LTC1536 Precision Triple Supply Monitor for PCI Applications U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO Simultaneously Monitors 5V, 3.3V and Adjustable Inputs Guaranteed Threshold Accuracy: ±0.75% Low Supply Current: 100µA Internal Reset Time Delay: 200ms Manual Pushbutton Reset Input Active Low and Active High Reset Outputs Active Low “Soft” Reset Output Power Supply Glitch Immunity Guaranteed Reset for Either VCC3 ≥ 1V or VCC5 ≥ 1V Meets PCI tFAIL Timing Specifications Rev 2.1 8-Pin SO and MSOP Packages U APPLICATIO S ■ ■ ■ ■ ■ For 3.3V and 5V supplies that are > 500mV below spec or for the condition when the 5V supply falls below the 3.3V supply, the LTC1536 has a very fast response time capable of meeting the PCI tFAIL timing specification. Tight 0.75% threshold accuracy and glitch immunity ensure reliable reset operation without false triggering. The RST output is guaranteed to be in the correct state for VCC5 or VCC3 down to 1V. The 100µA typical supply current makes the LTC1536 ideal for power-conscious systems. A manual pushbutton reset input provides the ability to generate a very narrow “soft” reset pulse (100µs typ) or a 200ms reset pulse equivalent to a power-on reset. Both SRST and RST outputs are open-drain and can be OR-tied with other reset sources. PCI-Based Systems Desktop Computers Notebook Computers Intelligent Instruments Portable Battery-Powered Equipment Network Servers , LTC and LT are registered trademarks of Linear Technology Corporation. U ■ The LTC®1536 is designed for PCI local bus applications with multiple supply voltages that require low power, small size, high speed and high accuracy supply monitoring. TYPICAL APPLICATIO Power Fail Waveform 5V Dropping Below 3.3V by 300mV Motherboard PCI RST Generation 0.1µF LTC1536 1 2 5V ± 5% 0.1µF PUSHBUTTON RESET 3 4 VCC3 PBR VCC5 SRST VCCA RST GND RST RPU 7 6 5 RST VCC5 = 5V TO 3V STEP VCC3 = VCCA = 3.3V 4.7k PULL-UP FROM RST TO VCC3 5 8 PCI LOCAL BUS PWR GOOD VOLTAGE (1V/DIV) 3.3V ± 0.3V 4 VCC5 3 2 RST 1 RPU SELECTED TO MEET RISE TIME SLEW RATE REQUIREMENTS (1k MIN) 1536 TA01 0 TIME (20ns/DIV) 1536 TA02 1 LTC1536 W W W AXI U U ABSOLUTE RATI GS (Notes 1, 2) Terminal Voltage VCC3, VCC5, VCCA .................................... – 0.3V to 7V RST, SRST ............................................ – 0.3V to 7V RST ......................................... – 0.3V to VCC3 + 0.3V PBR .......................................................... – 7V to 7V Operating Temperature Range LTC1536C .............................................. 0°C to 70°C LTC1536I ............................................ – 40°C to 85°C Storage Temperature Range ................ – 65°C to 150°C Lead Temperature (Soldering, 10 sec)................. 300°C W U U PACKAGE/ORDER I FOR ATIO ORDER PART NUMBER TOP VIEW VCC3 VCC5 VCCA GND 8 7 6 5 1 2 3 4 PBR SRST RST RST MS8 PACKAGE 8-LEAD PLASTIC MSOP LTC1536CMS8 VCC3 1 8 PBR VCC5 2 7 SRST VCCA 3 6 RST GND 4 5 RST MS8 PART MARKING TJMAX = 125°C, θJA = 160°C/ W ORDER PART NUMBER TOP VIEW LTBV LTC1536CS8 LTC1536IS8 S8 PART MARKING S8 PACKAGE 8-LEAD PLASTIC SO 1536 1536I TJMAX = 125°C, θJA = 150°C/ W Consult factory for Military grade parts. ELECTRICAL CHARACTERISTICS VCC3 = 3.3V, VCC5 = 5V, VCCA = VCC3, TA = 25°C unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS VRT3 Reset Threshold VCC3 