Overview
The AD8218BRMZ from Analog Devices Inc. is a high voltage, high resolution current shunt amplifier designed for bidirectional current measurements across a shunt resistor. It is particularly suited for various industrial and telecom applications, including motor control, battery management, and base station power amplifier bias control. The AD8218 features a set gain of 20 V/V and operates within a wide common-mode voltage range of 4 V to 80 V. It boasts excellent AC and DC performance, with a typical offset drift of ±100 nV/°C and a gain drift of ±5 ppm/°C. The device is available in an 8-lead MSOP package and supports a wide operating temperature range from -40°C to 125°C.
Key Specifications
| Parameter | Min | Typ | Max | Unit | Test Conditions/Comments |
|---|---|---|---|---|---|
| Gain | - | 20 | - | V/V | Initial gain |
| Gain Accuracy | - | - | ±0.35% | % | Over temperature range |
| Gain vs. Temperature | - | ±5 | - | ppm/°C | - |
| Offset Voltage | - | ±50 | ±200 | µV | At 25°C, over temperature range |
| Offset Drift | - | ±100 | - | nV/°C | - |
| Input Bias Current | - | 130 | 220 | µA | At TA, input common mode = 4 V, VS = 4 V |
| Common-Mode Input Voltage Range | 4 | - | 80 | V | - |
| Differential Input Voltage Range | 0 | - | 250 | mV | - |
| Operating Temperature Range | -40 | - | 125 | °C | - |
| Supply Voltage Range | 4 | - | 80 | V | - |
| CMRR | - | 110 | - | dB | At DC |
| Bandwidth | - | 450 kHz | - | - | Small signal -3dB bandwidth at Vs=5V |
| Slew Rate | - | 1 V/µs | - | - | Typical |
| Package Type | - | - | - | - | 8-lead MSOP |
Key Features
- High Common-Mode Voltage Range: Operates from 4 V to 80 V, with a survival range of -0.3 V to +85 V.
- Buffered Output Voltage: Directly interfaces with any typical converter, ensuring compatibility and ease of use.
- Excellent AC and DC Performance: Features a typical offset drift of ±100 nV/°C and a gain drift of ±5 ppm/°C, ensuring high accuracy over the operating temperature range.
- High Gain Accuracy: Initial gain of 20 V/V with a maximum ±0.35% gain error over the entire temperature range.
- Wide Operating Temperature Range: From -40°C to 125°C, making it suitable for a variety of applications.
- High CMRR and PSRR: 110 dB typical CMRR at DC and 110 dB typical Power Supply Rejection Ratio (PSRR).
- Zero-Drift Core: Provides breakthrough temperature stability and optimal accuracy and dynamic range.
- Internal LDO and Reference: Includes an internal LDO and an 80 mV reference for optimal dynamic range in unidirectional current sense applications.
Applications
- High-Side Current Sensing: Ideal for monitoring current in high-side configurations.
- 48V Telecom: Suitable for power management in telecom systems.
- Power Management: Used in various power management applications, including battery management and power amplifier bias control.
- Base Stations: Employed in base station power management and control systems.
- Bidirectional Motor Control: Facilitates precise current measurement in bidirectional motor control applications.
- Precision High Voltage Current Sources: Used in applications requiring high accuracy and high voltage current sourcing.
Q & A
- What is the gain of the AD8218BRMZ?
The AD8218BRMZ has an initial gain of 20 V/V.
- What is the operating temperature range of the AD8218BRMZ?
The operating temperature range is from -40°C to 125°C.
- What is the common-mode voltage range of the AD8218BRMZ?
The common-mode voltage range is from 4 V to 80 V.
- What is the typical offset drift of the AD8218BRMZ?
The typical offset drift is ±100 nV/°C.
- What is the bandwidth of the AD8218BRMZ?
The small signal -3dB bandwidth at Vs=5V is 450 kHz.
- What package types are available for the AD8218BRMZ?
The AD8218BRMZ is available in an 8-lead MSOP package.
- What are some typical applications of the AD8218BRMZ?
Typical applications include high-side current sensing, 48V telecom, power management, base stations, bidirectional motor control, and precision high voltage current sources.
- Does the AD8218BRMZ have an internal LDO and reference?
Yes, the AD8218BRMZ includes an internal LDO and an 80 mV reference.
- What is the CMRR of the AD8218BRMZ at DC?
The CMRR at DC is typically 110 dB.
- How does the AD8218BRMZ handle high common-mode voltages?
The AD8218BRMZ offers excellent input common-mode rejection from 4 V to 80 V, ensuring high accuracy in high common-mode voltage applications.
