SBAS602H December   2012  – October 2014 AFE4490

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 Handling Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Requirements: Serial Interface
    7. 7.7 Supply Ramp and Power-Down Timing Requirements
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Receiver Channel
        1. 8.3.1.1 Receiver Front-End
        2. 8.3.1.2 Ambient Cancellation Scheme
        3. 8.3.1.3 Receiver Control Signals
        4. 8.3.1.4 Receiver Timing
      2. 8.3.2 Clocking and Timing Signal Generation
      3. 8.3.3 Timer Module
        1. 8.3.3.1 Using the Timer Module
      4. 8.3.4 Receiver Subsystem Power Path
      5. 8.3.5 Transmit Section
        1. 8.3.5.1 Transmitter Power Path
        2. 8.3.5.2 LED Power Reduction During Periods of Inactivity
    4. 8.4 Device Functional Modes
      1. 8.4.1 ADC Operation and Averaging Module
        1. 8.4.1.1 Operation Without Averaging
        2. 8.4.1.2 Operation With Averaging
      2. 8.4.2 AFE Analog Output Mode (ADC Bypass Mode)
      3. 8.4.3 Diagnostics
        1. 8.4.3.1 Photodiode-Side Fault Detection
        2. 8.4.3.2 Transmitter-Side Fault Detection
        3. 8.4.3.3 Diagnostics Module
    5. 8.5 Programming
      1. 8.5.1 Serial Programming Interface
      2. 8.5.2 Reading and Writing Data
        1. 8.5.2.1 Writing Data
        2. 8.5.2.2 Reading Data
        3. 8.5.2.3 Multiple Data Reads and Writes
        4. 8.5.2.4 Register Initialization
        5. 8.5.2.5 AFE SPI Interface Design Considerations
    6. 8.6 Register Maps
      1. 8.6.1 AFE Register Description
  9. 9 Applications and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curve
  10. 10Power-Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Trademarks
    3. 12.3 Electrostatic Discharge Caution
    4. 12.4 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7 Specifications

7.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)(1)
MIN MAX UNIT
RX_ANA_SUP, RX_DIG_SUP to RX_ANA_GND, RX_DIG_GND –0.3 4 V
TX_CTRL_SUP, LED_DRV_SUP to LED_DRV_GND –0.3 6 V
RX_ANA_GND, RX_DIG_GND to LED_DRV_GND –0.3 0.3 V
Analog inputs RX_ANA_GND – 0.3 RX_ANA_SUP + 0.3 V
Digital inputs RX_DIG_GND – 0.3 RX_DIG_SUP + 0.3 V
TXP, TXN pins –0.3 Minimum [6, (LED_DRV_SUP + 0.3)] V
Input current to any pin except supply pins(2) ±7 mA
Input current Momentary ±50 mA
Continuous ±7 mA
Operating temperature range –40 85 °C
Maximum junction temperature, TJ 125 °C
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(2) Input pins are diode-clamped to the power-supply rails. Input signals that can swing beyond the supply rails must be current-limited to 10 mA or less.

7.2 Handling Ratings

MIN MAX UNIT
Tstg Storage temperature range –60 150 °C
V(ESD) Electrostatic discharge Human body model (HBM), per ANSI/ESDA/JEDEC JS-001, all pins(1) –1000 1000 V
Charged device model (CDM), per JEDEC specification JESD22-C101, all pins(2) –250 250
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.

7.3 Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)
MIN MAX UNIT
SUPPLIES
RX_ANA_SUP AFE analog supply 2.0 3.6 V
RX_DIG_SUP AFE digital supply 2.0 3.6 V
TX_CTRL_SUP Transmit controller supply 3.0 5.25 V
LED_DRV_SUP Transmit LED driver supply, H-bridge or common anode configuration [3.0 or (VHR + VLED + VCABLE)(3)(1)(2), whichever is greater] 5.25 V
Difference between LED_DRV_SUP and TX_CTRL_SUP –0.3 0.3 V
TEMPERATURE
Specified temperature range –40 85 °C
(1) VLED refers to the maximum voltage drop across the external LED (at maximum LED current) connected between the TXP and TXN pins (in H-bridge mode) and from the TXP and TXN pins to LED_DRV_SUP (in the common anode configuration).
(2) VCABLE refers to voltage drop across any cable, connector, or any other component in series with the LED.
(3) VHR refers to the required voltage headroom necessary to drive the LEDs. See Table 6 for the appropriate VHR value.

