LTC1985-1.8 Micropower Precision Triple Supply Monitor with Push-Pull Reset Output in a 5-Lead SOT-23 Package FEATURES DESCRIPTIO n Monitors Three Inputs Simultaneously: The LTC 1985-1.8 is a triple supply monitor intended for 3V, 1.8V and Adjustable systems with multiple supply voltages. The reset output n 1.5% Threshold Accuracy Over Temperature remains low until all three supplies have been in compli- n Very Low Supply Current: 10m A Typ ance for 200ms. Tight 1.5% accuracy specifications and n 200ms Reset Time Delay glitch immunity ensure reliable reset operation without n Power Supply Glitch Immunity false triggering. n Guaranteed RESET for V 1V or V 1V CC3 CC18 The RST output is guaranteed to be in the correct state for n 3V Active-Low Push-Pull Reset Output V or V down to 1V. The LTC1985 may also be CC18 CC3 n 5-Lead SOT-23 Package configured to monitor any one or two V inputs instead CC of three, depending on system requirements. U APPLICATIO S Very low (10m A typical) supply current makes the LTC1985 ideal for power conscious systems. n Desktop Computers n The LTC1985 is available in a 5-lead SOT-23 package. Notebook Computers n Intelligent Instruments , LTC and LT are registered trademarks of Linear Technology Corporation. n Portable Battery-Powered Equipment n Network Servers TYPICAL APPLICATION 3V 1.8V DC/DC SYSTEM CONVERTER LOGIC 2.5V 1 RST 5 V CC3 LTC1985-1.8 4 V CC18 R1 0.1F 130k 3 1% V CCA R2 GND 0.1F 100k 1985-1.8 TA01 1% 2 1 U ULTC1985-1.8 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Notes 1, 2) V , V , V ...................................... 0.3V to 7V CC3 CC18 CCA ORDER RST .......................................... 0.3V to (V + 0.3V) TOP VIEW CC3 PART NUMBER Operating Temperature Range RST 1 5 V CC3 (Note 3) ............................................. 40 C to 85 C LTC1985ES5-1.8 GND 2 Storage Temperature Range ................ 65 C to 150 C V 3 4 V CCA CC18 Lead Temperature (Soldering, 10 sec)................ 300 C S5 PACKAGE S5 PART MARKING 5-LEAD PLASTIC SOT-23 T = 125 C, q = 250 C/W JMAX JA LTNM Consult factory for Industrial and Military grade parts. ELECTRICAL CHARACTERISTICS The l denotes specifications which apply over the full operating temperature range, otherwise specificaitons are at T = 25 C. V = 3V, V = 1.8V, V = V unless otherwise noted. A CC3 CC18 CCA CC3 SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V Reset Threshold V V Input Threshold l 2.760 2.805 2.850 V RT3 CC3 CC3 V Reset Threshold V V Input Threshold l 1.656 1.683 1.710 V RT18 CC18 CC18 V Reset Threshold V V Input Threshold l 0.985 1.000 1.015 V RTA CCA CCA V V , V Operating Voltage RST in Correct Logic State l17 V CCOP CC3 CC18 I V Supply Current V > V l 12 m A VCC3 CC3 CC18 CC3 V < V , V = 3V (Note 4) l 10 20 m A CC18 CC3 CC3 I V Supply Current V < V , V = 1.8V (Note 4) l 12 m A VCC18 CC18 CC18 CC3 CC18 I V Input Current V = 1V l 15 0 15 nA VCCA CCA CCA t Reset Pulse Width RST Low (Note 5) l 140 200 280 ms RST t V Undervoltage Detect to RST V , V or V Less Than Reset (Note 5) 110 m s UV CC CC18 CC3 CCA Threshold V by More Than 1% RT V Output Voltage Low, RST I = 2.5mA, V = 3V, V = 0V l 0.15 0.4 V OL SINK CC3 CC18 I = 100m A, V = 1V, V = 0V l 0.05 0.3 V SINK CC3 CC18 I = 100m A, V = 0V, V = 1V l 0.05 0.3 V SINK CC3 CC18 I = 100m A, V = 1V, V = 1V l 0.05 0.3 V SINK CC3 CC18 V Output Voltage High, RST I = 200m A l 0.8V V OH SOURCE CC3 Note 1: Absolute Maximum Ratings are those values beyond which the life extended temperature limits of 40 C to 85 C but are not tested at these of the device may be impaired. temperatures. Note 2: All voltage values are with respect to GND. Note 4: Both V and V can act as the supply depending on which pin CC3 CC18 has the greatest potential. Note 3: The LTC1985E is guaranteed to meet specified performance from 0 C to 70 C and is designed, characterized and assured to meet the Note 5: Measured from when input passes through the input threshold voltage (V ) until RST passes through 1.5V. RTX 2 U WWW