`
`October 1996
`
`LMC6953
`PCI Local Bus Power Supervisor
`
`General Description
`The LMC6953 is a voltage supervisory chip designed to
`meet PCI (Peripheral Component Interconnect) Specifica-
`tions Revision 2.1. It monitors 5V and 3.3V power supplies.
`In cases of power-up, power-down, brown-out, power failure
`and manual reset interrupt, the LMC6953 provides an active
`low reset. RESET holds low for 100 ms after both 5V and
`3.3V powers recover, or after manual reset signal returns to
`high state. The external capacitor on pin 8 adjusts the reset
`delay.
`
`This part is ideal on PCI motherboards or add-in cards to
`ensure the integrity of the entire system when there is a
`fault condition. The active low reset sets the microprocessor
`or local device in a known state.
`
`The LMC6953 has a built-in bandgap reference that accu-
`rately determines all the threshold voltages. The internal re-
`set delay circuitry eliminates additional discrete compo-
`nents.
`
`Features
`Y Compliant to PCI specifications revision 2.1.
`Y Under and over voltage detectors for 5V and 3.3V
`Y Power
`failure detection (5V falling under 3.3V by
`300 mV max)
`Y Manual reset input pin
`Y Guaranteed RESET assertion at VDD e 1.5V
`Y Integrated reset delay circuitry
`Y Open drain output
`Y Adjustable reset delay
`Y Response time for over and under voltage
`detection
`Y Power failure response time
`Y Requires minimal external components
`
`490 ns Max
`90 ns Max
`
`Applications
`Y Desktop PCs
`Y PCI-Based Systems
`Y Network servers
`
`Typical Application Circuits
`On Mother Board
`
`On Add-in Cards
`
`TL/H/12846 – 23
`
`Ordering Information
`
`Package
`
`8-Pin Small
`Outline
`
`Commercial Temp Range
`0§C to a70§C
`
`LMC6953CM
`
`LMC6953CMX
`
`NSC
`Drawing
`
`M08A
`
`TL/H/12846 – 24
`
`Supplied
`As
`
`Rails
`
`2.5k Tape
`and Reel
`
`Connection
`Diagram
`
`8-Pin SO
`
`TL/H/12846 – 2
`Top View
`
`C1996 National Semiconductor Corporation
`
`TL/H/12846
`
`RRD-B30M116/Printed in U. S. A.
`
`http://www.national.com
`
`Petitioners
`Ex. 1063, p. 1
`
`
`
`Absolute Maximum Ratings (Note 1)
`If Military/Aerospace specified devices are required,
`please contact
`the National Semiconductor Sales
`Office/Distributors for availability and specifications.
`
`ESD Tolerance (Note 2)
`Human Body Model
`Machine Model
`
`Voltage at Input Pin
`
`Supply Voltage
`
`Current at Output Pin
`
`Current at Power Supply Pin (Note 3)
`
`2 kV
`200V
`
`7V
`
`7V
`
`15 mA
`
`10 mA
`
`Lead Temp. (Soldering, 10 sec.)
`
`Storage Temperature Range
`
`Junction Temperature
`
`260§C
`b65§C to a150§C
`150§C
`
`Operating Ratings (Note 1)
`Supply Voltage
`
`Junction Temperature Range
`LMC6953C
`Thermal Resistance (iJA)
`M Package
`
`1.5V to 6V
`
`0§C s TJ
`
`s 70§C
`
`165§C/W
`
`DC Electrical Characteristics
`Unless otherwise specified, all boldface limits guaranteed for TJ e 0§C to 70§C, VDD e 5V, RPULL-UP e 4.7 kX and CEXT e
`0.01 mF. Typical numbers are room temperature (25§C) performance.
