LTC2917/LTC2918 Voltage Supervisor with 27 Selectable Thresholds and Watchdog Timer FEATURES DESCRIPTION 9 Selectable Supply Voltages The LTC 2917-A/LTC2917-B and LTC2918-A/LTC2918-B 12V, 5V, 3.3V, 2.5V, 1.8V are low voltage single-supply monitors with selectable 1.5V, 1.2V, 1V, +ADJ (0.5V) thresholds and an adjustable watchdog timer. The parts 3 Selectable Tolerances operate from 1.5V to 5.5V and consume a quiescent cur- 5%, 10%, 15% (LTC2917) rent of only 30A. Manual Reset Input (LTC2918) Two three state inputs select one of nine internally pro- 1.5V to 5.5V Supply Operation grammed thresholds without the need for external resistors. Adjustable Watchdog Timeout For the LTC2917, an additional three state input determines Windowed Watchdog Timeout for Higher Reliability the tolerance (5%, 10%, 15%). The tolerance for the Applications (LTC2917-B, LTC2918-B) LTC2918 is xed at 5%. Threshold accuracy is guaranteed 6.2V Shunt Regulator for High Voltage Operation at 1.5% over the entire operating temperature range. Guaranteed Operation to 125C Glitch ltering ensures reliable reset operation without Guaranteed Threshold Accuracy: 1.5% false triggering. Low Quiescent Current: 30A Typical The reset timeout and the watchdog timeout may be set Power Supply Glitch Immunity with no external components, or adjusted using an exter- Guaranteed RST for V 0.8V CC nal capacitor. A windowed watchdog feature is available 10-Lead MSOP Packages and (3mm 2mm) DFN for high-reliability applications (B1 versions). A separate Packages manual reset input on the LTC2918-A/LTC2918-B allows APPLICATIONS a simple push button interface. Handheld Devices Operation to 125C makes the LTC2917-A/LTC2917-B Cell Phone Base Stations and LTC2918-A/LTC2918-B suitable for automotive Automotive Control Systems applications. Network Servers , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Optical Networking Systems TYPICAL APPLICATION 1.8V Supply Monitor with Manual Monitor Selection Table Reset and Internal Timers Selected NOMINAL VOLTAGE SEL1 SEL2 1.8V 12V V V CC CC 0.1F 10k 5V V Open CC V CC 3.3V V GND CC LTC2918-A P 2.5V Open V CC VM RST RST 1.8V Open Open RT WDI I/O 29178 TA01 1.5V Open GND WT SEL1 MR SEL2 1.2V GND V CC GND 1V GND Open t = 1.6s WDU t = 200ms RST ADJ (0.5V) GND GND 29178fb 1LTC2917/LTC2918 (Note 1, 2) ABSOLUTE MAXIMUM RATINGS Terminal Voltages Operating Temperature Range V (Note 3) .......................................... 0.3V to 5.7V LTC2917C/LTC2918C ............................... 0C to 70C CC SEL1, SEL2, TOL, WDI, MR, RST ......... 0.3V to 7.5V LTC2917I/LTC2918I .............................. 40C to 85C VM ......................................................... 0.3V to 15V LTC2917H/LTC2918H ......................... 40C to 125C RT, WT .......................................0.3V to (V + 0.3)V Storage Temperature Range ................... 65C to 150C CC Terminal Currents Lead Temperature (Soldering, 10 sec) V (Note 3) .......................................................5mA MSOP ...............................................................300C CC PIN CONFIGURATION LTC2917 LTC2917 TOP VIEW 1 10 GND RST TOP VIEW 2 9 TOL RT GND 1 10 RST TOL 2 9 RT 3 11 8 SEL2 WT SEL2 3 8 WT 4 7 SEL1 WDI SEL1 4 7 WDI VM 5 6 V 5 6 CC VM V CC MS PACKAGE DDB PACKAGE 10-LEAD PLASTIC MSOP 10-LEAD (3mm s 2mm) PLASTIC DFN T = 125C, = 200C/W JMAX JA T = 125C, = 43C/W JMAX JA LTC2917 EXPOSED PAD (PIN 11) PCB GND CONNECTION OPTIONAL LTC2917 LTC2918 LTC2918 TOP VIEW 1 10 GND RST TOP VIEW 2 9 MR RT GND 1 10 RST MR 2 9 RT 3 11 8 SEL2 WT SEL2 3 8 WT 4 7 SEL1 WDI SEL1 4 7 WDI VM 5 6 V 5 6 CC VM V CC MS PACKAGE DDB PACKAGE 10-LEAD PLASTIC MSOP 10-LEAD (3mm s 2mm) PLASTIC DFN T = 125C, = 200C/W JMAX JA T = 125C, = 43C/W JMAX JA LTC2918 EXPOSED PAD (PIN 11) PCB GND CONNECTION OPTIONAL LTC2918 29178fb 2