ina219 datasheet
Table Of Contents
- 1 Features
- 2 Applications
- 3 Description
- Table of Contents
- 4 Revision History
- 5 Related Products
- 6 Pin Configuration and Functions
- 7 Specifications
- 8 Detailed Description
- 8.1 Overview
- 8.2 Functional Block Diagram
- 8.3 Feature Description
- 8.4 Device Functional Modes
- 8.5 Programming
- 8.6 Register Maps
- 9 Application and Implementation
- 10 Power Supply Recommendations
- 11 Layout
- 12 Device and Documentation Support
- 13 Mechanical, Packaging, and Orderable Information
V = V - GND
BUS IN-
Range of 0V to 26V
Typical Application 12V
Data (SDA)
3.3V Supply
Clock (SCL)
´
Power Register
Current Register
I C-/SMBUS-
Compatible
Interface
2
Voltage Register
V
IN+
V
IN-
ADC
PGA
INA219
GND
A0
A1
V = V - V
SHUNT IN+ IN-
Typically < 50mV
Supply Load
-
+
INA219 Power-Supply Voltage
3V to 5.5V
V
S
R
SHUNT
INA219
SBOS448G –AUGUST 2008–REVISED DECEMBER 2015
www.ti.com
Feature Description (continued)
Figure 13. INA219 Configured for Shunt and Bus Voltage Measurement
Although the INA219 can be read at any time, and the data from the last conversion remain available, the
conversion ready bit (Status register, CNVR bit) is provided to help coordinate one-shot or triggered conversions.
The conversion ready bit is set after all conversions, averaging, and multiplication operations are complete.
The conversion ready bit clears under any of these conditions:
• Writing to the Configuration register, except when configuring the MODE bits for power down or ADC off
(disable) modes
• Reading the Status register
• Triggering a single-shot conversion with the convert pin
8.3.1.1 Power Measurement
Current and bus voltage are converted at different points in time, depending on the resolution and averaging
mode settings. For instance, when configured for 12-bit and 128 sample averaging, up to 68 ms in time between
sampling these two values is possible. Again, these calculations are performed in the background and do not add
to the overall conversion time.
8.3.1.2 PGA Function
If larger full-scale shunt voltages are desired, the INA219 provides a PGA function that increases the full-scale
range up to 2, 4, or 8 times (320 mV). Additionally, the bus voltage measurement has two full-scale ranges: 16 or
32 V.
8.3.1.3 Compatibility With TI Hot Swap Controllers
The INA219 is designed for compatibility with hot swap controllers such the TI TPS2490. The TPS2490 uses a
high-side shunt with a limit at 50 mV; the INA219 full-scale range of 40 mV enables the use of the same shunt for
current sensing below this limit. When sensing is required at (or through) the 50-mV sense point of the TPS2490,
the PGA of the INA219 can be set to /2 to provide an 80-mV full-scale range.
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