LM3537

SNVS634B – JUNE 2011 – REVISED MAY 2013

www.ti.com

Table 1. ALS Resistor Values

r_als[4]

r_als[3]

r_als[2]

r_als[1]

r_als[0]

RALS (typ) Value

Unit

1

1

1

1

1

0.651

k

Ω

1

1

1

1

0

0.672

k

Ω

1

1

1

0

1

0.695

k

Ω

1

1

1

0

0

0.720

k

Ω

1

1

0

1

1

0.747

k

Ω

1

1

0

1

0

0.776

k

Ω

1

1

0

0

1

0.806

k

Ω

1

1

0

0

0

0.840

k

Ω

1

0

1

1

1

0.876

k

Ω

1

0

1

1

0

0.916

k

Ω

1

0

1

0

1

0.960

k

Ω

1

0

1

0

0

1.01

k

Ω

1

0

0

1

1

1.06

k

Ω

1

0

0

1

0

1.12

k

Ω

1

0

0

0

1

1.19

k

Ω

1

0

0

0

0

1.26

k

Ω

0

1

1

1

1

1.34

k

Ω

0

1

1

1

0

1.44

k

Ω

0

1

1

0

1

1.55

k

Ω

0

1

1

0

0

1.68

k

Ω

0

1

0

1

1

1.83

k

Ω

0

1

0

1

0

2.02

k

Ω

0

1

0

0

1

2.24

k

Ω

0

1

0

0

0

2.52

k

Ω

0

0

1

1

1

2.88

k

Ω

0

0

1

1

0

3.36

k

Ω

0

0

1

0

1

4.03

k

Ω

0

0

1

0

0

5.00

k

Ω

0

0

0

1

1

6.72

k

Ω

0

0

0

1

0

10.1

k

Ω

0

0

0

0

1

20.2

k

Ω

0

0

0

0

0

HighZ

--

Automatic Gain Change

GPO pins of the LM3537 can be configured to serve as a gain control interface for sensors with HW controlled

gain, like ROHM BH1600-series. Please see Table 2. LM3537 changes sensor gain automatically based on

ambient light intensity changes.

Table 2. Sensor Gain Control

OUTPUT PIN STATUS

REGISTER SETTING

GPO1

GPO2

Can be set to "1" or "0" with REG 52H, bit

Can be set to "1" or "0" with REG 52H, bit

autogain_en = "0"

gpo1

gpo2

autogain_en = "1" (enables autogain

0

1

functionality) LOW GAIN

autogain_en = "1" (enables autogain

1

0

functionality) HIGH GAIN

14

Submit Documentation Feedback

Copyright © 2011–2013, Texas Instruments Incorporated

Product Folder Links: LM3537