Benchmark Ear 5.0 Datasheet
Document Number: 001873
Revision: 04.00 Copyright © 2020 by Valencell, Inc. Page 1 / 20
Patents: www.valencell.com/patents
Benchmark Biometric Sensor System for Hearable Devices
Features
• Chest-strap quality optical heart rate (HR)
measurement, step rate / count, distance, cycling
cadence, calories, R-R interval (RRi) and activity
recognition (running/lifestyle)
• The Benchmark
®
sensor and PerformTek® processor
minimize space impact to the hearable design and
provide design flexibility
• Sensor module contains an LED and optical detector
with data conversion circuitry mounted to a lens
assembly optimized for sensor system accuracy
• PerformTek low-power ARM
®
Cortex® processor
performs sensor data processing and provides a
communication interface to the system Host
processor
Figure 1: BE5.0 PerformTek MCU and Sensor
• Sensor Dimensions: 14-pin, 0.6 mm pitch,
(5.80 x 3.90 x 3.40) mm
• IMU Dimensions: LGA-12, 0.5 mm pitch,
(2.00 x 2.00 x 0.93) mm
• MCU Dimensions: CSP-49, 0.35 mm pitch,
(2.56 x 2.59 x 0.45) mm
• 400 kHz I2C or 57.6 kbps UART interface
• Processor and IMU VDD: 1.8 VDC to 3.3 VDC
• Sensor VLED: 2.8 to 5.5 VDC (IR LED Only)
• Sensor VLED: 3.1 to 5.5 VDC (Red + IR LED Only)
• VDD MCU current: 255 µA standard operation
• V
LED
Sensor current: 0.11 mA standard operation
• Field updatable processor firmware
Description
The PerformTek powered Benchmark Ear 5.0 (BE5.0)
Sensor System is the smallest biometric sensor
technology developed by Valencell, Inc. to date. The
modular design brings together the best available parts
of a successful biometric sensor system in a smaller
form factor and includes emitter/detector sensor
electronics in an optimized optical package with a
processor that is pre-programmed with Valencell’s
PerformTek advanced biometric algorithms.
Figure 2: BE5.0 Simplified Block Diagram
Applications
• In-canal or in-concha wired or wireless headphones
• Hearing aids
• Mono Bluetooth headsets
• Wireless smart audio assistants
Benchmark Ear 5.0 Datasheet
Document Number: 001873
Revision: 04.00 Copyright © 2020 by Valencell, Inc. Page 2 / 20
Patents: www.valencell.com/patents
Reference Documentation
Table 1: Related Documents
Document
Title
001917
PerformTek Low Power MCU Integration Guide
000638
PerformTek Interface Protocol Document
000964
PerformTek User Guide
002335
PerformTek Low Power Motion Detect Addendum
000532
Benchmark Ear Integration Guide
001926
BE 5.0 Sensor Window Drawing
001913
BE 5.0 Sensor Drawing
001912
BE 5.0 Sensor 3D CAD Model
Change Record
Table 2: Change Record
Author
Revision
Date
Description of change(s)
MEP
01.00
02MAY2019
Initial Release of Preliminary BE5.0 Datasheet
MEP
01.01
02AUG2019
Update based on design finalization.
