BH1715FVC

Ambient Light Sensor ICs Digital 16bit Serial Output Type Ambient Light Sensor IC BH1715FVC No.10046EBT06 ●Descriptions 2 BH1715FVC is an digital Ambient Light Sensor IC for I C bus interface. BH1715FVC is the most suitable to obtain the ambient light data for adjusting LCD and Keypad backlight power of Mobile phone. It is possible to detect wide range at High resolution. (1 - 65535 lx). ●Features 2 1) I C bus Interface (f / s Mode Support) 2) Spectral responsibility is approximately human eye response 3) Illuminance to Digital Converter 4) Wide range and High resolution. (1 – 65535 lx) 5) Low Current by power down function 6) 50Hz / 60Hz Light noise reject-function 7) 1.8V Logic input interface 8) No need any external parts 9) Light source dependency is little. (ex. Incandescent Lamp. Fluorescent Lamp. Halogen Lamp. White LED. Sun Light) 2 10) It is possible to select 2 type of I C slave-address. 11) Adjustable measurement result for influence of optical window (It is possible to detect min. 0.23 lx, max. 100000 lx by using this function.) 12) Small measurement variation (+/- 15%) ●Applications Mobile phone, LCD TV, NOTE PC, Portable game machine, Digital camera, Digital video camera, Car navigation, PDA, LCD display ●Absolute Maximum Ratings Parameter Supply Voltage Operating Temperature Storage Temperature SDA Sink Current Power Dissipation Symbol Vmax Topr Tstg Imax Pd Ratings 4.5 -40～85 -40～100 7 260※ Units V ℃ ℃ mA mW ※ 70mm × 70mm × 1.6mm glass epoxy board. Derating in done at 3.47mW/℃ for operating above Ta=25℃. ●Operating Conditions Parameter VCC Voltage I2C Reference Voltage Symbol Vcc VDVI Ratings Min. 2.4 1.65 Typ. 3.0 － Max. 3.6 VCC Units V V www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 1/16 2010.06 - Rev.B BH1715FVC ●Electrical Characteristics (VCC = 3.0V, DVI = 3.0V, Ta = 25℃, unless otherwise noted) Limits Parameter Symbol Min. Typ. Max. Supply Current Powerdown Current Peak Wave Length Measurement Accuracy Dark (0 lx) Sensor out H-Resolution Mode Resolution L-Resolution Mode Resolution H-Resolution Mode Measurement Time L-Resolution Mode Measurement Time Incandescent / Fluorescent Sensor out ratio ADDR Input ‘H’ Voltage ADDR Input ‘L’ Voltage DVI Input ‘L’ Voltage SCL, SDA Input ‘H’ Voltage 1 SCL, SDA Input ‘H’ Voltage 2 SCL, SDA Input ‘L’ Voltage 1 SCL, SDA Input ‘L’ Voltage 2 SCL, SDA, ADDR Input ‘H’ Current SCL, SDA, ADDR Input ‘L’ Current I2C SCL Clock Frequency I2C Bus Free Time I C Hold Time (repeated) START Condition I2C Set up time for a Repeated START Condition I2C Set up time for a Repeated STOP Condition I2C Data Hold Time I2C Data Setup Time I2C ‘L’ Period of the SCL Clock I2C ‘H’ Period of the SCL Clock I2C SDA Output ‘L’ Voltage 2 Technical Note Units µA µA nm times count lx lx ms ms times V V V V V V V µA µA kHz µs µs µs µs µs ns µs µs V Conditions Ev = 100 lx ※1 No input Light Icc1 Icc2 λp S/A S0 rHR rLR tHR tLR rIF VAH VAL VDVL VIH1 VIH2 VIL1 VIL2 IIH IIL fSCL tBUF tHDSTA tSUSTA tSUSTD tHDDAT tSUDAT tLOW tHIGH VOL － － － 1.02 0 － － － － － 0.7 * VCC － － 0.7 * DVI 1.26 － － － － － 1.3 0.6 0.6 0.6 0 100 1.3 0.6 0 120 0.01 560 1.2 0 1 4 120 16 1 － － － － － － － － － － － － － － － － － － － 190 1.0 － 1.38 2 － － 180 24 － － 0.3 * VCC 0.4 － － 0.3 * DVI DVI-1.26 10 10 400 － － － － 0.9 － － － 0.4 Sensor out / Actual lx 1, 2 EV = 1000 lx ※ ※ H-Resolution Mode ※3 EV = 1000 lx DVI ≧ 1.8V 1.65V ≦ DVI ＜ 