Quad Voltage Monitor and Sequencer ADM1185 Preliminary Technical Data FEATURES Powered from 2.7V to 5.5V on the VCC pin Monitors Four Supplies via 0.8% Accurate Comparators Four inputs can be programmed for voltage levels with resistor dividers Three Open-Drain Enable Outputs Open-Drain Power Good Output 10-pin MSOP Package FUNCTIONAL BLOCK DIAGRAM VCC ADM1185 POWER AND REFERENCE GENERATOR REF=0.6V OUT1 VIN1 REF=0.6V APPLICATIONS OUT2 Monitor and Alarm Functions Power Supply Sequencing Telecommunication and Datacommunication Equipment PC/Servers VIN2 REF=0.6V OUT3 VIN3 LOGIC REF=0.6V GENERAL DESCRIPTION The ADM1185 is an integrated four channel voltage monitoring device. A 2.7V to 5.5V power supply is required on the VCC pin to power the device. VIN4 PWRGD REF=0.6V Four precision comparators monitor four voltage rails. All comparators have a 0.6V reference with a worst-case accuracy of 0.8%. Resistor networks external to the VIN1-VIN4 pins set the trip points. GND Figure 1. There are four open-drain outputs on the device. A digital core interprets the comparator outputs and asserts the outputs as appropriate. APPLICATIONS DIAGRAM 3.3V IN 2.5V OUT 1.8V OUT 1.2V OUT IN Regulator1 VCC VIN1 OUT1 VIN2 OUT2 VIN3 OUT3 EN 2.5V OUT OUT IN VIN4 Regulator2 EN 1.8V OUT OUT ADM1185 GND IN PWRGD Regulator3 EN OUT 1.2V OUT POWER GOOD Figure 2. Rev. PrK June 2006 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 © 2006 Analog Devices, Inc. All rights reserved. ADM1185 Preliminary Technical Data TABLE OF CONTENTS REVISION HISTORY Rev. PrK | Page 2 of 12 Preliminary Technical Data ADM1185 ADM1185—SPECIFICATIONS VVCC = 2.7V to 5.5V, TA = -40°C to +85°C Table 1. Parameter VCC Pin Operating Voltage Range, VVCC Supply Current, IVCC VIN1-VIN4 Pins Input Current, IVINLEAK Input Rising Threshold, VTHR Input Rising Hysteresis, VHYST (=VTHR -VTHF) OUT1-OUT3, PWRGD Pins Output low voltage, VOUTL Leakage Current, IALERT VVCC that guarantees outputs valid VIN1 to OUT1 Delay VIN4 to PWRGD Delay High-to-Low Propagation Delay Low-to-High Propagation Delay Min Typ Max Units 30 5.5 100 V µA 100 0.6048 nA V mV VVINx = 0.7V 0.4 0.4 1 V V µA V VVCC = 2.7 V, ISINK = 2mA VVCC = 1 V, ISINK =100µA 2.7 -100 0.5952 0.6000 9 -1 1 100 100 190 190 280 280 30 30 Rev. PrK | Page 3 of 12 ms ms µs µs Conditions All outputs will be guaranteed to be either low or giving a valid output level from VVCC = 1V. VVIN1 Rising VVIN4 Rising, condition only valid at certain operational states, refer to state diagram VVCC =3.3V, see TPC1 VVCC =3.3V, see TPC1 ADM1185 Preliminary Technical Data ABSOLUTE MAXIMUM RATINGS Table 2. Parameter VCC Pin VIN1-VIN4 Pin OUT1-OUT3, PWRGD Pins Power Dissipation Storage Temperature Operating Temperature Range Lead Temperature Range (Soldering 10 sec) Junction Temperature Rating −0.3 V to +6 V −0.3 V to +6 V −0.3 V to +6 V TBD −65°C to +125°C −40°C to +85°C 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 listed in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions may affect device reliability. Ambient temperature = 25°C, unless otherwise noted. 