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● 2.962 2.925 2.985 2.985 3.000 3.008 V V VRT5 Reset Threshold VCC5 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● 4.687 4.625 4.725 4.725 4.750 4.762 V V VRTA Reset Threshold VCCA 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● 0.992 0.980 1.000 1.000 1.007 1.007 V V VCC VCC3 or VCC5 Operating Voltage RST in Correct Logic State ● 1 7 V IVCC3 VCC3 Supply Current PBR = VCC3 ● 100 200 µA IVCC5 VCC5 Input Current VCC5 = 5V ● 10 20 µA IVCCA VCCA Input Current VCCA = 1V, 0°C ≤ TA ≤ 70°C VCCA = 1V, – 40°C ≤ TA ≤ 85°C ● ● –5 – 15 0 0 5 15 nA nA tRST Reset Pulse Width RST Low with 10kΩ Pull-Up to VCC3 0°C to 70°C – 40°C to 85°C ● ● 140 140 200 200 280 300 ms ms ● 50 100 200 µs tSRST Soft Reset Pulse Width SRST Low with 10kΩ Pull-Up to VCC3 tUV VCC Undervoltage Detect to RST VCC5, VCC3 or VCCA Less Than Reset Threshold VRT by 1% 2 13 µs LTC1536 ELECTRICAL CHARACTERISTICS VCC3 = 3.3V, VCC5 = 5V, VCCA = VCC3, TA = 25°C unless otherwise noted. SYMBOL PARAMETER CONDITIONS IPBR PBR Pull-Up Current PBR = 0V, 0°C ≤ TA ≤ 70°C PBR = 0V, – 40°C ≤ TA ≤ 85°C VIL PBR, RST Input Low Voltage ● VIH PBR, RST Input High Voltage ● 2 V tPW PBR Min Pulse Width ● 40 ns tDB PBR Debounce Deassertion of PBR Input to SRST Output (PBR Pulse Width = 1µs) ● tPB PBR Assertion Time for Transition from Soft to Hard Reset Mode PBR Held Less Than VIL, 0°C to 70°C PBR Held Less Than VIL, – 40°C to 85°C ● ● VOL RST Output Voltage Low ISINK = 5mA ● ● MIN TYP MAX 3 3 7 7 10 15 0.8 1.4 1.4 UNITS µA µA V 20 35 ms 2.0 2.0 2.8 3.0 s s ● 0.15 0.4 V ISINK = 100µA 0°C ≤ TA ≤ 70°C VCC3 = 1V, VCC5 = 0V VCC3 = 0V, VCC5 = 1V VCC3 = 1V, VCC5 = 1V ● ● ● 0.05 0.05 0.05 0.4 0.4 0.4 V V V ISINK = 100µA – 40°C ≤ TA ≤ 85°C VCC3 = 1.1V, VCC5 = 0V VCC3 = 0V, VCC5 = 1.1V VCC3 = 1.1V, VCC5 = 1.1V ● ● ● 0.05 0.05 0.05 0.4 0.4 0.4 V V V SRST Output Voltage Low ISINK = 2.5mA ● 0.15 0.4 V RST Output Voltage Low ISINK = 2.5mA ● 0.15 0.4 V RST Output Voltage High (Note 3) ISOURCE = 1µA ● VCC3 – 1 V SRST Output Voltage High (Note 3) ISOURCE = 1µA ● VCC3 – 1 V RST Output Voltage High ISOURCE = 600µA ● VCC3 – 1 V tPHL Propagation Delay RST to RST High Input to Low Output CRST = 20pF 25 ns tPLH Propagation Delay RST to RST Low Input to High Output CRST = 20pF 45 ns tFAIL VCC5 or VCC3 0.5V Undervoltage to RST (Note 4) VCC5 Drops Below 4.25V or VCC3 Drops Below 2.5V (Note 5) ● 150 450 ns tPF VCC5 < (VCC3 – 300mV) RST (Note 4) VCC5 Drops Below VCC3 By 300mV (Note 6) ● 50 90 ns VOH The ● denotes specifications which apply over the full operating temperature range. Note 1: Absolute Maximum Ratings are those values beyond which the life of the device may be impaired. Note 2: All voltage values are with respect to GND. Note 3: The output pins SRST and RST have weak internal pull-ups to VCC3 of 6µA. However, external pull-up resistors may be used when faster rise times are required. Note 4: Conforms to PCI Local Bus Specification Rev 2.1, Sect. 4.3.2 for tFAIL. Note 5: VCC3 or VCC5 falling at – 0.1V/µs, time measured from VRTX – 500mV to RST at 1.5V. Note 6: VCC5 falling from 5V to 3V in ≤10ns, time measured from VCC5 = (VCC3 – 300mV) to RST at 1.5V. 3 LTC1536 U W TYPICAL PERFORMANCE CHARACTERISTICS IVCC3 vs Temperature 140 20.0 120 17.5 3 60 40 INPUT CURRENT (nA) IVCC5 (µA) 80 12.5 10.0 7.5 5.0 20 – 25 35 15 –5 55 TEMPERATURE (°C) 0 – 45 75 – 25 35 