`
`Symbol
`
`Parameter
`
`Conditions
`
`VH5
`
`VL5
`
`VH3.3
`
`VL3.3
`
`VDD Over-Voltage Threshold
`
`VDD Under-Voltage Threshold
`
`3.3V Over-Voltage Threshold
`
`3.3V Under-Voltage Threshold
`
`(Note 4)
`
`(Note 4)
`
`(Note 5)
`
`(Note 5)
`
`Min
`
`5.45
`
`4.25
`
`3.8
`
`2.5
`
`Typ
`
`5.6
`
`4.4
`
`3.95
`
`2.65
`
`Max
`
`5.75
`
`4.55
`
`4.1
`
`2.8
`
`2.8
`
`Units
`
`V
`
`V
`
`V
`
`V
`
`V
`
`VMR
`
`VPF
`
`RIN
`
`VOL
`
`IS
`
`Manual RESET Threshold
`
`Power Failure Differential Voltage
`(3.3V Pin – 5V Pin)
`
`(Note 6)
`
`Input Resistance at 5V and 3.3V Pins
`
`RESET Output Low
`
`Supply Current
`
`VDD e 1.5V to 6V
`
`(Note 3)
`
`2.5
`
`150
`
`35
`
`0.05
`
`0.8
`
`300
`
`0.1
`
`1.5
`
`mV
`
`kX
`
`V
`
`mA
`
`AC Electrical Characteristics
`Unless otherwise specified, all boldface limits guaranteed for TJ e 0§C to 70§C, VDD e 5V, RPULL-UP e 4.7 kX and CEXT e
`0.01 mF. Typical numbers are room temperature (25§C) performance.
`
`Symbol
`
`Parameter
`
`Conditions
`
`tD
`
`tPF
`
`Over or Under Voltage Response Time
`
`(Note 7)
`
`Power Failure Response Time
`
`(Note 8)
`
`tRESET
`
`Reset Delay
`
`CEXT e 0.01 mF
`
`LMC6953
`Limit
`
`490
`
`90
`
`Typ
`
`150
`
`40
`
`100
`
`Units
`
`ns
`max
`
`ns
`max
`
`ms
`
`Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
`intended to be functional, but specific performance is not guaranteed. For guaranteed specifications and the test conditions, see the Electrical Characteristics.
`
`Note 2: Human body model, 1.5 kX in series with 100 pF. Machine model. 200X in series with 100 pF.
`
`Note 3: Supply current measured at pins 1, 2, and 3. The 4.7 kX pull-up resistor on pin 7 is not tied to VDD in this measurement.
`Note 4: PCI Specifications Revision 2.1, Section 4.2.1.1 and Section 4.3.2.
`
`Note 5: PCI Specifications Revision 2.1, Section 4.2.2.1 and Section 4.3.2.
`
`Note 6: PCI Specifications Revision 2.1 and Section 4.3.2.
`
`Note 7: PCI Specifications Revision 2.1, Section 4.3.2. The response time is measured individually with g750 mV of overdrive applied to pin 2 then g600 mV of
`overdrive applied to pin 3 and taking the worst number of the four measurements.
`
`Note 8: PCI Specifications Revision 2.1, Section 4.3.2. The power failure response time is measured with a signal changing from 5V to 3V applied to pin 2 and a
`3.3V DC applied to pin 3.
`
`http://www.national.com
`
`2
`
`Petitioners
`Ex. 1063, p. 2
`
`
`
`LMC6953 Timing Diagram
`
`Note: tRESET, tD and tPF are not to scale.
