LT1129_1 LINEAR | Alldatasheet
Document overview
- Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
- PDF pages: 16
Technical content
LT1129/LT1129-3.3/LT1129-5 112935fc , LTC and LT are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. OUTPUT CURRENT (A) DROPOUT VOLTAGE (V) 0.4 0.5 0.6 0.3 0.5 0.3 0.2 0.1 LT1129 • TA02 Dropout Voltage5V Supply with Shutdown The LT 1129/LT1129-3.3/LT1129-5 are micropower low dropout regulators with shutdown. The devices are ca- pable of supplying 700mA of output current with a dropout voltage of 0.4V at maximum output. Designed for use in battery-powered systems the low quiescent current, 50µA operating and 16 µA in shutdown, make them an ideal choice. The quiescent current does not rise in dropout as it does with many other low dropout PNP regulators. Other features of the LT1129 /LT1129-3.3/LT1129-5 in- clude the ability to operate with small output capacitors. They are stable with only 3.3µF on the output while most older devices require between 10µF and 100µF for stabil- ity. Also the input may be connected to ground or a reverse voltage without reverse current flow from output to input. This makes the LT1129/LT1129-3.3/LT1129-5 ideal for backup power situations where the output is held high and the input is at ground or reversed. Under these conditions, only 16µA will flow from the output pin to ground. The devices are available in 5-lead TO-220, 5-lead DD and 3-lead SOT-223 packages. ■ 0.4V Dropout Voltage ■ 700mA Output Current ■ 50µA Quiescent Current ■ No Protection Diodes Needed ■ Adjustable Output from 3.8V to 30V ■ 3.3V and 5V Fixed Output Voltages ■ Controlled Quiescent Current in Dropout ■ Shutdown ■ 16µA Quiescent Current in Shutdown ■ Stable with 3.3µF Output Capacitor ■ Reverse Battery Protection ■ No Reverse Output Current ■ Thermal Limiting ■ Surface Mount SOT-223 and DD Packages ■ Low Current Regulator ■ Regulator for Battery-Powered Systems ■ Post Regulator for Switching Supplies ■ 5V to 3.3V Logic Regulator IN OUT LT1129-5 GND 5V OUT 500mA VIN > 5.5V 3.3µF SOLID TANTALUM SENSE LT1129 • TA01 VSHDN (PIN 4) < 0.25 > 2.8 NC OUTPUT OFF ON ON SHDN APPLICATIO SU
FEATURES
LT1129/LT1129-3.3/LT1129-5 112935fc OBSOLETE PACKAGE *PIN 2 = SENSE FOR LT1129-3.3/LT1129-5 = ADJ FOR LT1129 θJA ≈ 50°C/ W θJA ≈ 50°C/ W *PIN 2 = SENSE FOR LT1129-3.3/LT1129-5 = ADJ FOR LT1129 θJA ≈ 30°C/ W θJA ≈ 60°C/W *PIN 2 = SENSE FOR LT1129-3.3/LT1129-5 = ADJ FOR LT1129 ORDER PART NUMBER PART MARKING LT1129CST-3.3 LT1129CST-5 LT1129IST-3.3 LT1129IST-5 LT1129CT LT1129CT-3.3 LT1129CT-5 LT1129IT LT1129IT-3.3 LT1129IT-5 LT1129CQ LT1129CQ-3.3 LT1129CQ-5 LT1129IQ LT1129IQ-3.3 LT1129IQ-5 1129 11293 11295 1129I 1129I3 1129I5 ORDER PART NUMBER ORDER PART NUMBER LT1129CS8 LT1129CS8-3.3 LT1129CS8-5 LT1129IS8 LT1129IS8-3.3 