15 –5 55 TEMPERATURE (°C) –1 1536 G03 1536 G02 VCC5 Threshold Voltage vs Temperature VCC3 Threshold Voltage vs Temperature VCCA Threshold Voltage vs Temperature 3.010 1.005 4.745 3.005 1.004 4.740 4.735 4.730 4.725 4.720 4.715 4.710 4.705 4.700 – 60 – 40 – 20 0 20 40 60 TEMPERATURE (°C) 80 VCCA THRESHOLD VOLTAGE, VRTA (V) 4.750 VCC3 THRESHOLD VOLTAGE, VRT3 (V) VCC5 THRESHOLD VOLTAGE, VRT5 (V) 0 –3 0.8 0.85 0.9 0.95 1.0 1.05 1.1 1.15 1.2 INPUT VOLTAGE (V) 75 1536 G01 3.000 2.995 2.990 2.985 2.980 2.975 2.970 2.965 2.960 – 60 – 40 – 20 100 0 20 40 60 80 0.999 0.998 0.997 0.996 215 210 205 200 195 75 100 1536 G07 80 110.0 107.5 105.0 102.5 100.0 97.5 95.0 – 50 – 25 50 25 0 TEMPERATURE (°C) 100 1536 G06 PBR ASSERTION TIME TO RESET, tPB (SEC) SOFT RESET PULSE WIDTH, tSRST (µs) 220 4 1.000 PBR Assertion Time to Reset vs Temperature 112.5 50 25 0 TEMPERATURE (°C) 1.001 “Soft” Reset Pulse Width vs Temperature 225 – 25 1.002 1536 G05 Reset Pulse Width vs Temperature 190 – 50 1.003 0.995 – 60 – 40 – 20 0 20 40 60 TEMPERATURE (°C) 100 TEMPERATURE (°C) 1536 G04 RESET PULSE WIDTH, tRST (ms) 1 –2 2.5 0 – 45 TA = 25°C 2 15.0 100 IVCC3 (µA) VCCA Input Current vs Input Voltage IVCC5 vs Temperature 75 100 1536 G08 2.25 2.20 2.15 2.10 2.05 2.00 1.95 1.90 – 50 – 25 50 25 0 TEMPERATURE (°C) 75 100 1536 G09 LTC1536 U W TYPICAL PERFORMANCE CHARACTERISTICS VCC3 Typical Transient Duration vs Reset Comparator Overdrive VCC5 Typical Transient Duration vs Reset Comparator Overdrive 45 35 30 25 20 15 10 5 0 0.001 0.01 0.1 1 VCC3 RESET COMPARATOR OVERDRIVE, VRT3 – VCC3 (V) 35 30 25 20 15 10 5 0 0.01 0.1 1 0.001 VCC5 RESET COMPARATOR OVERDRIVE, VRT5 – VCC5 (V) 1536 G10 RESET OCCURS ABOVE CURVE 35 30 25 20 15 10 5 0 0.01 0.1 1 0.001 VCCA RESET COMPARATOR OVERDRIVE, VRTA – VCCA (V) 1536 G11 RST Output Voltage vs Supply Voltage 1536 G12 RST Output Voltage vs Supply Voltage 5.0 5.0 VCC5 = VCC3 = VCCA 4.7k PULL-UP FROM RST TO VCC5 TA = 25°C 4.0 VCC5 = VCC3 = VCCA RST PIN LOADED WITH 10MΩ TO GND TA = 25°C 4.5 RST OUTPUT VOLTAGE (V) 4.5 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 TYPICAL TRANSIENT DURATION (µs) 40 40 RESET OCCURS ABOVE CURVE 40 TYPICAL TRANSIENT DURATION (µs) RESET OCCURS ABOVE CURVE 45 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 SUPPLY VOLTAGE, VCC (V) 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 SUPPLY VOLTAGE, VCC (V) 1536 G13 1536 G16 Power-Fail Response Time vs Temperature Undervoltage Response Time vs Temperature DEVICE THRESHOLD PCI SPEC VCC3 VOLTAGE (1V/DIV) VOLTAGE (500mV/DIV) RST OUTPUT VOLTAGE (V) TYPICAL TRANSIENT DURATION (µs) 50 VCCA Typical Transient Duration vs Reset Comparator Overdrive 85° – 40° 25° tFAIL SPEC MARGIN VCC3 FALLING FROM 3.3V TO 2.3V AT (– 0.1V/µs) VCC5 85° – 40° 25° RST RST TIME (1µs/DIV) TIME (20ns/DIV) 1536 G15 1536 G14 5 LTC1536 U U U PIN FUNCTIONS VCC3 (Pin 1): 3.3V Sense Input and Power Supply Pin for the IC. Bypass to ground with ≥ 0.1µF ceramic capacitor. VCC5 (Pin 2): 5V Sense Input. Used as gate drive for RST output FET when the voltage on VCC5 is greater than the voltage on VCC3. VCCA (Pin 3): 1V Sense, High Impedance Input. Can be used as a logic input with a 1V threshold. If unused it can be tied to either VCC3 or VCC5. GND (Pin 4): Ground. RST (Pin 5): Reset Logic Output. Active high CMOS logic output, drives high to VCC3, buffered compliment of RST. An