LTC2953 Push Button On/Off Controller with Voltage Monitoring DESCRIPT

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LTC2953 Push Button On/Off Controller with Voltage Monitoring DESCRIPT

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LTC2953 Push Button On/Off Controller with Voltage Monitoring DESCRIPTION
LTC2953 push button On/Off controller that manages system power push button interface. enable output toggles system power while interrupt output provides debounced push button status. interrupt output used menu driven applications request system power down. LTC2953 also features input output power supply monitors. uncommitted power fail comparator provides real time input monitor information, while de-glitched under voltage lockout comparator gracefully initiates system power down. under voltage lockout comparator prevents system from powering from power supply. adjustable supply monitor input compared against accurate internal 0.5V reference. reset output remains until supply monitor input been compliance 200ms. LTC2953 operates over wide 2.7V input voltage range draws only current. versions part accommodate either positive negative enable polarities.
Lare registered trademarks Linear Technology Corporation. other trademarks property their respective owners.
Wide Operating Voltage Range: 2.7V Push Button Control System Power Supply Current: Power Fail Comparator Generates Warning UVLO Comparator Gracefully Latches Power Adjustable Supply Monitor with 200ms Reset Adjustable Power Down Timer Leakage Output (LTC2953-1) Allows DC/DC Converter Control High Voltage Output (LTC2953-2) Allows Circuit Breaker Control Simple Interface Allows Orderly System Power Power Down ±1.5% Threshold Tolerances ±10kV Input 12-Pin
APPLICATIONS
Push Button Power Path Control Battery Power Supervisor Portable Instrumentation, Blade Servers Desktop Notebook Computers
TYPICAL APPLICATION
VOUT DC/DC SHDN 100k 100k 100k 100k KILL tPDT SECONDS
2953f
2953 TA01
Push Button On/Off Control with Interrupt
3.3V
TURN PULSE SHORT INTERRUPT PULSE LONG TURN PULSE
8.4V 2150k UVLO
100k
23.2k 196k
LTC2953-1
499k
TURNS
STAYS
TURNS
ON/OFF
GPIO SYSTEM LOGIC KILL
INTERRUPT INTERRUPT
2954 TD01b
LTC2953 ABSOLUTE MAXIMUM RATINGS
(Note
CONFIGURATION
VIEW KILL EN/EN UVLO
Supply Voltage (VIN) -0.3V Input Voltages PFI, UVLO. -0.3V KILL -0.3V PDT. -0.3V 2.7V Output Voltages EN/EN, -0.3V RST, -0.3V Operating Temperature Range LTC2953C 70°C LTC2953I -40°C 85°C Storage Temperature Range. -65°C 125°C
PACKAGE 12-LEAD (3mm 3mm) PLASTIC TJMAX 125°C, 43°C/W EXPOSED (PIN GROUND CONNECTION OPTIONAL
ORDER INFORMATION
LEAD FREE FINISH LTC2953CDD-1#PBF LTC2953CDD-2#PBF LTC2953IDD-1#PBF LTC2953IDD-2#PBF TAPE REEL LTC2953CDD-1#TRPBF LTC2953CDD-2#TRPBF LTC2953IDD-1#TRPBF LTC2953IDD-2#TRPBF PART MARKING* LCWT LCQT LCWT LCQT PACKAGE DESCRIPTION 12-Lead (3mm 3mm) Plastic 12-Lead (3mm 3mm) Plastic 12-Lead (3mm 3mm) Plastic 12-Lead (3mm 3mm) Plastic TEMPERATURE RANGE 70°C 70°C -40°C 85°C -40°C 85°C
Consult Marketing parts specified with wider operating temperature ranges. *The temperature grade identified label shipping container. Consult Marketing information non-standard lead based finish parts. more information lead free part marking, http://www.linear.com/leadfree/ more information tape reel specifications,
ELECTRICAL CHARACTERISTICS
SYMBOL Supply (VIN) VUVL VPB(MIN, MAX) Supply Voltage Range Supply Current Undervoltage Lockout Operating Voltage Range Input Current PARAMETER
