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0.8% Accurate Quad Voltage Monitor ADM1184 FEATURES Powered from 2.7 V to 5.5 V on the VCC pin Monitors 4 supplies via 0.8% accurate comparators 4 inputs can be programmed to monitor different voltage levels with external resistor dividers 3 open-drain enable outputs (OUT1, OUT2, and OUT3) Open-drain power-good output (PWRGD) Internal 190 ms delay associated with assertion of PWRGD 10-lead MSOP FUNCTIONAL BLOCK DIAGRAM VCC POWER AND REF = 0.6V REFERENCE GENERATOR OUT1 VIN1 REF = 0.6V OUT2 VIN2 REF = 0.6V ADM1184 APPLICATIONS Monitor and alarm functions Telecommunications Microprocessor systems PC/servers VIN3 REF = 0.6V INTERNAL LOGIC OUT3 PWRGD VIN4 REF = 0.6V 07352-001 GND Figure 1. GENERAL DESCRIPTION The ADM1184 is an integrated, 4-channel voltage-monitoring device. A 2.7 V to 5.5 V power supply is required on the VCC pin to power the device. Four precision comparators monitor four voltage rails. Each comparator has a 0.6 V reference with a worst-case accuracy of 0.8%. Resistor networks that are external to the VIN1, VIN2, VIN3, and VIN4 pins set the trip points for the monitored supply rails. The ADM1184 has four open-drain outputs. OUT1 to OUT3 can be used to enable power supplies, and PWRGD is a common power-good output. OUT1 to OUT3 are dependent on their associated VINx input (that is, VIN1, VIN2, or VIN3). If a supply monitored by VINx drops below its programmed threshold, the associated OUTx pin and PWRGD are disabled. PWRGD is a common power-good output indicating the status of all monitored supplies. There is an internal 190 ms (typical) delay associated with the assertion of the PWRGD output. If VIN1, VIN2, VIN3, or VIN4 drops below its programmed threshold, PWRGD is deasserted immediately. The ADM1184 is available in a 10-lead mini small outline package (MSOP). Rev. 0 Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 (c)2008 Analog Devices, Inc. All rights reserved. ADM1184 TABLE OF CONTENTS Features .............................................................................................. 1 Applications....................................................................................... 1 Functional Block Diagram .............................................................. 1 General Description ......................................................................... 1 Revision History ............................................................................... 2 Specifications..................................................................................... 3 Absolute Maximum Ratings............................................................ 4 Thermal Resistance ...................................................................... 4 ESD Caution.................................................................................. 4 Pin Configuration and Function Descriptions..............................5 Typical Performance Characteristics ..............................................6 Theory of Operation .........................................................................9 Input Configuration......................................................................9 Output Configuration...................................................................9 Voltage Monitoring and Sequencing Application.................. 11 Outline Dimensions ....................................................................... 12 Ordering Guide .......................................................................... 