LTC2950-1/LTC Push Button On/Off Controller FEATURES DESCRIPTION APPLICATIONS TYPICAL APPLICATION

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1 LTC295-1/LTC295-2 Push Button On/Off Controller FEATURES Adjustable Push Button On/Off Timers Low Supply Current: 6μA Wide Operating Voltage Range: 2.7V to 26V Output (LTC295-1) Allows DC/DC Converter Control Output (LTC295-2) Allows Circuit Breaker Control Simple Interface Allows Graceful μp Shut Down High Input Voltage Pin with Internal Pull Up Resistor ±1kV ESD HBM on Input Accurate.6V Threshold on Comparator Input 8-Pin 3mm 2mm DFN and ThinSOT TM Packages APPLICATIONS Portable Instrumentation Meters Blade Servers Portable Customer Service PDA Desktop and Notebook Computers DESCRIPTION The LTC 295 is a micropower, wide input voltage range, push button ON/OFF controller. The part contains a push button input with independently programmable ON and OFF debounce times that control the toggling of an open drain enable output. The part also contains a simple microprocessor interface to allow for proper system housekeeping prior to power down. Under system fault conditions, an internal timer ensures proper power down. The LTC295 operates over a wide 2.7V to 26V input voltage range to accommodate a wide variety of input power supplies. Very low quiescent current (6μA typical) makes the LTC295 ideally suited for battery powered applications. Two versions of the part are available to accommodate either positive or negative enable polarities. The parts are available in either 8-lead 3mm 2mm DFN or ThinSOT packages. L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION 3V 26V V OUT Turn On Debounce DC/DC BUCK SHDN R1 1k 2V/DIV GND LTC295-1 ONT OFFT μp/μc C ONT *.33μF C OFFT *.33μF *OPTIONAL 295 TA1 1ms/DIV 295 TA1b 1

2 LTC295-1/LTC295-2 ABSOLUTE MAXIMUM RATINGS (Note 1) Supply Voltage ( )....3V to 33V Input Voltages... 6V to 33V ONT....3V to 2.7V OFFT....3V to 2.7V....3V to 7V Output Voltages....3V to 1V /....3V to 1V Operating Temperature Range LTC295-C1... C to 7 C LTC295-C2... C to 7 C LTC295-I C to 85 C LTC295-I C to 85 C Storage Temperature Range DFN Package C to 125 C TSOT C to 15 C Lead Temperature (Soldering, 1 sec)... 3 C PIN CONFIGURATION TOP VIEW GND ONT / OFFT 1 2 ONT 3 GND 4 TOP VIEW 8 7 OFFT 6 / 5 DDB8 PACKAGE 8-LEAD (3mm 2mm) PLASTIC DFN T JMAX = 125 C, θ JA = 165 C/W EXPOSED PAD (PIN 9) UNCONNECTED TS8 PACKAGE 8-LEAD PLASTIC TSOT-23 T JMAX = 125 C, θ JA = 14 C/W ORDER INFORMATION Lead Free Finish TAPE AND REEL (MINI) TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC295CDDB-1#TRMF LTC295CDDB-1#TRF LBKP 8-Lead Plastic DFN C to 7 C LTC295CDDB-2#TRMF LTC295CDDB-2#TRF LBNG 8-Lead Plastic DFN C to 7 C LTC295ICDDB-1#TRMF LTC295ICDDB-1#TRF LBKP 8-Lead Plastic DFN 4 C to 85 C LTC295ICDDB-2#TRMF LTC295ICDDB-2#TRF LBNG 8-Lead Plastic DFN 4 C to 85 C LTC295CTS8-1#TRMF LTC295CTS8-1#TRF LTBKN 8-Lead Plastic TSOT-23 C to 7 C LTC295CTS8-2#TRMF LTC295CTS8-2#TRF LTBNF 8-Lead Plastic TSOT-23 C to 7 C LTC295ITS8-1#TRMF LTC295ITS8-1#TRF LTBKN 8-Lead Plastic TSOT-23 4 C to 85 C LTC295ITS8-2#TRMF LTC295ITS8-2#TRF LTBNF 8-Lead Plastic TSOT-23 4 C to 85 C TRM = 5 pieces. *Temperature grades are identifi ed by a label on the shipping container. Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. Consult LTC Marketing for information on lead based fi nish parts. For more information on lead free part marking, go to: For more information on tape and reel specifi cations, go to: 2

