SI7021-A20 datasheet, PDF - EEWORLD Datasheet

Datasheet> All Categories > SI7021-A20

Preview

SI7021-A20: DescriptionIC HUMIDITY AND TEMPERATURE SENSOR; File Size910KB，36 Pages; ManufacturerSILABS; Websitehttp://www.silabs.com

Download Datasheet View All

SI7021-A20 Overview

IC HUMIDITY AND TEMPERATURE SENSOR

Preview

Download Datasheet

View All

S i7021- A2 0

C H

UMIDITY

Features



AND

E M P E R A T U R E

E N S O R

Precision Relative Humidity Sensor



± 3% RH (max), 0–80% RH

High Accuracy Temperature Sensor



±0.4 °C (max), –10 to 85 °C

0 to 100% RH operating range

Up to –40 to +125 °C operating

range

Wide operating voltage

(1.9 to 3.6 V)

Low Power Consumption



150

μA

active current



60 nA standby current



Factory-calibrated

C Interface

Integrated on-chip heater



3x3 mm DFN Package



Excellent long term stability



Optional factory-installed cover



Low-profile



Protection during reflow



Excludes liquids and particulates

Ordering Information:

See page 29.

Applications

HVAC/R

Thermostats/humidistats

Respiratory therapy



White goods



Indoor weather stations



Micro-environments/data centers



Automotive climate control and

Pin Assignments

defogging



Asset and goods tracking



Mobile phones and tablets

Top View

Description

The Si7021 I

C Humidity and Temperature Sensor is a monolithic CMOS IC

integrating humidity and temperature sensor elements, an analog-to-digital

converter, signal processing, calibration data, and an I

C Interface. The patented

use of industry-standard, low-K polymeric dielectrics for sensing humidity enables

the construction of low-power, monolithic CMOS Sensor ICs with low drift and

hysteresis, and excellent long term stability.

The humidity and temperature sensors are factory-calibrated and the calibration

data is stored in the on-chip non-volatile memory. This ensures that the sensors

are fully interchangeable, with no recalibration or software changes required.

The Si7021 is available in a 3x3 mm DFN package and is reflow solderable. It can

be used as a hardware- and software-compatible drop-in upgrade for existing RH/

temperature sensors in 3x3 mm DFN-6 packages, featuring precision sensing

over a wider range and lower power consumption. The optional factory-installed

cover offers a low profile, convenient means of protecting the sensor during

assembly (e.g., reflow soldering) and throughout the life of the product, excluding

liquids (hydrophobic/oleophobic) and particulates.

The Si7021 offers an accurate, low-power, factory-calibrated digital solution ideal

for measuring humidity, dew-point, and temperature, in applications ranging from

HVAC/R and asset tracking to industrial and consumer platforms.

Patent Protected. Patents pending

Rev. 1.1 6/15

Si7021-A20

Si7021-A 20

A B L E

Section

ONTENTS

Page

1. Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

2. Typical Application Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

3. Bill of Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

4. Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

4.1. Relative Humidity Sensor Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

4.2. Hysteresis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

4.3. Prolonged Exposure to High Humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

4.4. PCB Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

4.5. Protecting the Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

4.6. Bake/Hydrate Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

4.7. Long Term Drift/Aging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

5. I C Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

5.1. Issuing a Measurement Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

5.2. Reading and Writing User Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

5.3. Electronic Serial Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

5.4. Firmware Revision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

5.5. Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

6. Control Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

6.1. Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

7. Pin Descriptions: Si7021 (Top View) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

8. Ordering Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

9. Package Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30

9.1. Package Outline: 3x3 6-pin DFN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30

9.2. Package Outline: 3x3 6-pin DFN with Protective Cover . . . . . . . . . . . . . . . . . . . . . .31

10. PCB Land Pattern and Solder Mask Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

11. Top Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

11.1. Si7021 Top Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

11.2. Top Marking Explanation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

12. Additional Reference Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

Document Change List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35

Contact Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36

Rev. 1.1

Recommended Resources

Will you use the ultra-wide ultra-high voltage input power module PV200-29Bxx?

electric blanket circuit

New micropower low dropout voltage regulator application circuit 04

Anbaolo MA-2318 mechanical microwave oven circuit diagram

Using parallel resonance to increase crystal frequency circuit

Circuit diagram: Fat analyzer circuit schematic_page_4

About the installation problem of AODV-UU-0.9.5: My kernel version is Ubuntu 2.6.28. How can I install the aodv protocol on it? I am just starting out. I hope you can give me some detailed help....; wenli1985wl Embedded System

The hardware description of the LM4F232 development board for trial use, I hope everyone can finally get: Hardware resources:Processor: LM4F232H5QC, CORTEX M4 80MHz, 256k Flash, 32k SRAM Onboard 2MB SPI Flash (W25Q16)Onboard 2048-Bit I2C EEPROM (AT24L02) Support 2.8- inch TFT LCD with touch screen ( resol...; vvv9876 Microcontroller MCU

How to display images in the driver?: How do I display images in the driver? The more detailed the better?...; zhaopingsong Embedded System

Urgent help on simple current-stabilized power supply output: Why add a differential circuit?...; IT学徒 Power technology

Ask about the problem of interrupt function migration: I put the interrupt function in the main function, and the interrupt is executed normally. If I want to move the interrupt function to another .c file, the interrupt will not be executed. Please ask t...; jpxuchao ARM Technology

Questions about ICD2.5: In ICD2.5, how many states should the PIC16F877's 4th pin (RA2) and 7th pin (RA5) have? My RA5 is always high, and RA2 is always low, and I just can't find the target. Does anyone know what's going on...; 职尚 MCU

Shortcut: S0 S1 S2 S3 S4 S5 S6 S7 S8 S9 SA SB SC SD SE SF SG SH SI SJ SK SL SM SN SO SP SQ SR SS ST SU SV SW SX SY SZ T0 T1 T2 T3 T4 T5 T6 T7 T8 T9 TA TB TC TD TE TF TG TH TI TJ TK TL TM TN TO TP TQ TR TS TT TU TV TW TX TY TZ U0 U1 U2 U3 U4 U6 U7 U8 UA UB UC UD UE UF UG UH UI UJ UK UL UM UN UP UQ UR US UT UU UV UW UX UZ V0 V1 V2 V3 V4 V5 V6 V7 V8 V9 VA VB VC VD VE VF VG VH VI VJ VK VL VM VN VO VP VQ VR VS VT VU VV VW VX VY VZ W0 W1 W2 W3 W4 W5 W6 W7 W8 W9 WA WB WC WD WE WF WG WH WI WJ WK WL WM WN WO WP WR WS WT WU WV WW WY X0 X1 X2 X3 X4 X5 X7 X8 X9 XA XB XC XD XE XF XG XH XK XL XM XN XO XP XQ XR XS XT XU XV XW XX XY XZ Y0 Y1 Y2 Y4 Y5 Y6 Y9 YA YB YC YD YE YF YG YH YK YL YM YN YP YQ YR YS YT YX Z0 Z1 Z2 Z3 Z4 Z5 Z6 Z8 ZA ZB ZC ZD ZE ZF ZG ZH ZJ ZL ZM ZN ZP ZR ZS ZT ZU ZV ZW ZX ZY

Popular Components