external pull-down on the RST pin will drive this pin high. RST (Pin 6): Reset Logic Output. Active low, open-drain logic output with weak pull-up to VCC3. Can be pulled up greater than V CC3 when interfacing to 5V logic. Asserted when one or more of the supplies are below trip thresholds and held for 200ms after all supplies become valid. Also asserted after PBR is held low for more than two seconds and for an additional 200ms after PBR is released. SRST (Pin 7): “Soft” Reset. Active low, open-drain logic output with weak pull-up to VCC3. Can be pulled up greater than VCC3 when interfacing to 5V logic. Asserted for 100µs after PBR is held low for less than two seconds and released. PBR (Pin 8): Pushbutton Reset. Active low logic input with weak pull-up to VCC3. Can be pulled up greater than VCC3 when interfacing to 5V logic. When asserted for less than two seconds, outputs a soft reset 100µs pulse on the SRST pin. When PBR is asserted for greater than two seconds, the RST output is forced low and remains low until 200ms after PBR is released. W BLOCK DIAGRAM VCC3 VCC3 7µA PBR 8 TO POWER DETECT AND VCC INTERNAL VCC3 1 6µA SOFT RESET PBR TIMER RESET 7 SRST 6 RST 5 RST – FAST + – VCC3 SLOW + VCC3 6µA + FAST – 200ms RESET GENERATOR POWER DETECT/ GATE DRIVE VCC3 – VCC5 2 VCC5 FAST TO POWER DETECT + – SLOW + VCCA 3 – SLOW + GND 4 REF 1326 BD 6 LTC1536 WU W TI I G DIAGRA S VCC Monitor Timing VCCX Pushbutton Reset Function Timing PBR VRTX t < tPB tRST tPB tRST tDB RST RST tSRST 1536 TD01 1536 TD02 SRST Power-Fail Detect tFAIL Fast Undervoltage Detect SLEW RATE ≤0.1V/µs FALL TIME ≤ 10ns, VCC3 = 3.3V 3.3V VRTX 500mV VCC3 OR VCC5 300mV VCC5 tFAIL tPF RST RST 1536 TD03 1536 TD04 U W U U APPLICATIONS INFORMATION Operation The LTC1536 is a low power, high accuracy triple supply monitoring circuit. This reset generator has two basic functions: generation of a reset when power supplies are out of range, and generation of a reset or “soft” reset when the reset button is pushed. The LTC1536 has the added feature that when the reset supplies are grossly undervoltage there is a very short delay from undervoltage detect to assertion of RST. Supply Monitoring All three VCC inputs must be above predetermined thresholds for 200ms before the reset output is released. The LTC1536 will assert reset during power-up, power-down and brownout conditions on any one or more of the VCC inputs. On power-up, either the VCC5 or VCC3 pin can power the drive circuits for the RST pin. This ensures that RST will be low when either VCC5 or VCC3 reaches 1V. As long as any one of the VCC inputs is below its predetermined threshold, RST will stay a logic low. Once all of the VCC inputs rise above their thresholds, an internal timer is started and RST is released after 200ms. RST outputs the inverted state of what is seen on RST. RST is reasserted whenever any one of the VCC inputs drops below its predetermined threshold and remains asserted until 200ms after all of the VCC inputs are above their thresholds. On power-down, once any of the VCC inputs drops below its threshold, RST is held at a logic low. A logic low of 0.4V is guaranteed until VCC3 and VCC5 drops below 1V. Pushbutton Reset The LTC1536 provides a pushbutton reset input pin. The PBR input has an internal pull-up current source to VCC3. If the PBR pin is not used it can be left floating. 