3 ELECTRICAL CHARACTERISTICS LTC295-1/LTC295-2 The denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at T A = 25C. = 2.7V to 26.4V, unless otherwise noted. (Note 2) SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Supply Voltage Range Steady State Operation V I IN Supply Current System Power On, = 2.7V to 24V 6 12 μa V UVL Undervoltage Lockout Falling V V UVL(HYST) Undervoltage Lockout Hysteresis mv Push Button Pin () V (MIN, MAX) Voltage Range Single-Ended V I Input Current 2.5V < V < 26.4V V = 1V V =.6V V (VTH) Input Threshold Falling V V (VOC) Open Circuit Voltage I = 1μA V Debounce Timing Pins (ONT, OFFT) I ONT, OFFT(PU) ONT/OFFT Pull Up Current V ONT, OFFT = V μa I ONT, OFFT(PD) ONT/OFFT Pull Down Current V ONT, OFFT = 1.3V μa t DB, On Internal Turn On Debounce Time ONT Pin Float, Falling Enable Asserted ms t ONT Additional Adjustable Turn On Time C ONT = 15pF ms t DB, Off Internal Turn Off Debounce Time OFFT Pin Float, Falling Falling ms t OFFT Additional Adjustable Turn Off Time C OFFT = 15pF ms μp Handshake Pins (, ) I (LKG) Leakage Current T = 3V ±1 μa T(VOL) Output Voltage Low I = 3mA.11.4 V V (TH) Input Threshold Voltage Falling V V (HYST) Input Threshold Hysteresis mv I (LKG) Leakage Current V =.6V ±.1 μa t (PW) Minimum Pulse Width 3 μs t (PD) Propagation Delay Falling Enable Released 3 μs t, On Blank Turn On Blanking (Note 3) = Low, Enable Asserted Enable Released ms t, Off Delay Turn Off Delay (Note 4) = High, Asserted Enable Released ms t /, Lock Out / Lock Out Time (Note 5) Enable Released Enable Asserted ms I /(LKG) / Leakage Current V / = 1V, Sink Current Off ±.1 μa V /(VOL) / Voltage Output Low I / = 3mA.11.4 V ± μa μa μa 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: All currents into pins are positive; all voltages are referenced to GND unless otherwise noted. Note 3: The turn on blanking timer period is the waiting period immediately after the enable output is asserted. This blanking time allows sufficient time for the DC/DC converter and the μp to perform power up tasks. The and inputs are ignored during this period. If remains low at the end of this time period, the enable output is released, thus turning off system power. This time delay does not include t DB, ON or t ONT. Note 4: The turn off delay is the maximum delay from the initiation of a shutdown sequence ( falling), to the release of the enable output. If the input switches low at any time during this period, enable is released, thus turning off system power. This time is internally fixed at 124ms. This time delay does not include t DB, OFF or t OFFT. Note 5: The enable lock out time is designed to allow an application to properly power down such that the next power up sequence starts from a consistent powered down confi guration. is ignored during this lock out time. This time delay does not include t DB, ON or t ONT. 3

