INA238-Q1
High-Precision Digital Power MonitorThe INA238-Q1 is a high-precision digital power monitor from Texas Instruments. View the full INA238-Q1 datasheet below including electrical characteristics, absolute maximum ratings.
Manufacturer
Texas Instruments
Category
High-Precision Digital Power Monitor
Overview
Part: INA238 — Texas Instruments
Type: High-Precision Digital Power Monitor
Description: The INA238 is an ultra-precise 16-bit delta-sigma ADC digital power monitor designed for current-sensing applications, capable of measuring full-scale differential inputs of ±163.84 mV or ±40.96 mV with common-mode voltage support from -0.3 V to +85 V, and features a 2.94-MHz high-speed I2C interface.
Operating Conditions:
- Supply voltage: 2.7 V to 5.5 V
- Operating temperature: -40 to +125 °C
- Common-mode input range: -0.3 V to 85 V
Absolute Maximum Ratings:
- Max supply voltage: 6 V
- Max junction temperature: 150 °C
- Max storage temperature: 150 °C
Key Specs:
- Shunt offset voltage: ±5 μV (maximum, VCM = 48 V or 0 V)
- Shunt offset voltage drift: ±20 nV/°C (maximum, TA = -40°C to +125°C)
- Shunt voltage gain error: ±0.1% (maximum)
- Shunt voltage gain error drift: ±25 ppm/°C (maximum)
- Common-mode rejection: 140 dB (minimum, -0.3 V < VCM < 85 V, TA = -40°C to +125°C)
- Input bias current: 2.5 nA (maximum, VCM = 85 V)
- Power total measurement error (TME): ±0.7% (maximum, TA = -40°C to +125°C, at full scale)
- Quiescent current: 750 μA (maximum, VSENSE = 0 V, TA = 25°C)
Features:
- High-resolution, 16-bit delta-sigma ADC
- Fast alert response: 75 μs
- Wide common-mode range: -0.3 V to +85 V
- Bus voltage sense input: 0 V to 85 V
- Shunt full-scale differential range: ±163.84 mV / ±40.96 mV
- Integrated temperature sensor: ±1°C (maximum at 25°C)
- Programmable conversion time and averaging
- 2.94-MHz high-speed I2C interface with 16 pin-selectable addresses
Applications:
- DC/DC converters and power inverters
- Industrial battery packs
- Power-over-ethernet (PoE)
- Telecom equipment
- Enterprise servers
Package:
- VSSOP (10) - 3.00 mm × 3.00 mm
Features
- High-resolution, 16-bit delta-sigma ADC
- Current monitoring accuracy:
- -Offset voltage: ±5 μV (maximum)
- -Offset drift: ±0.02 μV/°C (maximum)
- -Gain error: ±0.1% (maximum)
- -Gain error drift: ±25 ppm/°C (maximum)
- -Common mode rejection: 140 dB (minimum)
- Power monitoring accuracy:
- -0.7% full scale, -40°C to +125°C (maximum)
- Fast alert response: 75 μs
- Wide common-mode range: -0.3 V to +85 V
- Bus voltage sense input: 0 V to 85 V
- Shunt full-scale differential range:
- ±163.84 mV / ±40.96 mV
- Input bias current: 2.5 nA (maximum)
- Temperature sensor: ±1°C (maximum at 25°C)
- Programmable conversion time and averaging
- 2.94-MHz high-speed I 2 C interface with 16 pinselectable addresses
- Operates from a 2.7-V to 5.5-V supply:
- -Operational current: 640 μA (typical)
- -Shutdown current: 5 μA (maximum)
Applications
- DC/DC converters and power inverters
- Industrial battery packs
- Power-over-ethernet (PoE)
- Telecom equipment
- Enterprise servers
Pin Configuration
Figure 5-1. DGS Package 10-Pin VSSOP Top View
Table 5-1. Pin Functions
| PIN | PIN | TYPE | DESCRIPTION |
|---|---|---|---|
| NO. | NAME | TYPE | DESCRIPTION |
| 1 | A1 | Digital input | I 2 C address pin. Connect to GND, SCL, SDA, or VS. |
| 2 | A0 | Digital input | I 2 C address pin. Connect to GND, SCL, SDA, or VS. |
| 3 | ALERT | Digital output | Open-drain alert output, default state is active low. |
| 4 | SDA | Digital input/output | Open-drain bidirectional I 2 C data. |
| 5 | SCL | Digital input | I 2 C clock input. |
| 6 | VS | Power supply | Power supply, 2.7 V to 5.5 V. |
| 7 | GND | Ground | Ground. |
| 8 | VBUS | Analog input | Bus voltage input. |
| 9 | IN- | Analog input | Negative input to the device. For high-side applications, connect to load side of sense resistor. For low-side applications, connect to ground side of sense resistor. |
| 10 | IN+ | Analog input | Positive input to the device. For high-side applications, connect to power supply side of sense resistor. For low-side applications, connect to load side of sense resistor. |
Electrical Characteristics
at T A = 25 °C, V S = 3.3 V, V SENSE = VIN+ - VIN- = 0 V, V CM = V IN- = 48 V (unless otherwise noted)
| PARAMETER | TEST CONDITIONS | MIN | TYP | MAX | UNIT | |
|---|---|---|---|---|---|---|
| INPUT | ||||||
| V CM | Common-mode input range | T A = -40°C to +125°C | -0.3 | 85 | V | |
| V VBUS | Bus voltage input range | 0 | 85 | V | ||
