LTC2952.pdf 데이터시트 (총 30 페이지) - 파일 다운로드 LTC2952 데이타시트 다운로드

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FEATURES
n Pushbutton On/Off Control
n Automatic Low Loss Switchover Between DC
Sources
n Wide Operating Voltage Range: 2.7V to 28V
n Low 25μA Shutdown Current
n Guaranteed Threshold Accuracy: ±1.5% of
Monitored Voltage Over Temperature
n Adjustable Pushbutton On/Off Timers
n Simple Interface Allows Graceful μP Shutdown
n Extendable Housekeeping Wait Time Prior to
Shutdown
n 200ms Reset Delay and 1.6s Watchdog Timeout
n ±8kV HBM ESD on PB Input
n 20-pin TSSOP and QFN (4mm × 4mm) Packages
APPLICATIONS
n Desktop and Notebook Computers
n Portable Instrumentations
n Cell Phones, PDA and Handheld Computers
n Servers and Computer Peripherals
n Battery Backup Systems
LTC2952
Pushbutton PowerPath
Controller with Supervisor
DESCRIPTION
The LTC®2952 is a power management device that features
three main functions: pushbutton on/off control of system
power, ideal diode PowerPath™ controllers and system
monitoring. The LTC2952’s pushbutton input, which pro-
vides on/off control of system power, has independently
adjustable ON and OFF debounce times. A simple micro-
processor interface involving an interrupt signal allows
for proper system housekeeping prior to power-down.
The ideal diode PowerPath controllers provide automatic
low loss switchover between two DC sources by regulating
two external P-channel MOSFETs to have a small 20mV
forward drop.
High reliability systems may utilize the LTC2952’s monitor-
ing features to ensure system integrity. These features in-
clude: power-fail, voltage monitoring and μP watchdog.
The LTC2952 operates over a wide operating voltage range
to accommodate a large variety of input power supplies. The
part’s combination of low 20mV external MOSFET regula-
tion and very low standby current matches battery powered
and power conscious application requirements.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
PowerPath and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks
are the property of their respective owners.
TYPICAL APPLICATION
Pushbutton Controller with Automatic Switchover Between Adapter and Battery
ADAPTER, 3V TO 25V
Si6993DQ
12V BATTERY
Si6993DQ
G1
G2
VS
PFI
VIN VOUT
LT1767-2.5
SHDN
511k
100k
V1 EN **
LTC2952
V2 VM
RST
M1 G1STAT
M2 PFO
INT
PB KILL
365k
100k
2.5V
1k
1k
1k
D2
D3
D1
ONT GND OFFT WDE
*22nF
*68nF
*OPTIONAL
**SHDN INTERNALLY PULLED UP BY THE LT1767-2.5
10k
μP
2952 TA01
Ideal Diode vs Schottky Diode
Forward Voltage Drop
1
CONSTANT
RON
IDEAL
DIODE
CONSTANT
VOLTAGE
SCHOTTKY
DIODE
0
0.02
FORWARD VOLTAGE (V)
0.50
2952 TA01b
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LTC2952
ABSOLUTE MAXIMUM RATINGS (Notes 1, 2)
Supply Voltages
V1, V2, VS.............................................. –0.3V to 30V
Input Voltages
PB.................................... –6V to MAX (V1, V2, VS) V
ONT, OFFT ............................................... –0.3V to 3V
M1, M2, PFI, VM, WDE, KILL................... –0.3V to 7V
Output Voltages
G1, G2, EN .................... –0.3V to MAX (V1, V2, VS) V
G1STAT, PFO, RST, INT............................ –0.3V to 7V
Input Currents
PB.......................................................–1mA to 100μA
Operating Temperature Range
LTC2952C ................................................ 0°C to 70°C
LTC2952I .............................................–40°C to 85°C
Storage Temperature Range .................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec)................... 300°C
PIN CONFIGURATION
M2 1
M1 2
KILL 3
VM 4
PFI 5
WDE
PB
RST
PFO
ONT
6
7
8
9
10
TOP VIEW
20 G1STAT
19 G1
18 V1
17 VS
16 V2
15 G2
14 EN
13 INT
12 GND
11 OFFT
F PACKAGE
20-LEAD PLASTIC TSSOP
TJMAX = 125°C, θJA = 90°C/W
TOP VIEW
20 19 18 17 16
VM 1
PFI 2
WDE 3
PB 4
RST 5
15 V1
14 VS
21 13 V2
12 G2
11 EN
6 7 8 9 10
UF PACKAGE
20-LEAD (4mm s 4mm) PLASTIC QFN
TJMAX = 125°C, θJA = 37°C/W
EXPOSED PAD (PIN 21), PCB GND CONNECTION OPTIONAL
ORDER INFORMATION
LEAD FREE FINISH
TAPE AND REEL
PART MARKING
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LTC2952CF#PBF
LTC2952CF#TRPBF
LTC2952CF
20-Lead Plastic TSSOP
0°C to 70°C
LTC2952IF#PBF
LTC2952IF#TRPBF
LTC2952IF
20-Lead Plastic TSSOP
–40°C to 85°C
LTC2952CUF#PBF
LTC2952CUF#TRPBF
2952
20-Lead 4mm × 4mm Plastic QFN
0°C to 70°C
LTC2952IUF#PBF
LTC2952IUF#TRPBF
2952
20-Lead 4mm × 4mm Plastic QFN
–40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
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LTC2952
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. V1 = V2 = VS = 2.7V to 28V unless otherwise noted. (Notes 2, 3)
SYMBOL
PARAMETER
CONDITIONS
MIN TYP MAX UNITS
VMAX
IIN_OFF
Operating Supply Voltage
Quiescent Supply Current Both Ideal
Diodes Switched Off
(M1 = Open, M2 = 0V)
V1, V2 or VS
V1 = 2.7V to 28V, V2 = 0V, VS = Open or
V2 = 2.7V to 28V, V1 = 0V, VS = Open.