denotes specifications which apply over full operating temperature range, otherwise specifications 25°C. 2.7V 27V, unless otherwise noted (Note
CONDITIONS Steady State Operation 2.7V Falling Single-Ended 2.5V 0.6V Falling
UNITS
Push Button, Enable (PB, EN/EN)
VPB(VTH) VPB(VOC)
Input Threshold Open Circuit Voltage
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LTC2953 ELECTRICAL CHARACTERISTICS
SYMBOL IEN(LKG) VEN(VOL) tEN, Lock tDB, IPDT(PU) IPDT(PD) tDB, tPD, tPDT tINT, tINT, VKILL(TH) VKILL(HYST) KILL(PW) tKILL(PD) tKILL, BLANK IKILL(LKG) IINT(LKG) VINT(VOL) VPFI(TH) VUVLO(TH) VM(TH) VPFI(HYST) VUVLO(HYST) VPFO(VOL) VRST(VOL) PARAMETER EN/EN Leakage Current EN/EN Voltage Output EN/EN Lock Time (Note Turn Debounce Time Pull Current Pull Down Current Turn Interrupt Debounce Time Internal Power Down Delay Time (Note Additional Adjustable Power Down Delay Time Minimum Pulse Width Maximum Pulse Width KILL Input Threshold Voltage KILL Input Threshold Hysteresis KILL Minimum Pulse Width KILL Propagation Delay KILL Turn Blanking (Note KILL Leakage Current Leakage Current Output Voltage Input Threshold Voltage UVLO Input Threshold Voltage Adjustable Reset Threshold PFI-UVLO Threshold Mismatch Input Hysteresis UVLO Input Hysteresis Output Voltage Output Voltage IPFO 500A KILL Falling Enable Released KILL Low, Enable Asserted Enable Released VKILL 0.6V VINT IINT Falling Falling Falling/Rising
denotes specifications which apply over full operating temperature range, otherwise specifications 25°C. 2.7V 27V, unless otherwise noted (Note
CONDITIONS VEN/ Sink Current VEN/ 40V, Sink Current IEN/ 500A Enable Released Enable Asserted Falling Enable Asserted VPDT VPDT 1.3V UVLO Falling Falling UVLO Falling Enable Released Open CPDT 1500pF Asserted Released CPDT 1500pF, Asserted Released KILL Falling
±0.1
UNITS
0.11 -2.4 0.57 11.5 43.5
-3.6 13.5 54.5 0.63
On/Off Timing Pins (PB, UVLO, PDT, INT)
Handshake Pins (KILL, INT)
±0.1 ±0.1
0.11 0.11 0.11
Power Fail Voltage Monitor Pins (PFI, PFO, UVLO, RST)
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LTC2953 ELECTRICAL CHARACTERISTICS
SYMBOL IPFI(LKG) IPFO(LKG) IUVLO(LKG) IVM(LKG) IRST(LKG) tPFI tRST PARAMETER Leakage Current Leakage Current UVLO Leakage Current Input Leakage Current Output Leakage Current Delay Reset Timeout Period Under Voltage Detect Less Than VM(TH) More Than
denotes specifications which apply over full operating temperature range, otherwise specifications 25°C. 2.7V 27V, unless otherwise noted (Note
CONDITIONS VPFI 0.5V VPFI VPFO VPFO VUVLO 0.5V VUVLO 0.5V VRST
±0.1
UNITS
Note Stresses beyond those listed under Absolute Maximum Ratings cause permanent damage device. Exposure Absolute Maximum Rating condition extended periods affect device reliability lifetime. Note currents into pins positive; voltages referenced unless otherwise noted. Note Enable Lock time designed allow application properly power down such that next power sequence starts from consistent powered down configuration. ignored during this lock time. This time delay does include tDB,
Note manually force release EN/EN pin, either UVLO must held least tPD, (internal default power down timer) tPDT (adjustable placing external capacitor pin). Note KILL turn blanking timer period (tKILL, BLANK) waiting period immediately after enable output asserted. This blanking time allows sufficient time DC/DC converter perform power tasks. KILL, UVLO inputs ignored during this period. KILL remains this blanking period, enable output released, thus turning system power.
