LTR-X1503 Optical Sensor Datasheet - Integrated Ambient Light and Proximity Sensing - I2C Interface - 3.0-3.6V - Technical Documentation

1. Product Overview

LTR-X1503 ni sensor ya mwanga iliyojumuishwa sana na ya voltage ya chini, inayounganisha sensor ya mwanga wa mazingira na sensor ya ukaribu pamoja na kiinua mwanga cha infrared kilichojengwa ndani, zote zikiwekwa ndani ya kifurushi kidogo cha chip-level, kisicho na risasi, na kinachoweza kushikanishwa kwenye uso. Usanidi huu wa kuunganisha unarahisisha usanidi wa saketi na kuokoa nafasi ya thamani kwenye bodi ya saketi kwa vifaa vya umeme vilivyo kompakt.

Upeo wa kimsingi wa sensor hii ni utendakazi wake wa pande mbili. Sensor ya mwanga wa mazingira hutoa mwitikio wa mwangaza unaofuata mstari kwenye anuwai pana ya mienendo, na kufanya iweze kutumika katika hali mbalimbali za mwanga wa mazingira, kutoka gizani kabisa hadi mwangaza mkali. Wakati huo huo, sensor ya ukaribu iliyojengwa ndani inaweza kugundua uwepo au kutokuwepo kwa vitu ndani ya umbali unaoweza kusanidiwa na mtumiaji, na hivyo kuwezesha utendakazi kama vile kuzima skrini wakati wa mazungumzo au kulemaza skrini ya kugusa.

Kifaa hiki kinalenga hasa soko la vifaa vya mkononi, vifaa vya kompyuta na vifaa vya elektroniki vya matumizi ya kawaida. Ukubwa wake mdogo sana, sifa ya matumizi ya nguvu chini yenye hali ya usingizi, na kiolesura cha dijiti cha I2C, hukifanya kiwe chaguo bora kwa simu janja, kompyuta kibao, kompyuta ya mkononi, vifaa vinavyovaliwa na vifaa vya IoT, ambapo usimamizi bora wa nguvu na utumiaji bora wa nafasi ni mambo muhimu ya kuzuia.

1.1 Core Features and Advantages

• Kihisi Kimoja cha Ufungashaji Mbili:Inaunganisha kihisi cha mwanga wa mazingira na kihisi cha ukaribu, na hupunguza idadi ya vipengele vya mzunguko na eneo linalochukuliwa na PCB.
• Kiolesura cha Dijiti cha I2C:Supports Standard Mode (100kHz) and Fast Mode (400kHz), facilitating communication with the master microcontroller.
• Ultra-Low Power Operation:Features both operating and standby modes. The typical supply current for two sensors operating simultaneously is 160 uA, while the standby current can drop to as low as 1 uA, significantly extending battery life.
• Programmable Interrupt Feature:The proximity sensor incorporates an interrupt system with programmable upper and lower thresholds and hysteresis. This eliminates the need for the main processor to continuously poll the sensor, thereby enhancing overall system efficiency and power savings.
• High-Performance Ambient Light Sensor:Inatoa azimio la ufanisi la biti 16, na mwitikio wa mstari katika anuwai pana, na mwitikio wa wigo unaokaribia jicho la binadamu. Inajumuisha utekelezaji wa kukandamiza kiotomatiki wa mwanga wa 50Hz/60Hz, ili kuhakikisha usomaji thabiti chini ya vyanzo vya mwanga vya bandia.
• Uhisiaji wa ukaribu thabiti:Inajumuisha kiendeshi cha LED kilichojengwa ndani, uwezo wa juu wa kukandamiza mwanga wa mazingira (hadi 10 klux), azimio la biti 16, na algorithm ya kuondoa usumbufu wa mawimbi, kufanikisha ugunduzi thabiti wa vitu.
• Urekebishaji wa kiwandani:One-time factory trimming minimizes device-to-device variation, ensures consistent performance, and reduces end-customer manufacturing calibration requirements.
• Wide Operating Range:Operating voltage range from 3.0V to 3.6V, temperature range from -40°C to +85°C, with built-in temperature compensation circuitry to ensure stable operation.

2. Maelezo ya Vipimo vya Kiufundi

2.1 Viwango vya Juu Kabisa

Stresses beyond these limits may cause permanent damage to the device.