300°C 150°C ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although this product features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality. Rev. PrK | Page 4 of 12 Preliminary Technical Data ADM1185 PIN CONFIGURATIONS GND 1 VIN1 2 VIN2 3 VIN3 4 VIN4 5 ADM1185 TOP VIEW 10 Vcc 9 OUT1 8 OUT2 (NOT TO SCALE) 7 OUT3 6 PWRGD Figure 3. Pin Configurations PIN FUNCTIONAL DESCRIPTIONS Table 3. Pin No. 1 2 Name GND VIN1 3 VIN2 4 VIN3 5 VIN4 6 PWRGD 7 OUT3 8 OUT2 9 OUT1 10 VCC Description Chip Ground Pin. Non-inverting input of comparator 1. The voltage on this pin is compared with a 0.6V reference. Can be used to monitor a voltage rail via a resistor divider. Non-inverting input of comparator 2. The voltage on this pin is compared with a 0.6V reference. Can be used to monitor a voltage rail via a resistor divider. Non-inverting input of comparator 3. The voltage on this pin is compared with a 0.6V reference. Can be used to monitor a voltage rail via a resistor divider. Non-inverting input of comparator 4. The voltage on this pin is compared with a 0.6V reference. Can be used to monitor a voltage rail via a resistor divider. Open-drain output. During a power-up sequence (before PWRGD asserts) this output will assert high when the voltage on VIN4 is greater than 0.6V. A time delay of 190ms (typical) is included before assertion of this pin. After power-up (after PWRGD asserts) this output will be driven low if any of the voltages on the VIN1VIN4 pins falls below 0.6V. Open-drain output. During a power-up sequence (before PWRGD asserts) this output will assert high when the voltage on VIN3 is greater than 0.6V. After power-up (after PWRGD asserts) this output will be driven low if the voltage on VIN1 falls below 0.6V. Open-drain output. During a power-up sequence (before PWRGD asserts) this output will assert high when the voltage on VIN2 is greater than 0.6V. After power-up (after PWRGD asserts) this output will be driven low if the voltage on VIN1 falls below 0.6V. Open-drain output. During a power-up sequence (before PWRGD asserts) this output will assert high when the voltage on VIN1 is greater than 0.6V. A time delay of 190ms (typical) is included before assertion of this pin. After power-up (after PWRGD asserts) this output will be driven low if the voltage on VIN1 falls below 0.6V. Positive supply input pin. The operating supply voltage range is 2.7 V to 5.5 V. Rev. PrK | Page 5 of 12 ADM1185 Preliminary Technical Data TYPICAL PERFORMANCE CURVES v(pad) Output 800 Low 775 Voltage (mV) 750 Voltage (mV) 725 700 675 650 625 600 575 550 525 500 475 x1e-3 450 425 400 375 350 325 300 275 250 2mA. 85degC/SLOW 225 200 175 150 125 100 75 50 25 0 .5 Duration (us) TPC 1. Maximum transient duration Without Causing an Output Pulse vs. Output Comparator Overdrive Rev. PrK | Page 6 of 12 1 1.5 2 2.5 3 3.5 vsupply Supply Voltage (V) 4 4.5 TPC 2. Output Low Voltage vs. Supply Voltage 5 5.5 Preliminary Technical Data ADM1185 Functional Description The operation of the ADM1185 is explained in this section in the context of the device in a voltage monitoring and sequencing application (figure 4, above). In this application, the ADM1185 will monitor four separate voltage rails, turn on three regulators in a predefined sequence and generate a power good signal to turn on a controller when all power supplies are up and stable. POWER ON SEQUENCING AND MONITORING The main supply (in this case 3.3V) powers up the device via the VCC pin as the voltage rises. A supply voltage of 2.7V to 5.5V is needed to power the device. The VIN1 pin is monitoring the main 3.3V supply. An external resistor divider will scale this voltage down for monitoring at the VIN1 pin. The resistor ratio is chosen so that the VIN1 voltage is 0.6V