SLAA486B January   2011  – June 2019 MSP430G2452

 

  1.   EKG-Based Heart-Rate Monitor Implementation Using the MSP430G2xx LaunchPad™ Development Kit
    1.     Trademarks
    2. 1 Introduction
    3. 2 Hardware Description
      1. 2.1 Hand Detection Circuit
      2. 2.2 Analog Front End (AFE)
      3. 2.3 Pin Functionality Mapping on the LaunchPad Kit
      4. 2.4 eZ430 RF Target Header
      5. 2.5 Power Supply Setup
    4. 3 Software
    5. 4 References
  2.   A Amplifier Options
    1.     A.1 Instrumentation Amplifier Options
    2.     A.2 Operational Amplifier Options
  3.   B Wired USB Demo With Back-Channel UART
  4.   C Wireless UART Demo With the eZ430 RF Target Board
  5.   D Hardware Schematic Diagrams
  6.   Revision History

A.2 Operational Amplifier Options

This reference design uses the TLV274 as the op-amp for the Sallen-Key low-pass filter implementation. Table 5 shows other options for the operational amplifier.

Table 5. Operational Amplifier Comparison

Device Name TLV274 TLV2375 TLV2765 TLV2765
TLV274_laa486.gif
TLV2375_laa486.gif
TLV2765_laa486.gif
TLV2785_laa486.gif
Supply current 470 μA/channel
(VDD = 2.7 V)		 470 μA/channel
(VDD = 2.7 V)		 20 μA/channel 650 μA/channel
Shutdown current No shutdown approximately 25 μA approximately 10 nA 900 nA
UGBW 2.4 MHz
(VDD = 2.7 V)		 2.4 MHz
(VDD = 2.7 V)		 500 kHz 8 MHz
Slew rate 2.1 V/μs
(VDD = 2.7V)		 2 V/μs (VDD = 2.7 V) 0.2 V/μs
(VDD = 2.4 V)		 4.8 V/μs
(VDD = 2.7 V)
Supply voltage 2.7 V to 16 V 2.7 V to 16 V 1.8 V to 3.6 V 1.8 V to 3.6 V
Price/1ku
(listed on http://www.ti.com)		 0.46 0.85 1.50 1.60

The TLV2375 has specifications similar to the TLV274 with the additional capability of shutdown pins. The TLV2765 and TLV2785 can operate in low-voltage range with sub-microamperes of current consumption in shutdown mode.