Si1141-A10-GM Silicon Laboratories Inc, Si1141-A10-GM Datasheet - Page 18

• Manufacturer Part Number: Si1141-A10-GM
• Description: Proximity Sensors IC INTERFACE
• Manufacturer: Silicon Laboratories Inc

Specifications of Si1141-A10-GM

• Maximum Operating Temperature: + 85 C
• Supply Voltage: 3.3 V
• Supply Current: 5.6 mA to 360 mA
• Operating Supply Voltage: 1.8 V to 3.6 V
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Current Rating: 359 mA
• Voltage Rating: 4 V
• Sensing Distance: 1 m
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Si1141/42/43
4. Programming Guide
4.1. Command and Response Structure
2
All Si1141/42/43 I
C registers (except writes to the COMMAND register) are read or written without waking up the
2
internal sequencer. A complete list of the I
C registers can be found in "4.5. I2C Registers" on page 28. In addition
2
to the I
C Registers, RAM parameters are memory locations maintained by the internal sequencer. These RAM
Parameters are accessible through a Command Protocol (see "4.6. Parameter RAM" on page 48). A complete list
of the RAM Parameters can be found in "4.6. Parameter RAM" on page 48.
The Si1141/42/43 can operate either in Forced Measurement or Autonomous Mode. When in Forced
Measurement mode, the Si1141/42/43 does not make any measurements unless the host specifically requests the
Si1141/42/43 to do so via specific commands (refer to the Section 3.2). The CHLIST parameter needs to be written
so that the Si1141/42/43 would know which measurements to make. The parameter MEAS_RATE, when zero,
places the internal sequencer in Forced Measurement mode. When in Forced Measurement mode, the internal
sequencer wakes up only when the host writes to the COMMAND register. The power consumption is lowest in
Forced Measurement mode (MEAS_RATE = 0).
The Si1141/42/43 operates in Autonomous Operation mode when MEAS_RATE is non-zero. The MEAS_RATE
represents the time interval at which the Si1141/42/43 wakes up periodically. Once the internal sequencer has
awoken, the sequencer manages an internal PS Counter and ALS Counter based on the PS_RATE and
ALS_RATE registers.
When the internal PS counter has expired, up to three proximity measurements are made (PS1, PS2 and PS3)
depending on which measurements are enabled via the upper bits of the CHLIST Parameter. All three PS
measurements are performed, in sequence, beginning with the PS1 measurement channel. In the same way, when
the ALS counter has expired, up to three measurements are made (ALS_VIS, ALS_IR and AUX) depending on
which measurements are enabled via the upper bits of the CHLIST Parameter. All three measurements are made
in the following sequence: ALS_VIS, ALS_IR and AUX.
PS_RATE and ALS_RATE are normally non-zero. A value of zero in PS_RATE or ALS_RATE causes the internal
sequencer to never perform that measurement group. Typically, PS_RATE or ALS_RATE represents a value of
one. A value of one essentially states that the specific measurement group is made every time the device wakes
up.
It is possible for both the PS Counter and ALS Counter to both expire at the same time. When that occurs, the PS
measurements are performed before the ALS measurements. When all measurements have been made, the
internal sequencer goes back to sleep until next time, as dictated by the MEAS_RATE parameter.
The operation of the Si1141/42/43 can be described as two measurement groups bound by some common factors.
The PS Measurement group consists of the three PS measurements while the ALS Measurement group consists of
the Visible Light Ambient Measurement (ALS_VIS), the Infrared Light Ambient Measurement (ALS_IR) and the
Auxiliary measurement (AUX). Each measurement group has three measurements each. The Channel List
(CHLIST) parameter enables the specific measurements for that measurement grouping.
Each measurement (PS1, PS2, PS3, ALS_VIS, ALS_IR, AUX) are controlled through a combination of I2C
Register or Parameter RAM. Tables 5 to 7 below can be used summarize the properties and resources used for
each measurement.
18
Rev. 1.1