Measured Current at V1 or V2.
l 2.7
28
l 24 60
V
μA
V1 = 2.7V to 28V, V2 = 3.5V, VS = Open.
Measured Current at V1.
l
5 15
μA
V1 = 2.7V to 28V, V2 = 3.5V, VS = Open.
Measured Current at V2.
l
23 50
μA
IIN_ON
Quiescent Supply Current Both Ideal
Diodes Switched On
(M1 = 0V, M2 = 0V)
V1 = VS = 2.7V to 28V, V2 = 0V or
l
V2 = VS = 2.7V to 28V, V1 = 0V. Measured
Combined Current at V1 and VS or V2 and VS.
65 170
μA
V2PREF_TH
V2 Preferential Threshold Voltage
(M1 = Open, M2 = 0V) (Note 4)
V1 = 28V, VS = Open.
l
3.3 3.8
V
ILEAK V1, V2 and VS Inter Pin Leakage to V1 = 28V, V2 = VS = 0V; V1 = VS = 0V,
the Highest Supply
V2 = 28V; V1 = V2 = 0V, VS = 28V
±3 μA
Ideal Diode Function
VFR
Ideal Diode PowerPath Forward
(V1 or V2) – VS, 2.7V ≤ (V1 or V2) ≤ 28V
l 10
20
35
mV
Regulation Voltage
VRTO
IG(SRC)
IG(SNK)
IG(FASTSRC)
IG(FASTSNK)
VG(ON)
VG(OFF)
tG(ON)
Ideal Diode PowerPath Fast Reverse (V1 or V2) – VS, 2.7V ≤ (V1 or V2) ≤ 28V
Turn-Off Threshold Voltage
IG ≤ –100μA/mV
l –20 –35 –64
Gate Turn-Off Current
G1 = G2 = VMAX – 1.5V
l –2
–5 –10
Gate Turn-On Current
V1 = V2 = 2.7V to 28V,
VS = (V1 or V2) – 40mV,
G1 = G2 = VMAX –1.5V.
l2
5 10
Gate Fast Turn-Off Source Current
V1 = V2 = 2.7V to 28V,
VS = (V1 or V2) + 0.1V,
G1 = G2 = VMAX –1.5V.
l –0.5 –2.5 –10
Gate Fast Turn-On Sink Current
V1 = V2 = 5V to 28V,
VS = (V1 or V2) – 0.1V,
G1 = G2 = VMAX – 1.5V.
l 0.3
0.7
2
Gate Clamp Voltage
IGX = 2μA, VX = 8V to 28V, VS = VX – 0.1V
l6
7
8
Measure VX – VGX
Gate Off Voltage
IGX = –2μA, VX = 2.7V to 28V, VS = VX + 0.1V l
Measure VMAX – VGX
0.2 0.4
Gate Turn-On Time
VG(OFF) to VGS ≤ –3V, CGATE = 1nF (Note 5),
V1 = V2 = 12V
0.1 2.5 10
mV
μA
μA
mA
mA
V
V
μs
tG(OFF)
Gate Turn-Off Time
Pushbutton Pin (PB)
VPB(VOC)
IPB
PB Open-Circuit Voltage
PB Input Current
VTH_PB
VHYS_PB
PB Input Threshold Voltage
PB Input Hysteresis
VG(ON) to VGS ≥ –1.5V, CGATE = 1nF (Note 6),
V1 = V2 = 12V
0.1 2.5 10
IPB = –1μA
VPB(VOC) < VPB ≤ 28V
0V ≤ VPB < VPB(VOC)
PB Falling From High to Low
l1 4 6
l
l –1
±1
–10 –25
l 0.65 0.77
0.8
l 10
25 150
μs
V
μA
μA
V
mV
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LTC2952
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. V1 = V2 = VS = 2.7V TO 28V unless otherwise noted. (Notes 2, 3)
SYMBOL
PARAMETER
CONDITIONS
MIN TYP MAX UNITS
Debounce Time Pins (ONT, OFFT)
IONT,OFFT
ONT/OFFT Pull-Up/Pull-Down Current VONT, VOFFT = 0V (Pull-Up), VONT, VOFFT = 1.5V l ±1.6 ±2.0 ±2.4
When Timer Is Active
(Pull-Down)
μA
tDB,ON/OFF
Internal Default On-Time/Off-Time tDB,ON: CONT = Open, Measured Time Between l 18 26 34
PB Low EN High, tDB,OFF: Measured Time
Between PB Low INT Low
ms
tONT,OFFT
Additional Adjustable Turn-On/Turn- CONT = 1500pF, COFFT = 1500pF
Off Time (Note 7)
Accurate Comparator Input Pins (VM, PFI, M1, M2, KILL)
l 10 15 20
ms
VTH_VM
VTH
VM Input Reset Threshold
PFI, M1, M2, KILL Input Threshold
Voltage
VHYS
IIN_LKG
PFI, M1, M2, KILL Input Hysteresis
VM, PFI, M2, KILL Input Current
IM1_SRC
M1 Input Pull-Up Current
VM1(VOC)
M1 Voltage Open-Circuit
IM1_LKG
M1 Input Leak Current
Watchdog/Extend Pin (WDE)
Both Falling and Rising
Falling
V = 0.5V
M1 = 1V
M1 = 6V
l 0.492
l 0.492
0.500
0.500
0.508
0.508
l5
15 25
l ±0.1
l –1.5
–3
–5
l1 4 6
l ±0.1
V
V
mV
μA
μA
V
μA
VWDE(H,TH)
Input High Threshold Voltage
