Datasheet
Table Of Contents
- FEATURES
- APPLICATIONS
- DESCRIPTION
- ABSOLUTE MAXIMUM RATINGS
- ELECTRICAL CHARACTERISTICS: Transmitter (Tx)
- ELECTRICAL CHARACTERISTICS: Power Amplifier (PA)
- ELECTRICAL CHARACTERISTICS: Receiver (Rx)
- ELECTRICAL CHARACTERISTICS: Digital
- ELECTRICAL CHARACTERISTICS: Two-Wire Interface
- ELECTRICAL CHARACTERISTICS: Internal Bias Generator
- ELECTRICAL CHARACTERISTICS: Power Supply
- THERMAL INFORMATION
- SPI TIMING REQUIREMENTS
- DEVICE INFORMATION
- TYPICAL CHARACTERISTICS
- APPLICATION INFORMATION
- Revision History
AVDD
2
External 1-nF
noise reduction capacitor
AVDD
R
R
AGND
Inside the AFE031
4 kW
biasInternal
REF2
External 1- F
noise reduction capacitor
m
PA_V
S
R
R
PA_GND
Inside the AFE031
4 kW
PA_V
2
S
bias
Internal
REF1
AFE031
SBOS531D –AUGUST 2010–REVISED MAY 2012
www.ti.com
REF1 and REF2 Blocks
The REF1 and REF2 blocks create midscale power-supply biasing points used internally to the AFE031. Each
reference divides its respective power-supply voltage in half with a precision resistive voltage divider. REF1
provides a PA_V
S
/2 voltage used for the PA, while REF2 provides an AV
DD
/2 voltage used for the Tx PGA, Tx
Filter, Rx PGA1, Rx Filter, and Rx PGA2. Each REF block has its output brought out to an external pin that can
be used for filtering and noise reduction. Figure 36 and Figure 37 show the proper connections of the external
noise-reducing capacitors. These capacitors are optional, but are recommended for best performance.
Figure 36. REF1 Functional Diagram
Figure 37. REF2 Functional Diagram
30 Copyright © 2010–2012, Texas Instruments Incorporated
Product Folder Link(s): AFE031