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LTC2953 TYPICAL PERFORMANCE CHARACTERISTICS
Supply Current Temperature
IVIN 3.3V IVIN tDB, (ms) 25°C
Supply Current Supply Voltage
Turn Debounce Time (tDB,
25°C
2.7V
TEMPERATURE (°C)
2953
2953
2953
Turn Interrupt Debounce Time (tDB, OFF)
25°C tPD,MIN tPDT (ms) 1000 tDB, (ms) 10000
Forced Power Down Delay Time (tPD, tPDT) External Capacitance
25°C 3.3V PULL-DOWN CURRENT -3.4
Pull-Down Current Temperature
3.3V
-3.2
-3.0
-2.8
2953
EXTERNAL CAPACITANCE (nF)
1000
-2.6
TEMPERATURE (°C)
2953
Pull-Up Current Temperature
-300 3.3V -250 -200 -150 -100
Current Voltage
25°C 3.3V
Voltage External Resistance Ground
3.3V
PULL-UP CURRENT
100°C VOLTAGE (mV) CURRENT VOLTAGE
-45°C 25°C
TEMPERATURE (°C)
2953
EXTERNAL RESISTANCE GROUND
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LTC2953 TYPICAL PERFORMANCE CHARACTERISTICS
(LTC2953-1) Voltage
25°C 100k PULL-UP FROM
(LTC2953-2) Voltage
25°C 100k PULL-UP FROM
Voltage
25°C 100k PULL-UP FROM
2953
2953
Voltage
25°C 100k PULL-UP FROM RST, (mV)
RST, Current Load
25°C 3.3V
RST, CURRENT LOAD (mA)
2953
2953
Threshold Voltage (VM, PFI, UVLO) Temperature
3.3V
EN/EN, Current Load
25°C 3.3V EN/EN, (mV)
THRESHOLD (mV)
TEMPERATURE (°C)
2953
EN/EN, CURRENT LOAD (mA)
2953
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LTC2953 FUNCTIONS
(Pin Ground. (Pin Voltage Monitor Input. Input accurate comparator with 0.5V threshold. controls state output independent UVLO status. voltage below 0.5V this asserts low. Connect unused. KILL (Pin KILL Input. Forcing KILL releases enable output. During system turn this blanked 512ms internal timer (tKILL, BLANK) allow system pull KILL high. This accurate 0.6V threshold used power kill voltage monitor. voltage above threshold unused. (Pin Power Down Time Input. capacitor ground determines additional time (6.4 seconds/F) that UVLO must held before releasing EN/EN outputs. this left open, power down delay time defaults 64ms. (Pin Push Button Input. Connecting ground through momentary switch provides On/Off control EN/EN outputs. internal 100k pull-up resistor connects internal 1.9V bias voltage. rugged input withstands ±10kV pulled externally without consuming extra current. Voltages below ground will damage pin. (Pin Power Supply Input: 2.7V 27V. UVLO (Pin UVLO Comparator Input. When UVLO drops below falling threshold (0.5V) more than 32ms, LTC2953 asserts low, thereby requesting system power down. UVLO remains below falling threshold (0.5V) longer than adjustable power down delay, enable output released. Additionally, UVLO provides lock feature that prevents user from asserting enable output when UVLO falls below threshold. Connect unused. (Pin Power Fail Comparator Input. Input accurate comparator with 0.5V falling threshold hysteresis. controls state output independent UVLO status. Connect unused. (Pin Power Fail Output. This high voltage open drain pull-down. pulls when below 0.5V. Open circuit when unused. (Pin 10): Reset Output. This open drain pull-down. Pulls when input below 0.5V held 200ms after input above 0.5V. Open circuit when unused. (LTC2953-1, 11): Open Drain Enable Output. This output intended enable system power. asserted high after valid turn event (tDB, ON). released KILL driven high within 512ms initial valid power turn event, KILL driven during normal operation, UVLO asserted held tPD, tPDT) during normal operation. (LTC2953-2, 11): Open Drain Enable Output. This output intended enable system power. asserted after valid turn event (tDB, ON). released high KILL driven high within 512ms initial valid power turn-on event, KILL driven during normal operation, UVLO asserted held tPD, tPDT) during normal operation. (Pin 12): Open Drain Interrupt Output. After turn event detected (tDB, OFF) from UVLO, LTC2953 interrupts system asserting low. would perform power down housekeeping tasks then assert KILL low, thus releasing enable output. pulse width minimum 32ms stays long asserted. asserted longer than tPD, tPDT, however, EN/EN outputs immediately released. Open circuit when unused. Exposed (Pin 13): Exposed left open connected ground.