Removed Preliminary marking
Removed PerformTek MCU information and added
reference to the PerformTek Low Power MCU
Integration Guide
SWC
01.02
02DEC2019
Fixed typo on page 16
Corrected the number of components listed in section
9 (from 2 to 3)
SWC
02.00
23DEC2019
Updated sensor dimensions and drawing
MEP
03.00
31MAR2020
Added power information for red LED
MEP
04.00
15OCT2020
Updates based on Official firmware release, version
1742
Updated section 3:
- Added information for Sleep mode
- Updated current consumption
- Corrected minimum storage temperature
- Increased recommended minimum VLED operating
voltage for IR LED to provide additional noise
immunity and support for future features
Benchmark Ear 5.0 Datasheet
Document Number: 001873
Revision: 04.00 Copyright © 2020 by Valencell, Inc. Page 3 / 20
Patents: www.valencell.com/patents
Table of Contents
Block Diagram / System Overview ............................................................................................................. 4
Sensor Pin Description ................................................................................................................................ 6
Electrical Characteristics ............................................................................................................................ 7
Sensor Electrical Integration ..................................................................................................................... 10
PerformTek Processor .............................................................................................................................. 11
Additional Electrical Design Guidelines ................................................................................................... 12
6.1 Power Supply Loading ...................................................................................................................... 12
6.2 Mixed Voltage Operation and Power Supply Separation ................................................................ 12
6.3 Audio Quality Design Guidelines ...................................................................................................... 12
Sensor Physical Integration ...................................................................................................................... 14
Accelerometer Physical Integration ......................................................................................................... 16
Benchmark Sensor Ordering Guide .......................................................................................................... 17
Valencell Product Development Design and Test Services .................................................................... 18
Contact Information .................................................................................................................................. 19
Statements ................................................................................................................................................ 20
Benchmark Ear 5.0 Datasheet
Document Number: 001873
Revision: 04.00 Copyright © 2020 by Valencell, Inc. Page 4 / 20
Patents: www.valencell.com/patents
Block Diagram / System Overview
The Benchmark Ear 5.0 Biometric Sensor solution is provided in three pieces, a sensor, an accelerometer,
and a Low Power PerformTek processor. Figure 3 shows how these pieces work together and is
described below.
Figure 3: Benchmark Ear 5.0 Functional Block Diagram
On the left of the diagram, the sensor module circuit board contains a digital optical detector system with
infrared and red LEDs. The detector and LEDs work together with the accelerometer to collect biometric
information via reflected light and movement from the wearer. This information is transmitted over an I2C
bus when requested by the PerformTek processor.
The PerformTek processor collects the sensor data and runs Valencell’s patent protected algorithms to
convert the raw measurements into biometric values such as heart rate or cadence and processes those
values further into higher level user assessments like calories burned. In addition, sensor module
diagnostics such as signal quality and error codes are available. This information is available to the Host
processor via the Host interface.
Benchmark Ear 5.0 Datasheet
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Patents: www.valencell.com/patents
The Host interface is shown on the right side of the diagram. Control lines for interfacing the Host
processor with the PerformTek processor include an I2C or UART, power-on self-test / sensor interrupt
output (POST / PTEK_INT_N), and sensor interrupt / bootloader mode select input (HOST_INT_N /
BOOT_OVERRIDE_N). For I2C serial communications with the Host processor, the PerformTek processor
acts as the I2C slave role and the Host processor acts as the I2C Master. More details on this interface
are provided in the PerformTek Low Power MCU Integration Guide.
Benchmark Ear 5.0 Datasheet
Document Number: 001873
Revision: 04.00 Copyright © 2020 by Valencell, Inc. Page 6 / 20
Patents: www.valencell.com/patents
Sensor Pin Description
Table 3 shows the pin definitions for the sensor. See Section 7 for the physical pinout and package dimensions of
the sensor,
Table 3: Sensor Pinout
Pin
Number
Symbol
Description
1
SDA
I2C Data Line. Connect to accelerometer and PerformTek Processor
2
SCL
I2C Clock Line. Connect to accelerometer and PerformTek Processor
3
LDO_EN
Connect to VLED
4
LDO
Internal LDO. Connect 1μF capacitor to GND_A
5
VLED
Sensor power: Connect VLED power to this pin via a zero Ohm resistor.
Option A: Add a 0.1μF ceramic capacitor and a 47uF polymer tantalum to
this pin and GND_L / GND (recommended to reduce risk of audible noise
due to piezoelectric effect and to provide path for future design changes
that may limit peak current demand from the sensor)
Option B: Add a 0.1μF ceramic capacitor and a 10uF ceramic capacitor to
this pin and GND_L / GND (minimum requirement)
6
NC
No Connect
7
NC
No Connect
8
NC
No Connect
9
GND_L
Connect to GND
10
GND_D
Tie to GND_A and connect to GND
11
GND_A
Tie to GND_D and connect to GND
12
VREF
Internal reference for sensor. Connect 1µF capacitor between this pin and
GND / GND_A
13
NC
No Connect
14
NC
No Connect
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