LT1129IS8-5 Consult factory for Military grade parts. ABSOLUTE AXI U RATI GSW WW U PACKAGE/ORDER I FOR ATIOUU W (Note 1) Q PACKAGE 5-LEAD PLASTIC DD FRONT VIEW VIN SHDN GND SENSE/ADJ* OUTPUT TAB IS GND TOP VIEW OUTPUT GND NC S8 PACKAGE 8-LEAD PLASTIC SO VIN GND GND SHDN SENSE/ ADJ* FRONT VIEW TAB IS GND ST PACKAGE 3-LEAD PLASTIC SOT-223 OUTPUT GND V IN T PACKAGE 5-LEAD PLASTIC TO-220 VIN SHDN GND SENSE/ADJ* OUTPUT FRONT VIEW TAB IS GND ORDER PART NUMBER LT1129CF-3.3 NOTE: ALL GROUND PINS ARE INTERNALLY CONNECTED θJA ≈ 40°C/ W Operating Junction Temperature Range (Note 2) LT1129C-X Extended Temperature Range * For applications requiring input voltage ratings greater than 30V, contact the factory. ORDER PART NUMBER TOP VIEW F PACKAGE 20-LEAD PLASTIC TSSOP GND GND GND GND GND GND OUT SENSE GND GND GND GND GND GND GND GND IN SHDN GND GND
LT1129/LT1129-3.3/LT1129-5 112935fc PARAMETER CONDITIONS MIN TYP MAX UNITS (Notes 4, 12) 4.3V < V IN < 20V, 1mA < IOUT < 700mA ● 3.200 3.300 3.400 V LT1129-5 V IN = 5.5V, IOUT = 1mA, TJ = 25°C 4.925 5.000 5.075 V 6V < VIN < 20V, 1mA < IOUT < 700mA ● 4.850 5.000 5.150 V LT1129 (Note 5) V IN = 4.3V, IOUT = 1mA, TJ = 25°C 3.695 3.750 3.805 V 4.8V < VIN < 20V, 1mA < IOUT < 700mA ● 3.640 3.750 3.860 V Line Regulation (Note 12) LT1129-3.3 ∆VIN = 4.8V to 20V, IOUT = 1mA ● 1.5 10 mV LT1129-5 ∆VIN = 5.5V to 20V, IOUT = 1mA ● 1.5 10 mV LT1129 (Note 5) ∆VIN = 4.3V to 20V, IOUT = 1mA ● 1.5 10 mV Load Regulation (Note 12) LT1129-3.3 ∆ILOAD = 1mA to 700mA, TJ = 25°C6 2 0 m V ∆ILOAD = 1mA to 700mA ● 15 30 mV LT1129-5 ∆ILOAD = 1mA to 700mA, TJ = 25°C6 2 0 m V ∆ILOAD = 1mA to 700mA ● 20 30 mV LT1129 (Note 5) ∆ILOAD = 1mA to 700mA, TJ = 25°C6 2 0 m V ∆ILOAD = 1mA to 700mA ● 15 30 mV Dropout Voltage I LOAD = 10mA, TJ = 25°C 0.13 0.20 V (Note 6) I LOAD = 10mA ● 0.25 V ILOAD = 100mA, TJ = 25°C 0.25 0.35 V ILOAD = 100mA ● 0.45 V ILOAD = 500mA, TJ = 25°C 0.37 0.45 V ILOAD = 500mA ● 0.60 V ILOAD = 700mA, TJ = 25°C 0.45 0.55 V ILOAD = 700mA ● 0.70 V Ground Pin Current I LOAD = 0mA ● 50 70 µA (Note 7) I LOAD = 10mA ● 310 450 µA ILOAD = 100mA ● 2.0 3.5 mA ILOAD = 300mA ● 10 20 mA ILOAD = 500mA ● 25 45 mA ILOAD = 700mA ● 50 90 mA Adjust Pin Bias Current (Notes 5, 8) T J = 25°C 150 300 nA Shutdown Threshold V OUT = Off to On ● 1.2 2.8 V VOUT = On to Off ● 0.25 0.75 V Shutdown Pin Current (Note 9) V SHDN = 0V ● 61 0 µA Quiescent Current in Shutdown V IN = 6V, VSHDN = 0V ● 15 25 µA (Note 10) Ripple Rejection V IN – VOUT = 1V (Avg), VRIPPLE = 0.5VP-P,5 2 6 4 d B fRIPPLE = 120Hz, ILOAD = 0.7A, TJ = 25°C Current Limit V IN – VOUT = 7V, TJ = 25°C 1.2 1.6 A Input Reverse Leakage Current V IN = –20V, VOUT = 0V ● 1.0 mA Reverse Output Current (Note 11) LT1129-3.3 V OUT = 3.3V, VIN = 0V 16 25 µA LT1129-5 V OUT = 5V, VIN = 0V 16 25 µA LT1129 (Note 5) V OUT = 3.8V, VIN = 0V 16 25 µA ELECTRICAL CHARACTERISTICSThe ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
