0

bit7

0

bit6

VFB

bit5

1

bit4

1

bit3

VM

bit2

EN1

bit1

EN0

bit0

MSB

LSB

General Purpose Control

Register Address: 0x10

ADR6

bit7

ADR5

bit6

ADR4

bit5

ADR3

bit4

ADR2

bit3

ADR1

bit2

ADR0

bit1

R/W

bit0

MSB

LSB

1

0

1

0

1

0

1

I

2

C Slave Address (chip address)

LM3553

www.ti.com

SNVS414B – FEBRUARY 2008 – REVISED MAY 2013

INTERNAL REGISTERS OF LM3553

Register

Internal Hex Address

Power On Value

General Purpose Register

0x10

0001 1000

Multi-Function Pin Control Register

0x20

1110 0000

Current Step Time Register

0x50

1111 1100

Torch Current Control Register

0xA0

1000 0000

Flash Current Control Register

0xB0

1000 0000

Flash Duration Control Register

0xC0

1111 0000

General Purpose Register

EN0-EN1: Set Flash LED mode

Indicator Mode sets ILED = 20mA. In this mode, D1 is enabled and D2 is disabled.

VM: Enables Voltage Mode. Current sinks D1 and D2 are turned off and the LM3553 will operate in a regulated

voltage boost mode. Setting the VM bit to a '1' does not override the EN0 and EN1 bits stored in the general

purpose register. The default setting is '0'. If the LM3553 is in Voltage Mode and an indicator, torch or flash

command is issued, the LM3553 will turn on the D1 and D2 current sources and begin regulating the output

voltage to a value equal to VFB (350mV or 450mV) + VLED.

VM

EN1

EN0

Function

0

0

0

Shutdown

0

0

1

Indicator Mode

0

1

0

Torch Mode

0

1

1

Flash Mode

1

0

0

Voltage Mode

1

0

1

Indicator Mode

1

1

0

Torch Mode

1

1

1

Flash Mode

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