VWDE(L,TH)
Input Low Threshold Voltage
IWDE(IN,HL)
High Low Input Current (Note 8)
IWDE(IN,HZ)
Hi-Z Input Current
Open-Drain Output Pins (G1STAT, INT, RST, PFO)
VWDE = 0.7V, 1.1V
l
l 0.3
l
l ±10
1.5 V
V
±25 μA
μA
IOUT_LKG
Leakage Current
VOL Voltage Output Low
High Voltage Open-Drain Output Pin (EN)
VPIN = 5V
IPIN = 1mA
l ±1 μA
l 0.4 V
IEN(LKG)
VEN(VOL)
EN Leakage Current
EN Voltage Output Low
Voltage Monitor/Watchdog Timing
VEN = 28V, EN Sink Current Off
IEN = 3mA
V1 = 1.2V and/or V2 = 1.2V, IEN = 100μA
l
l
l
±1
0.4
0.05 0.3
μA
V
V
tRST
tWDE
tWDE(PW MIN)
tVM(UV)
tPFI
Reset Timeout Period
Watchdog Timeout Period
Minimum Period Between
Consecutive Edges
VM Undervoltage Detect to RST
PFI Delay to PFO
VM Less Than VTH_VM by More Than 1%
PFI More or Less Than VPFI_TH by More
Than 1%
l 140 200 260
l 1.1 1.6 2.1
l 5 10
150
150
ms
s
μs
μs
μs
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LTC2952
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. V1 = V2 = VS = 2.7V to 28V unless otherwise noted. (Notes 2, 3)
SYMBOL
PARAMETER
CONDITIONS
MIN TYP MAX UNITS
μP Handshake Timing
tINT(MIN)
INT Minimum Pulse Width
tKILL(PW)
tKILL,ON BLANK
KILL Minimum Pulse Width
KILL On Blanking (Note 9)
tKILL, OFF WAIT
KILL Wait Time (Note 10)
Minimum Measured Time PB Rising to
INT Rising
l 10
50 250
Full Swing Pulse From 5V to 0V
l 150 500
KILL = 0V, Measured Time Between EN Rising l 270 400 530
EN Falling
BKeILtwL e=en1VI,NCTOFFFaTll=inOgPEN,
Measured
EN Falling
Time
l 270 400 530
μs
μs
ms
ms
tEN, LOCKOUT
Enable Lockout Time (Note 11)
Measured Time Between EN Falling EN
Rising
l 270 400 530
ms
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: The greatest of V1, V2 or VS is the internal supply voltage (VMAX).
Note 3: All currents into pins are positive; all voltages are referenced to
GND unless otherwise noted.
Note 4: V2PREF_TH is the minimum voltage level at which V2 becomes
the preferential source of quiescent current when both of the ideal diodes
are off.
Note 5: VS is stepped from (V1 or V2) + 0.2V to (V1 or V2) – 0.2V to
trigger the event. The gate voltages are initially VG(OFF).
Note 6: VS is stepped from VX – 0.2V to VX + 0.2V to trigger the event.
Gate voltages are initially clamped at VG(ON).
Note 7: The adjustable turn-on and turn-off timer period is the adjustable
debounce period following the Internal default-on and default-off timer
period, respectively.
Note 8: The input current to the three-state WDE pin are the pull-up
and the pull-down current when the pin is either set to 3.3V or GND,
respectively. In the open state, the maximum pull-up or pull-down leakage
current permissible is 10μA.
Note 9: The turn-on KILL blanking time is the waiting period immediately
following the EN pin switching high; at the end of this period the input
to the KILL needs to be high to indicate that the system has powered up
properly, otherwise the EN pin is immediately switched low.
Note 10: The KILL wait time during the power-down process is the wait
period immediately following a valid turn-off command until the EN pin
switches low.
Note 11: The enable lockout time is the minimum wait time between the
last falling edge and the next rising edge on the EN pin.
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