4 LTC295-1/LTC295-2 TYPICAL PERFORMANCE CHARACTERISTICS Supply Current vs Temperature Supply Current vs Supply Voltage Internal Default Turn On Debounce Time (t DB, ON ) vs 1 = 26.4V I VIN (μa) 6 4 = 3.3V = 2.7V I VIN (μa) 6 4 t DB, ON (ms) TEMPERATURE ( C) (V) (V) 295 G1 295 G2 295 G3 Turn On Debounce Time (t DB, ON + t ONT ) vs ONT External Capacitor ONT Pull-Down Current vs Temperature Internal Default Turn Off Debounce Time (t DB, OFF ) vs t DB, ON + t ONT (ms) = 3.3V ONT PULL-DOWN CURRT (μa) = 2.7V = 26.4V t DB, OFF (ms) ONT EXTERNAL CAPACITOR (nf) TEMPERATURE ( C) (V) G4 295 G5 295 G6 Turn Off Debounce Time (t DB, OFF + t OFFT ) vs OFFT External Capacitor OFFT Pull-Down Current vs Temperature Current vs Voltage t DB, OFF + t OFFT (ms) = 3.3V OFFT PULL-DOWN CURRT (μa) = 2.7V = 26.4V CURRT (μa) = 3.3V OFFT EXTERNAL CAPACITOR (nf) TEMPERATURE ( C) VOLTAGE (V) 295 G7 295 G8 295 G9 4

5 TYPICAL PERFORMANCE CHARACTERISTICS LTC295-1/LTC295-2 Voltage vs External Resistance to Ground / V OL vs Current Load 3 25 = 3.3V 5 4 = 3.3V VOLTAGE (mv) T A = 1 C T A = 45 C / VOLTAGE (mv) EXTERNAL RESISTANCE TO GROUND (kω) 295 G / CURRT LOAD (ma) 295 G (LTC295-1) Voltage vs 1k PULL-UP FROM TO 4 3 (LTC295-2) Voltage vs 1k PULL-UP FROM TO (V).6.4 (V) (V) (V) 295 G G13 5

6 LTC295-1/LTC295-2 PIN FUNCTIONS (TSOT-23/DFN) (Pin 1/Pin 4): Power Supply Input: 2.7V to 26.4V. (Pin 2/Pin 3): Push Button Input. Connecting to ground through a momentary switch provides on/off control via the / pin. An internal 1k pull-up resistor connects to an internal 1.9V bias voltage. The rugged input can be pulled up to 26.4V externally without consuming extra current. ONT (Pin 3/Pin 2): Additional Adjustable Turn On Time Input. Placing an external capacitor to ground determines the additional time (beyond the internal default 32ms) the pin must be held low before the enable output is asserted. Floating this pin results in a default turn on debounce time of 32ms. GND (Pin 4/Pin 1): Device Ground. (Pin 5/Pin 8): Open Drain Interrupt Output. After a push button turn-off event is detected, the LTC295 interrupts the system (μp) by bringing the pin low. Once the system finishes its power down and housekeeping tasks, it sets low, which in turn releases the enable output. If at the end of the power down timer (124ms) is still high, the enable output is released immediately. may optionally be tied to to release the enable output immediately after the turn-off event has been detected ( = low). (LTC295-1, Pin 6/Pin 7): Open Drain Enable Output. This pin is intended to enable system power. is asserted high after a valid turn on event. is released low if: a) is not driven high (by μp) within 512ms of the initial valid power turn-on event, b) is driven low during normal operation, c) a second valid event (power turn-off) is detected. The operating range for this pin is V to 1V. (LTC295-2, Pin 6/Pin 7): Open Drain Enable Output. This pin is intended to enable system power. is asserted low after a valid turn-on event. releases high if: a) is not driven high (by μp) within 512ms of the initial valid power turn-on event, b) is driven low during normal operation, c) a second valid event (power turn-off) is detected. The operating range of this pin is V to 1V. OFFT (Pin 7/Pin 6): Additional Adjustable Turn Off Time Input. A capacitor to ground determines the additional time (beyond the internal default 32ms) that the pin must be held low before initiating a power down sequence ( falling). Floating this pin results in a default turn off time of 32ms. (Pin 8/Pin 5): Input. Forcing low releases the enable output. During system turn on, this pin is blanked by a 512ms internal timer to allow the system to pull high. This pin has an accurate.6v threshold and can be used as a voltage monitor input. Exposed Pad (Pin 9): Exposed Pad may be left open or connected to device ground. 6