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LTC2953 BLOCK DIAGRAM
2.7V REGULATOR 1.5k ZENER 2.4V
0.5V
DELAY
2.4V
100k DEBOUNCE FILTER 0.8V LOGIC 0.6V KILL
UVLO
0.5V
DEBOUNCE FILTER
OSCILLATOR INDICATES HIGH VOLTAGE
2953
0.5V
(-1) (-2)
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LTC2953 TIMING DIAGRAMS
tDB, UVLO KILL IGNORED tKILL, BLANK
(LTC2953-1)
KILL
CARE
SYSTEM SETS KILL HIGH
2953 TD01
Figure Power Timing (UVLO 0.55V)
tDB,
UVLO IGNORED tPDT
tPD, tINT, UVLO
UVLO IGNORED
(LTC2953-1)
ENABLE DOES SWITCH
2953 TD02
Figure Interrupt Pulse: tDB,OFF (tPD, tPDT) (Enable Remains Active)
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LTC2953 TIMING DIAGRAMS
UVLO tDB, UVLO IGNORED tPDT
tPD, tINT,
IGNORED
(LTC2953-1)
ENABLE DOES SWITCH
2953 TD03
Figure UVLO Interrupt Pulse: UVLO tDB,OFF (tPD, tPDT) (Enable Remains Active)
tDB,
IGNORED
CYCLES tPD, tINT, (LTC2953-1) tPDT
UVLO
UVLO IGNORED
2953 TD04
Figure Push Button Power Down Timing: Pressed Held (tPD, tPDT)
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LTC2953 TIMING DIAGRAMS
UVLO UVLO IGNORED tDB, CYCLES tPD, tINT, (LTC2953-1) tPDT
IGNORED
2953 TD05
Figure UVLO Power Down Timing: UVLO (tPD, tPDT)
0.5V
0.5V
0.5V
0.504V
tRST
2953 TD06
tPFI
tPFI
2953 TD07
Figure Voltage Monitor Reset Timing
Figure Power Fail Comparator Timing
0.6V KILL
tKILL(PW)
0.63V
(LTC2953-1)
tKILL(PD)
2953 TD08
Figure KILL Minimum Pulse Width Propagation Delay
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LTC2953 OPERATION
LTC2953 push button On/Off controller with dual function input output supply monitors. part contains circuitry needed debounce push button input provides simple handshake protocol reliable toggling system power. LTC2953 operates over wide 2.7V input voltage range draws only current. LTC2953 features dual function supply monitoring: power fail comparator generates early warning under voltage lock-out comparator initiates controlled system power down. Push Button Controller push button input controls enable interrupt outputs. enable output toggles system power while interrupt output provides debounced push button status. interrupt output used menu driven applications request system power down. power kill input allows microprocessor other logic release enable output, thus immediately powering down system. assert enable output (turn system power), press push button (PB) input hold least 32ms. Figure Once system power been enabled, user request system power down again pressing push button least 32ms releasing before timer counts cycles. LTC2953 then asserts interrupt output subsequently sets KILL input turn system power. Note that UVLO input also assert interrupt output. Figure Figure Dual Function Supply Monitors section. event that does respond interrupt request, user force release enable output pressing holding down push button UVLO) until timer times out. Figure Figure Dual Function Supply Monitors uncommitted power fail comparator provides real time supply threshold information. power fail input (PFI) compared against accurate internal 0.5V reference comparison result passed directly power fail output (PFO) pin. operation power fail comparator de-coupled from other functionality always active. Figure under voltage lockout comparator provides user with another method initiate controlled system power down. UVLO voltage falls below falling threshold (0.5V) longer than 32ms, interrupt output asserted minimum 32ms. UVLO voltage remains below threshold (0.5V) additional time given external capacitor, then enable automatically released (thus powering down system). Figure Figure This comparator also serves under voltage lockout. system power (enable released) UVLO 0.5V, UVLO comparator prevents push button from turning system power (asserting enable output). Voltage Supervisor with 200ms Reset LTC2953 provides single adjustable supply monitor with nominal 200ms reset delay. When input voltage drops below 0.5V, output pulled low. remains 200ms after input risen above 0.5V. input 0.5V threshold guaranteed accuracy ±1.5% over temperature process. operation supply monitor de-coupled from other functionality always active. Figure
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LTC2953 APPLICATIONS INFORMATION
PUSH BUTTON CONTROL Power Sequence enable system power, push button input (PB) must held continuously 32ms (tDB, ON). Once enable output (EN/EN) asserted, LTC2953 starts 512ms internal timer (tKILL, BLANK). KILL input must driven high within this 512ms window. This blanking time represents maximum time allowed system power initialize circuits driving KILL input. KILL remains blanking period, enable output released (see "Aborted Power Sequence" section). Figure shows normal power sequence.