`
`TL/H/12846 – 3
`
`3
`
`http://www.national.com
`
`Petitioners
`Ex. 1063, p. 3
`
`
`
`Typical Performance Characteristics Unless otherwise specified, TA e 25§C
`
`Supply Current vs Temperature
`
`Output Voltage vs Supply Voltage
`
`TL/H/12846 – 4
`
`TL/H/12846 – 12
`
`Power-Up Supply Voltage
`vs Temperature
`
`VH5 vs Temperature
`
`TL/H/12846 – 9
`
`TL/H/12846 – 5
`
`VL5 vs Temperature
`
`VH3.3 vs Temperature
`
`TL/H/12846 – 6
`
`TL/H/12846 – 7
`
`http://www.national.com
`
`4
`
`Petitioners
`Ex. 1063, p. 4
`
`
`
`Typical Performance Characteristics Unless otherwise specified, TA e 25§C (Continued)
`
`VL3.3 vs Temperature
`
`Over-Voltage Response Time
`vs Temperature
`
`TL/H/12846 – 8
`
`TL/H/12846 – 13
`
`Under-Voltage Response Time
`vs Temperature
`
`Power Failure Response Time
`vs Temperature
`
`TL/H/12846 – 14
`
`TL/H/12846 – 15
`
`VOL vs RPULL-UP
`
`IOL vs RPULL-UP
`
`TL/H/12846 – 19
`
`TL/H/12846 – 20
`
`5
`
`http://www.national.com
`
`Petitioners
`Ex. 1063, p. 5
`
`
`
`Typical Performance Characteristics Unless otherwise specified, TA e 25§C (Continued)
`
`Reset Delay vs CEXT
`
`Reset Delay vs Temperature
`with CEXT e 0.01 mF
`
`TL/H/12846 – 10
`
`TL/H/12846 – 11
`
`http://www.national.com
`
`6
`
`Petitioners
`Ex. 1063, p. 6
`
`
`
`Block Diagram of the LMC6953
`
`** All five comparators’ positive power supplies are connected to VDD
`
`Truth Table
`
`Power Failure
`
`5V Over-Voltage
`
`5V Under-Voltage
`
`3.3V Over-Voltage
`
`3.3V Under-Voltage
`
`MR
`
`RESET
`
`TL/H/12846 – 25
`
`Fail
`
`X
`
`X
`
`X
`
`X
`
`X
`
`OK
`
`X
`
`Fail
`
`X
`
`X
`
`X
`
`X
`
`OK
`
`X e Don’t Care
`
`Pin Description
`
`Pin
`
`Name
`
`X
`
`X
`
`Fail
`
`X
`
`X
`
`X
`
`OK
`
`X
`
`X
`
`X
`
`Fail
`
`X
`
`X
`
`OK
`
`Function
`
`X
`
`X
`
`X
`
`X
`
`Fail
`
`X
`
`OK
`
`High
`
`High
`
`High
`
`High
`
`High
`
`Low
`
`High
`
`Low
`
`Low
`
`Low
`
`Low
`
`Low
`
`Low
`
`High
`
`1
`
`2
`
`3
`
`4
`
`5
`
`6
`
`7
`
`8
`
`VDD
`
`5V
`
`3.3V
`
`MR
`
`5V input supply voltage. This pin supplies power to the internal comparators. It can be connected to a
`capacitor acting as a back-up battery. Otherwise, it should be shorted to the 5V pin.
`
`5V input supply voltage. This pin is not connected to the positive power supply of the internal comparators. It
`provides input signal to the 5V window comparators as well as the power failure comparator.
`
`3.3V input supply voltage. This pin provides input signal to the 3.3V window comparators and the power failure
`comparator.
`
`Manual reset input pin. It takes 5V CMOS logic low and triggers RESET. If not used, this pin should be
`connected to VDD.
`
`PWRdžGND Ground.
`GND
`This pin should be grounded at all times.
`
`RESET
`
`Active low reset output. RESET holds low for 100 ms after both 5V and 3.3V powers recover, or after manual
`reset signal returns to high state.
`
`CEXT
`
`External capacitor pin. The value of CEXT sets the reset delay.
`
`7
`
`http://www.national.com
`
`Petitioners
`Ex. 1063, p. 7
`
`
`
`5V AND VDD PINS
`By having the 5V and the VDD pins separately, a capacitor
`can be used as a back-up power supply in event of a sud-
`den power supply failure. This circuit is shown in the appli-
`cation circuit section titled ‘‘On Motherboard With Capacitor
`as a Back-up Power Supply.’’ Under normal condition, the
`diode is forward-biased and the capacitor is charged up to
`VDD b 0.7V. If the power supply goes away, the diode be-
`comes reverse-biased, isolating the 5V and the VDD pins.
`The capacitor provides power to the internal comparators
`for a short duration for the LMC6953 to operate.
`
`CEXT SETS RESET DELAY IN LINEAR FASHION
`The LMC6953 has internal delay circuitry to generate the
`reset delay. By choosing different values of capacitor CEXT,
`reset delay can be programmed to the desired length for the
`system to stabilize after a fault condition occurs.