1.8V DVI ≧ 1.8V 1.65V ≦ DVI ＜ 1.8V IOL = 3 mA ※1 White LED is used as optical source. ※2 Measurement Accuracy typical value is possible to change '1' by "Measurement result adjustment function". ※3 Use H-Resolution Mode if dark data (less than 10 lx) is need. www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 2/16 2010.06 - Rev.B BH1715FVC ●Reference Data 1.2 Technical Note 64 56 100000 1 Measurement Result 0.8 40 32 24 16 8 0 Measurement Result 48 10000 1000 Ratio 0.6 H-Res. H-Res. L-Res. 100 0.4 10 0.2 L-Res. 1 0 8 16 0 400 500 600 700 800 900 1000 1100 Wavelength [ nm ] Illuminance [ lx ] 24 32 40 48 56 64 1 10 100 1000 10000 100000 Illuminance [ lx ] Fig.1 Spectral Response 1.2 1 0.8 1.2 1 Fig.2 Illuminance – Measurement Result 1 10 Fig.3 Illuminance – Measurement Result 2 8 1pin + 受信指向角特性 0.8 Measurement Result Ratio Ratio 6 0.6 0.4 + 0.6 0.4 0.2 0 - - 蛍光灯白熱灯感度比 1pin 4 0.2 0 -90 -60 -30 0 30 60 90 + + -90 -60 -30 0 30 60 90 2 H-Res. 0 -40 -10 20 50 80 110 Angle [ deg ] Angle [ deg ] Ta [ ℃ ] Fig.4 Directional Characteristics 1 Fig.5 Directional Characteristics 2 Fig.6 Dark Response 1.2 1 0.8 Fluorescent Light 200 Ratio 0.6 0.4 0.2 0 -40 -10 20 50 80 110 Halogen Light Kripton Light Artifical Sun Light White LED 0 0.5 1 1.5 2 ICC @ Measurement Incandescent Light 150 VCC vs. ICC@ 測定 中 100 50 0 2 2.5 3 VCC [ V ] 3.5 4 Ta [ ℃ ] Ratio Fig.7 Measurement Result Temperature Dependency 10 Fig.8 Light Source Dependency ( Fluorescent Light is set to '1' ) 1.2 Fig.9 VCC – ICC ( During measurement ) 1.2 ICC @ POWER DOWN [ uA ] 1 1 1 DVI=1.8V 0.8 VCC=3V 0.8 Ratio 0.6 Ratio 2 2.5 3 3.5 4 0.6 0.1 0.4 0.4 0.2 0.2 0.01 -40 -20 0 20 40 60 80 0 0 Ta [ ℃ ] VCC [ V ] 1.5 2 Fig.10 VCC – ICC@0 Lx ( POWER DOWN ) Fig.11 Measurement Result VCC Dependency DVI [ V ] 2.5 3 3.5 Fig.12 Measurement Result DVI Dependency www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 3/16 2010.06 - Rev.B BH1715FVC ●Block Diagram VCC DVI Technical Note AMP ADC Logic + I2C Interface SCL SDA PD OSC GND ADDR ●Block Diagram Descriptions ●PD Photo diode with approximately human eye response. ●AMP Integration-OPAMP for converting from PD current to Voltage. ●ADC AD converter for obtainment Digital 16bit data. 2 ●Logic + I C Interface 2 Ambient Light Calculation and I C BUS Interface. It is including below register. Data Register → This is for registration of Ambient Light Data. Initial Value is "0000_0000_0000_0000". Measurement Time Register → This is for registration of measurement time. Initial Value is "0100_0101". ●OSC Internal Oscillator (typ. 320kHz). It is CLK for internal logic. ●Measurement Procedure Power supply State is automatically changed to Power Down mode. Power Down Initial state is Power Down mode after VCC and DVI supply. Power On Measurement Command One Time Measurement Continuous Measurement State Transition by I2C write-command. Automatically State Transition * "Power On" Command is possible to omit. www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 4/16 2010.06 - Rev.B BH1715FVC ●Instruction Set Architecture Instruction Power Down Opecode 0000_0000 No active state. Comments Technical Note Power On 0000_0001 Waiting for measurement command. Reset Data register value. Reset command is not acceptable in Power Down mode. Start measurement at 1lx resolution. Measurement Time is typically 120ms. Start measurement at 4lx resolution. Measurement Time