High Voltage Pushbutton Controllers

High Voltage Pushbutton Controllers
The LTC®2955 pushbutton on/off controller manages system power via a pushbutton interface or presence of a supply. Pushbutton
controllers typically initiate system power-ups only with the toggle of a pushbutton. However, the LTC2955 will also automatically
turn on a system when power is applied from a primary or secondary supply, such as a wall adapter or car battery. When powered
up, the LTC2955 can power-down a system via pushbutton and can optionally use interrupt logic to request for a system powerdown in menu-driven applications (“soft” shutdown), or automatically power-down a system if the primary or secondary supply is
removed.
LTC2955 Pushbutton On/Off with Interrupt
LTC2955 Features:
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Automatic Turn-On with Voltage Monitor Input
Wide Input Supply Range: 1.5V to 36V
Low Supply Current: 1.2µA
±25kV ESD HBM on PB Input
±36V Wide Input Voltage for PB Input
Low Leakage EN Output Allows DC/DC Converter
Control (LTC2955-1)
High Voltage EN Output Drives External P-Channel
MOSFET (LTC2955-2)
Simple Interface Allows Graceful µP Shutdown
Adjustable Turn-Off Timer
10-Lead 3mm × 2mm DFN and 8-Lead ThinSOT™
Packages
TURN-ON PULSE
SHORT PULSE
LONG PULSE
PB
EN
TURNS ON
STAYS ON
TURNS OFF
INT
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered
trademarks and ThinSOT and PowerPath are trademarks of Linear Technology
Corporation. All other trademarks are the property of their respective owners.
INTERRUPT
INTERRUPT
LTC2952 Pushbutton PowerPath Controller with Supervisor
Four PowerPath Configurations
ADAPTER, 3V TO 25V
VIN
Si6993DQ
LT1767-2.5
SHDN
12V BATTERY
Si6993DQ
PFI
G2
LTC2952
2. PB Controller with Preferential Wall Adapter
Operation and Automatic Switchover to Battery
10k
1k
3. PB Control of Ideal Diode Drivers
1k
4. Battery Backup with PB PowerPath Controller
100k
D2
EN
V1
V2
1k
365k
511k
VS
G1
1. PB Controller with Automatic Switchover
between Wall Adaptor and Battery
2.5V
VOUT
D3
100k
VM
Ideal Diode vs Schottky Diode
Forward Voltage Drop
D1
RST
M1
G1STAT
M2
PFO
1
µP
CONSTANT
RON
INT
PB
CURRENT (A)
ONT
KILL
WDE
GND OFFT
*22nF
*68nF
IDEAL
DIODE
CONSTANT
VOLTAGE
*OPTIONAL
0
SCHOTTKY
DIODE
0.02
0.50
FORWARD VOLTAGE (V)
The LTC2952 is a power management device that features three main functions: pushbutton on/off control of system power, ideal
diode PowerPath™ controllers and system monitoring. The pushbutton input, which provides on/off control of system power, has
independently adjustable ON and OFF debounce times. A simple microprocessor interface involving an interrupt signal allows for
proper system housekeeping prior to power-down. The ideal diode PowerPath controllers provide automatic low loss switchover
between two DC sources by regulating two external P-channel MOSFETs to have a small 20mV forward drop. High reliability systems
can use the LTC2952’s monitoring features including power-fail, voltage monitoring and μP watchdog to ensure system integrity.
Linear Technology Pushbutton Controllers
Supply
Voltage
Turn-On System OK Interrupt
Turn-Off
Supply Debounce Response Debounce Debounce
Current
Time
Time
Time
Time
Turn-Off
Delay
ESD
Packages
n/a
1024ms
±10kV
TSOT-8
DFN-8
Adj
n/a
Adj
±10kV
TSOT-8
DFN-8
400ms
26ms
Adj
400ms
±8kV
TSSOP-20
QFN-20
32ms
512ms
32ms
Adj
n/a
±10kV
DFN-12
6µA
Adj
512ms
32ms
Adj
n/a
±10kV
TSOT-8
DFN-8
1.5V to 36V
1.2µA
32ms
512ms
32ms
Adj
n/a
±25kV
TSOT-8
DFN-10
1.5V to 36V
1µA
32ms
n/a
32ms
Adj
n/a
±25kV
MSOP-12
DFN-12
Part Number
Description
LTC2950
Basic Pushbutton Controller
2.7V to 26V
6µA
Adj
512ms
Adj
LTC2951
Basic Pushbutton Controller
2.7V to 26V
6µA
128ms
512ms
LTC2952
Pushbutton Controller with 2 Ideal Diode-OR
Controllers for Load Sharing or Automatic
Switchover Applications
2.7V to 28V
25µA
Adj
LTC2953
Pushbutton Controller with Supply Monitor, UVLO 2.7V to 27V
and Power Fail Comparators for Supervisory
Applications
12µA
LTC2954
Pushbutton Controller with Interrupt Logic for
Menu-Driven Applications
2.7V to 26V
LTC2955
Pushbutton Controller with Automatic Turn-On
and Interrupt Logic for Menu Driven Applications
LTC2956
Wake-Up Timer with Pushbutton Control
www.linear.com/pushbutton n 1-800-4-LINEAR
0115C