tDB, UVLO KILL IGNORED tKILL, BLANK
Short Pulse Interrupt interrupt either UVLO must least 32ms (tDB, OFF). This signals either that user pressed push button that supply running low. would then perform power down housekeeping tasks assert KILL when done. This turn releases enable output, thus shutting system power. Figure Note that either UVLO control power down sequence, both same time. example, both UVLO high user presses push button, will active UVLO will ignored until released power down sequence complete. Forced Power Sequence LTC2953 provides failsafe feature that allows user manually force system power down. cases when fails respond interrupt signal, user force power down pressing holding either push button UVLO inputs low. length time required release enable output given fixed internal 64ms delay (tPD, Min) plus adjustable power down timer delay (tPDT). adjustable delay placing external capacitor pin. following equation calculate capacitance desired extra delay. CPDT external capacitor: CPDT 1.56E-4 [F/ms] (tPDT 1ms) Figure
(LTC2953-1)
KILL
CARE
SYSTEM SETS KILL HIGH
2953
Figure Power Timing (UVLO 0.55V)
Note that only push button input enable system power. LTC2953 provides enable output polarities allow DC/DC converter control (LTC2953-1) external power PFET control (LTC2953-2).
UVLO SHORT PULSE tDB,
UVLO
LONG PULSE
tPD, (LTC2953-1)
CYCLES tINT,
KILL
CARE
SYSTEM SETS KILL
tPDT
(LTC2953-1)
SYSTEM POWER
2953
2953
Figure Power Interrupt Timing
Figure Forced Power Timing with Adjustable Delay (See Figure More Details)
2953f
LTC2953 APPLICATIONS INFORMATION
tDB, UVLO KILL IGNORED tKILL, BLANK KILL SYSTEM SETS KILL
(LTC2953-1)
TURN ABORTED (LTC2953-1) SYSTEM FAILS KILL HIGH
2953
SYSTEM POWER
2953
KILL
tKILL(PD)
Figure Aborted Power Sequence, KILL Remaining Aborts Power Sequence
Figure Turns System Power
Aborted Power Sequence LTC2953 provides internal 512ms timer detect when system fails power properly. power sequence begins debouncing input. After enable subsequently asserted, LTC2953 starts 512ms blanking timer (tKILL, BLANK). KILL input driven high within this 512ms time window, enable immediately released, thus turning system power. This failsafe feature prevents user from turning device when circuits driving KILL input respond within 512ms after enable been asserted. Figure Turns System Power During Normal Operation Once system powered operating normally, turn power asserting KILL input low. Figure DUAL FUNCTION BATTERY SUPERVISOR LTC2953 provides comparators battery monitoring: uncommitted power fail comparator latched battery comparator with interrupt. application shown Figure monitors cell Li-Ion battery stack.
Power Fail Comparator This comparator provides real time threshold information serve first warning decaying battery supply. output driven when input voltage drops below falling threshold (0.5V) high impedance when rises above rising threshold (0.504V). leakage, high voltage input (10nA, maximum) allows large valued external resistors, which lowers system current consumption. UVLO Comparator under voltage lockout comparator performs three functions: interrupts when supply glitch drives UVLO voltage below falling threshold (0.5V) longer than 32ms, followed forces system power when UVLO voltage falls below falling threshold (0.5V) tPD, tPDT, locks enable (prevents system power output UVLO voltage below falling threshold (0.5V) during system power Figures 15B. leakage (10nA, maximum), high voltage UVLO input allows large valued external resistors. Figure
2953f
LTC2953 APPLICATIONS INFORMATION
8.4V LTC2953-1
DEBOUNCE 2150k UVLO 5.4V UVLO COMPARATOR
offset architecture comparators, UVLO thresholds close ±5mV apart. trip thresholds circuit Figure 6.04V 5.40V power fail battery (UVLO) comparators, respectively. Push Button Lockout LTC2953 provides push button lock feature that prevents user from turning system with dead battery. push button input ignored when UVLO input voltage less than falling threshold (0.5V). Figure 15B.