7 LTC1536 U U W U APPLICATIONS INFORMATION When the PBR is pulled low for less than tPB (≈ 2 sec), a narrow (100µs typ) soft reset pulse is generated on the SRST output pin after the button is released. The pushbutton circuitry contains an internal debounce counter which delays the output of the soft reset pulse by typically 20ms. This pin can be OR-tied to the RST pin and issue what is called a “soft” reset. The SRST thereby resets the microprocessor without interrupting the DRAM refresh cycle. In this manner DRAM information remains undisturbed. Alternatively, SRST may be monitored by the processor to initiate a software-controlled reset. When the PBR pin is held low for longer than tPB (≈ 2 sec), a standard reset is generated. Once the 2-second period has elapsed, a reset signal is produced by the pushbutton logic, thereby clearing the reset counter. Once the PBR pin is released, the reset counter begins counting the reset period (200ms nominal). Consequently, the reset outputs remain asserted for approximately 200ms after the button is released. Fast Undervoltage for PCI Applications The LTC1536 is designed for PCI Local Bus applications that require reset to be asserted quickly in response to one or both of the power supply rails (5V and 3.3V) going out of spec. The spec for tFAIL and tPF are met with enough margin to give the designer the ability to add follow-on logic as needed by system requirements. The VCCA pin can be used to monitor the “power good” signal and keep reset applied until both supplies are in spec and the power good signal is high. Glitch Immunity and Fast Undervoltage Detection The LTC1536 achieves its high speed characteristics while maintaining glitch immunity by using two sets of comparators. The VCC5 and VCC3 sense inputs each have two comparators set at different thresholds. A slow, very accurate comparator monitors the supply for precision undervoltage detection. In parallel, but with a threshold 250mV lower than the precision threshold, is a very fast comparator that detects when the supply is quickly going out of specification. Because the fast comparator threshold is set 250mV above the PCI specification, typical values for tFAIL can be negative. 3V or 5V Power Detect/Gate Drive The LTC1536 for the most part is powered internally from the VCC3 pin. The exception is at the gate drive of the output FET on the RST pin. On the gate to this FET is power detect circuitry used to detect and drive the gate from either the 3.3V pin or the 5V pin, whichever pin has the highest potential. This ensures the part pulls the RST pin low as soon as either input pin is ≥ 1V. Extended ESD Tolerance of the PBR Input Pin The PBR pin is susceptible to ESD since it can be brought out to a front panel in normal applications. The ESD tolerance of this pin can be increased by adding a resistor in series with the PBR pin. A 10k resistor can increase the ESD tolerance of the PBR pin to approximately 10kV. The PBR’s internal pull-up current of 7µA typical means there is only 70mV (150mV max) dropped across the resistor. U TYPICAL APPLICATIONS N Dual Supply Monitor (3.3V and 5V, VCCA Input Monitoring “Power Good”) PCI Expansion Board RST Generation 3.3V SUPPLY LTC1536 0.1µF PCI LOCAL BUS LTC1536 1 2 5V SUPPLY 0.1µF 3 4 RESET 8 VCC3 PBR VCC5 SRST VCCA RST GND RST 8 3.3V 7 5V 6 5 ONBOARD DEVICE 1536 TA08 PWR