is typically 16ms. Start measurement at 1lx resolution. Measurement Time is typically 120ms. It is automatically set to Power Down mode after measurement. Start measurement at 4lx resolution. Measurement Time is typically 16ms. It is automatically set to Power Down mode after measurement. Reset 0000_0111 Continuously H-Resolution Mode 0001_0000 Continuously L-Resolution Mode 0001_0011 One Time H-Resolution Mode 0010_0000 One Time L-Resolution Mode Change Measurement time (High bit) Change Measurement time (Low bit) ※ Don't input the other opecode. 0010_0011 01000_MT[7,6,5] Change measurement time. ※ Please refer "adjust measurement result for influence of optical window." 011_MT[4,3,2,1, Change measurement time. ※ Please refer "adjust measurement result for influence of optical window." 0] ●Measurement mode explanation Measurement Mode H-Resolution Mode L-Resolution Mode Measurement Time. Typ. 120ms. Typ. 16ms. Resolution 1 Lx. 4 Lx. We recommend to use H-Resolution Mode. Measurement time (integration time) of H-Resolution Mode is so long that some kind of noise(including in 50Hz / 60Hz noise) is rejected. And H-Resolution Mode is 1 lx resolution so that it is suitable for darkness (less than 10 lx) ●Explanation of Asynchronous reset and Reset command "0000_0111" 1) Asynchronous reset All registers are reset. It is necessary on power supply sequence. Please refer "Timing chart for VCC and DVI power supply sequence" in this page. It is power down mode during DVI = 'L'. 2) Reset command Reset command is for only reset Illuminance data register. (reset value is '0') It is not necessary even power supply sequence. It is used for removing previous measurement result. This command is not working in power down mode, so that please set the power on mode before input this command. www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 5/16 2010.06 - Rev.B BH1715FVC Technical Note ●Timing chart for VCC and DVI power supply sequence DVI is I2C bus reference voltage terminal. And it is also asynchrono reset terminal. It is necessary to set to 'L' supplied. In DVI 'L' term, internal state is set to Power Down mode. 1) Recommended Timing chart1 for VCC and DVI supply. after VCC is VCC DVI Reset Term ( more than 1µs ) 2) Timing chart2 for VCC and DVI supply. (If DVI rises within 1us after VCC supply) VCC DVI Reset Term ( more than 1µs ) Don't care state ADDR, SDA, SCL is not stable if DVI 'L' term ( 1µs ) is not given by systems. In this case, please connect the resisters ( approximately 100kOhm ) to ADDR without directly connecting to VCC or GND,because it is 3 state buffer for Internal testing. www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 6/16 2010.06 - Rev.B BH1715FVC ●Measurement sequence example from "Write instruction" to "Read measurement result" ex1) Continuously H-resolution mode (ADDR = 'L') from Slave to Master Technical Note from Master to Slave ① Send "Continuously H-resolution mode " instruction ST 0100011 0 Ack 00010000 Ack SP ② Wait to complete 1st H-resolution mode measurement.(max. 180ms.) ③ Read measurement result. ST 0100011 1 Ack High Byte [ 15:8 ] Ack Low Byte [ 7:0 ] Ack SP How to calculate when the data High Byte is "10000011" and Low Byte is "10010000" 15 9 8 7 4 (2 + 2 + 2 + 2 + 2 ) / 1.2 ≒ 28067 [ lx ] The result of continuously measurement mode is updated.