12 REVISION HISTORY 2/08--Revision 0: Initial Version Rev. 0 | Page 2 of 12 ADM1184 SPECIFICATIONS VCC = 2.7 V to 5.5 V, TA = -40C to +85C. Table 1. Parameter VCC Pin Operating Voltage Range, VCC Supply Current, IVCC VIN1 to VIN4 (VINx) Pins Input Current, IVINLEAK Input Threshold, VTH OUT1 to OUT3 (OUTx), PWRGD Pins Output Low Voltage, VOUTL Leakage Current, IALERT VCC that Guarantees Valid Outputs TIMING DELAYS VIN1 to OUT1, VIN2 to OUT2, VIN3 to OUT3 Low-to-High Propagation Delay High-to-Low Propagation Delay, All Inputs All Inputs High to PWRGD Rising Delay Min 2.7 Typ 3.3 24 Max 5.5 80 +20 0.6048 0.4 0.4 +1 Unit V A nA V V V A V VVINx = 0.7 V Conditions -20 0.5952 0.6000 VCC = 2.7 V, ISINK = 2 mA VCC = 1 V, ISINK = 100 A All outputs are guaranteed to be either low or to give a valid output level from VCC = 1 V Refer to the timing diagrams in Figure 18 and Figure 19 VCC = 3.3 V VCC = 3.3 V VCC = 3.3 V -1 1 100 30 30 190 280 s s ms Rev. 0 | Page 3 of 12 ADM1184 ABSOLUTE MAXIMUM RATINGS TA = 25C, unless otherwise noted. Table 2. Parameter VCC Pin VINx Pins OUTx, PWRGD Pins Storage Temperature Range Operating Temperature Range Lead Temperature Soldering (10 sec) Junction Temperature Rating -0.3 V to +6 V -0.3 V to +6 V -0.3 V to +6 V -65C to +125C -40C to +85C 300C 150C THERMAL RESISTANCE JA is specified for the worst-case conditions, that is, a device soldered in a circuit board for surface-mount packages. Table 3. Thermal Resistance Package Type 10-Lead MSOP JA 137.5 Unit C/W ESD CAUTION Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Rev. 0 | Page 4 of 12 ADM1184 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS GND 1 VIN1 2 VIN2 3 VIN3 4 VIN4 5 10 VCC OUT1 OUT2 PWRGD 07352-002 ADM1184 TOP VIEW (Not to Scale) 9 8 7 6 OUT3 Figure 2. Pin Configuration Table 4. Pin Function Descriptions Pin No. 1 2 3 4 5 6 Mnemonic GND VIN1 VIN2 VIN3 VIN4 PWRGD Description Chip Ground Pin. Noninverting Input of Comparator 1. The voltage on this pin is compared with a 0.6 V reference. Can be used to monitor a voltage rail via a resistor divider. Noninverting Input of Comparator 2. The voltage on this pin is compared with a 0.6 V reference. Can be used to monitor a voltage rail via a resistor divider. Noninverting Input of Comparator 3. The voltage on this pin is compared with a 0.6 V reference. Can be used to monitor a voltage rail via a resistor divider. Noninverting Input of Comparator 4. The voltage on this pin is compared with a 0.6 V reference. Can be used to monitor a voltage rail via a resistor divider. Active High, Open-Drain Output. When the voltage on each VINx input exceeds 0.6 V, PWRGD is asserted after a 190 ms delay. Once PWRGD has been asserted, if the voltage monitored by VIN1, VIN2, VIN3, or VIN4 falls below 0.6 V, the PWRGD output is deasserted immediately. Active High, Open-Drain Output. When the voltage on VIN3 exceeds 0.6 V, OUT3 is asserted. OUT3 remains asserted until the voltage monitored by VIN3 falls below 0.6 V, and then it is driven low. Active High, Open-Drain Output. When the voltage on VIN2 exceeds 0.6 V, OUT2 is asserted. OUT2 remains asserted until the voltage monitored by VIN2 falls below 0.6 V, and then it is driven low. Active High, Open-Drain Output. When the voltage on VIN1 exceeds 0.6 V, OUT1 is asserted. OUT1 remains asserted until the voltage monitored by VIN1 falls below 0.6 V, and then it is driven low. Positive Supply Input Pin. The operating supply voltage range is 2.7 V to 5.5 V. 7 8 9 10 OUT3 OUT2 OUT1 VCC Rev. 0 | Page 5 of 12 ADM1184 TYPICAL PERFORMANCE CHARACTERISTICS 50 45 40 280 100mV OVERDRIVE 260 240 SUPPLY CURRENT (A) RISING DELAY (ms) 07352-003 35 30 25 20 15 10 5 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 SUPPLY VOLTAGE (V) 220 200 180 160 140 120 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5 SUPPLY VOLTAGE (V) Figure 3. Supply Current vs. Supply Voltage 50 45 40 Figure 6. All Inputs High to PWRGD Rising Delay vs. Supply Voltage 50 45 40 VCC = 3.3V, 100mV OVERDRIVE SUPPLY CURRENT (A) 30 25 20 15 10 5 VCC = 5V VCC = 3.3V RISING DELAY (s) 35 35 30 25 20 15 10 5 VCC = 2.7V 07352-004 0 10 20 30 40 50 60 70 80 90 0 10 20 30 40 50 60 70 80 90 TEMPERATURE (C) TEMPERATURE (C) Figure 4. Supply Current vs. Temperature 280 VCC = 3.3V, 100mV OVERDRIVE 260 240 Figure 7. VIN1/VIN2/VIN3 to