7.4 Thermal Information

THERMAL METRIC(1) AFE4490 UNIT
RHA (VQFN)
40 PINS
RθJA Junction-to-ambient thermal resistance 35 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 31
RθJB Junction-to-board thermal resistance 26
ψJT Junction-to-top characterization parameter 0.1
ψJB Junction-to-board characterization parameter N/A
RθJC(bot) Junction-to-case (bottom) thermal resistance N/A
(1) For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.

7.5 Electrical Characteristics

Minimum and maximum specifications are at TA = –40°C to 85°C. Typical specifications are at 25°C.
All specifications are at RX_ANA_SUP = RX_DIG_SUP = 3 V, TX_CTRL_SUP = LED_DRV_SUP = 5 V, stage 2 amplifier disabled, and fCLK = 8 MHz, unless otherwise noted.
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
PERFORMANCE (Full-Signal Chain)
IIN_FS Full-scale input current RF = 10 kΩ 50 µA
RF = 25 kΩ 20 µA
RF = 50 kΩ 10 µA
RF = 100 kΩ 5 µA
RF = 250 kΩ 2 µA
RF = 500 kΩ 1 µA
RF = 1 MΩ 0.5 µA
PRF Pulse repetition frequency 62.5 5000 SPS
DCPRF PRF duty cycle 25%
CMRR Common-mode rejection ratio fCM = 50 Hz and 60 Hz, LED1 and LED2 with RSERIES = 500 kΩ, RF = 500 kΩ 75 dB
fCM = 50 Hz and 60 Hz, LED1-AMB and
LED2-AMB with RSERIES = 500 kΩ, RF = 500 kΩ		 95 dB
PSRR Power-supply rejection ratio fPS = 50 Hz, 60 Hz at PRF = 200 Hz 100 dB
fCM = 50 Hz, 60 Hz at PRF = 600 Hz 106 dB
PSRRLED PSRR, transmit LED driver With respect to ripple on LED_DRV_SUP 75 dB
PSRRTx PSRR, transmit control With respect to ripple on TX_CTRL_SUP 60 dB
PSRRRx PSRR, receiver With respect to ripple on RX_ANA_SUP and RX_DIG_SUP 60 dB
Total integrated noise current, input-referred (receiver with transmitter loop back, 0.1-Hz to 20-Hz bandwidth) RF = 100 kΩ with stage 2 gain disabled,
PRF = 1200 Hz, duty cycle = 5%		 36 pARMS
RF = 500 kΩ with ambient cancellation enabled and stage 2 gain = 4, PRF = 1200 Hz,
duty cycle = 25%		 13 pARMS
NFB Noise-free bits (receiver with transmitter loop back, 0.1-Hz to 20-Hz bandwidth)(1) RF = 100 kΩ, PRF = 1200 Hz, duty cycle = 5% 14.3 Bits
RF = 500 kΩ, PRF = 1200 Hz, duty cycle = 25% 13.5 Bits
RECEIVER FUNCTIONAL BLOCK LEVEL SPECIFICATION
Total integrated noise current,
input-referred (receiver alone) over 0.1-Hz to 5-Hz bandwidth		 RF = 500 kΩ, ambient cancellation enabled,
stage 2 gain = 4, PRF = 1300 Hz,
LED duty cycle = 25%		 1.4 pARMS
RF = 500 kΩ, ambient cancellation enabled,
stage 2 gain = 4, PRF = 1300 Hz,
LED duty cycle = 5%		 5 pARMS
I-V TRANSIMPEDANCE AMPLIFIER
G Gain RF = 10 kΩ to RF = 1 MΩ See the Receiver Channel section for details V/µA
Gain accuracy ±7%
Feedback resistance RF 10k, 25k, 50k, 100k, 250k,
500k, and 1M		 Ω
Feedback resistor tolerance RF ±7%
Feedback capacitance CF 5, 10, 25, 50, 100, and 250 pF
Feedback capacitor tolerance CF ±20%
VOD(fs) Full-scale differential output voltage 1 V