• Voltage ya usambazaji wa umeme (VDD):3.6 V
• Pini za I/O za dijiti (SCL, SDA, INT):Suitable for normal operation of the device.
• LED anode voltage (V_LED):-0.5 V to 4.6 V
• LED driver pin voltage (V_LDR):-0.5 V to 3.6 V
• Storage temperature:-40°C to 100°C
• ESD protection (HBM):2000 V

2.2 Recommended Operating Conditions

For normal device operation.

• Voltage ya usambazaji wa umeme (VDD):3.0 V to 3.6 V
• LED supply voltage (V_LED):2.8 V to 4.0 V
• Operating Temperature:-40°C to 85°C
• I2C High-Level Input:1.5 V to VDD
• I2C Low-Level Input:0 V hadi 0.4 V

2.3 Electrical and Optical Specifications

Vipimo kwa kawaida hutolewa chini ya hali ya VDD = 1.8V na Ta = 25°C.

2.3.1 Power Consumption Characteristics

• Supply Current (Both ALS and PS Active):160 uA (Typical, with a measurement repetition rate of 100ms).
• ALS Operating Current:160 uA (Typical).
• PS Operating Current:57 uA (typical, 8 pulses, 100% duty cycle, 32us pulse width).
• Standby current:1 uA (typical).
• Wake-up time from standby:0.25 ms (kiwango cha kawaida).

2.3.2 Sifa za Sensor ya Mwanga wa Mazingira

• Uwezo wa kutofautisha:Programmable to 13, 14, 15, or 16 bits of effective resolution.
• Lux Accuracy:±10% (typical, under white LED illumination).
• Dark Level Count:0 to 5 counts (at 0 lux, 16-bit resolution, 512x gain, 100ms integration time).
• Integration Time:Programmable, ranging from 0.2 ms to 200 ms.
• Flicker Noise Suppression:For 50Hz/60Hz lighting, the error is ±5%.
• Spectral Response:Close to the photopic response of the human eye.

2.3.3 Sifa za Sensor ya Ukaribu

• Uwezo wa kutofautisha:16-bit effective resolution.
• Peak Sensitivity Wavelength:940 nm (typical, for integrated IR emitter).
• Detection Range:Inaweza kufikia hadi 20 cm (thamani ya kawaida, inaweza kusanidiwa kulingana na idadi ya mipigo, faida na mipangilio ya mkondo).
• Mkondo wa mipigo wa LED:Inaweza kupangwa programu, inaweza kufikia hadi 186 mA (thamani ya kawaida).
• Upana wa mipigo wa LED:Programmable: 8, 16, 32, or 64 us.
• Number of LED Pulses:Programmable, from 1 to 256 pulses per measurement.
• Uvamizi wa Mwangaza wa Mazingira:Hadi 10 klux (mionzi ya moja kwa moja ya jua). Inapozidi kiwango hiki, utendaji wa usalama wa kushindwa huzuia kusababishwa vibaya.

3. Uchambuzi wa Mkunjo wa Utendaji

3.1 ALS Spectral Response

The ambient light photodiode of this sensor is designed with a filter that matches the CIE photopic luminosity function, which defines the standard response of the human eye to light. This ensures that the lux readings reported by the sensor accurately represent the brightness perceived by humans, not just the raw radiant energy. This is crucial for achieving automatic display brightness control that feels natural to the user.

3.2 PS Performance vs. Distance

The performance characteristic of a proximity sensor is represented as a function of the reflected signal strength versus the distance to a standard reflective object (typically with 88% reflectivity). This relationship is nonlinear and follows the inverse square law. The graph shows that under typical settings (e.g., VDD=1.8V, LED current 104mA, 16 pulses), a clear and measurable signal can be obtained, allowing for the setting of a reliable detection threshold for specific application distances (e.g., 5cm for phone earpiece detection).