`
`EVALUATING THE LMC6953
`
`To Measure Over-Voltages and Under-Voltages.
`Connect a 3.3V DC to the 3.3V pin and a 5V DC to the VDD
`and the 5V pins (VDD and 5V pins are shorted). RESET
`output is high because voltages are within window. These
`voltages should be monitored. While keeping the 3.3V con-
`stant, increase the 5V DC signal until a RESET low is de-
`tected. The point on the 5V DC signal at which RESET
`changes from high to low is the 5V over-voltage. It is typical-
`ly 5.6V. To detect 5V under-voltage, start the 5V DC signal
`from 5V and decrease it until a RESET low is detected. The
`point on the 5V DC signal at which RESET changes from
`high to low is the 5V under-voltage. It is typically 4.4V.
`
`To find 3.3V over-voltage and under-voltage, keep the 5V
`DC at 5V and vary the 3.3V DC signal until a RESET low is
`detected.
`
`To Measure Timing Specifications.
`For evaluation purposes only, the VDD and the 5V pins
`should have separate signals. It is easier to measure re-
`sponse time in this manner. The VDD pin is connected to a
`steady 5V DC and the 5V pin is connected to a pulse gener-
`ator. To simulate the power supply voltages going out of
`window, a pulse generator with disable/enable feature and
`rise and fall time adjustment is recommended. To measure
`the RESET signal, a oscilloscope is recommended because
`of its ability to capture and store a signal.
`
`Application Note
`
`HOW THE LMC6953 FUNCTIONS
`
`The LMC6953 is a power supply supervisor with its perform-
`ance specifications compliant to PCI Specifications Revi-
`sion 2.1. The chip monitors power-up, power-down, brown-
`out, power failure and manual reset interrupt situations.
`
`During power-up, the LMC6953 holds RESET low for 100
`ms after both 5V and 3.3V are within specified windows. It
`asserts reset in 490 ns when a brown-out is detected.
`Brown-out occurs when 5V supply is above 5.75V over-volt-
`age or below 4.25V under-voltage or when 3.3V supply is
`above 4.1V over-voltage or 2.5V under-voltage. In case of
`power failure where the 5V supply falls under 3.3V supply by
`300 mV maximum, reset is asserted in 90 ns. RESET also
`can be asserted by sending a 5V CMOS logic low to the
`manual reset pin.
`
`Each time RESET is asserted, it holds low for 100 ms after a
`fault condition is recovered. The 100 ms reset delay is gen-
`erated by the 0.01 mF CEXT capacitor, and can be adjusted
`by changing the value of CEXT.
`It is highly recommended to place lands on printed circuit
`boards for 120 pF capacitors between pin 2 and ground and
`also between pin 3 and ground. As power supplies may
`change abruptly, there can be very high frequency noise
`present and the capacitors can minimize the noise,
`
`MINIMUM SUPPLY VOLTAGE FOR RESET ASSERTION
`The LMC6953 guarantees VDD e 1.5V as the minimum
`supply voltage to achieve consistent RESET assertion. This
`ensures system stability in initialization state.
`
`TL/H/12846 – 12
`FIGURE 1. Output Voltage vs Supply Voltage
`
`Figure 1 is measured by shorting pins 1, 2 and 3 together
`when supply voltage is from 0V to 3.3V. Then pin 3 is con-
`nected with a constant 3.3 VDC and pins 1 and 2 are con-
`nected to a separate power supply that continues to vary
`from 3.3V to 6V.