| CMRR | Common-mode rejection | -0.3 V < V CM < 85 V, T A = -40°C to +125°C | 140 | 160 | dB | |
| V | Shunt voltage input range | T A = -40°C to +125°C, ADCRANGE = 0 | -163.84 | 163.84 | mV | |
| DIFF | T A = -40°C to +125°C, ADCRANGE = 1 | -40.96 | 40.96 | mV | ||
| V | Shunt offset voltage | V CM = 48 V | ±1.5 | ±5 | μV | |
| os | V CM = 0 V | ±1.5 | ±5 | μV | ||
| dV os /dT | Shunt offset voltage drift | T A = -40°C to +125°C | ±2 | ±20 | nV/°C | |
| PSRR | Shunt offset voltage vs power supply | V S = 2.7 V to 5.5 V, T A = -40°C to +125°C | ±0.1 | ±1 | μV/V | |
| V os_bus | V BUS offset voltage | V BUS = 20 mV | ±1 | ±5 | mV | |
| dV os /dT | V BUS offset voltage drift | T A = -40°C to +125°C | ±4 | ±40 | μV/°C | |
| PSRR | V BUS offset voltage vs power supply | V S = 2.7 V to 5.5 V | ±1.1 | mV/V | ||
| I B | Input bias current | Either input, IN+ or IN-, V CM = 85 V | 0.1 | 2.5 | nA | |
| Z VBUS | VBUS pin input impedance | Active mode | 0.8 | 1 | 1.2 | MΩ |
| I VBUS | VBUS pin leakage current | Shutdown mode, V BUS = 85 V | 10 | nA | ||
| R DIFF | Input differential impedance | Active mode, V IN+ - V IN- < 164 mV | 92 | kΩ | ||
| DC | ACCURACY | |||||
| G SERR | Shunt voltage gain error | ±0.01 | ±0.1 | % | ||
| G S_DRFT | Shunt voltage gain error drift | ±25 | ppm/°C | |||
| G BERR | V BUS voltage gain error | ±0.01 | ±0.1 | % | ||
| G B_DRFT | V BUS voltage gain error drift | ±25 | ppm/°C | |||
| P TME | Power total measurement error (TME) ADC resolution | T A = -40°C to +125°C, at full scale Shunt voltage, ADCRANGE = 0 | 16 5 | ±0.7 | % Bits μV | |
| 1 LSB step size | Shunt voltage, ADCRANGE = 1 Bus voltage Temperature | 1.25 3.125 125 | μV mV m°C | |||
| T CT | (1) ADC conversion-time | Conversion time field = 0h Conversion time field = 1h Conversion time field = 2h Conversion time field = 3h Conversion time field = 4h Conversion time field = 5h Conversion time field = 6h Conversion time field = 7h | 50 84 150 280 540 1052 2074 4120 | μs | ||
| INL | Integral Non-Linearity | ±2 | m% | |||
| DNL | Differential Non-Linearity | 0.2 | LSB | |||
| CLOCK | SOURCE | |||||
| F OSC | Internal oscillator frequency | 1 | MHz | |||
| F | Internal oscillator frequency tolerance | T A = 25°C | ±0.5 | % | ||
| OSC_TOL | T A = -40°C to +125°C | ±1 | % |
Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted) (1)
| MIN | MAX | UNIT | ||
|---|---|---|---|---|
| V S | Supply voltage | 6 | V | |
| V IN+ , V IN- (2) | Differential (V IN+ ) - (V IN- ) | -40 | 40 | V |
| V IN+ , V IN- (2) | Common-mode | -0.3 | 85 | V |
| V VBUS | -0.3 | 85 | V | |
| V ALERT | ALERT | -0.3 | V S + 0.3 | V |
| V IO | SDA, SCL | -0.3 | 6 | V |
| I IN | Input current into any pin | 5 | mA | |
| I OUT | Digital output current | 10 | mA | |
| T J | Junction temperature | 150 | °C | |
| T stg | Storage temperature | -65 | 150 | °C |
- (2) VIN+ and VIN- are the voltages at the IN+ and IN- pins, respectively.
Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
| MIN | NOM | MAX | UNIT | ||
|---|---|---|---|---|---|
| V CM | Common-mode input range | -0.3 | 85 | V | |
| V S | Operating supply range | 2.7 | 5.5 | V | |
| T A | Ambient temperature | -40 | 125 | °C |
Thermal Information
| THERMAL METRIC (1) | THERMAL METRIC (1) | INA238 DGS (VSSOP) 10 PINS | UNIT |
|---|---|---|---|
| R θJA | Junction-to-ambient thermal resistance | 177.6 | °C/W |
| R θJC(top) | Junction-to-case (top) thermal resistance | 66.4 | °C/W |
| R θJB | Junction-to-board thermal resistance | 99.5 | °C/W |
| Ψ JT | Junction-to-top characterization parameter | 9.7 | °C/W |
| Y JB | Junction-to-board characterization parameter | 97.6 | °C/W |
| R θJC(bot) | Junction-to-case (bottom) thermal resistance | N/A | °C/W |
Typical Application
The low offset voltage and low input bias current of the INA238 allow accurate monitoring of a wide range of currents. To accurately monitor currents with high resolution, select the value of the shunt resistor so that the resulting sense voltage is close to the maximum allowable differential input voltage range (either ±163.84 mV or ±40.96 mV, depending on register settings). The circuit for monitoring currents in a high-side configuration is shown in Figure 8-2.
Figure 8-2. INA238 High-Side Sensing Application Diagram
Related Variants
The following components are covered by the same datasheet.
| Part Number | Manufacturer | Package |
|---|---|---|
| INA238 | Texas Instruments | — |
| INA238AIDGSR | Texas Instruments | VSSOP-10-0.5mm |
Get structured datasheet data via API
Get started free