OUT1/OUT2/OUT3 Rising Delay vs. Temperature 50 45 40 100mV OVERDRIVE RISING DELAY (ms) 220 200 180 160 RISING DELAY (s) 35 30 25 20 15 10 140 120 -40 -30 -20 -10 5 07352-005 0 10 20 30 40 50 60 70 80 90 TEMPERATURE (C) SUPPLY VOLTAGE (V) Figure 5. All Inputs High to PWRGD Rising Delay vs. Temperature Figure 8. VIN1/VIN2/VIN3 to OUT1/OUT2/OUT3 Rising Delay vs. Supply Voltage Rev. 0 | Page 6 of 12 07352-008 0 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5 07352-007 0 -40 -30 -20 -10 0 -40 -30 -20 -10 07352-006 ADM1184 60 100mV OVERDRIVE 50 180 MAXIMUM TRANSIENT DURATION (s) 07352-009 160 140 120 100 80 60 40 20 07352-012 07352-014 FALLING DELAY (s) 40 30 20 10 0 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5 SUPPLY VOLTAGE (V) 0 0 10 20 30 40 50 60 70 80 90 100 INPUT OVERDRIVE (mV) Figure 9. VINx to Output Falling Delay vs. Supply Voltage 50 VCC = 3.3V, 100mV OVERDRIVE 40 Figure 12. Trip Threshold Maximum Transient Duration vs. Input Overdrive 200 180 PROPAGATION DELAY (s) 160 140 120 100 80 60 40 20 APPLICABLE TO CHANNEL 1, CHANNEL 2, AND CHANNEL 3 FALLING DELAY (s) 30 20 10 07352-010 0 10 20 30 40 50 60 70 80 90 0 10 20 30 40 50 60 70 80 90 100 TEMPERATURE (C) INPUT OVERDRIVE (mV) Figure 10. VINx to Output Falling Delay vs. Temperature 0.610 0.608 OUTPUT LOW VOLTAGE (mV) Figure 13. Propagation Delay vs. Input Overdrive 400 350 300 250 200 150 100 50 0 0 2 4 6 8 10 12 14 16 18 20 22 24 OUTPUT SINK CURRENT (mA) 0.606 VINx TRIP THRESHOLD (V) 0.604 0.602 0.600 0.598 0.596 0.594 0.592 0 10 20 30 40 50 60 70 80 90 07352-011 0.590 -40 -30 -20 -10 TEMPERATURE (C) Figure 11. VINx Trip Threshold vs. Temperature Figure 14. Output Low Voltage vs. Output Sink Current Rev. 0 | Page 7 of 12 07352-013 0 -40 -30 -20 -10 0 ADM1184 100 90 OUTPUT LOW VOLTAGE (mV) 80 70 60 50 40 1mA SINK 30 20 10 0 1.0 100A SINK 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 07352-015 SUPPLY VOLTAGE (V) Figure 15. Output Low Voltage vs. Supply Voltage Rev. 0 | Page 8 of 12 ADM1184 THEORY OF OPERATION The ADM1184 is an integrated, 4-channel voltage-monitoring device. A 2.7 V to 5.5 V power supply is required on the VCC pin to power the device. VCC = 2.7V TO 5.5V 3.3V 2.5V 1.8V 1.2V OUTPUT CONFIGURATION The ADM1184 has four open-drain, active high outputs. Of these outputs, OUT1 to OUT3 can be used to enable power supplies, and PWRGD is a common power-good output. Output OUT1 to Output OUT3 are dependent on their associated input (that is, VIN1, VIN2, or VIN3). Before the voltage on a VINx input reaches 0.6 V, the corresponding output is switched to ground if there is 1 V on the VCC pin of the ADM1184. When VINx detects 0.6 V, OUTx is asserted after a 30 s (typical) delay. When all four monitored supplies exceed 0.6 V, a system powergood signal (PWRGD) is asserted. There is an internal 190 ms (typical) delay associated with the assertion of the PWRGD output. After PWRGD is asserted, if any of the four monitored supplies drops below its programmed threshold, the corresponding OUTx output and the PWRGD output are deasserted. If only the supply monitored by VIN4 drops below its programmed threshold, just the PWRGD output is deasserted. The ADM1184 functional truth table is shown in Table 5. Note that the functional operation described in Table 5 applies to the operation both before and after the assertion of PWRGD. Table 5. Functional Truth Table VIN1 01 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 2 VCC ADM1184 VIN1 VIN2 VIN3 VIN4 POWER GOOD 07352-016 OUT1 OUT2 OUT3 ENABLE SIGNALS GND PWRGD Figure 16. Typical Applications Circuit INPUT CONFIGURATION Four precision comparators monitor four voltage rails. Each comparator has a 0.6 V reference with a worst-case accuracy of 0.8%. Resistor networks external to the VIN1, VIN2, VIN3, and VIN4 pins set the trip points for the monitored supply rails. Typically, the threshold voltage at each of the four adjustable inputs (that is, VIN1, VIN2, VIN3, and