Common-mode voltage on input pins Set internally 0.9 V
External differential input capacitance Includes equivalent capacitance of photodiode, cables, EMI filter, and so forth 10 1000 pF
VO(shield) Shield output voltage, VCM With a 1-kΩ series resistor and a 10-nF decoupling capacitor to ground, when loaded with a small current (for example, of a few µA or less) 0.8 0.9 1.0 V
AMBIENT CANCELLATION STAGE
G Gain 0, 3.5, 6, 9.5, and 12 dB
Current DAC range 0 10 µA
Current DAC step size 1 µA
LOW-PASS FILTER
Low-pass corner frequency 3-dB attenuation 0.5 and 1 kHz
Pass-band attenuation, 2 Hz to 10 Hz Duty cycle = 25% 0.004 dB
Duty cycle = 10% 0.041 dB
Filter settling time After diagnostics mode with filter corner = 500 Hz 28 ms
After diagnostics mode with filter corner =
1000 Hz		 16 ms
ADC bypass outputs output impedance RXOUTP and RXOUTN 1 kΩ
ANALOG-TO-DIGITAL CONVERTER
Resolution 22 Bits
Sample rate See the ADC Operation and Averaging Module section 4 × PRF SPS
ADC full-scale voltage ±1.2 V
ADC conversion time See the ADC Operation and Averaging Module section 50 PRF / 4 µs
ADC reset time 2 tCLK
TRANSMITTER
Output current range 0, 50, 75, 100, 150, and 200
(see the LEDCNTRL: LED Control Register for details)		 mA
LED current DAC error ±5%
Output current resolution 8 Bits
Transmitter noise dynamic range 0.1-Hz to 20-Hz bandwidth, at 25-mA output current 110 dB
0.1-Hz to 20-Hz bandwidth, at 100-mA output current 110 dB
Minimum sample time of LED1 and LED2 pulses 50 µs
LED current DAC leakage current LED_ON = 0 1 µA
LED_ON = 1 50 µA
LED current DAC linearity Percent of full-scale current 0.5%
Output current settling time
(with resistive load)		 From zero current to 150 mA 7 µs
From 150 mA to zero current 7 µs
DIAGNOSTICS
Duration of diagnostics state machine EN_SLOW_DIAG = 0
Start of diagnostics after the DIAG_EN register bit is set.
End of diagnostic indicated by DIAG_END going high.		 8 ms
EN_SLOW_DIAG = 1
Start of diagnostics after the DIAG_EN register bit is set.
End of diagnostic indicated by DIAG_END going high.		 16 ms
Open fault resistance > 100 kΩ
Short fault resistance < 10 kΩ
Diagnostics current During diagnostics mode < 100 µA
INTERNAL OSCILLATOR
fCLKOUT CLKOUT frequency With an 8-MHz crystal connected to the XIN and XOUT pins 4 MHz
DCCLKOUT CLKOUT duty cycle 50%
Crystal oscillator start-up time With an 8-MHz crystal connected to the XIN and XOUT pins 200 µs
EXTERNAL CLOCK
Maximum allowable external clock jitter 50 ps
External clock input frequency ±10% 8 MHz
External clock input voltage Voltage input high (VIH) 0.75 × RX_DIG_SUP V
Voltage input low (VIL) 0.25 × RX_DIG_SUP V
External clock input current 1 µA
TIMING
Wake-up time from complete power-down 1000 ms
Wake-up time from Rx power-down 100 µs
Wake-up time from Tx power-down 1000 ms
