LM3554_16 Datasheet, PDF(24/47 Page) Texas Instruments

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LM3554_16 Datasheet, PDF (24/47 Pages) Texas Instruments – Synchronous Boost Converter

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LM3554

SNVS549C â JUNE 2009 â REVISED FEBRUARY 2016

www.ti.com

Table 2. Torch Brightness Register Bit Settings

Bit 7 (IND1) Bit 6 (IND0)

Indicator Current Select Bits

00 = 2.3 mA

01 = 4.6 mA (default state)

10 = 6.9 mA

11 = 8.2 mA

Bit 5 (TC2)

Bit 4 (TC1)

Bit 3 (TC0)

Torch Current Select Bits

000 = 17 mA (34 mA total)

001 = 35.5 mA (71 mA total)

010 = 54 mA (108 mA total) default state

011 = 73 mA (146mA total)

100 = 90 mA (180mA total)

101 = 109 mA (218 mA total)

110 = 128 mA (256 mA total)

111 = 147.5 mA (295 mA total)

Bit 2 (VM)

Bit 1 (EN1)

Bit 0 (EN0)

Enable Bits

000 = Shutdown (default)

001 = Indicator Mode

010 = Torch Mode

011 = Flash Mode (bits reset at timeout)

100 = voltage-output mode

101 = Voltage Output + Indicator Mode

110 = Voltage Output + Torch Mode

111 = Voltage Output + Flash Mode (bits [1:0] are

reset at end of timeout)

7.6.1.2 Flash Brightness Register

Bits [2:0] of the Torch Brightness Register, or bits [2:0] of the Flash Brightness Register place the device in

shutdown or control the on/off state of Torch, Flash, the Indicator LED and the voltage-output mode. Writing to

the Flash Brightness Register bits [2:0] automatically updates the Torch Brightness Register bits [2:0]. Bits [6:3]

set the current level in Flash mode (see Table 3). Bit [7] sets the STROBE Termination select bit (STR) (see

Table 3).

MSB

Flash Brightness Register

LSB

STR

Bit 7

FC3

Bit 6

FC2

Bit 5

FC1

Bit 4

FC0

Bit 3

Bit 2

EN1

Bit 1

EN0

Bit 0

Flash Brightness Register Description

Bit 7 (STR)

STROBE Edge or Level

Select

0 = (Level Sensitive) When

STROBE goes high, flash

current turns on and remain

on for the duration the

STROBE pin is held high or

when flash timeout occurs,

whichever comes

first.(default)

1 = (Edge Triggered) When

STROBE goes high, flash

current turns on and remain

on for the duration of the

Flash Timeout.

Table 3. Flash Brightness Register Bit Settings

Bit 6 (FC3) Bit 5 (FC2) Bit 4 (FC1)

Flash Current Select Bits

0000 = 35.5 mA (71 mA total)

0001 = 73 mA (146 mA total)

0010 = 109 mA (218 mA total)

0011 = 147.5 mA (295 mA total)

0100 = 182.5 mA (365 mA total)

0101 = 220.5 mA (441 mA total)

0110 = 259 mA (518 mA total)

111 = 298 mA (596 mA total)

1000 =326 mA (652 mA total)

1001 = 364.5 mA (729 mA total)

1010 = 402.5 mA (805 mA total)

1011 = 440.5 mA (881 mA total)

1100 = 480 mA (960 mA total)

1101 = 518.5 mA (1037 mA total) Default

1110 = 556.5 mA (1113 mA total)

1111 = 595.5 mA (1191 mA total)

Bit 3 (FC0) Bit 2 (VM) Bit 1 (EN1) Bit 0 (EN0)

Enable Bits

000 = Shutdown (default)

001 = Indicator mode

010 = Torch mode

011 = Flash mode (bits reset at timeout)

100 = Voltage-output mode

101 = Voltage output + indicator mode

110 = Voltage output + torch mode

111 = Voltage output + flash mode (bits [1:0]

are reset at end of timeout)

7.6.1.3 Flash Duration Register

Bits [4:0] of the Flash Duration Register set the Flash Timeout duration. Bits [6:5] set the switch current limit. Bit

[7] defaults as a 1 and is not used (see Table 4).

Flash Duration Register

MSB

LSB

N/A