LT1129/LT1129-3.3/LT1129-5 112935fc Note 6: Dropout voltage is the minimum input/output voltage required to maintain regulation at the specified output current. In dropout the output voltage will be equal to (V IN – VDROPOUT). Dropout voltage is measured between the input pin and the output pin. External voltage drops between the output pin and the sense pin will add to the dropout voltage. Note 7: Ground pin current is tested with VIN = VOUT (nominal) and a current source load. This means that the device is tested while operating in its dropout region. This is the worst case ground pin current. The ground pin current will decrease slightly at higher input voltages. Note 8: Adjust pin bias current flows into the adjust pin. Note 9: Shutdown pin current at V SHDN = 0V flows out of the shutdown pin. Note 10: Quiescent current in shutdown is equal to the sum total of the shutdown pin current (6µA) and the ground pin current (9µA). Note 11: Reverse output current is tested with the input pin grounded. The output pin and the sense pin are forced to the rated output voltage. This current flows into the sense pin and out of the ground pin. For the LT1129 (adjustable version) the sense pin is internally tied to the output pin. Note 12: For C-grade devices Regulated Output Voltage, Line Regulation, and Load Regulation are guaranteed over the extended temperature range of –40°C to 125°C. These parameters are not tested or quality assurance sampled at –40°C. They are guaranteed by design, correlation and/or inference from 25°C and/or 0°C tests. Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The shutdown pin input voltage rating is required for a low impedance source. Internal protection devices connected to the shutdown pin will turn on and clamp the pin to approximately 7V or –0.6V. This range allows the use of 5V logic devices to drive the pin directly. For high impedance sources or logic running on supply voltages greater than 5.5V, the maximum current driven into the shutdown pin must be limited to less than 20mA. Note 3: For junction temperatures greater than 110°C, a minimum load of 1mA is recommended. For T J > 110°C and IOUT < 1mA, output voltage may increase by 1%. Note 4: Operating conditions are limited by maximum junction temperature. The regulated output voltage specification will not apply for all possible combinations of input voltage and output current. When operating at maximum input voltage, the output current range must be limited. When operating at maximum output current the input voltage range must be limited. Note 5: The LT1129 is tested and specified with the adjust pin connected to the output pin.
