1
dc1836af
DEMO MANUAL DC1836A
Description
LTC2955
Pushbutton On/Off Controller
with Automatic Turn-On
Demonstration circuit 1836A-A and 1836A-B feature the
LT C
®
2955-1 and LTC2995-2, respectively. The LTC2955 is
a micropower, pushbutton on/off controller that manages
system power by generating a clean enable output from
the supply monitor input and the debounced pushbut-
ton input. It features an interrupt output that notifies the
system of a pushbutton event or low level at the ON pin. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
BoarD photo
When the system receives an INT signal, it may use the
power kill input to shut off power. If the pushbutton remains
pressed for more than the configurable turn-off duration
(3s or 32ms), the system power is forced off.
Design files for this circuit board are available at
http://www.linear.com/demo
Figure 1. Proper Test Equipment Setup
1.6V TO 36V SUPPLY
PULSE WAVE GENERATOR
I/O
dc1836a F01
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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
edges to activate system turn-on and turn-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: Can be linked to VIN through the VIN/ON jumper, however,
can also be externally connected to a power source. Is con-
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
demo board is populated with an LTC2955-1 or LTC2955-2.
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.
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dc1836af
DEMO MANUAL DC1836A
operating principles
Figure 2. PB Going Low For 46.1ms, and EN Pulling High,
Showing a Proper Turn-On Sequence
Figure 3. PB Going Low for 28.6ms, and EN Remaining High,
Showing Too Short of a PB Pulse to Properly Activate the Enable Pin
Figure 4. A Turn-On Sequence Where VIN and ON Activate EN, as Opposed to PB.
Notice the 924ms Delay Between VIN Going High and EN Activating
Connect a 1.6V to 36V power supply to VIN. If VIN is
less than 5.5V, set the LDO_IN jumper to EXTERNAL and
connect a 5.5V to 36V supply to the LDO_IN turret. The
LTC2955 will still operate with no power applied to LDO_IN,
but monitor LEDs will not function.
On the DC1836A, a pushbutton switch shorts the PB pin
to ground which in turn sets the EN pin low (DC1836A-B)
or the EN pin high (DC1836A-A). Shorting PB to ground
a second time and holding (duration depending on the
TMR_PERIOD jumper) subsequently de-asserts the
EN/EN pin. The EN/EN pin is unobtrusively monitored by
the LT6700 comparator.
An internal 512ms timer blanks (ignores) the KILL signal
during system power-up. This allows sufficient time for
the DC/DC converter and a controller to perform power-
up tasks.
A high to low transition on PB starts the turn-off sequence.
In order to assert INT low, PB must stay low continuously
for 32ms. Users can also force the system to power down
by holding the pushbutton down for a long period; this
period is set using the TMR_PERIOD jumper on the board.
After the EN/EN pin has been released, the LTC2955 starts
a one second lockout time. During this lockout time, the
PB and ON inputs are ignored—this is meant to allow the
voltage regulator to turn off and for its output to decay to 0V.
dc1836a F04
EN
PB
VIN
0N
dc1836a F03
PB
EN
PB
EN
dc1836a F02
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dc1836af
