ATA5428-PLSW datasheet(52/100 Pages) ATMEL

52 / 100 page

4841D–WIRE–10/07

ATA5423/ATA5425/ATA5428/ATA5429

Operation Modes

9.1

RX Operation

The transceiver is set to RX operation with the bits OPM0 and OPM1 in control register 1.

The transceiver is designed to consume less than 1 mA in RX operation while remaining sensi-

tive to signals from a corresponding transmitter. This is achieved via the polling circuit. This

circuit enables the signal path periodically for a short time. During this time the bit-check logic

verifies the presence of a valid transmitter signal. Only if a valid signal is detected does the

transceiver remain active and transfer the data to the connected microcontroller. This transfer

takes place either via the TX/RX data buffer or via the pin SDO_TMDO. When there is no valid

signal present, the transceiver is in sleep mode most of the time, resulting in low current con-

sumption. This condition is called RX polling mode. A connected microcontroller can be disabled

during this time.

All relevant parameters of the polling logic can be configured by the connected microcontroller.

This flexibility enables the user to meet the specifications in terms of current consumption, sys-

tem response time, data rate, etc.

In RX mode the RF transceiver is enabled permanently and the bit-check logic verifies the pres-

ence of a valid transmitter signal. When a valid signal is detected the transceiver transfers the

data to the connected microcontroller. This transfer take place either via the TX/RX data buffer

or via the pin SDO_TMDO.

9.1.1

RX Polling Mode

When the transceiver is in RX polling mode it stays in a continuous cycle of three different

modes. In sleep mode the RF transceiver is disabled for the time period T

Sleep while consuming

low current of I

S = IIDLE_X. During the start-up period, TStartup_PLL and TStartup_Sig_Proc, all signal pro-

cessing circuits are enabled and settled. In the following bit-check mode, the incoming data

stream is analyzed bit by bit to see if it is a valid transmitter signal. If no valid signal is present,

the transceiver is set back to sleep mode after the period T

Bit-check. This period varies check by

check as it is a statistical process. An average value for T

Bit-check is given in the electrical charac-

teristics. During T

Startup_PLL the current consumption is IS = IStartup_PLL_X. During TStartup_Sig_Proc

and T

Bit-check the current consumption is IS = IRX_X. The condition of the transceiver is indicated

on pin RX_ACTIVE (see Figure 9-1 on page 54 and Figure 9-2 on page 55). The average cur-

rent consumption in RX polling mode I

P is different in 1 Li battery application (3V), 2 Li battery

application (6V) or Base-station Application (5V). To calculate I

P the index X must be replaced

by VS1,VS2 in 1 Li battery application (3V), VS2 in 2 Li battery application (6V) or VS2,VAUX in

Base-station Application (5V) (see section “Electrical Characteristics: General” on page 67).

Table 9-1.

Control Register 1

OPM1

OPM0

Function

RX polling mode

RX mode

IDLE_X

Sleep

Startup_PLL_X

Startup_PLL

RX_X

Startup_Sig_Proc

Bitcheck

()

Sleep

Startup_PLL

Startup_Sig_Proc

Bit_check

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

ATA5428-PLSW Datasheet(PDF) 52 Page - ATMEL Corporation

ATA5428-PLSW Datasheet(HTML) 52 Page - ATMEL Corporation

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100

Datasheet Download

Link URL