tRESET Active low RESET pulse duration 1 ms
tDIAGEND DIAG_END pulse duration at diagnostics completion 4 CLKOUT cycles
tADCRDY ADC_RDY pulse duration 1 CLKOUT cycles
DIGITAL SIGNAL CHARACTERISTICS
VIH Logic high input voltage AFE_PDN, SPI CLK, SPI SIMO, SPI STE, RESET 0.75 × RX_DIG_SUP V
VIL Logic low input voltage AFE_PDN, SPI CLK, SPI SIMO, SPI STE, RESET 0.25 × RX_DIG_SUP V
IIN Logic input current Digital inputs at VIH or VIL 0.1 µA
VOH Logic high output voltage DIAG_END, LED_ALM, PD_ALM, SPI SOMI, ADC_RDY, CLKOUT RX_DIG_SUP – 0.1 V
VOL Logic low output voltage DIAG_END, LED_ALM, PD_ALM, SPI SOMI, ADC_RDY, CLKOUT 0.1 V
PIN LEAKAGE CURRENT
Pin leakage current To GND and supply 1 nA
SUPPLY CURRENT
Receiver analog supply current RX_ANA_SUP = 3.0 V, with 8-MHz clock running, Rx stage 2 disabled 0.6 mA
RX_ANA_SUP = 3.0 V, with 8-MHz clock running, Rx stage 2 enabled 0.7 mA
Receiver digital supply current RX_DIG_SUP = 3.0 V 0.27 mA
ADC bypass mode RX_ANA_SUP + RX_DIG_SUP
(Excluding external ADC current)		 1.8 mA
LED_DRV_SUP LED driver supply current With zero LED current setting 55 µA
TX_CTRL_SUP Transmitter control supply current 15 µA
Complete power-down
(using AFE_PDN pin)		 Receiver current only
(RX_ANA_SUP)		 3 µA
Receiver current only
(RX_DIG_SUP)		 3 µA
Transmitter current only
(LED_DRV_SUP)		 1 µA
Transmitter current only
(TX_CTRL_SUP)		 1 µA
Power-down Rx alone Receiver current only
(RX_ANA_SUP)		 220 µA
Receiver current only
(RX_DIG_SUP)		 220 µA
Power-down Tx alone Transmitter current only
(LED_DRV_SUP)		 2 µA
Transmitter current only
(TX_CTRL_SUP)		 2 µA
POWER DISSIPATION
PD(q) Quiescent power dissipation Normal operation (excluding LEDs) 2.84 mW
Power-down 0.1 mW
Power-down with the AFE_PDN pin LED_DRV_SUP LED_DRV_SUP current value.
Does not include LED current.		 1 µA
TX_CTRL_SUP 1 µA
RX_ANA_SUP 5 µA
RX_DIG_SUP 0.1 µA
Power-down with the PDNAFE register bit LED_DRV_SUP LED_DRV_SUP current value.
Does not include LED current.		 1 µA
TX_CTRL_SUP 1 µA
RX_ANA_SUP 15 µA
RX_DIG_SUP 20 µA
Power-down Rx LED_DRV_SUP LED_DRV_SUP current value.
Does not include LED current.		 50 µA
TX_CTRL_SUP 15 µA
RX_ANA_SUP 220 µA
RX_DIG_SUP 220 µA
Power-down Tx LED_DRV_SUP LED_DRV_SUP current value.
Does not include LED current.		 2 µA
TX_CTRL_SUP 2 µA
RX_ANA_SUP 600 µA
RX_DIG_SUP 230 µA
After reset, with 8-MHz clock running LED_DRV_SUP LED_DRV_SUP current value.
Does not include LED current.		 55 µA
TX_CTRL_SUP 15 µA
RX_ANA_SUP 600 µA
RX_DIG_SUP 230 µA
With stage 2 mode enabled and 8-MHz clock running LED_DRV_SUP LED_DRV_SUP current value.
Does not include LED current.		 55 µA
TX_CTRL_SUP 15 µA
RX_ANA_SUP 700 µA
RX_DIG_SUP 270 µA
(1) Noise-free bits (NFB) are defined as:
q_nfb_bas597.gif
where: IPD is the photodiode current, and INOISE is the input-referred RMS noise current.

