Information

76 | Signal Chain Guide 2013 Texas Instruments
Monitoring and Control
Current Shunt Monitors/Current Sense Amplifiers
Get more information: www.ti.com/product/INA3221
Get more information: www.ti.com/product/LMP8480,
www.ti.com/product/LMP8481
Triple Channel Shunt and Bus Voltage Monitor
INA3221
Precison 76 V High-Side Current Sense Amps with Volt Output
LMP8480/1
INA3221 functional block diagram
LMP8480/1 functional block diagram
The INA3221 is a three-channel, high-side current and bus voltage monitor with an I
2
C
interface. The INA3221 monitors both shunt voltage drops and bus supply voltages
in addition to having programmable conversion times and averaging modes for these
signals. The INA3221 offers both critical and warning alerts to detect multiple program
-
mable out-of-range conditions for each channel.
The LMP8480 and LMP8481 ar
e precision high-side current sense amplifiers that
amplify a small differential voltage developed across a current sense resistor in the
presence of high input common-mode voltages.
These amplifiers are designed for bidirectional (LMP8481) or unidirectional (LMP8480)
current applications and will accept input signals with common-mode voltage range
from 4 V to 76 V with a bandwidth of 270 kHz.
Key Features
• Sensesbusvoltagesfrom0Vto+26V
• Reportsshuntandbusvoltage
• Highaccuracy
• Configurableaveragingoptions
• Fourprogrammableaddresses
• Power-supplyoperation:2.7Vto5.5V
• Programmablealertandwarning
outputs
Applications
• Computers
• Powermanagement
• Telecomequipment
• Batterychargers
• Powersupplies
• Testequipment
Key Features
• Bi-directionaloruni-directionalsensing
• Commonmodevoltagerange4.0Vto
76 V
• Supplyvoltagerange4.5Vto76V
• Fixedgains20,50,60and100V/V
• Gainaccuracy±0.1%
• Offset±80µV
• Bandwidth(–3dB)270KHz
• Quiescentcurrent<100µA
• Bufferedhigh-currentoutput>5mA
• Inputbiascurrent7µA
Applications
• EnergyManagement
• High-sidecurrentsense
• LaserorLEDDrivers
• Motorcontrols
• Solarpanelmonitoring
• Telecommunications
• Vehiclecurrentmeasurement
Power Supply
(0V to 26V)
Power Supply
(0V to 26V)
Power Supply
(0V to 26V)
Load 2
Load 1
Load 3
GND
CH3
CH2
CH1
Bus
Voltages 1-3
Shunt
Voltages 1-3
Critical Limit
Alerts 1-3
Shunt Voltage
Sum Alerts
VPU
Power Valid
Critical
Warning
Timing Control
I
2
C
Interface
SDA
SCL
A0
10 kΩ
10 kΩ
V
PU
V
S
Vs (Supply
Voltage)
C
BYPASS
0.1 µF
V
IN+
2
V
IN-
2
V
IN+
1 V
IN-
1
V
IN+
3 V
IN-
3
ADC
V
CC
= +4.5 V to +76 V
C1
0.1 µF
V
OUT
To Load
R
SENSE
I
SENSE
ADC
RSN
RSP
REFA
REFB
GND
LMP8481
LM4140ACM-1.2
V
IN
+
V
IN
-
V
REF
C2
0.1 µF
V
SENSE