3.3 Mwitikio wa Pembe ya ALS

传感器的角度响应图（针对X轴和Y轴）显示了测量光强如何随入射角变化。对于大多数环境光传感应用，完美的余弦（朗伯）响应是理想的。LTR-X1503表现出接近这种理想的响应，确保无论主光源相对于传感器的方向如何，都能获得准确的读数。在极端角度（> ±60度）下与理想余弦响应的偏差，由于封装和光学设计的限制，在大多数传感器中是典型的。

4. Taarifa za Mitambo na Ufungaji

LTR-X1503 inatumia ufungaji mdogo sana wa chip-level wenye pini 8 wa kusakinishwa kwenye uso. Vipimo halisi vya muundo vinatolewa kwenye mchoro wa vipimo katika karatasi ya data, ikijumuisha mtazamo wa juu, mtazamo wa upande na mtazamo wa chini, na kuonyesha vipimo muhimu kama urefu wa ufungaji, upana, urefu, umbali wa pini na ukubwa wa pedi. Taarifa hii ni muhimu kwa muundo wa ufungaji wa PCB na kuhakikisha muafaka sahihi wa mitambo katika bidhaa ya mwisho.

4.1 Pin Configuration and Functions

• Pini 1 (VDD):Power Input (3.0V - 3.6V).
• Pin 2 (SCL):I2C Serial Clock Input.
• Pin 3 (GND):Muunganisho wa ardhi.
• Pini 4 (LEDA):Muunganisho wa anodi ya LED ya infrared iliyojumuishwa. Lazima iunganishwe kwenye reli ya umeme ya LED (V_LED).
• Pini 5 (LDR):Kiunganishi cha kiongozi cha LED. Kwa kuwa kiongozi kimejumuishwa ndani, pini hii inapaswa kuachwa wazi (NC).
• Pini 6 (NC):Hakuna muunganisho wa ndani. Inaweza kushikwa hewa au kuunganishwa ardhini.
• Pini 7 (INT):Pato la kukatiza lenye ufanisi wa kiwango cha chini. Pato hili la kufungua mfereji linaweka kiwango cha chini wakati tukio la ukaribu (kugundua/kutoa kitu) litakapotokea kulingana na kizingiti kilichowekwa programu.
• Pini 8 (SDA):Ingizo la data ya mfululizo ya I2C / pato (tundu wazi).

5. Application Circuit and Design Guide

5.1 Recommended Application Circuit

A typical application circuit includes the sensor, necessary decoupling capacitors, and I2C pull-up resistors.

• Power Supply Decoupling:A 1uF ceramic capacitor (C1) should be placed as close as possible between VDD and GND. An additional 0.1uF capacitor (C2) can be added to suppress high-frequency noise.
• LED Power Supply Decoupling:It is recommended to place a 1uF capacitor (C3) between the LEDA pin (and the V_LED power rail) and GND.
• I2C Pull-up Resistors:Resistors (Rp1, Rp2) with values between 1 kΩ and 10 kΩ are required on the SCL and SDA lines. The specific value depends on the bus capacitance and the required rise time; a lower value provides stronger pull-up capability but increases current consumption. If an INT line is used, a similar pull-up resistor may also be required.

5.2 Power Sequence

Key Requirements:Ni lazima kufuata mpangilio sahihi wa umeme ili kuzuia uwezekano wa kufungia au kuharibika.

• Kuwasha umeme:VDD (Chanzo kikuu cha umeme cha mantiki) lazima kiwe ndani yaZamaniWasha.
• Zima umeme:V_LED lazima iwe ndani yaZamani VDD.

Power off.

6. Mwongozo wa Uchomeaji na Usanikishaji

Kipengele hiki ni kifaa cha kukandamiza kwenye uso, kilichoundwa kwa ajili ya mchakato wa kuchomea reflow unaojulikana katika utengenezaji wa umeme kwa wingi.

6.1 Mkunjo wa Joto wa Reflow Soldering

• Ingawa maelezo maalum ya data huenda hayakuelezewa kwa kina kuhusu mkunjo wa joto, mkunjo wa kawaida wa kuyeyusha tena usio na risasi (unaokidhi RoHS) unatumika. Hii kwa kawaida inajumuisha:Kupasha joto kabla/Kuongezeka kwa joto:
• Kuongezeka kwa joto polepole (1-3°C/s) hadi takriban 150-200°C, ili kuamilisha flux na kupunguza mshtuko wa joto.Soo la joto:
• Weka kipindi cha joto kwenye 150-200°C kwa sekunde 60-120, ili kuhakikisha joto linasambaa sawasawa kwenye bodi nzima na kuyeyusha vitu vinavyogeuka kuwa gesi.Eneo la reflow:
• Pasha joto haraka hadi kufikia kilele cha joto. Kilele cha joto kisizidi thamani ya juu kabisa iliyoidhinishwa kwa kifuniko (inaweza kuwa 260°C kwa muda mfupi, kwa mfano sekunde 10-30 zaidi ya 245°C).Kupoa:

Hatua ya kupoa iliyodhibitiwa.