DEMO MANUAL DC1836A
parts list
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 0 C1 CAP., OPT, 1206
2 1 C2 CAP., X7R, 0.1µF, 50V, 10%, 0805 AVX, 08055C104KAT2A
3 0 C3, C7 CAP., OPT, 0603
4 1 C4 CAP., X5R, 0.47µF, 10V, 10%, 0603 TAIYO YUDEN, LMK107BJ474KA
5 1 C5 CAP., X5R, 1µF, 10V, 10%, 0603 AVX, 0603ZD105KAT2A
6 1 C6 CAP., X7R 10nF 10V, 10%, 0603 AVX, 0603ZC103KAT2A
7 1 C8 CAP., X5R, 2.2µF, 10V, 10%, 0603 MURATA, GRM188R61A225K
8 1 C9 CAP., X5R, 0.1µF, 10V, 10%, 0603 AVX, 0603ZD104KAT2A
9 13 E1-E13 TP, TURRET, 0.064", PAD120-064 MILL-MAX, 2308-2-00-80-00-00-07-0
10 5 JP1-JP5 HD1×3-079 SAMTEC, TMM103-02-L-S
11 5 XJP1-XJP5 SHUNT SAMTEC, 2SN-BK-G
12 2 D1, D2 LED, GREEN PANASONIC, LN1351-C-TR
13 1 D3 LED, RED PANASONIC, LN1251-C-TR
14 1 D4 LED, AMBER PANASONIC, LN1451-C-TR
15 1 R1 RES., CHIP, 1k, 1/10W, 1%, 0603 VISHAY, CRCW06031K00FKEA
16 2 R2, R4 RES., CHIP, 200k, 1/16W, 1%, 0402 VISHAY, CRCW0402200KFKED
17 1 R3 RES., CHIP, 5.1k, 1/16W, 1%, 0402 VISHAY, CRCW04025K10FKED
18 0 R5, R7 RES., OPT., 0402
19 1 R8 RES., CHIP, 100k, 1/16W, 1%, 0402 VISHAY, CRCW0402100KFKED
20 1 R9 RES., CHIP, 845k, 1/16W, 1%, 0402 VISHAY, CRCW0402845KFKED
21 1 R10 RES., CHIP, 115k, 1/16W, 1%, 0402 VISHAY, CRCW0402115KFKED
22 4 R11, R12, R13, R14 RES., CHIP, 475, 1/16W, 1%, 0402 VISHAY, CRCW0402475RFKED
23 2 R6, R19 RES., CHIP, 10k, 1/16W, 1%, 0402 VISHAY, CRCW040210KFKED
24 1 SW1 SWITCH, PUSHBUTTON PANASONIC, EVQPJS05K
25 1 U3 I.C., LT3060ETS8, TS8 LINEAR TECHNOLOGY, LT3060ETS8
26 2 U6, U7 I.C., LT6700CS6-1, SOT23-6 LINEAR TECHNOLOGY, LT6700CS6-1
27 2 STENCIL TOP AND BOTTOM STENCIL, DC1836A
DC1836A-A Required Circuit Components
1 1 U1 I.C., LTC2955IDDB-1, DFN10DDB LINEAR TECHNOLOGY, LTC2955IDDB-1
2 2 R15, R16 Res., Chip, 100k, 1/16W, 1%, 0402 VISHAY, CRCW0402100KFKED
3 0 R17, R18 Res., OPT., 0402
4 1 FAB, PRINTED CIRCUIT BOARD DEMO CIRCUIT 1836A
DC1836A-B Required Circuit Components
1 1 U1 I.C., LTC2955IDDB-2, DFN10DDB LINEAR TECHNOLOGY, LTC2955IDDB-2
2 2 R17, R18 Res., Chip, 100k, 1/16W, 1%, 0402 VISHAY, CRCW0402100KFKED
3 0 R15, R16 Res., OPT., 0402
4 1 FAB, PRINTED CIRCUIT BOARD DEMO CIRCUIT 1836A
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dc1836af
DEMO MANUAL DC1836A
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
Figure 5. Pushbutton On/Off Controller with µP Interrupt
5
5
4
4
3
3
2
2
1
1
D D
C C
B B
A A
NOTE: UNLESS OTHERWISE SPECIFIED
ALL CAPACITORS ARE IN MICROFARADS, 0603.
1. ALL RESISTORS ARE IN OHMS, 0402.
-A LTC2955IDDB-1
U1 R15,R16
-B
ASSY
100K
*
OPT
R17,R18
ENLTC2955IDDB-2 100K
OPT
INSTALL FOR ENABLE (TRUE)
INSTALL FOR ENABLE #
LDO_OUT
PGD INT
EN / EN
*
E6
EN
VIN
EN/EN
EN/EN
LDO_OUT
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
VLADIMIR O. PRODUCTION404-13-12
__
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
VLADIMIR O. PRODUCTION404-13-12
__
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
VLADIMIR O. PRODUCTION404-13-12
__
SIZE
DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
SCALE = NONE
www.linear.com
4
Friday, April 13, 2012
11
PUSH BUTTON ON / OFF CONTROLLER WITH uP INTERRUPT
LT
VLADIMIR O.
N/A
LTC2955IDDB-1 / -2
DEMO CIRCUIT 1836A
SIZE
DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
SCALE = NONE
www.linear.com
4
Friday, April 13, 2012
11
PUSH BUTTON ON / OFF CONTROLLER WITH uP INTERRUPT
LT
VLADIMIR O.
