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HM301D
ECG analog front-end
Fully integrated, mixed-signal diagnostic quality ECG acquisition system
STMicroelectronics’ HM301D
is the world’s most highly
integrated front-end chip for
ECG (Electrocardiogram)
applications. This mixed-signal
device provides all of the analog
and digital signal-conditioning
and filtering functions required
to transform the small electrical
signals picked up by the
electrodes attached to the
patient into fully conditioned
digital data that can be stored
or displayed in diagnostic-quality
ECG equipment.
KEY FEATURES
TARGETED APPLICATIONS
• 3 channels with integrated
• Cardiographs
analog high-pass filters
• Bed side monitors
• Embedded pace detection
• Automatic external defibrillators
• 1 bio-impedance channel
• Holter monitors
with 2- or 4-wire measurement
• Configurable digital band-pass
filtering for all channels
• Wearable remote monitoring
• ECG (electrocardiogram)
• Multi-chip configuration
• EEG (electroencephalogram)
• Maximum data rate: 125 kSPS
• EMG (electromyography)
• Less than 1 mA/channel power
consumption at full bandwidth
with drivers on
• SPI serial interface
• Available in LGA 6 x 6 mm, 40 leads
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The HM301D is a highly integrated
diagnostic-quality biopotential acquisition
system with 3 differential and one impedance
channel.
Multi master/slave configuration supports up
to 16 channels of simultaneous sampling
(12 biopotential acquisitions and
4 bio-impedance channels).
A fully integrated analog high-pass filter
removes the DC component of the signal
to enable the channels to work with the
AC component only. Each channel provides
high resolution and low noise conversion of
biopotential signals up to 10 kHz.
The input connection circuit matrix
guarantees maximum flexibility in terms of
electrode cables and connectors.
The HM301D includes a dedicated
impedance measurement channel that can
be used to measure both body impedance
average value and variation due to
respiration. This channel delivers both the
real and the imaginary parts of the body and
the breathing impedances.
The WCT circuit and driver block implements
the driving functions (right leg driver and
shield driver) and the Wilson common
terminal commonly used in ECG systems.
The electrode-to-skin contact is checked
by injecting an AC or DC current. A digital
filtering and preprocessing (DFP) block
implements configurable band-pass filters,
IQ impedance demodulation and enables
specific algorithm implementation for lead-off
check and pacemaker detection.
The SPI interface allows the exchange of
data with both the microcontroller and
other HM301D devices in case of chain
connection. Full configurability and low
power design techniques make it ideal for
many applications, including battery-powered
devices. High quality recordings are obtained
with a small, power-saving system. It is
available in a 6 x 6 mm 40-lead LGA.
APPLICATION DIAGRAM
CIP
CIN
RA
Current
injection
Body
impedance
measurement
IN1P
IN1N
DC and AC
contact check
ECG and pace
maker channel # 1
IN2P
IN2N
DC and AC
contact check
ECG and pace
maker channel # 2
DC and AC
contact check
ECG and pace
maker channel # 3
IN3P
IN3N
Input
connection
circuit
Impedance
bus
Ch1 bus
HM301D
Digitalfiltering
and
preprocessing
Ch2 bus
SPI
slave
MISO
MOSI
SS
SCK
Pace
maker
detection
Ch3 bus
Bat_bus
RL
LL
RLD
WCT
Shield
WCT circuit
and drivers
Voltage
references
Timing
logic and clock
Low-voltage supervisory
and battery charge check
PRODUCT DETAILS
Part number
HM301D
Input channels Impedance Resolution(n) Gain typ Sample rate Supply voltage Current consumption
Interface
typ
channel
typ (b)
(W/W)
typ
min - max (V)
typ (A)
3
Yes
16
8 - 64
125 kSPS
1.7 - 3.6
0.003
SPI
Package
LGA 40L 6 x 6 x 0.9 mm
The STEVAL-IME002V1 and STEVAL-IME002V2 are respectively designed to demonstrate the use of HM301D in Electrocardiogram (ECG) and
Automated External Defibrillator (AED) configurations.
• STEVAL-IME002V1 Multi-lead electrocardiogram (ECG) and body impedance demonstration board
• STEVAL-IME002V2 Single-lead electrocardiogram (ECG) and body impedance evaluation board
© STMicroelectronics - May 2014 - Printed in United Kingdom - All rights reserved
The STMicroelectronics corporate logo is a registered trademark of the STMicroelectronics group of companies
All other names are the property of their respective owners
Order code: FLHM301D0514
For more information on ST products and solutions, visit www.st.com
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