TSL2521 datasheet(14/81 Pages) OSRAM

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Datasheet, Public

Page 13

[v3-00] 2022-Dec-21

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TSL2521 − Detailed Description

Upon power-up, POR, the device initializes. During initialization

(typically 500μs), the device will deterministically send NAK on

I²C and cannot accept I²C transactions. All communication with

the device must be delayed, and all outputs from the device

must be ignored including interrupts. After initialization, the

device enters the SLEEP state. In this operational state the

internal oscillator and other circuitry are not active, resulting in

ultra-low power consumption. If an I²C transaction occurs

during this state, the I²C core wakes up temporarily to service

the communication. Once the Power ON bit, PON, is enabled,

the device enters the IDLE state in which the internal oscillator

and attendant circuitry are active, but power consumption

remains low. Whenever a function is enabled

(AEN = 1)the device exits the IDLE state. If all functions are

disabled (AEN = 0), the device returns to the IDLE state.

As depicted in Figure 15 and Figure 16, the ambient light

sensing and flicker sampling functions operate in parallel when

enabled. Each function is individually configured (e.g. gain,

ADC integration time, wait time, persistence, thresholds, etc.).

If Sleep after Interrupt is enabled (SAI = 1 in register 0xA1), the

state machine will enter SLEEP when an interrupt occurs.

Entering SLEEP does not automatically change any of the

operational state is over-ridden by SLEEP state). SLEEP state is

terminated when the SAI_ACTIVE bit is cleared (the status bit is

in register 0x9F and the clear status bit is in register 0xB1).

Detailed Description

TSL2521 Arkusz danych(PDF) 14 Page - OSRAM GmbH