LTC2902 Programmable Quad Supply Monitor with Adjustable Reset Timer and Supply Tolerance FEATURES DESCRIPTIO n Simultaneously Monitors Four Supplies The LTC 2902 is a programmable supply monitor for sys- n 16 User Selectable Combinations of 5V, 3.3V, 3V, tems with up to four supply voltages. One of 16 preset or 2.5V, 1.8V, 1.5V and/or Adjustable Voltage adjustable voltage monitor combinations can be selected Thresholds using an external resistor divider connected to the pro- n Guaranteed Threshold Accuracy: 1.5% of Monitored gram pin. The preset voltage thresholds are digitally pro- Voltage Over Temperature grammable to 5%, 7.5%, 10% or 12.5% below the nomi- n Selectable Supply Tolerance: 5%, 7.5%, nal operating voltage, and are accurate to 1.5% over tem- 10%, 12.5% Below Monitored Voltage perature. All four voltage comparator outputs are con- n Low Supply Current: 43m A Typ nected to separate pins for individual supply monitoring. n Adjustable Reset Time The reset delay time is adjustable using an external n RESET Disable Pin for Margining Applications capacitor. Tight voltage threshold accuracy and glitch n Open-Drain RST Output (LTC2902-1) immunity ensure reliable reset operation without false n Push-Pull RST Output (LTC2902-2) triggering. The RST output is guaranteed to be in the n Individual Nondelayed Monitor Outputs for Each Supply correct state for V down to 1V and may be disabled CC n Power Supply Glitch Immunity during supply margin testing. The LTC2902-1 features n Guaranteed RESET for V 1V CC an open-drain RST output, while the LTC2902-2 has a U push-pull RST output. APPLICATIO S The 43m A supply current makes the LTC2902 ideal for power n Desktop and Notebook Computers conscious systems and the part may be configured to n Multivoltage Systems monitor less than four inputs. The LTC2902-1/LTC2902-2 n Telecom Equipment are available in the 16-lead narrow SSOP package. n Portable Battery-Powered Equipment n Network Servers , LTC and LT are registered trademarks of Linear Technology Corporation. TYPICAL APPLICATIO Quad Supply Monitor with Adjustable Tolerance (5V, 3.3V, 2.5V, 1.8V) 5V 3.3V DC/DC SYSTEM 2.5V CONVERTER LOGIC 1.8V 3 13 R3 POWER 10k V3 V4 GOOD 4 2 V1 COMP1 16 COMP2 14 1 V2 COMP3 15 C1 C2 LTC2902-2 COMP4 0.1F 0.1F 12 6 V RST REF 8 RDIS MARGIN R1 7 59k T0 1% 11 TOLERANCE = 5% 9 V T1 PG R2 GND CRT t = 216ms 40.2k RST 10 5 1% C RT 47nF 2902 TA01 2902f 1 U ULTC2902 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Notes 1, 2, 3) V1, V2, V3, V4, V ..................................... 0.3V to 7V ORDER PART PG TOP VIEW NUMBER RST (LTC2902-1)........................................ 0.3V to 7V COMP3 1 16 COMP2 RST (LTC2902-2).......................... 0.3V to (V2 + 0.3V) COMP1 2 15 COMP4 LTC2902-1CGN COMPX, RDIS ............................................. 0.3V to 7V V3 3 14 V2 LTC2902-2CGN T0, T1 .......................................... 0.3V to (V + 0.3V) CC V1 4 13 V4 LTC2902-1IGN CRT ............................................. 0.3V to (V + 0.3V) CC CRT 5 12 V REF LTC2902-2IGN V ............................................. 0.3V to (V + 0.3V) REF CC RST 6 11 V PG Reference Load Current (I ) ............................ 1mA GN16 PART MARKING T0 7 VREF 10 GND V4 Input Current ( ADJ Mode) ............................ 1mA RDIS 8 9 T1 29021 Operating Temperature Range GN PACKAGE 29022 16-LEAD PLASTIC SSOP LTC2902-1C/LTC2902-2C ....................... 0 C to 70 C 29021I T = 125 C, q = 130 C/W JMAX JA LTC2902-1I/LTC2902-2I .................... 40 C to 85 C 29022I Storage Temperature Range .................. 65 C to 150 C Consult LTC Marketing for parts specified with wider operating temperature ranges. Lead Temperature (Soldering, 10 sec)................... 300 C ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T = 25 C. V = 5V, unless otherwise noted. (Note 3) A CC SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V 5V, 5% Reset Threshold V1 Input Threshold l 4.600 4.675 4.750 V RT50 5V, 7.5% Reset Threshold l 4.475 4.550 4.625 V 5V, 10% Reset Threshold l 4.350 4.425 4.500 V 5V, 12.5% Reset Threshold l 4.225 4.300 4.375 V V 3.3V, 5% Reset Threshold V1, V2 Input Threshold l 3.036 3.086 3.135 V RT33 3.3V, 7.5% Reset Threshold l 2.954 3.003 3.053 V 3.3V, 10% Reset Threshold l 2.871 2.921 2.970 V 3.3V, 12.5% Reset Threshold l 2.789 2.838 2.888 V V 3V, 5% Reset Threshold V2 Input Threshold l 2.760 2.805 2.850 V RT30 3V, 7.5% Reset Threshold l 2.685 2.730 2.775 V 3V, 10% Reset Threshold l 2.610 2.655 2.700 V l 2.535 2.580 2.625 V 3V, 12.5% Reset Threshold V 2.5V, 5% Reset Threshold V2, V3 Input Threshold l 2.300 2.338 2.375 V RT25 2.5V, 7.5% Reset Threshold l 2.238 2.275 2.313 V 2.5V, 10% Reset Threshold l 2.175 2.213 2.250 V 2.5V, 12.5% Reset Threshold l 2.113 2.150 2.188 V V 1.8V, 5% Reset Threshold V3, V4 Input Threshold l 1.656 1.683 1.710 V RT18 1.8V, 7.5% Reset Threshold l 1.611 1.638 1.665 V 1.8V, 10% Reset Threshold l 1.566 1.593 1.620 V 1.8V, 12.5% Reset Threshold l 1.521 1.548 1.575 V V 1.5V, 5% Reset Threshold V3, V4 Input Threshold l 1.380 1.403 1.425 V RT15 1.5V, 7.5% Reset Threshold l 1.343 1.365 1.388 V 1.5V, 10% Reset Threshold l 1.305 1.328 1.350 V 1.5V, 12.5% Reset Threshold l 1.268 1.290 1.313 V V ADJ, 5% Reset Threshold V3, V4 Input Threshold l 0.492 0.500 0.508 V RTA ADJ, 7.5% Reset Threshold l 0.479 0.487 0.494 V ADJ, 10% Reset Threshold l 0.466 0.473 0.481 V ADJ, 12.5% Reset Threshold l 0.453 0.460 0.467 V 2902f 2 U WWW