7 BLOCK DIAGRAMS LTC295-1/LTC295-2 / 2.7V TO 26.4V REGULATOR 2.4V 2.4V 1k OSCILLATOR LOGIC DEBOUNCE.6V.8V OSCILLATOR GND ONT OFFT 295 BD TIMING DIAGRAMS t (PW) t (PD) / 295 TD1 7

8 LTC295-1/LTC295-2 TIMING DIAGRAMS & IGNORED t DB, ON t ONT t, ON BLANK 16 CYCLES (LTC295-1) (LTC295-2) 295 TD2 Power On Timing IGNORED t DB, OFF t OFFT OFFT 16 CYCLES t, OFF DELAY (LTC295-1) (LTC295-2) 295 TD3 Power Off Timing, >.6V 8

9 APPLICATIONS INFORMATION Description The LTC295 is a low power (6μA), wide input voltage range (2.7V to 26.4V), push button on/off controller that can interface to a μp and a power supply. The turn-on and turn-off debounce times are extendable using optional external capacitors. A simple interface ( output, input) allows a system to power on and power off in a controlled manner. Turn On When power is fi rst applied to the LTC295, the part initializes the output pins. Any DC/DC converters connected to the / pin will therefore be held off. To assert the enable output, must be held low for a minimum of 32ms (t DB, ON ). The LTC295 provides additional turn on debounce time via an optional capacitor connected to the ONT pin (t ONT ). The following equation describes the additional time that must be held low before asserting the enable output. C ONT is the ONT external capacitor: C ONT = 1.56E-4 [μf/ms] (t ONT 1ms) Once the enable output is asserted, any DC/DC converters connected to this pin are turned on. The input from the μp is ignored during a succeeding 512ms blanking time (t, ON BLANK). This blanking time represents the maximum time required to power up the DC/DC converter and the μp. If is not brought high during this 512ms time window, the enable output is released. The assumption is that 512ms is sufficient time for the system to power up. Turn Off To initiate a power off sequence, must be held low for a minimum of 32ms (t DB, OFF ). Additional turn off debounce time may be added via an optional capacitor connected to the OFFT pin (t OFFT ). The following equation describes the additional time that must be held low to initiate a power off sequence. C OFFT is the OFFT external capacitor: C OFFT = 1.56E-4 [μf/ms] (t OFFT 1ms) Once has been validly pressed, is switched low. This alerts the μp to perform its power down and housekeeping tasks. The power down time given to the μp is 124ms. LTC295-1/LTC295-2 Note that the input can be pulled low (thereby releasing the enable output) at any time after t, ON BLANK period. Simplified Power On/Off Sequence Figure 1 shows a simplified LTC295-1 power on and power off sequence. A high to low transition on (t 1 ) initiates the power on sequence. This diagram does not show any bounce on. In order to assert the enable output, the pin must stay low continuously ( high resets timers) for a time controlled by the default 32ms and the external ONT capacitor (t 2 t 1 ). Once goes high (t 2 ), an internal 512ms blanking timer is started. This blanking timer is designed to give sufficient time for the DC/DC converter to reach its final voltage, and to allow the μp enough time to perform power on tasks. The pin must be pulled high within 512ms of the pin going high. Failure to do so results in the pin going low 512ms after it went high. ( = low, see Figure 2). Note that the LTC295 does not sample and until after the 512ms internal timer has expired. The reason is ignored is to ensure that the system is not forced off while powering on. Once the 512ms timer expires (t 4 ), the release of the pin is then debounced with an internal 32ms timer. The system has now properly powered on and the LTC295 monitors and (for a turnoff command) while consuming only 6μA of supply current. A high to low transition on (t 5 ) initiates the power off sequence. must stay low continuously ( high resets debounce timer) for a period controlled by the default 32ms and the external OFFT capacitor (t 6 t 5 ). At the completion of the OFFT timing (t 6 ), an interrupt () is set, signifying that will be switched low in 124ms. Once a system has finished performing its power down operations, it can set low (t 7 ) and thus immediately set low), terminating the internal 124ms timer. The release of the pin is then debounced with an internal 32ms timer. The system is now in its reset state: where the LTC295 is in low power mode (6μA). is monitored for a high to low transition. 9

