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: n n n n n n n n n n 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