`
`http://www.national.com
`
`8
`
`Petitioners
`Ex. 1063, p. 8
`
`
`
`Application Note (Continued)
`To measure the 5V under-voltage response time on the
`LMC6953, set the pulse generator to trigger mode and pro-
`gram the amplitude to have a high value of 5V and a low
`value of the 5V under-voltage threshold measured previous-
`ly with 50 mV overdrive. For example, if the measured 5V
`under-voltage is 4.4V, then a 50 mV overdrive on this signal
`is 4.35V. The disable feature on the pulse generator should
`be on. Program the fall time of the pulse to be 30 ns and
`program the scope to trigger on the falling edge, with trigger
`level of 4.5V. Set the scope to 200 ns/division. The probes
`should be connected to the 5V pin and the RESET pin. Now
`enable the 5V signal from the pulse generator and trigger
`the signal. Be aware that when the signal is enabled, there
`is high frequency noise present, and putting a 120 pF ca-
`pacitor between the 5V pin and ground suppresses some of
`the noise. Response time is measured by taking the 5V
`under-voltage threshold on the 5V signal
`to the point
`
`where RESET goes low. Figure2 shows a scope photo of
`5V under-voltage waveforms. It is taken with a signal going
`from 5V to 4.25V at the 5V pin.
`
`To measure the 100 ms RESET delay, change the scope to
`50 ms/division and trigger the 5V signal again. RESET
`should stay low for 100 ms after the 5V is recovered and
`within window.
`
`Other over-voltages and under-voltages can be measured
`by changing the pulse generator to different voltage steps.
`Putting a 120 pF capacitor between the 3.3V pin and ground
`is recommended in evaluating 3.3V signal.
`
`To measure power-failure response time, set the pulse gen-
`erator from 5V to 3V with fall time of the pulse 3 ns and
`connect it to the 5V pin. RESET should go low within 90 ns
`of power failure. Figure 3 shows a scope photo of power
`failure waveforms. It is taken with a signal going from 5V to
`3V at the 5V pin.
`
`TL/H/12846 – 21
`FIGURE 2. 5V Under-Voltage Waveforms
`
`TL/H/12846 – 22
`FIGURE 3. Power Failure Waveforms
`
`9
`
`http://www.national.com
`
`Petitioners
`Ex. 1063, p. 9
`
`
`
`Typical Application Circuits
`
`On Mother Board
`
`On Mother Board with Capacitor as a Back-up Power Supply
`
`TL/H/12846 – 17
`
`TL/H/12846 – 26
`
`On Add-In Cards
`
`TL/H/12846 – 18
`
`http://www.national.com
`
`10
`
`Petitioners
`Ex. 1063, p. 10
`
`
`
`11
`
`http://www.national.com
`
`Petitioners
`Ex. 1063, p. 11
`
`
`
`Physical Dimensions inches (millimeters) unless otherwise noted
`
`LMC6953PCILocalBusPowerSupervisor
`
`8-Pin Small Outline Package
`Order Number LMC6953CM or LMC6953CMX
`NS Package Number M08A
`
`LIFE SUPPORT POLICY
`
`NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
`DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL
`SEMICONDUCTOR CORPORATION. As used herein:
`
`1. Life support devices or systems are devices or
`systems which, (a) are intended for surgical
`implant
`into the body, or (b) support or sustain life, and whose
`failure to perform, when properly used in accordance
`with instructions for use provided in the labeling, can
`be reasonably expected to result in a significant injury
`to the user.
`
`is any component of a life
`2. A critical component
`support device or system whose failure to perform can
`be reasonably expected to cause the failure of the life
`support device or system, or to affect its safety or
`effectiveness.
`
`National Semiconductor
`Corporation
`1111 West Bardin Road
`Arlington, TX 76017
`Tel: 1(800) 272-9959
`Fax: 1(800) 737-7018
`
`http://www.national.com
`
`National Semiconductor
`Europe
`
`Fax: a49 (0) 180-530 85 86
`Email: europe.support ꉆ nsc.com
`Deutsch Tel: a49 (0) 180-530 85 85
`English Tel: a49 (0) 180-532 78 32
`Fran3ais Tel: a49 (0) 180-532 93 58
`Italiano Tel: a49 (0) 180-534 16 80
`
`National Semiconductor
`Hong Kong Ltd.
`13th Floor, Straight Block,
`Ocean Centre, 5 Canton Rd.
`Tsimshatsui, Kowloon
`Hong Kong
`Tel: (852) 2737-1600
`Fax: (852) 2736-9960
`
`National Semiconductor
`Japan Ltd.
`Tel: 81-043-299-2308
`Fax: 81-043-299-2408
`
`National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.
`
`Petitioners
`Ex. 1063, p. 12
`
`