DLP9000 datasheet(34/58 Pages) TI2

34 / 58 page

DLP9000

DLPS036B – SEPTEMBER 2014 – REVISED OCTOBER 2016

www.ti.com

Product Folder Links: DLP9000

Submit Documentation Feedback

Micromirror Array Temperature Calculation (continued)

QARRAY = 9.87 W + (0.00274 W/lm × 2000 lm) = 15.35 W

TARRAY = 55°C + (15.35 W × 0.5 ºC/W) = 62.68°C

9.7 Micromirror Landed-On/Landed-Off Duty Cycle

9.7.1 Definition of Micromirror Landed-On/Landed-Off Duty Cycle

The micromirror landed-on/landed-off duty cycle (landed duty cycle) denotes the amount of time (as a

percentage) that an individual micromirror is landed in the On–state versus the amount of time the same

micromirror is landed in the Off–state.

As an example, a landed duty cycle of 100/0 indicates that the referenced pixel is in the On-state 100% of the

time (and in the Off-state 0% of the time); whereas 0/100 would indicate that the pixel is in the Off-state 100% of

the time. Likewise, 50/50 indicates that the pixel is On 50% of the time and Off 50% of the time.

Note that when assessing landed duty cycle, the time spent switching from one state (ON or OFF) to the other

state (OFF or ON) is considered negligible and is thus ignored.

Since a micromirror can only be landed in one state or the other (On or Off), the two numbers (percentages)

always add to 100.

9.7.2 Landed Duty Cycle and Useful Life of the DMD

Knowing the long-term average landed duty cycle (of the end product or application) is important because

subjecting all (or a portion) of the DMD’s micromirror array (also called the active array) to an asymmetric landed

duty cycle for a prolonged period of time can reduce the DMD’s usable life.

Note that it is the symmetry/asymmetry of the landed duty cycle that is of relevance. The symmetry of the landed

duty cycle is determined by how close the two numbers (percentages) are to being equal. For example, a landed

duty cycle of 50/50 is perfectly symmetrical whereas a landed duty cycle of 100/0 or 0/100 is perfectly

asymmetrical.

Individual DMD mirror duty cycles vary by application as well as the mirror location on the DMD within any

specific application. DMD mirror useful life are maximized when every individual mirror within a DMD approaches

50/50 (or 1/1) duty cycle. Therefore, for the DLPC900 and DLP9000 chipset, it is recommended that DMD Idle

Mode be enabled as often as possible. Examples are whenever the system is idle, the illumination is disabled,

between sequential pattern exposures (if possible), or when the exposure pattern sequence is stopped for any

reason. This software mode provides a 50/50 duty cycle across the entire DMD mirror array, where the mirrors

are continuously flipped between the on and off states. Refer to the DLPC900 Programmer’s Guide DLPU018 for

a description of the DMD Idle Mode command. For the DLPC910 and DLP9000X chipset, it is recommended the

controlling applications processor provide a 50/50 pattern sequence to the DLPC910 for display on the

DLP9000X as often as possible, similar to the above examples stated for the DLPC900. The pattern provides a

50/50 duty cycle across the entire DMD mirror array, where the mirrors are continuously flipped between the on

and off states.

9.7.3 Landed Duty Cycle and Operational DMD Temperature

Operational DMD Temperature and Landed Duty Cycle interact to affect the DMD’s usable life, and this

interaction can be exploited to reduce the impact that an asymmetrical Landed Duty Cycle has on the DMD’s

usable life. This is quantified in the de-rating curve shown in Figure 16. The importance of this curve is that:

•

All points along this curve represent the same usable life.

•

All points above this curve represent lower usable life (and the further away from the curve, the lower the

usable life).

•

All points below this curve represent higher usable life (and the further away from the curve, the higher the

usable life).

In practice, this curve specifies the Maximum Operating DMD Temperature that the DMD should be operated at

for a give long-term average Landed Duty Cycle.

DLP9000 Datasheet(PDF) 34 Page - Texas Instruments

DLP9000 Datasheet(HTML) 34 Page - Texas Instruments

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

Datasheet Download

Link URL