7.6 Timing Requirements: Serial Interface

MIN TYP MAX UNIT
tCLK Clock frequency on XIN pin 8 MHz
tSCLK Serial shift clock period 62.5 ns
tSTECLK STE low to SCLK rising edge, setup time 10 ns
tCLKSTEH,L SCLK transition to SPI STE high or low 10 ns
tSIMOSU SIMO data to SCLK rising edge, setup time 10 ns
tSIMOHD Valid SIMO data after SCLK rising edge, hold time 10 ns
tSOMIPD SCLK falling edge to valid SOMI, setup time 17 ns
tSOMIHD SCLK rising edge to invalid data, hold time 0.5 tSCLK
tim_serial_read_bas601.gif
1. The SPI_READ register bit must be enabled before attempting a register read.
2. Specify the register address whose contents must be read back on A[7:0].
3. The AFE outputs the contents of the specified register on the SOMI pin.
Figure 1. Serial Interface Timing Diagram, Read Operation123(1)(2)(3)
tim_serial_write_bas601.gifFigure 2. Serial Interface Timing Diagram, Write Operation

7.7 Supply Ramp and Power-Down Timing Requirements

VALUE
t1 Time between Rx and Tx supplies ramping up Keep as small as possible
(for example, ±10 ms)
t2 Time between both supplies stabilizing and high-going edge of RESET > 100 ms
t3 RESET pulse width > 0.5 ms
t4 Time between RESET and SPI commands > 1 µs
t5 Time between SPI commands and the ADC_RESET which corresponds to valid data > 3 ms of cumulative sampling time in each phase(1)(2)(3)
t6 Time between RESET pulse and high-accuracy data coming out of the signal chain > 1 s(3)
t7 Time from AFE_PDN high-going edge and RESET pulse(4) > 100 ms
t8 Time from AFE_PDN high-going edge (or PDN_AFE bit reset) to high-accuracy data coming out of the signal chain > 1 s(3)
(1) This time is required for each of the four switched RC filters to fully settle to the new settings. The same time is applicable whenever there is a change to any of the signal chain controls (for example, LED current setting, TIA gain, and so forth)
(2) If the SPI commands involve a change in the value of TX_REF from its default, then there is additional wait time that is approximately 1 s (for a 2.2-µF decoupling capacitor on the TX_REF pin).
(3) Dependent on the value of the capacitors on the BG and TX_REF pins. The 1-s wait time is necessary when the capacitors are 2.2 µF and scale down proportionate to the capacitor value. A very low capacitor (for example, 0.1 µF) on these pins causes the transmitter dynamic range to reduce to approximately 100 dB.
(4) After an active power-down from AFE_PDN, reset the device by using a low-going pulse on RESET.
spply_rmp_hrdwr_pwr_dwn_tmng_SBAS602.gifFigure 3. Supply Ramp and Hardware Power-Down Timing
spply_rmp_sftwr_SBAS602.gifFigure 4. Supply Ramp and Software Power-Down Timing

