LS521 Version Issue Date File Name Total Pages : A.001 : 2008/06/17 : SP-LS521-A.001.doc : 11 ILLUMINATION-TO-DIGITAL CONVERTER with SMBUS INTERFACE 新竹市科學園區展業一路 9 號 7 樓之 1 SILICON TOUCH TECHNOLOGY INC. 9-7F-1, Prosperity Road I, Science Based Industrial Park, Hsin-Chu, Taiwan 300, R.O.C. Tel：886-3-5645656 Fax：886-3-5645626 點晶科技股份有限公司 LS521 SILICON TOUCH TECHNOLOGY INC. ILLUMINATION-TO-DIGITAL CONVERTERS GENERAL DESCRIPTION The LS521 is a low-noise, high-sensitivity and illumination-to-digital converter with two-wire SMBus serial interface. The device integrates a photodiode, a trans-impedance amplifier, and 8-bits analog-to-digital converter (ADC) in a single IC to provide illumination information over an effective 8-bit dynamic range. The digital output is directly proportional to ambient illumination. The LS521 is characterized with the C.I.E. response as the human eye’s visual response, which peaks at 555nm. Illumination information can be used to control display panel backlighting with the purpose of extending battery life and providing optimum viewing in diverse lighting conditions. Also, illumination information can further be used to manage exposure control in digital cameras and camcorders. The LS521 device is ideal in notebook/tablet PCs, flat-panel televisions, cellular phones, LCD monitors, digital cameras, camcorder, and street/room lighting control, etc. FEATURES 1. Characterized with the C.I.E. response as the human eye’s response 2. 8-bit linear digital output for ambient illumination with two wire SMBus interface. 3. Tunable illumination sensitivity by an external resistor 4. Rejection of 50Hz/60Hz light ripple by an external resistor (RL) and an external capacitor (CL) 5. Wide power supply range (2.7~5.5V) 6. Low power dissipation in shut-down mode. 7. Tiny SMD type package: Width: 3.0mm Height: 3.0 mm Depth: 1.1mm 8. High sensing illuminance range (0~14000 lux). SP-LS521-A.001 -1- Version：A.001 點晶科技股份有限公司 LS521 SILICON TOUCH TECHNOLOGY INC. FUNCTIONAL BLOCK DIAGRAM and APPLICATION VDD 0.1uF Oscillator CL RL Control Logic A/D converter Command Register SMBus Interface REXT VSS SCL SDA ADC Register ABSOLUTE MAXIMUM RATINGS Item Supply Voltage Input Voltage for SCLK, SDA, REXT Input Current for SCLK, SDA Output Current for SDA Operating Temperature Storage Temperature Electrostatic Damage, (HBM) Symbol VDD VIN IIN IOUT Topr Tstg ESD Ratings -0.4 ~ 6 -0.4 ~ VDD+0.4 +20 -1 -25 to +85 -40 to +125 3 Unit V mA mA mA ℃ ℃ kV RECOMMENDED OPERATING CONDITIONS Item Supply Voltage Operating Temperature Input Low Voltage for SCLK, SDA Input High Voltage for SCLK, SDA Operating Frequency for SCLK SP-LS521-A.001 Symbol VDD Topr VIL VIH fSCLK -2- Min. 2.7 -25 2.1 10 Typ. Max. 5.5 85 0.8 VDD 400 Version：A.001 Unit V ℃ V V KHz 點晶科技股份有限公司 LS521 SILICON TOUCH TECHNOLOGY INC. ELECTRICAL CHARACTERISTICS (VDD=3V, TA=25℃ if not mentioned ) Item Symbol SMBus Output Low Voltage VOL Supply Current Test Conditions Min. Typ. Max. Unit IO =10uA - 0.01 - V IO =350uA - - 0.4 V - 0.38 0.43 - 0.65 0.75 - 30 35 - 80 92 - 0.33 0.38 - 0.6 0.7 VDD Power-up, =3V VSMBCLK =VSMBDAT=VDD, Ee =0, VDD =5.5V VDD Power-down, =3V VSMBCLK=VSMBDAT = VDD, Ee =0 VDD =5.5V VDD Shut-down ADC, =3V VSMBCLK=VSMBDAT =VDD, Ee =0 VDD =5.5V IDD mA uA mA High Level Input Current IIH VSDA(or VSCL)=VDD - - 5 uA Low Level Input Current IIL VSDA(or VSCL)= 0V - - -5 uA DC OPERATING CHARACTERISTICS (VDD=3V, TA=25℃, RL=11.9kΩ, CL=100uF, unless otherwise noted) Item Symbol Test Conditions Min. Typ. Max. Unit Full scale ADC count - - - - 255 counts - 0 2 83 104 125 0.208 0.26 0.312 Ee =0 ADC count value Illuminance responsivity DOUT Rv counts Ee =400 lux, Fluorescent light (note.1) Fluorescent light (note.1) NOTE: 1. Using a white LED as the fluorescent light source. SP-LS521-A.001 -3- Version：A.001 counts/ lux 點晶科技股份有限公司 LS521 SILICON TOUCH TECHNOLOGY INC. MAXIMUM ILLUMINANCE RANGE SETTING Max. illuminance range(LUX) RL(KΩ) 1000 2000 5000 14000 12 6 2.4 0.857 Table 1. Maximum illuminance range vs RL For example, if we need the maximum illuminance range to be 2000 lux, then RL = 1200 = 6( KΩ) 0.1× 2000 where 1200 and 0.1 are constants, 2000 is max. lux REJECTION OF LIGHT RIPPLE Cut off frequency(Hz) RL (kΩ) CL (uF) Table 2. 