GOOD 1 2 3 4 VCC3 PBR VCC5 SRST VCCA RST GND RST 8 7 6 SYSTEM RESET 5 1536 TA04 LTC1536 U TYPICAL APPLICATIONS N RESET Valid for VCC3 Down to 0V in a Dual Supply Application Triple Supply Monitor (3.3V, 5V and Adjustable) LTC1536 1 3.3V ADJUSTABLE SUPPLY OR DC/DC FEEDBACK DIVIDER R1 2 5V 3 4 R2 PBR VCC3 VCC5 SRST VCCA GND RST RST 8 10k* PUSHBUTTON RESET LTC1536 3.3V 7 6 3 SYSTEM RESET 5 4 VCC5 SRST VCCA RST GND RST 8 100k 7 6 5 SYSTEM RESET 1536 TA03 Using VCCA Tied to DC/DC Feedback Divider LTC1435 3.3V VOSENSE 4.7k 6 ADJUSTABLE RESET TRIP THRESHOLD 2.74V 6µA RST 6 35.7k 1% LTC1536 3.3V 2.8k 1% RESET SRST 7 PBR 2.9V PUSHBUTTON 8 6µA VCC3 1536 TA09 SRST Tied to RST and OR-Tying Other Sources to RST to Generate Reset and Reset PBR 2 5V *OPTIONAL RESISTOR EXTENDS ESD TOLERANCE OF PBR INPUT 8kV TO 10kV LTC1536 1 22.1k 1% 5V 1 2 3 4 VCC3 PBR VCC5 SRST VCCA RST GND RST 8 7 6 SYSTEM RESET 5 1536 TA07 OTHER OPEN DRAIN RESET SOURCES OR-TIED TO RESET VCC3 RST 5 RESET 1536 TA05 9 LTC1536 U PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted. MS8 Package 8-Lead Plastic MSOP (LTC DWG # 05-08-1660) 0.118 ± 0.004* (3.00 ± 0.102) 8 7 6 5 0.118 ± 0.004** (3.00 ± 0.102) 0.192 ± 0.004 (4.88 ± 0.10) 1 0.040 ± 0.006 (1.02 ± 0.15) 0.007 (0.18) 2 3 4 0.034 ± 0.004 (0.86 ± 0.102) 0° – 6° TYP 0.021 ± 0.006 (0.53 ± 0.015) SEATING PLANE 0.012 (0.30) 0.0256 REF (0.65) TYP 0.006 ± 0.004 (0.15 ± 0.102) MSOP (MS8) 1197 * DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE ** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE 10 LTC1536 U PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted. S8 Package 8-Lead Plastic Small Outline (Narrow 0.150) (LTC DWG # 05-08-1610) 0.189 – 0.197* (4.801 – 5.004) 8 7 6 5 0.150 – 0.157** (3.810 – 3.988) 0.228 – 0.244 (5.791 – 6.197) 1 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 0.053 – 0.069 (1.346 – 1.752) 0°– 8° TYP 0.016 – 0.050 0.406 – 1.270 0.014 – 0.019 (0.355 – 0.483) 2 3 4 0.004 – 0.010 (0.101 – 0.254) 0.050 (1.270) TYP *DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE **DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. SO8 0996 11 LTC1536 U TYPICAL APPLICATIONS N Quad Supply Monitor: 12V: Undervoltage, Overvoltage 5V: Undervoltage, Overvoltage 3.3V: Undervoltage, Overvoltage – 12V: Undervoltage 3.3V ± 0.3V 3 2.37M 1% 1.21M 1% 0.1µF 100k LTC1444 LTC1536 4 – 5 + 1 A 2 2 5V 3 12V 5V ± 5% 4.02M 1% 6 – 7 + 1.21M 12V ± 5% 9.31M 1% 10 1.21M 1% – 12V ±10% PBR VCC5 SRST VCCA RST GND RST 8 7 6 5 SYSTEM RESET 1.05M 1% B 1 102k 1% OPTIONAL PWR GOOD – C 1M 10.7M 1% 4 VCC3 11 + 12 – 13 + D 16 15 REF 1.221V 8 14 9 HYST 1536 TA07 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LTC690 5V Supply Monitor, Watchdog Timer and Battery Backup 4.65V Threshold LTC694-3.3 3.3V Supply Monitor, Watchdog Timer and Battery Backup 2.9V Threshold LTC699 5V Supply Monitor and Watchdog Timer 4.65V Threshold LTC1232 5V Supply Monitor, Watchdog Timer and Pushbutton Reset 4.37V/4.62V Threshold LTC1326 Micropower Precision Triple Supply Monitor 4.725V, 3.118V, 1V Thresholds (±0.75%) LTC1326-2.5 Micropower Precision Triple Supply Monitor 2.363V, 3.118V, 1V Thresholds (±0.75%) 12 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417● (408) 432-1900 FAX: (408) 434-0507● TELEX: 499-3977 ● www.linear-tech.com 1536f, sn1536a LT/TP 0498 4K • PRINTED IN THE USA LINEAR TECHNOLOGY CORPORATION 1997