Datasheet

Datasheet EK-H4
www.sensirion.com Version 4 – July 2015 2/8
Specification
Electrical specification:
Parameter
min
typ
max
Unit
External Supply
Input Voltage
8
9
10
V
Input Voltage Ripple
0.5
V
Supply Current
170
280
mA
USB Supply
Input Voltage
4.75
5
5.25
V
Supply Current
170
280
mA
Sensor Supply
Voltage
Range
1.8
3.0
3.6
V
Resolution
0.1
V
Accuracy
2
5
%
Output current
40
110
1
mA
Temperature Resolution
11
14
Bit
Humidity Resolution
8
12
Bit
Measurement interval
1
1440
s
Communication
USB (via Virtual Com Port (VCP))
Operating
Temperature
0 to 50°C (multiplexer box)
-20 to 70°C (cables, sensor)
Default Configuration
After power-up two different voltages ranges (2.1V to 3.6V
& 1.8V) can be chosen through the push button on the top
of the evaluation kit.
Parameter
Default value
Sensor Supply Voltage
3.0 V
Temperature Resolution
12 Bit
Humidity Resolution
12 Bit
Measurement interval
1 s
Heater
off
OTP reload
SHT7x
on
SHT2x
off
Power Supply
Used Connection
EK-H4 supplied from
DC
DC (9V)
DC and USB
DC (9V)
USB
USB (5V)
The EK-H4 may be supplied by DC Power Supply Unit at
9V or USB connection at 5V. Power supply by USB is only
possible if USB driver is installed correctly.
Pin
Name
Comment
-
GND
Ground
+
Positive
Voltage
9V Supply
1
short circuit current
Table 1 DC Power Supply: Pin Diagram
EK-H4 Circuit Board
EK-H4 Pin Assignment
RJ45 Pin
Sensor Pin
Name
Description
1
3
VSS
Ground
3
1
SCL
Serial clock
5
2
VDD
Supply voltage
7
4
SDA
Serial data
Table 2 Pin Assignments: Female RJ45 pin diagram on the
left – SHTxx on PCB, SHT71 and SHTxx on FPCB sensors on
the right of the upper panel.
LED Functions
LED
Function
Power LED
LED off denotes low supply
voltage (DC < 8V, USB < 4.75V)
or not connected.
RJ45
Connector
Green LED
Sensor detected
Orange LED
Measurement is in progress
4 sensor channels
Display
2 buttons for
display modes
User field
connected to MCU
Micro Controller Unit
Debug interface
Reset button
USB interface
Power supply
Power LED
8 1
1 2 3 4
2 1 3 4
1 2 3 4
+