60 6 0.45 1 2.4 1.2 6 27 2.4 67 RL , CL setting For example, if light ripple(f)=60Hz, RL=6kΩ, then CL > 1 1 = = 0.4421(uF ) 2πR × f 2π × 6000 × 60 AC OPERATING CHARACTERISTICS (VDD=3V, TA=25℃ unless otherwise noted) Item Symbol Min. Typ. Max. Unit kHz Clock frequency f(SMBCLK) 10 - 400 Bus free time between start and stop condition Hold time after (repeated) start condition. After this period, the first clock is generated. t(BUF) 4.7 - - us t(HDSTA) 4 - - us Repeated start condition setup time t(SUSTA) 4.7 - - us Stop condition setup time t(SUSTO) 4 - - us Data hold time t(HDDAT) 300 - - ns Data setup time t(SUDAT) 250 - - ns SMBCLK clock low period t(LOW) 4.7 - - us SMBCLK clock high period t(HIGH) 4 - 50 us Detect clock low timeout t(TIMEOUT) 25 - 35 ms Clock/data fall time tF - - 300 ns Clock/data rise time tR - - 1000 ns Input pin capacitance Ci - - 10 pF SP-LS521-A.001 -4- Version：A.001 點晶科技股份有限公司 LS521 SILICON TOUCH TECHNOLOGY INC. PARAMETER MEASUREMENT INFORMATION SMBUS TIMING DIAGRAM SP-LS521-A.001 -5- Version：A.001 點晶科技股份有限公司 LS521 SILICON TOUCH TECHNOLOGY INC. SLAVE ADDRESS SELECTION Address Description 0010000 Address of LS521. COMMAND SELECTION Command 0x00h 0x01h 0x02h 0x80h Description Power-up mode/Read Data Register Power-down mode Shut down ADC Read Command Register SMBUS PROTOCOLS(For more detail about SMBUS protocols, please refer to the website http://www.smbus.org/specs/ ) Figure 4. SMBUS packet protocol diagram element key SP-LS521-A.001 -6- Version：A.001 點晶科技股份有限公司 LS521 SILICON TOUCH TECHNOLOGY INC. Figure 5. SMBUS send byte protocol Figure 6. SMBUS receive byte protocol Figure 7. SMBUS read byte protocol Figure 8. SMBUS read word protocol SP-LS521-A.001 -7- Version：A.001 點晶科技股份有限公司 LS521 SILICON TOUCH TECHNOLOGY INC. Spectral response LIGHT TO DIGITAL@VDD=3V (fluorescent light) 1.2 relative responsivity 280 Digital output(counts) 240 200 RL=1.2KΩ RL=6KΩ 160 120 80 40 0.8 0.6 0.4 0.2 0 0 2000 4000 6000 8000 10000 LS521 CIE 1.0 0.0 12000 14000 300 Ambient light(lux) 500 700 900 1100 wavelength(nm) Digital variation Temperature variation@VDD=3V 60 60 50 40 Digital output Digital output 50 Ee=800lux(flourescent), R=1.2KΩ 30 20 Ee=500lux(flourescent), R=1.2KΩ 40 Ee=0lux, R=1.2KΩ 30 20 10 0 10 -10 0 -40 -30 -20 -10 2 3 4 VDD(volt) 5 IDD vs Temp.@Ee=0lux TOP view 1.0 3V Y 5V X IDD(mA) Digital output 10 20 30 40 50 60 70 80 90 Temperature(℃) Incident angle vs Responsivity@VDD=3V fluorescent light Ee=500lux 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 0 6 0.5 0.0 -90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 Incident angle SP-LS521-A.001 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 Temperature(℃) -8- Version：A.001 點晶科技股份有限公司 LS521 SILICON TOUCH TECHNOLOGY INC. PACKAGE DESCRIPTIONS IPLCC8 z ● 3mm x 3mm x 1.1mm Top View SP-LS521-A.001 ● Bottom View -9- PAD DESCRIPTIONS PIN NO. PIN NAME DESCRIPTIONS 1 2 3 SCL VDD VSS Serial Clock IN Power Ground 4 5 6 7 8 --- --- SDA Serial Data I/O -- -- Rext External Resistor Version：A.001 點晶科技股份有限公司 LS521 SILICON TOUCH TECHNOLOGY INC. REFLOW SOLDERING The products listed herein are designed for ordinary electronic applications, such as electrical appliances, audio-visual equipment, communications devices and so on. Hence, it is advisable that the devices should not be used in medical instruments, surgical implants, aerospace machinery, nuclear power control systems, disaster/crime-prevention equipment and the like. Misusing those products may directly or indirectly endanger human life, or cause injury and property loss. Silicon Touch Technology, Inc. will not take any responsibilities regarding the misusage of the products mentioned above. Anyone who purchases any products described herein with the above-mentioned intention or with such misused applications should accept full responsibility and indemnify. Silicon Touch Technology, Inc. and its distributors and all their officers and employees shall defend jointly and severally against any and all claims and litigation and all damages, cost and expenses associated with such intention and manipulation. SP-LS521-A.001 -10- Version：A.001