SIMPLY SMARTER™

PATIENT MONITORING AND DIAGNOSTIC EQUIPMENT SOLUTIONS

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Medical Solutions

Introduction

Purpose• Introduce Intersil solutions for

patient monitors and medical diagnostic equipment

Objectives• Overview of several sub-blocks of

the patient monitor systems and various medical diagnostic equipment

• Present Intersil feature products with select application circuits

Content• 16 pages

Learning time• 30-40 minutes (estimated)

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Patient Monitors –High Level System

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Intersil Products

Products Highlighted•Op Amps•Data Converters•Switches and Multiplexers•RS-485/422 Interfaces•Voltage references•Digital Potentiometers (DCPs)•Real Time Clocks•PWM Controllers•Integrated FET Switching Regulators•Isolated Power•Battery Chargers•Voltage monitoring

Other Intersil Products•Ambient Light Sensor/Proximity Detector•LED Backlighting•Audio Amplifiers

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ECG / EKG

ECG signals basics

• Typically 0.05 Hz to 150 Hz bandwidth, 1mV to 10mV pp

• Systems are EMI sensitive

Analog Frontend Requirements

• Low noise at low frequency, high impedance (low leakage) components are required

– ISL28110 for low noise, high impedance body probe buffers

– ISL28217 for right leg drivers

• Other analog components:

– ISL54500 for lead switching

– ISL21009D for low power VREFs

• Accuracy depends on AC or DC coupling approach from 10-bit to 16-bit.

Power• Multi output voltage solutions for powering

processors or FPGA

– ISL9440A triple output controller and single LDO controller generates the rails for a FPGA.

– ISL80101 LDO family can reduce EMI in noise sensitive areas.

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Blood Pressure (NiBP)- Non-Invasive Blood Pressure

Pressure Sensor Basics• Strain Gauge, ROUT ≈ 5kΩ, 0-300mm

Hg Range, FSOUT= 300mV, BW = 5Hz

Analog Frontend Requirements• Low noise and gain signal

conditioning. Low noise at low frequency, high DC accuracy, low power vs. low noise

– ISL28217 or ISL28233 for low noise, high voltage for gain amplification (10x to 20x)

• Active Filters. Low pass filters for cuff pressure. Bandpass filters to capture oscillations, ISL28217 or ISL28233, use INTERSIL’S FILTER DESIGNER.

• See Intersil’s Medical Brochure for other analog components. http://www.intersil.com/literature/images/LC-097.pdf

Power• For portable monitors, efficiency

and size are the main focus. – ISL9440A, ISL9104, ISL8033 are

some of the products that can power the FPGA and also work well to generate the power to the amplifiers in the system.

http://web.transim.com/iSimFilter/Pages/DesignReq.aspx

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SpO2 – Pulse Oximetry(saturation oxygen in blood)

Pulse Oximetry Basics• Pulse Oximetry is the non-invasive

measurement of the arterial blood’s oxygen saturation.

• Detectors are needed to determine deoxygenated vs. oxygenated blood.

Analog Frontend Requirements• Diagnostic SpO2 typically uses JFET-input

op amps, or CMOS op amps are used to construct the transimpedance amplifier frontends.

– The ISL28110/210 is a precision JFET-input op amp that can be used for these applications because of its low noise and high impedance.

Power• The majority of these oximetry monitors are

portable and run from 1 or 2 cell Li-ion batteries. These are rechargeable devices.

– The ISL9220A can be used in these applications to recharge at higher efficiency with up to 2A charge current.

– The ISL9104 fully integrated 500mA Switching regulator can be used to generate a very compact switching solution because of its high switching frequency.

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Body TemperatureTemperature Sensor Basics

• Type varies for surgical, patient-care, home care. Typically either infrared, thermistor, or thermopile/ pyroelectric sensors.

• System consists of a small sensor voltage, then gain and filter signal conditioning.

Analog Frontend Requirements• Diagnostic (professional) vs. home use (ear-

type) vary. For diagnostic body temp monitors, use precision op amps for signal conditioning.

– Intersil provides several options for high DC precision, low temperature offset drift and lower power :

– For IR sensors: ISL28130 Low Cost, Low Power

– For Thermistor: ISL28217, ISL28207, ISL28218 for precision

– For Pyroelectric/Thermopile: ISL28110, ISL28133, ISL28217

Power• Making the power solution compact

with a reduced BOM is critical. – The low current switching regulators and

multi- output low current LDO’s are a good fit for power here.

ISL3232ISL4221E

SIMPLY SMARTER™

Product Specifics

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ISL28110/210: JFET-Input, Low Noise Op Amps

Feature Benefit

Low Input Bias Current: •2pA max @ room•4.5pA max @ 60°C•50pA max @ 85°C

•High input impedance sensors

•Photodiode, amperometric,

transimpedance application

Low Voltage Noise: •6nV/√Hz @ 1kHz•580 nVpp @ 0.1Hz to 10HzLow Current Noise:•9fA/√Hz @ 1kHz

•Low noise for better accuracy

and improved SNR

Precision•Low offset voltage: 300µV max•Low Drift: 1µV/°C

•Precision signal conditioning

Superior AC (Dynamic) Performance•BW = 12.5MHz•Slew Rate = 23V/µs•THD = 0.00002%

(G=1, f=1kHz, 4Vpp, RL=2kΩ)