VIN4) is 0.6 V. To monitor a voltage greater than 0.6 V, connect a resistor divider network to the circuit as depicted in Figure 17. V 3.3V 2.9V 0V 2.9V SUPPLY GIVES 0.6V AT VIN1 PIN t 4.6k VIN1 0.6V 07352-017 ADM1184 TO LOGIC CORE 1.2k Figure 17. Setting the Undervoltage Threshold In this example, the VIN1 pin monitors a 3.3 V supply. An external resistor divider scales this voltage down for monitoring at the VIN1 pin. The resistor ratio is chosen so that the VIN1 voltage is 0.6 V when the main voltage rises to the preferred level at startup (a voltage below the nominal 3.3 V level). R1 is 4.6 k and R2 is 1.2 k; therefore, a voltage level of 2.9 V corresponds to 0.6 V on the noninverting input of the first comparator (see Figure 17). VIN2 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 VIN3 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 VIN4 0 12 0 1 0 1 0 1 0 1 0 1 0 1 0 1 OUT1 Low Low Low Low Low Low Low Low High High High High High High High High OUT2 Low Low Low Low High High High High Low Low Low Low High High High High OUT3 Low Low High High Low Low High High Low Low High High Low Low High High PWRGD Low Low Low Low Low Low Low Low Low Low Low Low Low Low Low High Figure 18 and Figure 19 show waveforms that illustrate the behavior of the ADM1184. Rev. 0 | Page 9 of 12 ADM1184 VTH ALL INPUTS, VINx 30s OUT1 OUT2 OUT3 PWRGD 190ms Figure 18. Power-Up Waveforms VIN1/VIN2/VIN3 VTH 30s 30s VIN4 VTH OUT1/OUT2/OUT3 30s 30s 07352-019 PWRGD 190ms Figure 19. Waveforms Showing Reaction to a Temporary Low Glitch on VIN1, VIN2, VIN3, or VIN4 Rev. 0 | Page 10 of 12 07352-018 190ms ADM1184 VOLTAGE MONITORING AND SEQUENCING APPLICATION 3.3V IN 2.5V OUT 1.8V OUT 1.2V OUT VCC IN REGULATOR 1 EN OUT GND IN REGULATOR 2 EN PWRGD OUT GND IN REGULATOR 3 EN POWER GOOD OUT GND ADM1184 VIN1 VIN2 VIN3 VIN4 GND OUT1 OUT2 OUT3 2.5V OUT 1.8V OUT 1.2V OUT 07352-020 Figure 20. Voltage-Monitoring and Sequencing Application Diagram Figure 20 depicts an application in which the ADM1184 monitors four separate voltage rails, turns on three regulators in a sequence, and generates a power-good signal to turn on a controller when all power supplies are up and stable. The main supply, in this case 3.3 V, powers up the device via the VCC pin. The VIN1 pin monitors the main 3.3 V supply. In this example application, OUT1 is connected to the enable pin of a regulator. Before the voltage on VIN1 reaches 0.6 V, this output is switched to ground, disabling Regulator 1. When the main system voltage reaches 2.9 V, VIN1 detects 0.6 V. This causes OUT1 to assert, which drives the enable pin of Regulator 1 high, thus turning on its output. The 2.5 V output of this regulator begins to rise and is detected by input Pin VIN2. When VIN2 detects the 2.5 V rail rising above its voltage threshold point, it asserts OUT2, which turns on Regulator 2. The same scheme is implemented with the other input and output pins. Every rail that is turned on via an output pin, OUTx, is monitored via an input pin, VIN(x + 1). When all four monitored supplies are above their programmed threshold levels PWRGD asserts after a 190 ms (typical) delay. Rev. 0 | Page 11 of 12 ADM1184 OUTLINE DIMENSIONS 3.10 3.00 2.90 3.10 3.00 2.90 PIN 1 0.50 BSC 0.95 0.85 0.75 0.15 0.05 0.33 0.17 COPLANARITY 0.10 COMPLIANT TO JEDEC STANDARDS MO-187-BA 1.10 MAX 8 0 0.80 0.60 0.40 10 6 1 5 5.15 4.90 4.65 SEATING PLANE 0.23 0.08 Figure 21. 10-Lead Mini Small Outline Package [MSOP] (RM-10) Dimensions shown in millimeters ORDERING GUIDE Model ADM1184ARMZ 1 ADM1184ARMZ-REEL71 1 Temperature Range -40C to +85C -40C to +85C Package Description 10-Lead Mini Small Outline Package [MSOP] 10-Lead Mini Small Outline Package [MSOP] Package Option RM-10 RM-10 Branding MB0 MB0 Z = RoHS Compliant Part. (c)2008 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D07352-0-2/08(0) Rev. 0 | Page 12 of 12 |
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