LD20 Liquid Flow Sensor Series

www.sensirion.com

Preliminary version 0.6 – December 2016

3/6

3 Communication with the Sensor (Preliminary data, subject to change)

The LD20-2600B flow sensor shows bi-directional,

linear transfer characteristics. The product comes fully

calibrated for water.

Digital sampling time, 16 bit

74 ms

Digital sampling time, 9 bit

1 ms

3.1 Electrical Specifications

Parameter

Conditions

Min. Typ. Max. Units

Power supply

DC, VDD

Sensor only

3.3

3.5

3.7

V

Operating

current

VDD = 3.5 V

5.1

mA

Table 2: DC characteristics

3.2 Electrical Connector and Pad Assignment

The liquid flow sensor is equipped with metal contact

Pad

Description

1

SDA (data)

2

SCL (clock)

3

VDDD

4

VDDA

5

GND

Table 3: Electrical pad layout

g

Please note, that the electrical connector provided as part of the

evaluation kit for testing purposes will not be commercially

available. Its design is in the scope of the customer.

3.3 Digital Communication via I²C-Bus

Digital communication between a master and the

LD20 sensor runs via the standard I²C-interface. The

physical interface consists of two bus lines, a data line

(SDA) and a clock line (SCL) which need to be

connected via pull-up resistors to the bus voltage of

(hexadecimal: 40, binary: 1000000).

These lines can be used on the 3.3 V level with a

clock frequency of 100 kHz. For the detailed

specifications of this I²C communication, please refer

to the specific I²C Application Notes from Sensirion.

Parameter

Min.

Typ. Max. Units

100

kHz

Output voltage low

0.1

0.5

V

Low level output current

(SDA/SCL)

6

mA

High level input voltage

(SDA/SCL)

2.0

V

Low level input voltage

(SDA/SCL)

1.0

V

Table 4: I²C output characteristics

1 … 5