INA186A1IDCKR — Bidirectional Zero-Drift Current-Sense Amplifier
1. Component Overview
"(《世界人权宣言》) INA186A1IDCKR is a high-precision, bidirectional, zero-drift current-sense amplifier (also known as a current shunt monitor) manufactured by 德州仪器. It is designed to sense the voltage drop across a shunt resistor and provide a scaled output voltage proportional to the current flowing through the load, independent of the common-mode bus voltage.
The “A1” variant features a fixed gain of 25 V/V. The device operates from a single supply of 1.7V to 5.5V and can handle common-mode voltages from –0.2V to +40V. Its ultra-low input bias current of 500 pA (typical) enables accurate microamp-level current measurements using larger sense resistors. The zero-drift architecture delivers an offset voltage of only ±50 µV (max), extending the measurable dynamic range significantly.
Housed in a compact 6-pin SC70 (DCK) package, the INA186A1IDCKR is ideal for space-constrained applications in consumer electronics, industrial systems, and IoT devices.
2. Key Specifications
| Parameter | Value |
|---|---|
| 制造商 | 德州仪器 |
| 部件编号 | INA186A1IDCKR |
| Component Type | Current-Sense Amplifier (Zero-Drift) |
| Amplifier Type | 电流感应 |
| Fixed Gain | 25 V/V |
| Common-Mode Voltage Range | –0.2V to +40V |
| Supply Voltage (VS) | 1.7V to 5.5V |
| Quiescent Current (IQ) | 48 µA (typ), 90 µA (max) |
| Input Bias Current (IIB) | 500 pA (typ) |
| Input Offset Voltage (VOS) | ±5 µV (typ), ±50 µV (max) |
| Offset Voltage Drift | 0.5 µV/°C (max) |
| Gain Error | ±1% (max) |
| Gain Drift | 10 ppm/°C (max) |
| Common-Mode Rejection Ratio (CMRR) | 120 dB (min), ~150 dB (typ) |
| Gain Bandwidth Product | 45 kHz |
| 压摆率 | 0.3 V/µs |
| 输出类型 | Rail-to-Rail |
| Current Sensing Direction | Bidirectional |
| 包装 | SC70-6 (DCK) |
| 安装类型 | Surface Mount (SMT) |
| 工作温度 | –40°C to +125°C |
| ESD 额定值（HBM） | ±3,000 V |
| ESD 等级（CDM） | ±1,000 V |
| Packing | Tape & Reel (3,000 units/reel) |
| RoHS Compliant | Yes |
3. Pin Configuration & Package
封装: 6-Pin SC70 (DCK) — 2.00 mm × 1.25 mm
| 针脚编号. | 引脚名称 | 功能 |
|---|---|---|
| 1 | REF | Reference Pin — sets output zero-point for bidirectional sensing; connect to GND for unidirectional mode |
| 2 | 接地 | Ground Reference |
| 3 | IN+ | Non-Inverting Input (connect to high-side of shunt) |
| 4 | VS | Supply Voltage (1.7V – 5.5V) |
| 5 | IN– | Inverting Input (connect to low-side of shunt) |
| 6 | 出局 | Amplifier Output (rail-to-rail) |
Note: The SC70 package does not include a dedicated ENABLE pin. The DCK and DDF packages support the REF pin for bidirectional operation.
4. Features & Functional Description
- Zero-Drift Architecture: Chopper-stabilized design continuously corrects offset voltage, achieving ±5 µV typical offset. This enables precision measurement of very small voltage drops across low-value shunt resistors.
- Ultra-Low Input Bias Current: 500 pA typical input bias current allows the use of higher-value sense resistors for microamp-level current measurement without significant measurement error.
- Capacitively Coupled Input Stage: DC common-mode voltages are inherently blocked from downstream amplifier circuits, resulting in exceptionally high common-mode rejection (120 dB minimum, ~150 dB typical).
- Ultra-Low Power Consumption: Only 48 µA quiescent current makes the INA186 ideal for battery-powered and energy-harvesting applications.
- Bidirectional Current Sensing: The REF pin allows the output to be centered at a reference voltage, enabling measurement of current flowing in both directions through the shunt.
- Wide Common-Mode Range: –0.2V to +40V common-mode range covers most bus voltages in consumer, industrial, and automotive systems.
- Rail-to-Rail Output: Output swings to within 40 mV of the positive rail and 1 mV of ground, maximizing dynamic range especially at low supply voltages (e.g., 1.8V).
- Five Gain Options Available: INA186A1 (25 V/V), A2 (50 V/V), A3 (100 V/V), A4 (200 V/V), A5 (500 V/V).
5.典型应用
- Battery Monitoring: Charge/discharge current measurement in smartphones, laptops, and portable electronics.
- Overcurrent Protection: Precise threshold detection for system protection in power supplies and motor drivers.
- Power Management: Load current monitoring and power budgeting in servers, BBU (baseband units), and networking equipment.
- Motor Control Feedback: Closed-loop current sensing in BLDC and stepper motor drive systems.
- IoT Energy Meters: Ultra-low power consumption suits battery-operated smart meters and wireless sensors.
- Solar Charge Controllers: Precise current measurement for MPPT optimization.
- USB Type-C Power Delivery: Current monitoring for PD negotiation and overcurrent protection.
6. Equivalent & Alternative Parts
| 部件编号 | 制造商 | 说明 | Key Differences |
|---|---|---|---|
| INA186A2IDCKR | 德州仪器 | Same device, 50 V/V gain | Double the gain of A1 variant |
| INA186A3IDCKR | 德州仪器 | Same device, 100 V/V gain | Higher gain for smaller shunt measurements |
| INA180A1 | 德州仪器 | Similar zero-drift current sense amp | Different gain options, different package options |
| INA228 | 德州仪器 | Digital (I²C) current/power monitor | Digital output vs. analog; integrated ADC |
| MAX4080F | Analog Devices / Maxim | High-side current sense amplifier | Single supply, fixed gain, unidirectional |
| ACS37800 | Allegro MicroSystems | Isolated current sensor | Galvanic isolation, higher current range |
| INA185A1 | 德州仪器 | Bidirectional current sense amplifier | Lower CMRR, lower cost, different bandwidth |
7. Design Recommendations
- Select a shunt resistor value that produces an input differential voltage within the amplifier’s linear range. For 25 V/V gain and a 3.3V supply, maximum sense voltage is approximately 130 mV.
- Place the INA186 as close as possible to the shunt resistor to minimize PCB trace resistance errors and noise pickup.
- Use a 0.1 µF bypass capacitor on the VS pin near the IC for stable operation and noise filtering.
- For bidirectional sensing, buffer the REF pin voltage with a low-impedance source to avoid CMRR degradation. A simple resistor divider without buffering is not recommended.
- Add series protection resistors (≤ 1 kΩ) on IN+ and IN– inputs if the application is subject to voltage transients exceeding the absolute maximum ratings.
- For transient protection, use Zener diodes or transzorbs (not standard TVS) to clamp fast voltage spikes, as specified in the TI application notes.
- The SC70-6 package supports both high-side and low-side current sensing configurations. For low-side sensing, ensure the common-mode voltage stays within the specified –0.2V to +40V range.
English 
简体中文 
Español 
العربية