UVLO 0.5V SUPPLY GLITCH 0.55V
50mV 0.5V
23.2k
DEBOUNCE DELAY
6.04V 196k
0.5V
POWER FAIL COMPARATOR
2953
tDB,
2953 F15a
tINT,
Figure Dual Function Battery Comparators
Which Input Initiated Power Down: UVLO? circuit Figure determines whether power down initiated user pressing push button battery drooping low. both outputs low, then battery condition initiated power down. UVLO Thresholds circuit depicted Figure uses resistive divider network both power fail battery comparators. power fail comparator trips higher battery voltage than battery comparator, thus providing battery warning before power down sequence initiated.
UVLO
Figure 15A. Supply Glitch Generates Interrupt
0.5V tDB, SUPPLY CONDITION
tPD, tPDT SUPPLY LOCKS ENABLE
2953 F15b
Figure 15B. Supply Initiates System Power Down Locks Enable
2953f
LTC2953 TYPICAL APPLICATIONS
Push Button Buffer circuit Figure shows power fail comparator sensing push button input. output toggles each time push button crosses 0.5V. This application provides early warning push button activity. Disconnect Input Resistive Divider Save Power order prolong battery life when system power been turned off, LTC2953-2 power fail comparator used disconnect external battery monitor resistive divider. circuit Figure connects bottom resistive divider.
8.4V 1070k UVLO ON/OFF
2953
0.5V
100k
100k
110k
0.5V
Figure Push Button Buffer
Power Path Switching high voltage output LTC2953-2 designed switch On/Off external power PFET. This allows user connect/disconnect power supply battery) load toggling pin. Figure shows LTC2953-2 wall adapter application.
100k ON/OFF LTC2953-2 100k LOAD
LTC2953-2
2953
Figure Disconnect Input Resistive Divider Save Power
When user presses push button turn system power low), output power fail comparator asserts low. battery external resistive divider thus enabled monitor input supply. voltage UVLO input falls less than 0.5V, system power down sequence initiated. Note that drop across internal NFET typically less than 0.2mV when UVLO voltage 0.5V. Once system power been turned high), external resistive divider disconnected thus consumes zero current.
2953
Figure Power Path Switching
2953f
LTC2953 TYPICAL APPLICATIONS
Push Button Controlled Reset circuit Figure used keep reset 200ms after push button enabled system power. After system power stabilized, voltage monitor input continues monitor supply load end.
LOAD 3.3V 100k LTC2953-2 ON/OFF
2953
Push Button Controlled Supply Sequencing circuit Figure uses LTC2953-2 sequence supply rails. Power sequencing begins pressing push button 32ms. This asserts output low, which turns supply. 200ms after reaches final value (2.66V), supply enabled. When voltage reaches final value (2V), supply enabled. Note that there internal delay from input output enabled same time rises above power down supply sequence begins when these inputs asserted: UVLO KILL When pulls VIN, disconnects first. When decays 2.66V, immediately disabled (there 200ms delay from during power down). When decays immediately disabled. Figure timing diagram.
200ms 32ms POWER POWER
100k 499k 100k 510k
0.5V
Figure Push Button Controlled Reset
3.3V 100k LTC2953-2 ON/OFF 2.66V 100k 866k 200k 3.3V
200ms
2953
DC/DC 2.01V 200k SHDN VOUT 604k 2.5V
Figure Push Button Controlled Supply Sequence Timing
DC/DC
2953
SHDN VOUT
1.8V
Figure Push Button Controlled Supply Sequencing
2953f
LTC2953 TYPICAL APPLICATIONS
Dual Supply Monitor with Reset circuit Figure monitors supplies provides reset. When either input voltage falls below threshold (0.5V), output asserted low. remains 200ms after both inputs rise above 0.5V. leakage output allows large valued external resistors.
LTC2953
Operation with Supply Transients over application circuit Figure operates from nominal supply, withstand supply transients high 40V. high voltage output LTC2953-2 absolute maximum rating 50V, which makes suitable driving gate external power PFET. external Zener diode (Z1) current limiting resistor (RZ) protect supply LTC2953-2. Note that under normal operation, external Zener diode does conduct current. voltage drop across should kept below should have breakdown voltage smaller than PFET's gate-to-source breakdown voltage.
