Overview
The AFE4400RHAT is a fully-integrated analog front-end (AFE) designed by Texas Instruments, specifically tailored for heart-rate monitors and low-cost pulse oximeters. This device is packaged in a compact VQFN-40 package, measuring 6 mm × 6 mm, and operates within a temperature range of 0°C to 70°C. It features a low-noise receiver channel with an integrated analog-to-digital converter (ADC), an LED transmit section, and comprehensive diagnostics for sensor and LED fault detection. The AFE4400RHAT also includes an integrated oscillator that functions from an external crystal, providing a low-jitter clock, and communicates with external microcontrollers or host processors via an SPI™ interface.
Key Specifications
| Parameter | Description |
|---|---|
| Manufacturer | Texas Instruments |
| Part Number | AFE4400RHAT |
| Package Type | VQFN-40 (RHA) |
| Pins | 40 |
| Operating Temperature Range | 0°C to 70°C |
| Supply Voltage (Rx) | 2.0 V to 3.6 V |
| Supply Voltage (Tx) | 3.0 V to 5.25 V |
| Interface | SPI |
| Number of LEDs | 2 |
| Resolution | 22 Bits |
| Sample Rate (max) | 5 KSPS |
| Special Features | Optical biosensing, integrated fault diagnostics |
| RoHS Compliance | Yes |
Key Features
- Fully-integrated analog front-end for pulse oximeter applications, including a low-noise receiver channel with an integrated ADC and an LED transmit section.
- Flexible pulse sequencing and timing control, allowing for customizable device timing characteristics.
- Integrated LED driver with programmable current up to 50 mA and 8-bit current resolution.
- Low power consumption: 100 µA + average LED current and < 670 µA at 3.3-V supply.
- High dynamic range receive channel with 13 noise-free bits and flexible receive sample time.
- Integrated fault diagnostics for photodiode and LED open and short detection, as well as cable on and off detection.
- Compact VQFN-40 package (6 mm × 6 mm) and specified temperature range of 0°C to 70°C.
Applications
- Heart-rate monitors
- Low-cost pulse oximeters
- Optical biosensing applications
Q & A
- What is the primary application of the AFE4400RHAT?
The AFE4400RHAT is primarily used in heart-rate monitors and low-cost pulse oximeters.
- What is the package type and pin count of the AFE4400RHAT?
The AFE4400RHAT is packaged in a VQFN-40 (RHA) package with 40 pins.
- What is the operating temperature range of the AFE4400RHAT?
The operating temperature range is 0°C to 70°C.
- What interface does the AFE4400RHAT use for communication?
The device communicates using an SPI™ interface.
- How many LEDs does the AFE4400RHAT support?
The device supports 2 LEDs.
- What is the resolution of the AFE4400RHAT?
The resolution is 22 bits.
- What are some of the special features of the AFE4400RHAT?
It includes optical biosensing, integrated fault diagnostics, and a flexible pulse sequencing and timing control.
- Is the AFE4400RHAT RoHS compliant?
Yes, the AFE4400RHAT is RoHS compliant.
- What is the maximum sample rate of the AFE4400RHAT?
The maximum sample rate is 5 KSPS.
- Does the AFE4400RHAT have integrated fault diagnostics?
Yes, it includes diagnostics for photodiode and LED open and short detection, as well as cable on and off detection.