when the main voltage rises to the preferred level at start-up (some voltage below the nominal 3.3V level). In this case, R1 is 4.6K and R2 is 1.2K so that a voltage level of 2.9V will correspond to 0.6V on the non-inverting input of the first comparator. VOLTAGE MONITORING AFTER POWER ON V 3.3V 2.9V 0V t ADM1185 4.6K VIN1 2.9V supply gives 0.6V at VIN1 pin The assertion of OUT1 will turn on Regulator1. The 2.5V output of this regulator will begin to rise. This will be detected by input VIN2 (with a similar resistor divider scheme as shows in figure 5). When VIN2 sees the 2.5V rail rise above its UV point it will assert output OUT2, turning on Regulator2. A capacitor can be placed on the VIN2 pin to slow the rise of the voltage on this pin- this effectively sets a time delay between the 2.5V rail powering up and the next Regulator being enabled. The same scheme is implemented with the other input and output pins. Every rail that is turned on via an output pin OUT(n) is monitored via input pin VIN(n+1). The final comparator inside the VIN4 pin detects the final supply turning on, which is 1.2V in this case. All of the output pins (OUT1-OUT3) are logically ANDed together to generate a system power good signal (PWRGD). There is an internal 190ms delay associated with the assertion of the PWRGD output. Table 4 below is a truth table that steps through the power on sequence of the outputs. Any associated internal time delays are also shown. 1.2K 0.6V TO LOGIC CORE Once PWRGD is asserted the logical core latches into a different mode of operation. During the initial power up phase each output is directly dependant on an input (i.e. VIN3 asserting causes OUT3 to assert). When power up is complete this function is redundant. Once in the PWRGD state the following behavior can be observed: • If the main 3.3V supply that is monitored via VIN1 faults in the power good state then the PWRGD output is deasserted to warn the downstream controller and all of the outputs OUT1-OUT3 are immediately turned off, disabling all locally generated supplies. • If a supply monitored by VIN2-VIN4 fails the PWRGD output is deasserted to warn the controller but the other outputs are not deasserted. Figure 4.Setting the undervoltage threshold with an external resistor divider OUT1 is an open drain active high output. In this application, OUT1 is connected to the enable pin of a regulator. Before the voltage on VIN1 has reached 0.6V this output is switched to ground, disabling regulator 1. (Note that all outputs are driven to ground as long as there is 1V on the VCC pin of the ADM1185). When the main system voltage reaches 2.9V VIN1 will detect 0.6V and this will cause OUT1 to assert after a 190ms delay. When this occurs the open drain output will switch high and the external pull-up resistor will pull the voltage on the regulator 1 enable pin above its turn-on threshold, turning on the output of regulator 1. Table 5 and table 6 are truth tables that highlight the behavior of the ADM1185 under various fault situations during normal operation (i.e. in the mode of operation after PWRGD has asserted). Rev. PrK | Page 7 of 12 ADM1185 Preliminary Technical Data 3.3V IN 2.5V OUT 1.8V OUT 1.2V OUT IN Regulator1 VCC VIN1 OUT1 VIN2 OUT2 VIN3 OUT3 EN 2.5V OUT OUT IN Regulator2 VIN4 EN 1.8V OUT OUT ADM1185 GND IN PWRGD Regulator3 EN OUT 1.2V OUT POWER GOOD Figure 5. Applications Diagram showing ADM1185 in a