10 LTC295-1/LTC295-2 APPLICATIONS INFORMATION t 1 t 2 t 3 t 4 t 5 t 6 t 7 & IGNORED IGNORED t DB, ON t ONT t, ON BLANK t DB, OFF < t, OFF DELAY ONT t OFFT OFFT <t, OFF DELAY 295 F1 Figure 1. Simplifi ed Power On/Off Sequence for LTC295-1 t ABORT t DB, ON + t ONT 512ms ERNAL TIMER POWER ON TIMING μp FAILED TO SET HIGH POWER TURNED OFF 295 F2 Figure 2. Aborted Power On Sequence for LTC

11 APPLICATIONS INFORMATION Aborted Power On Sequence The power on sequence is aborted when the remains low after the end of the 512ms blanking time. Figure 2 is a simplified version of an aborted power on sequence. At time t ABORT, since is still low, pulls low (thus turning off the DC/DC converter). μp Turns Off Power During Normal Operation Once the system has powered on and is operating normally, the μp can turn off power by setting low, as shown in Figure 3. At time t, is set low by the μp. This immediately pulls low, thus turning off the DC/DC converter. DC/DC Turn Off Blanking When the DC/DC converter is turned off, it can take a significant amount of time for its output to decay to ground. It is desirable to wait until the output of the DC/DC converter is near ground before allowing the user (via ) to restart the converter. This condition guarantees that the μp has always powered down completely before it is restarted. LTC295-1/LTC295-2 Figure 4 shows the μp turning power off. After a low on releases enable, the internal 256ms timer ignores the pin. This is shown as t /, LOCKOUT in Figure 4. LTC295-1, LTC295-2 VERSIONS The LTC295-1 (high true ) and LTC295-2 (low true ) differ only by the polarity of the / pin. Both versions allow the user to extend the amount of time that the must be held low in order to begin a valid power on/off sequence. An external capacitor placed on the ONT pin adds additional time to the turn on time. An external capacitor placed on the OFFT pin adds additional time to the turn off time. If no capacitor is placed on the ONT (OFFT) pin, then the turn on (off) duration is given by an internally fixed 32ms timer. The LTC295 fixes the turn off delay time (t, OFF DELAY) at 124ms. This means that the / pin will be switched low/high a maximum of 124ms after initiating a valid turn off sequence. Note that in a typical application, a μp or μc would set low prior to the 124ms timer period (t 7 in Figure 1). t /, LOCKOUT POWER ON IGNORED t BLANKING DC/DC TURNS OFF 256ms DC/DC TURNS OFF μp SETS LOW μp SETS LOW XXX DON T CARE XXX DON T CARE 295 F3 295 F4 Figure 3. μp Turns Off Power (LTC295-1) Figure 4. DC/DC Turn Off Blanking (LTC295-1) 11