•Ideal for high performance

instrumentation, DAQ

Operating Voltage: •9 to 40V or ±4.5V to ±20V

•Wide operating voltage range

Outstanding Noise Performance

Low Bias Current of TIA Applications

High Impedance Buffers

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Precision Low Noise JFET Operational Amplifier

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Competitive Summary

Medical Applications Pulse Oximetry ECG/EEG In Vitro – Biochemical Analyzers Anesthesia Equipment Blood Flow Measurement

Competitor A Competitor B Competitor C ISL282101

10

100

1000

10000

25C 60C 85C 125C

Ibias (pA)

ISL28210 Input Bias Current (Max)ISL28210 Input Bias Current (Max)ISL28210 Input Bias Current (Max)ISL28210 Input Bias Current (Max)ISL28210 Input Bias Current (Max)ISL28110/210 Input Bias Current (Max)

10x Better

300 fA Typical

Mfg

Max Ibias (pA)

DifferentialInput

Capacitance(pf)

Noise @ 1kHznV/rt Hz

Noise .1 to 10Hz

nVp-p BW

(MHz)Min SR (V/us)

Max Vos (uV)

Max Is (mA)

ISIL 2 8.3 6 580 12.5 20 300 2.9Comp A 75 12.5 8 2400 8 20 900 2.3Comp B 50 4 13 2100 8 20 600 2.5Comp C 10 8 6 1800 25 40 100 3Comp D 50 1 8 ** 5 14 500 4.8

ISL28110/210 Superior Low IBIAS

and Noise

Performance

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ISL28130/230/430: 1.65V to 6V Micropower Rail-Rail, Precision Amps

Feature Benefit

Precision•Low offset voltage: 40µV max•Low Offset Drift: 150nV/°C max

•DC Accuracy for 12-bit to 16-bit applications

Operating Voltage: •Rail-Rail Input and Output•1.65V to 6V Single Supply•±0.825V to ±2.75V Dual Supply

• Lowest operating voltage vs. competition, allows operation at low battery levels

Low Power•25µA max

• Low power consumption for precision

Low Voltage Noise: •1.1 µV p-p @ 0.01 Hz to 10Hz

• Ideal for high performance instrumentation, DAQ

Low Cost Precision (single/dual/quad)

• Ideal for medical consumer applications

Ear Thermometer Temperature

ISL28130

1.65V

ISL28130

0.825V

- 0.825V

Lowest Operating Voltages

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ISL9440A: Triple Output PWM Controller With a Single LDO Controller

Feature Benefit

Integration• Three fully integrated

PWM controllers and one LDO controller

• Single solution to generate three rails to power a Processor/FPGA

Separate rail control• Separate enable and

power good• Independently

programmable voltage outputs

• Allows user to power on or off each rail independent of the other rails.

• Facilitates ease of sequencing

Synchronous regulation• Each switching rail is

fully synchronous

• Gives a more efficient method of delivering power to the load

Out of Phase switching• 0°/180°/0° Phase shift

between channels

• Allows for reduction of RMS input current and voltage ripple so input capacitance can be reduced

Protection• Integrated UV/OV/OC/OT

protection

• Provides protection against various fault modes

Medical Applications ECG / EEGImaging systemsPatient monitoringDialysis machines

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ISL9220: Switching Charger for 1 & 2 Cell Li-Ion Batteries

Feature Benefit

Switching topology• Synchronous Buck Topology, with

Integrated Power FETs

• More efficient charging of 1 and 2 cell

• Li-ion batteries 90% + efficiency to optimize the charging time

Integration• Integrated FET’s for a fully Synchronous

& compact solution

•Allows for a compact solution•Fewer external components

Charging current• Up to 2A charging current

• Allows faster charging or helps to reduce charge time

VBAT = 3.6V

VBAT = 3.0V

VBAT = 4.0V

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.270

75

80

85

90

95Battery Charge Efficiency

Charge current (A)

Eff

icie

ncy

(%

)

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ISL9305: Compact Power Management IC Reduces Complexity

• Available in WLCSP & QFN packages• I2C interface to set voltage, set on/off

sequence and En/Disable PFM mode• 15mV Pk-Pk PFM ripple • Excellent load transient response

• Dual High Fsw Buck + Dual Low VIN LDO• 3MHz fixed switching frequency • 800 mA from the buck regulators (H

version: 1500mA)• 300mA output current from the LDOs

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ISL9103/4: Low Power Switching Regulator

• 2.5MHz/4.3MHz Synchronous Buck Regulator with up to 95% efficiency

• 500mA Buck Regulator with high switching frequency and ultrasonic mode of operation

• Low Quiescent current of 20µA IQ in PFM Mode

• 2.7V to 6V Vin range• 3% Output Accuracy Over-

Temperature and Line for Fixed Output Options

• 100% Maximum Duty Cycle for Lowest Dropout

• Discharge Output Capacitor when Disabled

• Tiny 1.6x1.6mm Package

C22.2µF

LPHASE

GND

FB

VIN

EN

INPUT:

2.7V- 6V

OUTPUT2.5V/0.4A

C12.2µF

ISL9104-2.5 1.0 uH

Tiny 1µH inductor

www.intersil.com

Closing