voltage monitoring and sequencing application State1 Start IN1=OK (Delay=100ms min) State2 OUT1 On IN2=OK IN1=FAULT State3 OUT1,2 On IN3=OK IN1=FAULT State4 OUT1,2,3 On IN4=OK (Delay=100ms min) IN1=FAULT State5 PWRGD IN1=FAULT IN2.IN3.IN3=FAULT Figure 6. Flow Diagram highlighting the different modes of operation o the logical core State 1 2 3 4 5 State Name OUT1 OUT2 OUT3 OUT4 Next Event Next State Reset* Out1 On Out1,2 On Out1,2,3 On PowerGood 0 1 1 1 1 0 0 1 1 1 0 0 0 1 1 0 0 0 0 1 IN1 High for 190ms IN1 and IN2 High for 30us IN1 and IN3 High for 30us All High for 190ms IN2 or IN3 or IN4 Low for 30us IN1 Low for 30 us Out1 On Out1,2 On Out1,2,3 On PowerGood Out1,2,3 On Table 4. Truth table Rev. PrK | Page 8 of 12 Start Preliminary Technical Data ADM1185 VIN1 V T(falling) =0.6V VIN1 V T (rising) V T (rising) tPROP tPROP OUT1 OUT1 OUT2 190ms OUT2 190ms tPROP OUT3 OUT3 PWRGD PWRGD 190ms 190ms NOTE* The rising threshold on the VIN1-VIN4 pins will be slightly higher than 0.6V as there is some hysteresis on this pin. Figure 6. Power-up Waveforms NOTE* The rising threshold on the VIN1-VIN4 pins will be slightly higher than 0.6V as there is some hysteresis on this pin. Figure 7. Waveforms showing reaction to a temporary low glitch on the main supply Rev. PrK | Page 9 of 12 ADM1185 Preliminary Technical Data CASCADING MULTIPLE DEVICES Multiple ADM1185 devices can be cascaded in situations where a large number of supplies must be monitored and/or sequenced. There are numerous configurations for interconnecting devices. The most suitable configuration will depend on the application. Figures 8, 9 and 10 show some methods for cascading multiple ADM1185 devices. 3.3V 3.3V ADM1185-A VCC 3.3V VIN1 V1 VIN2 V2 VIN3 V3 VIN4 Reg1 OUT1 EN1 V1 Reg2 OUT2 Reg3 OUT3 GND Note: Supplies scaled down with resistor dividers V2 EN2 EN3 V3 PWRGD 3.3V ADM1185-B VCC VIN1 V4 VIN2 V5 VIN3 V6 VIN4 Reg4 OUT1 EN4 OUT2 V5 EN5 Reg6 OUT3 GND V4 Reg5 EN6 PWRGD Figure 8. Cascading multiple ADM1185 devices, option 1 Rev. PrK | Page 10 of 12 V6 POWER GOOD Preliminary Technical Data ADM1185 3.3V 3.3V ADM1185-A VCC 3.3V Reg1 VIN1 V1 VIN2 V2 VIN3 3.3V VIN4 OUT1 EN1 V1 Reg2 OUT2 V2 EN2 Reg3 OUT3 GND EN3 V3 PWRGD Note: Supplies scaled down with resistor dividers 3.3V ADM1185-B VCC V3 Reg4 VIN1 V4 VIN2 V5 VIN3 V6 VIN4 OUT1 EN4 V4 Reg5 OUT2 V5 EN5 Reg6 OUT3 GND EN6 V6 PWRGD POWER GOOD Figure 9. Cascading multiple ADM1185 devices, option 2 3.3V 3.3V ADM1185-A VCC 3.3V VIN1 V1 VIN2 V2 VIN3 3.3V VIN4 Reg1 OUT1 EN1 V1 Reg2 OUT2 V2 EN2 Reg3 OUT3 GND EN3 V3 PWRGD Note: Supplies scaled down with resistor dividers 3.3V ADM1185-B VCC 3.3V VIN1 OUT1 V3 VIN2 OUT2 V5 VIN3 V6 VIN4 Reg4 Reg5 OUT3 GND V4 EN4 EN5 PWRGD V5 POWER GOOD Figure 10. Cascading multiple ADM1185 devices, option 3 Rev. PrK | Page 11 of 12 ADM1185 Preliminary Technical Data OUTLINE DIMENSIONS 0.122 (3.10) 0.114 (2.90) 10 6 0.114 (2.90) 1 PR06196-0-6/06(PrK) 0.199 (5.05) 0.187 (4.75) 0.122 (3.10) 5 PIN 1 0.0197 (0.50) BSC 0.120 (3.05) 0.120 (3.05) 0.112 (2.85) 0.037 (0.94) 0.112 (2.85) 0.043 (1.10) MAX 0.031 (0.78) 0.006 (0.15) 0.012 (0.30) 0.002 (0.05) 0.006 (0.15) SEATING PLANE 0.009 (0.23) 6o o 0 0.005 (0.13) 0.028 (0.70) 0.016 (0.40) Figure 9. 10-Lead MSOP Package (RM-10) Dimensions shown in millimeters ORDERING GUIDE Model ADM1185ARMZ1 Temperature Range -40°C to +85°C Package Description MSOP-10 Z=PB-free part Rev. PrK | Page 12 of 12 Package Outline RM-10