ISO1540
ISO1541
www.ti.com
SLLSEB6B –JULY 2012–REVISED MAY 2013
Typical Application Circuit
VS
0.1μF
3.3V
2
MBR0520L
MBR0520L
1:2.2
5V
ISO
0.1μF
3
1
1
5
2
Vcc
D2
IN
OUT
8
10μF
LP2981-50
ON GND
VDD
4
SN6501
10μF 0.1μF
9
10
1
3
SDA
AIN0
4 Analog
Inputs
D1
SCL
GND
4,5
ADS1115
1Ω
10μF
ADDR
AIN3
7
GND RDY
3
2
5V
ISO
5V
ISO
6
2
ISO-BARRIER
V
V
IN
OUT
5V
ISO
22μF
1μF
0.1μF
REF5040
GND
4
0.1μF
0.1μF
15
4
12
3
0.1μF
1.5k
9
1.5k
1.5k
1.5k
A2 VDD
SDA
IOV
V
DD REF
H
11
10
9
1
V A
OUT
2
1
8
SCL
LDAC
A1
VCC1
VCC2
SDA2
4 Analog
Outputs
DVcc
DAC8574
5
6
2
3
7
6
XOUT
XIN
SDA1
SDA
MSP430
G2132
DVss
ISO1541
8
14
SCL1
GND1
4
SCL2
GND2
5
V
D
SCL
OUT
8
A0 A3 GND
V L
REF
13 16
6
5
4
Figure 11. Isolated I2C Data Acquisition System
In Figure 11, the ultra low-power micro controller, MSP430G2132, controls the I2C data traffic of configuration
data and conversion results for the analog inputs and outputs. Low-power data converters build the analog
interface to sensors and actuators. The ISO1541 provides the necessary isolation between different ground
potentials of the system controller, remote sensor, and actuator circuitry to prevent ground loop currents that
otherwise may falsify the acquired data.
The entire circuit operates from a single 3.3 V supply. A low-power push-pull converter, SN6501, drives a center-
tapped transformer whose output is rectified and linearly regulated to provide a stable 5 V supply for the data
converters.
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