7.8 Typical Characteristics

At TA = 25°C, RX_ANA_SUP = RX_DIG_SUP = 3.0 V, TX_CTRL_SUP = LED_DRV_SUP = 5 V, and fCLK = 8 MHz, unless otherwise noted.
C001_SBAS602.png
Figure 5. Total Rx Current vs PRF
C003_SBAS602.png
Figure 7. TX_CTRL_SUP Current vs
TX_CTRL_SUP Voltage
C005_SBAS602.png
Figure 9. Input-Referred Noise Current vs
PLETH Current (BW = 5 Hz, PRF = 100 Hz)
C007_SBAS602.png
Figure 11. Input-Referred Noise Current vs
PLETH Current (BW = 5 Hz, PRF = 600 Hz)
C009_SBAS602.png
Figure 13. Input-Referred Noise Current vs
PLETH Current (BW = 5 Hz, PRF = 2500 Hz)
C011_SBAS602.png
Figure 15. Input-Referred Noise Current vs
PLETH Current (BW = 20 Hz, PRF = 100 Hz)
C013_SBAS602.png
Figure 17. Input-Referred Noise Current vs
PLETH Current (BW = 20 Hz, PRF = 600 Hz)
C015_SBAS602.png
Figure 19. Input-Referred Noise Current vs
PLETH Current (BW = 20 Hz, PRF = 2500 Hz)
C017_SBAS602.png
Figure 21. Noise-Free Bits vs
PLETH Current (BW = 5 Hz, PRF = 100 Hz)
C019_SBAS602.png
Figure 23. Noise-Free Bits vs
PLETH Current (BW = 5 Hz, PRF = 600 Hz)
C021_SBAS602.png
Figure 25. Noise-Free Bits vs
PLETH Current (BW = 5 Hz, PRF = 2500 Hz)
C023_SBAS602.png
Figure 27. Noise-Free Bits vs
PLETH Current (BW = 20 Hz, PRF = 100 Hz)
C025_SBAS602.png
Figure 29. Noise-Free Bits vs
PLETH Current (BW = 20 Hz, PRF = 600 Hz)
C027_SBAS602.png
Figure 31. Noise-Free Bits vs
PLETH Current (BW = 20 Hz, PRF = 2500 Hz)
C029_SBAS602.png
Figure 33. Transmitter Dynamic Range
(5-Hz BW)
C031_SBAS602.png
Figure 35. Transmitter DAC Current Step Error
(200 mA, Max)
C033_SBAS602.png
Figure 37. Transmitter DAC Current Step Error
(100 mA, Max)
C035_SBAS602.png
Figure 39. Transmitter DAC Current Step Error
(50 mA, Max)
C037_SBAS602.png
Figure 41. Transmitter Current Linearity
(75-mA Range)
C039_SBAS602.png
Figure 43. Transmitter Current Linearity
(150-mA Range)
C043_SBAS602.png
Figure 45. LED Current with Tx DAC Setting = 17
(10 mA)
C045_SBAS602.png
Figure 47. LED Current with Tx DAC Setting = 120
(70 mA)
C047_SBAS602.png
Figure 49. Receiver Supplies vs PRF
C049_SBAS602.png
Figure 51. Power Supplies vs Temperature
C051_SBAS602.png
Figure 53. Noise-Free Bits vs Temperature
C002_SBAS602.png
Figure 6. Total Rx Current vs PRF
C004_SBAS602.png
Figure 8. LED_DRV_SUP Current vs
LED_DRV_SUP Voltage
C006_SBAS602.png
Figure 10. Input-Referred Noise Current vs
PLETH Current (BW = 5 Hz, PRF = 300 Hz)
C008_SBAS602.png
Figure 12. Input-Referred Noise Current vs
PLETH Current (BW = 5 Hz, PRF = 1200 Hz)
C010_SBAS602.png
Figure 14. Input-Referred Noise Current vs
PLETH Current (BW = 5 Hz, PRF = 5000 Hz)
C012_SBAS602.png
Figure 16. Input-Referred Noise Current vs
PLETH Current (BW = 20 Hz, PRF = 300 Hz)
C014_SBAS602.png
Figure 18. Input-Referred Noise Current vs
PLETH Current (BW = 20 Hz, PRF = 1200 Hz)
C016_SBAS602.png
Figure 20. Input-Referred Noise Current vs
PLETH Current (BW = 20 Hz, PRF = 5000 Hz)
C018_SBAS602.png
Figure 22. Noise-Free Bits vs
PLETH Current (BW = 5 Hz, PRF = 300 Hz)
C020_SBAS602.png
Figure 24. Noise-Free Bits vs
PLETH Current (BW = 5 Hz, PRF = 1200 Hz)
C022_SBAS602.png
Figure 26. Noise-Free Bits vs
PLETH Current (BW = 5 Hz, PRF = 5000 Hz)
C024_SBAS602.png
Figure 28. Noise-Free Bits vs
PLETH Current (BW = 20 Hz, PRF = 300 Hz)
C026_SBAS602.png
Figure 30. Noise-Free Bits vs
PLETH Current (BW = 20 Hz, PRF = 1200 Hz)
C028_SBAS602.png
Figure 32. Noise-Free Bits vs
PLETH Current (BW = 20 Hz, PRF = 5000 Hz)
C030_SBAS602.png
Figure 34. Transmitter Dynamic Range
(20-Hz BW)
C032_SBAS602.png
Figure 36. Transmitter DAC Current Step Error
(150 mA, Max)
C034_SBAS602.png
Figure 38. Transmitter DAC Current Step Error
(75 mA, Max)
C036_SBAS602.png
Figure 40. Transmitter Current Linearity
(50-mA Range)
C038_SBAS602.png
Figure 42. Transmitter Current Linearity
(100-mA Range)
C040_SBAS602.png
Figure 44. Transmitter Current Linearity
(200-mA Range)
C044_SBAS602.png
Figure 46. LED Current with Tx DAC Setting = 60
(35 mA)
C046_SBAS602.png
Figure 48. LED Current with Tx DAC Setting = 255
(150 mA)
C048_SBAS602.png
Figure 50. Transmitter Supplies vs TX_REF
C050_SBAS602.png
Figure 52. Input-Referred Noise vs Temperature
C052_SBAS602.png
Figure 54. Filter Response vs Duty Cycle