(120ms.typ at H-resolution mode, 16ms.typ at L-resolution mode) ex2) One time L-resolution mode (ADDR = 'H') ① Send "One time L-resolution mode " instruction ST 1011100 0 Ack 00100011 Ack SP ② Wait to complete L-resolution mode measurement.(max. 24ms.) ③ Read measurement result ST 1011100 1 Ack High Byte [ 15:8 ] Ack Low Byte [ 7:0 ] Ack SP How to calculate when the data High Byte is "00000001" and Low Byte is "00010000" 8 4 (2 + 2 ) / 1.2 ≒ 227 [ lx ] In one time measurement, Statement moves to power down mode after measurement completion. If updated result is need then please resend measurement instruction. www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 7/16 2010.06 - Rev.B BH1715FVC Technical Note ●Application circuit example of DVI terminal The DVI terminal is an asynchronous reset terminal. Please note that there is a possibility that IC doesn't operate normally if the reset section is not installed after the start-up of VCC. (Please refer to the paragraph of "Timing chart for VCC and DVI power supply sequence") The description concerning SDA and the terminal SCL is omitted in this application circuit example. Please design the 2 application the standard of the I C bus as it finishes being satisfactory. Moreover, the description concerning the terminal ADDR is omitted. Please refer to the paragraph of "Timing chart for VCC and DVI power supply sequence" about the terminal ADDR design. ex 1) The control signal line such as CPU is connected. BH1715FVC VCC 0.1µF ADDR GND SCL DVI SDA 0.1µF Micro Controller ex 2) Reset IC is used. 1, For Reset IC of the Push-Pull type BH1715FVC 0.1µF VCC ADDR GND SCL DVI SDA Reset IC( Push-Pull type ) 0.1µF RESET 2, For Reset IC of the Open drain output BH1715FVC 0.1µF VCC ADDR GND SCL DVI SDA Reset IC( Open drain type ) 0.1µF RESET 1kOhm ex 3) A different power supply is used. BH1715FVC 0.1µF V1 VCC ADDR GND SCL DVI SDA V2 0.1µF ※ Power supply of DVI must stand up later than power supply of VCC stand up, because it is necessary to secure reset section (1µs or more). www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. 8/16 2010.06 - Rev.B BH1715FVC Technical Note ex 4) LPF using CR is inserted between VCC and DVI. This method has the possibility that the Reset section of turning on the power supply can not satisfied. cannot be satisfied. Please design the set considering the characteristic of the power supply enough. R1 : 1kOhm BH1715FVC VCC 0.1µF ADDR GND SCL DVI SDA C1 : 1µF ◆ ※ ※ ※ Notes when CR is inserted between VCC and DVI Please note that there is a possibility that reset section (1µs) can not be satisfied because the power supply is turned on when the rise time of VCC is slow When VCC is turned off, the DVI voltage becomes higher than VCC voltage but IC destruction is not occurred if recommended constant (R1 = 1kOhm, C1 = 1µF) is used. Please note that there is a possibility that Reset section (1µsec) cannot be satisfied if wait time is not enough long after turning off VCC. (It is necessary to consider DVI voltage level after turning off VCC.) t1 t2 VCC DVI 2.4V 0.4V 0V Reset Section : 1µs or more *Please do the application design to secure Reset section 1µs or more after the reclosing of the power supply. ◆ Example of designing set when CR (C = 1µF, R = 1kΩ) is inserted between VCC and DVI with VCC=2.8V ① The rise time to 0→2.4V of VCC must use the power supply of 100µs or less. ② Please wait 25ms or more after VCC turn off (VCC