SL900A-ASWB datasheet(13/90 Pages) AMSCO

13 / 90 page

ams Datasheet: 2014-May-06 [v1-01]

SL900A – 13

S y st em D e scription

Figure 14 shows the different states and their interactions.

Figure 22 shows the command overview.

Initializing the Chip

A virgin chip (not initialized) can be initialized either through

the SPI port or through the electromagnetic field from a reader

in the standby mode. The power source is either from a battery

(VBAT) or extracted from the RF field via the AFE circuit. After

the initializing procedure, the chip will enter the ready mode.

Power Modes

Ready Mode

In the ready mode, all parameters can be set, read and changed

through a reader with the appropriate passwords.

Active Mode

In active mode, the real-time clock (RTC) is running, the desired

parameters are set, and the on-chip temperature sensor is in

standby.

Logging Mode

A log flag from the timer will enable the logging mode in which

the sensor and the A/D converter will be activated, and the

measured value will be stored in the EEPROM together with the

time of the event. If the external sensor flag is set, the external

sensors will also be activated and the measured data stored.

The A/D converter can be multiplexed between internal

temperature sensor, external sensors or battery voltage. After

the event, the chip will return to the active mode.

Interrupt Mode

In the interrupt mode, the external sensor interrupt block is

running with minimal power consumption. When the external

sensor value exceeds a specified threshold, the chip goes into

the logging mode where the selected sensor values and real

time of the event are stored to the EEPROM.

Stand-by Mode

In passive mode, all blocks in the chip are turned off and only

the leakage current is flowing. When the label enters an RF field,

it will go from Stand-by mode to Ready mode. If the SEN pin

rises high, the chip will go from the Stand by mode to the serial

mode

System Description

SL900A-ASWB 데이터시트(PDF) 13 Page - ams AG