12 LTC295-1/LTC295-2 APPLICATIONS INFORMATION The following equations describe the turn on and turn off times. C ONT and C OFFT are the external programming capacitors: t BD,ON + t ONT = 32ms + 1ms + (6.7x1 6 ) C ONT t BD,OFF + t OFFT = 32ms + 1ms + (6.7x1 6 ) C OFFT High Voltage Pins The and pins can operate at voltages up to 26.4V. can, additionally, operate below ground ( 6V) without latching up the device. has an ESD HBM rating of ±1kV. If the push button switch connected to exhibits high leakage current, then an external pull-up resistor to VIN is recommended. Furthermore, if the push button switch is physically located far from the LTC295 pin, parasitic capacitances may couple onto the high impedance input. Additionally, parasitic series inductance may cause unpredictable ringing at the pin. Placing a 5k resistor from the pin to the push button switch would mitigate parasitic inductance problems. Placing a.1μf capacitor on the pin would lessen the impact of parasitic capacitive coupling. TYPICAL APPLICATIONS Voltage Monitoring with Input The pin can be used as a voltage monitor. Figure 5 shows an application where the pin has a dual function. It is driven by a low leakage open drain output of the μp. It is also connected to a resistor divider that monitors battery voltage ( ). When the battery voltage falls below the set value, the voltage at the pin falls below.6v and the pin is quickly pulled low. Note that the resistor values should be as large as possible, but small enough to keep leakage currents from tripping the.6v comparator. The DC/DC converter shown has an internal pull-up current on its SHDN pin. A pull-up resistor on is thus not needed. Operation Without μp Figure 6 shows how to connect the pin when there is no circuitry available to drive it. The minimum pulse width detected is 3μs. If there are glitches on the resistor 9V V OUT 3.3V 9V V OUT 3.3V LT SHDN LT SHDN C4.1μF 5.4V THRESHOLD LTC295-1 GND ONT OFFT R3 86k 1% R2 1k 1% R1 1k μp (OP DRAIN) C4.1μF LTC295-1 GND ONT OFFT + R1 1k C3*.1μF 295 F5 C ONT *.33μF C OFFT *.33μF *OPTIONAL C ONT *.33μF C OFFT *.33μF *OPTIONAL 295 F6 Figure 5. Input Voltage Monitoring with Input Figure 6. No μp Application 12

13 LTC295-1/LTC295-2 TYPICAL APPLICATIONS pull-up voltage that are wider than 3μs and transition below.6v, then an appropriate bypass capacitor should be connected to the pin. Power Path Switching The open drain output of the LTC295-2 is designed to switch on/off an external power PFET. This allows a user to connect/disconnect a power supply (or battery) to its load by toggling the pin. Figure 7 shows the LTC295-2 controlling a two cell Li-Ion battery application. The and pins are connected to the output of the PFET through a resistor divider. The pin serves as a voltage monitor. When V OUT drops below 6V, the pin is open circuited 3μs later. Pin in a Noisy Environment The rugged pin is designed to operate in noisy environments. Transients below ground (> 6V) and above VIN (<3V) will not damage the rugged pin. Additionally, the pin can withstand ESD HBM strikes up to ±1kV. In order to keep external noise from coupling inside the LTC295, place an R-C network close to the pin. A 5k resistor and a.1μf capacitor should suffice for most noisy applications (see Figure 8). External Pull-Up Resistor on An internal pull-up resistor on the pin makes an external pull-up resistor unnecessary. Leakage current on R5 1K M1 V OUT V OUT,TRIP PO = 6V 4.2V SINGLE CELL Li-Ion BATTERY 4.2V SINGLE CELL Li-Ion BATTERY + C4.1μF CERAMIC + LTC295-2 GND ONT OFFT C ONT *.33μF OP DRAIN OUTPUT V TH =.6PUT C OFFT *.33μF *OPTIONAL R4 1k 1% R1 99k 1% OPTIONAL GLITCH FILTER CAPACITOR C3*.1μF 295 F7 Figure 7. Power Path Control with 6V Under Voltage Detect PARASITICS TRACE CAPACITANCE NOISE R6 5k LTC295-1 TRACE INDUCTANCE C5.1μF GND ONT OFFT DETAILS OMITTED FOR CLARITY 295 F8 Figure 8. Noisy Trace 13

