Overview
The AFE4490RHAR from Texas Instruments is a fully-integrated analog front-end (AFE) designed specifically for pulse-oximeter applications. This device combines a low-noise receiver channel, an LED transmit section, and comprehensive diagnostics for sensor and LED fault detection. It features a highly configurable timing controller, allowing users to have complete control over the device’s timing characteristics. The AFE4490 also includes an integrated oscillator that can operate from an external crystal or a clock from an external host processor, ensuring low-jitter clocking. Communication with an external microcontroller or host processor is facilitated through an SPI interface.
Key Specifications
| Parameter | Specification |
|---|---|
| Package Type | VQFN-40 (6 mm × 6 mm) |
| Number of Channels | 1 |
| Voltage - Supply, Analog | 2.0 V to 3.6 V |
| Voltage - Supply, Digital | 2.0 V to 3.6 V |
| Voltage - Supply, Tx Control | 3.0 V to 5.25 V |
| Voltage - Supply, LED Driver | 3.0 V to 5.25 V |
| Operating Temperature Range | –40°C to 85°C |
| Analog-to-Digital Converter (ADC) | 22-bit |
| Mounting Type | Surface Mount |
Key Features
- Low-Noise Receiver Channel: Optimized for high sensitivity and low noise in pulse-oximeter applications.
- LED Transmit Section: Includes settings for LED current control and transmitter reference voltage.
- Diagnostics for Sensor and LED Fault Detection: Comprehensive diagnostics to ensure reliable operation.
- Configurable Timing Controller: Allows complete control over device timing characteristics.
- Integrated Oscillator: Can operate from an external crystal or an external host processor clock, providing a low-jitter clock.
- SPI Interface: Facilitates communication with an external microcontroller or host processor.
- Compact Packaging: VQFN-40 package (6 mm × 6 mm) for space-efficient designs.
Applications
The AFE4490RHAR is ideally suited for pulse-oximeter applications, which include:
- Pulse Oximetry in Medical Devices
- Non-Invasive Blood Oxygen Level Monitoring
- Health Monitoring Systems
- Portable Medical Devices
Q & A
- What is the primary application of the AFE4490RHAR?
The AFE4490RHAR is primarily used in pulse-oximeter applications for non-invasive blood oxygen level monitoring.
- What type of package does the AFE4490RHAR come in?
The AFE4490RHAR is packaged in a VQFN-40 package (6 mm × 6 mm).
- What is the operating temperature range of the AFE4490RHAR?
The operating temperature range is –40°C to 85°C.
- How does the AFE4490RHAR communicate with an external host processor?
The device communicates using an SPI interface.
- What are the key components of the AFE4490RHAR?
The device includes a low-noise receiver channel, an LED transmit section, and diagnostics for sensor and LED fault detection.
- What is the resolution of the analog-to-digital converter (ADC) in the AFE4490RHAR?
The ADC has a 22-bit resolution.
- Can the AFE4490RHAR operate from different power supply voltages?
Yes, it can operate from various supply voltages: 2.0 V to 3.6 V for analog and digital supplies, and 3.0 V to 5.25 V for Tx control and LED driver supplies.
- Does the AFE4490RHAR have integrated clocking capabilities?
Yes, it includes an integrated oscillator that can operate from an external crystal or an external host processor clock.
- What are some of the configurable settings available on the AFE4490RHAR?
Settings include LED current control, transmitter reference voltage, gain settings for the receiver channel, and filter corner frequency selection.
- Is the AFE4490RHAR suitable for portable medical devices?
Yes, its compact packaging and low power consumption make it suitable for portable medical devices.
