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

6 Pin Configuration and Functions

RHA Package
VQFN-40
(Top View)
po_bas602.gif
1. DNC = Do not connect.

Pin Functions

PIN FUNCTION DESCRIPTION
NAME NO.
ADC_RDY 28 Digital Output signal that indicates ADC conversion completion.
Can be connected to the interrupt input pin of an external microcontroller.
AFE_PDN 20 Digital AFE-only power-down input; active low.
Can be connected to the port pin of an external microcontroller.
BG 7 Reference Decoupling capacitor for internal band-gap voltage to ground
(2.2-µF decoupling capacitor to ground, expected voltage = 1.0 V).
CLKOUT 30 Digital Buffered 4-MHz output clock output.
Can be connected to the clock input pin of an external microcontroller.
DIAG_END 21 Digital Output signal that indicates completion of diagnostics.
Can be connected to the port pin of an external microcontroller.
DNC(1) 5, 6, 10 — Do not connect these pins. Leave as open-circuit.
INN 1 Analog Receiver input pin. Connect to photodiode anode.
INP 2 Analog Receiver input pin. Connect to photodiode cathode.
LED_DRV_GND 12, 13, 16 Supply LED driver ground pin, H-bridge. Connect to common board ground.
LED_DRV_SUP 17, 18 Supply LED driver supply pin, H-bridge. Connect to an external power supply capable of supplying the large LED current, which is drawn by this supply pin.
LED_ALM 22 Digital Output signal that indicates an LED cable fault.
Can be connected to the port pin of an external microcontroller.
PD_ALM/ADC Reset 23 Digital Output signal that indicates a PD sensor or cable fault.
Can be connected to the port pin of an external microcontroller.
In ADC bypass mode, the PD_ALM pin can be used to bring out the ADC reset signal.
RESET 29 Digital AFE-only reset input, active low.
Can be connected to the port pin of an external microcontroller.
RX_ANA_GND 3, 36, 40 Supply Rx analog ground pin. Connect to common board ground.
RX_ANA_SUP 33, 39 Supply Rx analog supply pin; 0.1-µF decoupling capacitor to ground
RX_DIG_GND 19, 32 Supply Rx digital ground pin. Connect to common board ground.
RX_DIG_SUP 31 Supply Rx digital supply pin; 0.1-µF decoupling capacitor to ground
RXOUTN 34 Analog External ADC negative input when in ADC bypass mode
RXOUTP 35 Analog External ADC positive input when in ADC bypass mode
SCLK 24 SPI SPI clock pin
SPISIMO 26 SPI SPI serial in master out
SPISOMI 25 SPI SPI serial out master in
SPISTE 27 SPI SPI serial interface enable
TX_CTRL_SUP 11 Supply Transmit control supply pin (0.1-µF decoupling capacitor to ground)
TX_REF 9 Reference Transmitter reference voltage, 0.75 V default after reset.
Connect a 2.2-μF decoupling capacitor to ground.
TXN 14 Analog LED driver out B, H-bridge output. Connect to LED.
TXP 15 Analog LED driver out B, H-bridge output. Connect to LED.
VCM 4 Reference Input common-mode voltage output.
Connect a series resistor (1 kΩ) and a decoupling capacitor (10 nF) to ground.
The voltage across the capacitor can be used to shield (guard) the INP, INN traces.
Expected voltage = 0.9 V.
VSS 8 Supply Substrate ground. Connect to common board ground.
XOUT 37 Digital Crystal oscillator pins.
Connect an external 8-MHz crystal between these pins with the correct load capacitor
(as specified by vendor) to ground.
XIN 38 Digital Crystal oscillator pins.
Connect an external 8-MHz crystal between these pins with the correct load capacitor
(as specified by vendor) to ground.
(1) Leave pins as open circuit. Do not connect.