N/A
LTC2955IDDB-1 / -2
DEMO CIRCUIT 1836A
SIZE
DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
SCALE = NONE
www.linear.com
4
Friday, April 13, 2012
11
PUSH BUTTON ON / OFF CONTROLLER WITH uP INTERRUPT
LT
VLADIMIR O.
N/A
LTC2955IDDB-1 / -2
DEMO CIRCUIT 1836A
U3
LT3060ETS8
U3
LT3060ETS8
IN
5
REF/BYP 8
SHDN
1
GND1
2
GND2
3
GND3
4
ADJ 7
OUT 6
R2
200K
R2
200K
JP2
TMR PERIOD
3.0S
32MS
JP2
TMR PERIOD
3.0S
32MS
1
3
2
JP5
VIN / ON
CON
DIS JP5
VIN / ON
CON
DIS
1
3
2
C5
1uF
C5
1uF
R14
475
R14
475
R9
845K
R9
845K
R3
5.1K
R3
5.1K
R7
OPT
R7
OPT
U1
*
U1
*
INT 1
PGD 2
EN/EN 3
SEL
7
VIN
4
GND 6
KILL 9
ON
10
GND
11
PB
5
TMR
8
+
-
400mV
-
+
U7
LT6700CS6-1
+
-
400mV
-
+
U7
LT6700CS6-1
-INB
4
OUTA 1
+INA
3
OUTB 6
GND
2VS 5
E10
LDO_IN
E10
LDO_IN
JP1
ON FUNCTION
ON ACTIVE
ON BLOCKED
JP1
ON FUNCTION
ON ACTIVE
ON BLOCKED
1
3
2
SW1
EVQPJS05KNO_PB SW1
EVQPJS05KNO_PB
1 2
JP3
KILL
TIE
SEPARATE
JP3
KILL
TIE
SEPARATE
1
3
2
E1
1.6V - 36V
VIN
E1
1.6V - 36V
VIN
D4
AMBER
D4
AMBER
2 1
C8
2.2uF
C8
2.2uF
C6
10nF
C6
10nF
R12
475
R12
475
R10
115K
R10
115K
E12
GND
E12
GND
+
-
400mV
-
+
U6
LT6700CS6-1
+
-
400mV
-
+
U6
LT6700CS6-1
-INB
4
OUTA 1
+INA
3
OUTB 6
GND
2VS 5
R8
100K
R8
100K
E5
LDO_OUT
E5
LDO_OUT
R16
*
R16
*
C9
0.1uF
C9
0.1uF
C7
OPT
C7
OPT
R17
*
R17
*
E4
GND
E4
GND
C1
OPT
1206
C1
OPT
1206 R5
OPT
R5
OPT
R1
1K
0603
R1
1K
0603
R18
*
R18
*
D2
GREEN
D2
GREEN
2 1
R11
475
R11
475
E8
PGD
E8
PGD
R4
200K
R4
200K
E7
INT
E7
INT
E9
KILL
E9
KILL
E2
ON
E2
ON
E3
PB
E3
PB
E11
VIN
E11
VIN
E6E6
R13
475
R13
475
JP4
LDO_IN
VIN
EXTERNAL
JP4
LDO_IN
VIN
EXTERNAL
1
3
2
R19
10K
R19
10K
D1
GREEN
D1
GREEN
2 1
E13
GND
E13
GND
R15
*
R15
*
R6
10K
R6
10K
D3
RED
D3
RED
2 1
C2
0.1uF
0805
C2
0.1uF
0805
C3
OPT
C3
OPT
C4
0.47uF
C4
0.47uF
schematic Diagram
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dc1836af
DEMO MANUAL DC1836A
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com
LINEAR TECHNOLOGY CORPORATION 2012
LT 0612 • PRINTED IN USA
DEMONSTRATION BOARD IMPORTANT NOTICE
Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions:
This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT
OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete
in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety
measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union
directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations.
If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date
of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU
OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS
FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR
ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LTC from all claims
arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all
appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or
agency certified (FCC, UL, CE, etc.).
No License is granted under any patent right or other intellectual property whatsoever. LTC assumes no liability for applications assistance,
customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind.
LTC currently services a variety of customers for products around the world, and therefore this transaction is not exclusive.
Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and
observe good laboratory practice standards. Common sense is encouraged.
This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LTC applica-
tion engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