Tafadhali angalia kiwango cha unyevunyevu nyeti cha kifurushi, ikiwa kifaa kimewekwa wazi kwa unyevunyevu wa mazingira unaozidi kizingiti chake kilichopimwa, tafadhali fuata taratibu zinazofaa za kukausha na usindikaji.

6.2 Masharti ya Uhifadhi

7. Packaging and Ordering Information

LTR-X1503 inatolewa kwa namna ya mkanda uliojipinda unaofaa kwa mashine ya kukamata kiotomatiki.

• Nambari ya Sehemu:LTR-X1503
• Aina ya Ufungaji:Chip-scale package yenye pini 8.
• Ufungaji:Reel.
• Standard quantity per reel:3,000 pieces.

8. Application Recommendations

8.1 Typical Application Scenarios

• Simu mahiri/Tabuleti:Usanidi wa Mwangaza wa Skrini Otomatiki (ALS) na kuzima skrini/kulemaza kugusa (PS) wakati kifaa kinasogezwa karibu na sikio wakati wa mazungumzo.
• Kompyuta ya Mkononi na Kionyeshi:Marekebisho ya Mwangaza wa Nyuma ya Mazingira Kulingana na Mwangaza wa Mazingira, kwa ajili ya kuokoa nguvu na kuboresha starehe ya kutazama.
• Vifaa Vinavyovaliwa:Display activation (PS) upon gesture wake-up or user gaze, along with brightness management.
• Consumer Electronics:Automatic on/off control, contactless switching, and presence detection in home appliances.

8.2 Kuzingatia Katika Ubunifu na Mazoea Bora

• Optical Path:Ensure the ambient light sensor has a clear, unobstructed optical path. For proximity sensors, design a window or aperture so that infrared light can be emitted effectively and reflected light can return effectively. Avoid placing the sensor behind dark or infrared-absorbing materials.
• Infrared Interference:The proximity sensor uses 940nm infrared light. Sunlight and some artificial light sources contain infrared components. The sensor's high ambient light suppression and crosstalk cancellation features help, but keeping it away from direct, intense infrared light sources can improve performance.
• I2C Bus Management:Tumia kipengele cha kukatiza ili kuweka MCU kuu kulala, na uiamshe tu wakati tukio la ukaribu linatokea. Chunguza sensor ya mwanga wa mazingira kwa kiwango cha wastani (kwa mfano, mara moja kwa sekunde), isipokuwa inahitajika kufuatilia mabadiliko ya haraka ya mwangaza.
• Urekebishaji wa kizingiti:Lazima urekebishe kizingiti cha kugundua cha sensor ya ukaribu ndani ya kifuniko cha bidhaa ya mwisho, ili kuzingatia unene wa glasi ya kifuniko, uakisi, na uakisi wa ndani (crosstalk). Hii kawaida hufanywa wakati wa utengenezaji.

9. Ulinganisho wa Teknolojia na Tofauti

LTR-X1503 competes in the integrated ALS/PS solution market. Its main differentiation advantages may include:

• High Integration:Kuunganisha mtoa miale ya infrared na sensor ndani ya kifurushi kimoja ni faida kubwa, ikipunguza orodha ya vifaa na kurahisisha usawazishaji wa macho ikilinganishwa na suluhu zinazohitaji LED za infrared tofauti.
• Utendaji:Sensor zote mbili zina azimio la biti 16, kuzuia kwa nguvu mwanga wa mazingira (10 klux), na vigezo vya kipimo vinavyoweza kutengenezwa programu, hivyo kutoa ubunifu wa muundo na utendaji thabiti.
• Ufanisi wa nishati:Mkondo wa chini wa kufanya kazi na wa kusubiri wenye ushindani ni muhimu kwa vifaa vinavyotumia betri.
• Kiolesura cha kidijitali:Kiolesura cha I2C ni basi ya kawaida na inayoungwa mkono sana, na hufanya ushirikiano uwe rahisi na wa moja kwa moja.

