LX1977 datasheet(4/23 Pages) MICROSEMI

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LX1977

PRODUCTION DATASHEET

Microsemi

Analog Mixed Signal Group

11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570

Page 4

SMBus Ambient Light Sensor

Rev. 1.0, 2010-03-25

ELECTRI CAL CHARACTERISTICS

Unless otherwise specified, the following specifications apply over the operating ambient temperature 0

°C

≤ T

≤ 70°C and the

following test conditions: 3.0V ≤VDD ≤ 4.5V

Parameter

Symbol

Test Conditions / Comment

Min

Typ

Max

Units

EV = 0 lux, TA = 70°C, RANGE_SEL=00b,

TINT=100mS, Note 7

SMBUS INTERFACE

Clock Frequency

FCLK

400

kHz

High Level Input Voltage

0.8

Low Level Input Voltage

VSDA

VSCL

2.1

Input Leakage Current

ISDA/ISCL

-5

µA

SDA Low Output Voltage

VSDA

ISDA = 3mA

0.4

SDA Current Sinking Capacity

ISDA

INT Low Output Voltage

VINT

IINT = 3mA

0.4

INT Leakage Current

ILEAK

-10

µA

ADR High Level Input Voltage

80%

VDD

ADR Open

40%

60%

VDD

ADR Low Level Input Voltage

VADR

20%

VDD

ADR Input Leakage Current

IADR

-10

µA

Notes:

1. In production, the input irradiance is supplied from a point source which is a white LED.

2. See Figure 3

)

V(WHITE)

COUNT

V(WHITE)

COUNT

V(IR)

V(WHITE)

COUNT

−

4. Guarantee by scan tests.

5. Specifications in the EC table are for 3.0V ~ 4.5V. Device is operational down to 2.5V and up to 5.0V with relaxed specifications.

6. Gain1 = (DCOUNT2-DCOUNT1) / (Lux2-Lux1), Gain2 = (DCOUNT3-DCOUNT2) / (Lux3-Lux2), DNL1 = (Gain1 * 2 / (Gain1+Gain2) -1) %, DNL2 = (Gain2 *

2 / (Gain1+Gain2) – 1) %. Lux1 = 100 lux, Lux2 = 200 lux, Lux3 = 500 lux.

7. For the setting RANGE_SEL=00b and TINT=100mS, the full scale output is typical 3723 decimal. A dark ADC output count of maximum 18 at

TA = 70°C is only 0.5% of 3723.

TES T CIR C UITS

VDD

To Test

Computer

White

LED

810nm

Part

LX1977

SDA

VSS

VDD

SCL

INT

ADR

RSET

Figure 3 –

ALS Output Measurement

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