Datasheet

AFE030
SBOS588A –DECEMBER 2011– REVISED DECEMBER 2011 www.ti.com
POWER SUPPLIES
The AFE030 has two low-voltage analog power-supply pins and one low-voltage digital supply pin. Internally, the
two analog supply pins are connected to each other through back-to-back electrostatic discharge (ESD)
protection diodes. These pins must be connected to each other on the application printed circuit board (PCB). It
is also recommended to connect the digital supply pin and the two analog supply pins together on the PCB. Both
low-voltage analog ground pins are also connected internally through back-to-back ESD protection diodes. These
ground pins should also be connected to the digital ground pin on the PCB. It is recommended to bypass the
low-voltage power supplies with a parallel combination of a 10-μf and 100-nf capacitor. The PA block is biased
separately from a high-voltage, high-current supply.
Two PA power supply pins and two PA ground pins are available to provide a path for the high currents
associated with driving the low impedance of the ac mains. Connecting the two PA supply pins together as close
as possible to the AFE030 is recommended. It is also recommended to place a bypass capacitor of 47 μF to 100
μF in parallel with 100 nF as close as possible to the AFE030. Care must be taken when routing the high current
ground lines on the PCB to avoid creating voltage drops in the PCB ground that may vary with changes in load
current.
The AFE030 has many options to enable or disable the functional blocks to allow for flexible power-savings
modes. Table 17 shows the specific power supply that each functional block draws power from, as well as the
typical amount of power drawn from the associated power supplies for both the enabled and disabled states. For
additional information on power-supply requirements refer to Application Report SBOA130, Analog Front-End
Design for a Narrowband Power-Line Communications Modem Using the AFE031 (available for download at
www.ti.com).
Table 17. Power Consumption with Enable and Disable Times (Typical)
AVDD SUPPLY DVDD SUPPLY PA SUPPLY
BLOCK STATUS ENABLE TIME DISABLE TIME CURRENT CURRENT CURRENT
On 10 μs — — — 40 mA
PA
Off — 10 μs — — 70 μA
On 10 μs — 3.7 mA — —
Tx
Off — 10 μs 1 μA — —
On 10 μs — 5.3 mA — —
Rx
Off — 10 μs 1 μA — —
On 10 μs — 900 μA — —
ERx
Off — 10 μs 1 μA — —
On 10 μs — 1.2 mA — —
ETx
Off — 10 μs 1 μA — —
On 10 μs — — 16 μA —
DAC
Off — 10 μs — 1 μA —
On 10 μs — 25 μA — —
ZC
Off — 10 μs 1 μA — —
On 10 μs — — — 26 μA
REF1
Off — 10 μs — — 8 μA
On 10 μs — 25 μA — —
REF2
Off — 10 μs 4 μA — —
40 Copyright © 2011, Texas Instruments Incorporated
Product Folder Link(s): AFE030