NOMINAL, TRANSIENTS FDS4685 Si2319DS NDS9407 100k LTC2953-2 ON/OFF
0.5V
0.5V
2953
BZX84C30
BZX84C10 100k
Figure Dual Supply Monitor with Reset
Reverse Battery Protection protect LTC2953 from reverse battery connection, place resistor (R8) series with pin. Figure
2953
Figure Operation with Supply Transients
Power Path Controller with Battery Detect
8.4V ON/OFF LTC2953-1 910k SHDN
2953
VOUT LT1761
application Figure uses push button completely disconnect load from battery. battery voltage falls below user specified threshold, push button prevented from turning system power (asserting enable output).
Figure Reverse Battery Protection Using
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LTC2953 PACKAGE DESCRIPTION
Package 12-Lead Plastic (3mm 3mm)
(Reference 05-08-1725
0.70 ±0.05
3.50 ±0.05 2.10 ±0.05
2.38 ±0.05 1.65 ±0.05 PACKAGE OUTLINE
0.25 0.05 0.45 2.25 RECOMMENDED SOLDER PITCH DIMENSIONS APPLY SOLDER MASK AREAS THAT SOLDERED
0.115
0.40 0.10
3.00 ±0.10 SIDES) MARK (SEE NOTE
2.38 ±0.10 1.65 0.10 NOTCH 0.20 0.25 CHAMFER
0.200 0.75 ±0.05 2.25 0.00 0.05
0.23 0.05 0.45
(DD12) 0106
BOTTOM VIEW-EXPOSED NOTE: DRAWING JEDEC PACKAGE OUTLINE DRAWING SCALE DIMENSIONS MILLIMETERS DIMENSIONS EXPOSED BOTTOM PACKAGE INCLUDE MOLD FLASH. MOLD FLASH, PRESENT, SHALL EXCEED 0.15mm SIDE EXPOSED BARS SHALL SOLDER PLATED SHADED AREA ONLY REFERENCE LOCATION BOTTOM PACKAGE
2953f
Information furnished Linear Technology Corporation believed accurate reliable. However, responsibility assumed use. Linear Technology Corporation makes representation that interconnection circuits described herein will infringe existing patent rights.
LTC2953 TYPICAL APPLICATION
FDN360P VOUT
8.4V
2150k UVLO 23.2k 196k
100k
100k
DC/DC SHDN
3.3V
LTC2953-2
499k 100k KILL
100k 100k 100k SYSTEM LOGIC KILL
2953
ON/OFF
tPDT SECONDS
Figure PowerPath Controller with Battery Detect
RELATED PARTS
PART NUMBER LTC2900 LTC2904/LTC2905 LTC2909 LTC2912 LTC2950/LTC2951 LTC2952 LTC2954 LTC4055 LTC4411 LTC4412HV DESCRIPTION Programmable Quad Supply Monitor Pin-Programmable Dual Supply Monitors COMMENTS Adjustable Reset, 10-Lead MSOP Packages Adjustable Reset Tolerance, 8-Lead SOT-23 Packages
Precision Tripple/Dual Input Negative 6.5V Shunt Regulator High Voltage Operation Voltage Monitor Single UV/OV Monitor Push Button On/Off Controllers Push Button Power Path Controller with Supervisor Push Button On/Off Controller with Interrupt Power Controller Li-Ion Charger 2.6A Loss Ideal Diode ThinSOT PowerPath Controller ThinSOT DFN, 8-Pin ThinSOT Packages High Voltage, Power Push Button Controller Automatic Loss Switchover Between Sources Allow Controlled Software System Shutdown Automatic Switchover, Charges 1-Cell Li-Ion Batteries External MOSFET, Automatic Switching Between Sources Efficient Diode-ORing, Automatic Switching Between Sources,
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Linear Technology Corporation
(408) 432-1900 FAX: (408) 434-0507
0607 PRINTED
1630 McCarthy Blvd., Milpitas, 95035-7417
www.linear.com
LINEAR TECHNOLOGY CORPORATION 2007

LTC2953 Push Button On/Off Controller with Voltage Monitoring DESCRIPT

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