and sign-extended.

Table 2 shows the output codes for various input levels.

Table 2. Output Codes for Different Input Signals

Data Rate

Differential Input Signal

-2.048V

-1LSB

0 (Ideal)

+1LSB

+2.048V

15SPS

8000H

FFFFH

0000H

0001H

7FFFH

30SPS

C000H

FFFFH

0000H

0001H

3FFFH

60SPS

E000H

FFFFH

0000H

0001H

1FFFH

240SPS

F800H

FFFFH

0000H

0001H

07FFH

Note 1: Differential input; do not drive the MS1100 absolute inputs below −200mV.

The output code is given by the expression:

Output Code = -1×Minimum Code×PGA× (

) ( )

IN+

IN-

V

- V

2.048V

..............................(VIN+＜VIN-)

Output Code = 1×Maximum Code×PGA× (

) ( )

IN+

IN-

V

- V

2.048V

..............................(VIN+≥VIN-)

The maximum code is 2n-1

-1, while the minimum code is -1×2n-1.