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dc1836af

DEMO MANUAL DC1836A

harDware setup

JumPEr SETTingS

Tmr PEriOD: Sets the amount of time the user has to

hold down the pushbutton in order to cause a shutdown

event. It can either be set to 32ms or 3 seconds.

On FunCTiOn: Connect to ON BLOCKED to block the ON

pin falling edge from activating system turn-off. Connect

to ON ACTIVE to allow both the ON pin rising and falling

edgestoactivatesystemturn-onandturn-off,respectively.

Vin/On: Connects or disconnects VIN from ON. Unless

external circuitry has been connected to ON, for ON to

function correctly, this should be set to ON.

KiLL: Ties or separates INT from KILL. Set to TIE for au-

tomatic shutdown when a long press on the pushbutton

is detected.

LDO_in: Chooses the input to the onboard LT3060 regula-

tor. The user can either set it to VIN to have it connected

to the VIN pin or EXTERNAL in order to have it driven by

the LDO_IN turret. See the Operating Principles section.

Only for LED/monitor circuitry.

EXTErnAL COnnECTiOnS

Signal connections are made via the row of turret posts

along the edges of the board.

gnD: (3 turrets) These turrets are connected directly to

the ground planes.

Vin: Connect a 1.6V to 36V power supply to this turret.

On:CanbelinkedtoVINthroughtheVIN/ONjumper,however,

canalsobeexternallyconnectedtoapowersource.Iscon-

nected directly to the ON pin of the LTC2955. If the ON

function jumper is set to active, this pin can be used to turn

on the EN pin, or turn off the EN pin, depending on if the

demoboardispopulatedwithanLTC2955-1orLTC2955-2.

PB: This pin is already driven by the pushbutton, however,

if needed it can be driven by an external signal to simulate

a pushbutton press.

LDO_in: Can be used to provide the LT3060 with power

when the LDO_IN jumper is set to external.

LDO_OuT: Output from the LT3060. The state of this can

also be monitored at D1.

DigiTAL COnnECTiOnS

En/EN: Active high (LTC2955-1), or active low (LTC2955-

2) signal. Should go active either on a valid ON signal or

with a debounced PB press.

INT: Goes low on a pushbutton press when EN/EN is

active. Can be tied to KILL to turn off the part.

KILL: A low signal at this input will disable EN/EN. The

TMR period jumper sets how long the input signal must

be held low.

PgD: Power good output from the LTC2955. This pin

indicates the status of the ON pin in order to let the sys-

tem differentiate between pushbutton turn-on and supply

button turn-on events.