DC1099A - Demo Manual

QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1099
PUSH BUTTON ON/OFF CONTROLLER WITH BATTERY AND SUPPLY MONITORING
LTC2953CDD-1
DESCRIPTION
Demonstration circuit 1099 features the LTC2953, a
push button On/Off controller that manages system
power via a push button interface. An enable output
toggles system power while an interrupt output provides debounced push button status. The interrupt
output can be used in menu driven applications to
request a system power down.
The length of time that the push button must be held
low for a power down is configurable with an external
capacitor. The LTC2953 allows a user to force an
immediate power down by tying /INT with /KILL and a
push button turn off.
The LTC2953 also features input and output supply
monitors. An uncommitted power fail comparator
provides real time input monitor threshold information, while a de-glitched under voltage lockout comparator gracefully initiates a system power down.
The under voltage lockout comparator prevents from
powering from a bad battery.
The adjustable supply monitor input is compared
against an accurate internal 0.5V reference. The reset
output remains low until the supply monitor input has
been in compliance for 200ms.
The DC1099 accepts voltages of 2.7V to 27V over the
operating range of the LTC2953 input voltage. The
LTC2953 draws only 12uA of current. Reverse polarity protection is provided with RPP and CPP on the
DC1099. Two versions of the part accommodate either positive or negative enable polarities. For the
DC1099, the LTC2953-1 with Enable active high is
shown.
On the DC1099, an LT3010 is used to demonstrate a
supply with its shutdown pin driven by the enable of
the LTC2953.
Design files for this circuit board are available. Call
the LTC factory.
LTC is a trademark of Linear Technology Corporation
Table 1. Typical Performance Summary (TA = 25°C)
PARAMETER
CONDITION
VALUE
Input Voltage Range VIN
Operating Range (Note 1)
2.7V to 27V
DC/DC Out 2P6V
DC/DC LT3010 Enabled through Push Button
2.6V
Power Fail Input Voltage PFI
VIN Threshold, Resistor Divider (R14 + R13) and R12
3.00V
UVLO Monitor Input Voltage
VIN Threshold, Resistor Divider R14 and (R13 + R12)
2.65V
Voltage Monitor VM
Voltage Threshold to VM (2P6V), Resistor Divider R3 and R2
2.33V
Monitor Pins Threshold Voltage
/PFI, VM, UVLO
500mV
UVLO Input Hysteresis
UVLO Pin (Note 1)
30mV
Turn ON Debounce Time
Push Button Turn On
32ms
JP2 Set to OPEN, Push Button Turn Off
32ms
JP2 Set to CAP to Connect 0.47uF to PDT Pin (Note 2)
32ms + 3008ms
Turn OFF Debounce Time
Note 1: The resistor divider at UVLO sets 2.7V above the UVLO threshold. Supply must first ramp up above 3.0V to exceed the UVLO Input Hysteresis for operation
between 2.7V to 3.0V.
Note 2: 0.47uF * (6.4 seconds / uF) = 3.008 seconds
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QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1099
PUSH BUTTON ON/OFF CONTROLLER WITH BATTERY AND SUPPLY MONITORING
QUICK START PROCEDURE
Demonstration circuit 1099 is easy to set up to
evaluate the performance of the LTC2953. Refer to
Figure 1 for proper measurement equipment setup
and follow the procedure below.
1. Place jumpers in the following positions:
JP1
UNTIE
JP2
CAP
2. Apply a voltage of 3.0V to 27V across VIN and
5. Again, push down on Push Button SW1 for a Turn
On.
6. Ramp down supply below 3.0V and no lower than
2.7V. /PFO LED will turn on.
7. Ramp down supply below 2.65V.
/INT LED will
momentarily turn on, then turn off along with 2P6V
LED and /PFO LED.
Additional Tests:
8. Move JP2 to OPEN for a faster Push Button power
GND.
3. Push down on Push Button SW1 for a Turn On.
2P6V LED will turn on from the 2.6V output.
4. Push down on Push Button SW1 for over 3 sec-
down time and repeat steps 1 through 8.
9. Move JP1 to TIE for an immediate Push Button
shutdown.
onds for a turn off. /INT LED will momentarily turn
on then turn off along with 2P6V LED.
Figure 1. Proper Measurement Equipment Setup
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QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1099
PUSH BUTTON ON/OFF CONTROLLER WITH BATTERY AND SUPPLY MONITORING
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