10. Maswali Yanayoulizwa Mara kwa Mara (Kulingana na Vigezo vya Kiufundi)

10.1 How to set the detection distance of a proximity sensor?

Umbali wa kugundua sio kigezo kimoja cha kudumu, bali ni matokeo ya mipangilio kadhaa inayoweza kusanidiwa: mkondo wa mwendo wa LED, upana wa mwendo, idadi ya mwendo, na faida ya kipokeaji. Kwa kuongeza mkondo wa LED, idadi ya mwendo, au faida, nguvu ya ishara inayojitokeza itaongezeka, na hivyo kuweza kugundua vitu vilivyo mbali zaidi au vilivyo na kiwango cha chini cha kutafakari. Kizingiti maalum cha "kugundua" huwekwa na mtumiaji katika rejista ya kizingiti cha usumbufu, kwa njia ya kuonyesha data ya hesabu ya sensor ya ukaribu katika umbali unaohitajika katika bidhaa ya mwisho.

10.2 Why is the power sequence between VDD and V_LED important?

Mpangilio usio sahihi unaweza kusababisha mkondo mkubwa wa mawimbi kupitia muundo wa ulinzi wa ndani wa ESD au mzunguko wa mantiki, unaoweza kusababisha kufungwa - hali ya mkondo wa juu ambayo inaweza kusababisha uharibifu wa kifaa. Kufuata mpangilio maalum (VDD kwanza, kisha V_LED kuwasha; V_LED kwanza, kisha VDD kuzima) kuhakikisha kwamba transistor za ndani zinapata upendeleo sahihi kabla ya kutumia au kuondoa usambazaji wa umeme wa LED wenye voltage ya juu.

10.3 Kwa kichunguzi cha ukaribu, "kuondoa usumbufu wa mawasiliano" linamaanisha nini?

Msongamano unarejelea miondoko ya ndani ndani ya moduli ya kifaa au kifuniko chake, ambapo mwanga wa infrared kutoka kwa transmitter unafika moja kwa moja kwenye photodiode ya sensor ya ukaribu bila kuakisiwa na kitu cha nje. Hii husababisha uhamisho wa usuli, ambao unaweza kusababisha kusukumwa vibaya au kupunguza usikivu. LTR-X1503 hutumia algorithm (kwa kawaida inahusisha kipimo cha msingi wakati LED imezimwa) kupima na kutoa sehemu hii ya msongamano kutoka kwa data ya mwisho ya sensor ya ukaribu, na hivyo kuboresha usahihi wa kugundua vitu.

10.4 How does the ambient light sensor achieve 50/60Hz flicker rejection?

Incandescent and fluorescent lamps powered by AC mains fluctuate in intensity at 100Hz or 120Hz (twice the line frequency). If the sensor's integration time is an integer multiple of the flicker period (e.g., 10ms, 20ms, 100ms), it averages over complete light cycles, thereby canceling the variation and providing a stable lux reading. The sensor's integration time is programmable to integer multiples of these periods to achieve this rejection.

11. Design and Application Case Studies

11.1 Implementing Energy-Efficient Display Control in Smartwatches

Tukio:Saa ya mkono ya kisasa inahitaji kuongeza uimara wa betri kwa kiwango cha juu. Skrini inapaswa kuwa angavu nje, giza ndani, na kuzimwa kabisa isipokuwa inatazamwa (kwa mfano, wakati mkono wa mtumiaji umeshushwa chini).

Kutumia LTR-X1503 kutekeleza:

1. Jukumu la ALS:The ambient light sensor is configured with 16-bit resolution and a 100ms integration time (for flicker suppression). The main MCU reads the ambient light sensor data via I2C once per second. The lux value is mapped to the corresponding PWM duty cycle for the display backlight via a lookup table or algorithm to achieve smooth automatic brightness adjustment.
2. PS Role:The proximity sensor is configured with appropriate pulse current and count based on the expected viewing distance (e.g., approximately 30cm). Set interrupt thresholds: a lower threshold for "object removal" (not viewing the watch) and an upper threshold for "object detection" (raising the watch to view). The INT pin is connected to a wake-up capable GPIO on the MCU.
3. Power Saving Workflow:
   • Wakati mtumiaji anaposhusha mkono, hesabu ya kichunguzi cha ukaribu hushuka chini ya kizingiti cha chini, na kusababisha usumbufu.
   • MCU inaamka kutoka usingizini, inasoma hali ya usumbufu, na kuamuru skrini iingie katika hali ya nguvu ya chini ya kuzima.
   • Kisha MCU inaweza kujiweka yenyewe na sensorer (labda isipokuwa hali ya ufuatiliaji ya sensorer ya karibu ya nguvu ya chini) kulala tena.
   • Wakati mtumiaji anainua mkono wake kutazama saa, sensorer ya karibu hugundua kitu, kusababisha usumbufu, kuamsha MCU, MCU kisha inatoa nguvu kamili kwa skrini na sensorer ya mwanga wa mazingira, kuonyesha wakati sahihi kwa mwangaza unaofaa.

Ikilinganishwa na skrini iliyo wazi daima au inayodhibitiwa na wakati tu, mchanganyiko huu umepunguza kwa kiasi kikubwa wastani wa matumizi ya nguvu ya mfumo.

12. Introduction to Working Principles

12.1 Ambient Light Sensing Principle

The ambient light sensing function is based on a photodiode, a semiconductor device where the generated minute current is proportional to the intensity of light falling on it. In the LTR-X1503, this photodiode is covered with a filter that mimics the sensitivity of the human eye across the entire visible spectrum. The generated photocurrent is very small (picoampere to nanoampere range). An integrated transimpedance amplifier converts this current into a voltage, which is then digitized by a high-resolution analog-to-digital converter. The digital value is processed and made available via I2C registers, representing illuminance in counts, which can be converted to lux units using a calibration formula.

12.2 Kanuni za Kugundua Ukaribu

The proximity sensor operates based on the active infrared reflection principle. An integrated infrared LED emits short pulses of 940nm light, invisible to the human eye. A separate, dedicated photodiode (different from the ambient light sensing diode) acts as the receiver. When an object is within range, a portion of the emitted infrared light reflects off the object and returns to the receiver photodiode. The sensor measures the amount of reflected light received during and after each LED pulse. By comparing this signal with the ambient infrared level (measured with the LED off) and after crosstalk cancellation, the sensor calculates a proximity data count. A higher count indicates a closer object or higher reflectivity. This count is compared to a user-programmed threshold to trigger an interrupt.

13. Mwelekeo wa Teknolojia

The market for integrated optical sensors like the LTR-X1503 is driven by several distinct trends in the electronics industry:

• Miniaturization:The ongoing demand for smaller package sizes (e.g., chip-scale) to accommodate increasingly slim devices with larger screens and batteries.
• Increased Integration:Mwelekeo unazidi kukidhi zaidi ya kuunganisha tu kihisio cha mwanga wa mazingira na kihisio cha ukaribu. Kihisio cha baadaye kinaweza kuunganisha vihisio vingine vya mazingira (rangi, ishara, wakati wa kukimbia), na hivyo kupunguza zaidi utata wa mfumo.
• Ujasusi wa ukingoni:Vihisio vinapata uwezo zaidi wa usindikaji kwenye chip. Toleo la baadaye linaweza si tu kutoa data ya awali, bali pia kutekeleza hesabu za lux, mantiki ya mashine ya hali ya ukaribu na utambuzi wa ishara ndani yake, na kutuma tu arifa za matukio ya kiwango cha juu kwa kichakataji kikuu, na hivyo kuokoa zaidi nguvu ya mfumo.
• Uboreshaji wa utendaji:Matarajio ya usahihi, anuwai ya mienendo na matumizi ya nguvu yanaendelea kuongezeka. Maendeleo ya michakato ya semiconductor na muundo wa optiki yanafanya iwezekane kwa ADC zenye kelele ndogo, azimio la juu zaidi na LED zenye ufanisi zaidi.
• Kusanifishwa na Usaidizi wa Programu:Madereva thabiti na yaliyosanifishwa ya programu (kwa mfano, kwa Android, Linux) yanakuwa muhimu sawa na utendaji wa vifaa, na hivyo kupunguza muda wa kufikia soko kwa watengenezaji wa vifaa.