14 LTC295-1/LTC295-2 TYPICAL APPLICATIONS the board trace, however, will affect the open circuit voltage on the pin. If the leakage is too large (>2μA), the voltage may fall close to the threshold window. To mitigate the effect of the board leakage, a 1k resistor to is recommended (see Figure 9). Reverse Battery Protection To protect the LTC295 from a reverse battery connection, place a 1k resistor in series with the pin (see Figure 1). R7 1k EXTERNAL BOARD LEAKAGE CURRT >2μA IF EXTERNAL PARASITIC BOARD LEAKAGE >2μA, USE EXTERNAL PULL-UP RESISTOR LTC295-1/ LTC V 1k GND PINS OMITTED FOR CLARITY 295 F9 Figure 9. External Pull-Up Resistor on Pin PACKAGE DESCRIPTION DDB Package 8-Lead Plastic DFN (3mm 2mm) (Reference LTC DWG # ) (2 SIDES).7.5 PACKAGE OUTLINE BSC (2 SIDES) RECOMMDED SOLDER PAD PITCH AND DIMSIONS PIN 1 BAR TOP MARK (SEE NOTE 6).2 REF 3..1 (2 SIDES) 2..1 (2 SIDES) R =.5 TYP.56.5 (2 SIDES) R =.115 TYP (2 SIDES) BOTTOM VIEW EXPOSED PAD BSC PIN 1 R =.2 OR CHAMFER (DDB8) DFN 95 REV B NOTE: 1. DRAWING CONFORMS TO VERSION (WECD-1) IN JEDEC PACKAGE OUTLINE M DRAWING NOT TO SCALE 3. ALL DIMSIONS ARE IN MILLIMETERS 4. DIMSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PREST, SHALL NOT EXCEED.15mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE 14

15 PACKAGE DESCRIPTION TS8 Package 8-Lead Plastic TSOT-23 (Reference LTC DWG # ) LTC295-1/LTC MAX.65 REF 2.9 BSC (NOTE 4) 1.22 REF 3.85 MAX 2.62 REF 1.4 MIN 2.8 BSC (NOTE 4) PIN ONE ID RECOMMDED SOLDER PAD LAYOUT PER IPC CALCULATOR.65 BSC PLCS (NOTE 3) BSC DATUM A 1. MAX REF BSC (NOTE 3) TS8 TSOT NOTE: 1. DIMSIONS ARE IN MILLIMETERS 2. DRAWING NOT TO SCALE 3. DIMSIONS ARE INCLUSIVE OF PLATING 4. DIMSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 5. MOLD FLASH SHALL NOT EXCEED.254mm 6. JEDEC PACKAGE REFERCE IS MO-193 Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. 15

16 LTC295-1/LTC295-2 TYPICAL APPLICATION 9V BATTERY + R8 1k R5 91k V OUT LT SHDN 1.8V C4.1μF LTC295-1 R1 1k μp GND ONT OFFT C ONT *.33μF C OFFT *.33μF *OPTIONAL Figure 1. Reverse Battery Protection 295 F1 RELATED PARTS PART NUMBER DESCRIPTION COMMTS LTC29 Programmable Quad Supply Monitor Adjustable RESET, 1-Lead MSOP and 3mm x 3mm DFN Packages LTC294/295 Pin-Programmable Dual Supply Monitors Adjustable RESET and Tolerance, 8-Lead SOT-23 and 3mm x 2mm DFN Packages LTC A Low Loss Ideal Diode in ThinSOT No External MOSFET, Automatic Switching Between DC Sources LTC4412HV Power Path Controller in ThinSOT Effi cient Diode-ORing, Automatic Switching Between DC Sources, 3V to 36V LTC455 USB Power Controller and Li-Ion Charger Automatic Switchover, Charges 1-Cell Li-Ion Batteries 16 LT 28 REV B PRED IN USA Linear Technology Corporation 163 McCarthy Blvd., Milpitas, CA (48) FAX: (48) LINEAR TECHNOLOGY CORPORATION 28