ELECTRICAL CHARACTERISTICS
LT1129/LT1129-3.3/LT1129-5 112935fc Quiescent Current LT1129-3.3 Output Voltage LT1129 Adjust Pin Voltage LT1129 Quiescent Current LT1129-5 Quiescent Current LT1129-3.3 Quiescent Current Guaranteed Dropout Voltage Dropout Voltage LT1129-5 Output Voltage OUTPUT CURRENT (A) DROPOUT VOLTAGE (V) 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.2 0.4 0.5
1129 G02
0.1 0.3 0.6 0.70 = TEST POINTS TJ ≤ 125°C TJ ≤ 25°C TEMPERATURE (°C) –50 DROPOUT VOLTAGE (V) 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 50 75
1129 G10
–25 25 100 125 A C D E B A. ILOAD = 700mA B. ILOAD = 500mA C. ILOAD = 300mA D. ILOAD = 100mA E. ILOAD = 10mA TEMPERATURE (°C) –50 QUIESCENT CURRENT (µA) 0 50 75
1129 G11
–25 25 100 125 VSHDN = 0V VSHDN = OPEN (HI) INPUT VOLTAGE (V) QUIESCENT CURRENT (µA) 250 225 200 175 150 125 100
1129 G13
VSHDN = 0V ILOAD = 0 RLOAD = ∞ VOUT = VADJ VSHDN = OPEN (HI) INPUT VOLTAGE (V) QUIESCENT CURRENT (µA) 250 225 200 175 150 125 100
1129 G14
VSHDN = 0V ILOAD = 0 RLOAD = ∞ VSHDN = OPEN (HI) INPUT VOLTAGE (V) QUIESCENT CURRENT (µA) 250 225 200 175 150 125 100
1129 G12
ILOAD = 0 RLOAD = ∞ VSHDN = 0V VSHDN = OPEN (HI) TEMPERATURE (°C) –50 ADJUST PIN VOLTAGE (V) 3.400 3.375 3.350 3.325 3.300 3.275 3.250 3.225 3.200 0 50 75
1129 G06
–25 25 100 125 ILOAD = 1mA TEMPERATURE (°C) –50 ADJUST PIN VOLTAGE (V) 3.850 3.825 3.800 3.775 3.750 3.725 3.700 3.675 3.650 0 50 75
1129 G05
–25 25 100 125 ILOAD = 1mA TEMPERATURE (°C) –50 OUTPUT VOLTAGE (V) 5.100 5.075 5.050 5.025 5.000 4.975 4.950 4.925 4.900 0 50 75
1129 G04
–25 25 100 125 ILOAD = 1mA TYPICAL PERFOR A CE CHARACTERISTICSUW
LT1129/LT1129-3.3/LT1129-5 112935fc INPUT VOLTAGE (V) GROUND PIN CURRENT (mA) 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2
1129 G20
RLOAD = 75Ω ILOAD = 50mA* RLOAD = 375Ω ILOAD = 10mA* RLOAD = 38Ω ILOAD = 100mA* *For VOUT = 3.75V TJ = 25°C VOUT = VADJ INPUT VOLTAGE (V) GROUND PIN CURRENT (mA) 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2
1129 G19
RLOAD = 100Ω ILOAD = 50mA* RLOAD = 500Ω ILOAD = 10mA* RLOAD = 50Ω ILOAD = 100mA* *For VOUT = 5V TJ = 25°C VOUT = VSENSE LT1129 Ground Pin Current LT1129-5 Ground Pin Current LT1129-3.3 Ground Pin Current INPUT VOLTAGE (V) GROUND PIN CURRENT (mA) 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2
1129 G18
RLOAD = 66Ω ILOAD = 50mA* RLOAD = 330Ω ILOAD = 10mA* RLOAD = 33Ω ILOAD = 100mA* TJ = 25°C VOUT = VSENSE *For VOUT = 3.3V LT1129-3.3 Ground Pin Current INPUT VOLTAGE (V) GROUND PIN CURRENT (mA)
1129 G22
RLOAD = 10Ω ILOAD = 500mA* RLOAD = 16.6Ω ILOAD = 300mA* RLOAD = 7.1Ω ILOAD = 700mA* *For VOUT = 5V TJ = 25°C VOUT = VSENSE LT1129-5 Ground Pin Current INPUT VOLTAGE (V) GROUND PIN CURRENT (mA)
1129 G23
RLOAD = 7.5Ω ILOAD = 500mA* RLOAD = 12.6Ω ILOAD = 300mA* RLOAD = 5.3Ω ILOAD = 700mA* *For VOUT = 3.75V TJ = 25°C VOUT = VADJ LT1129 Ground Pin Current Ground Pin Current OUTPUT CURRENT (A) GROUND PIN CURRENT (mA) 0.2 0.4 0.5
1129 G15
0.1 0.3 0.6 0.7 TJ = 25°C TJ = 125°C TJ = –50°C VIN = 3.3V (LT1129-3.3) VIN = 5V (LT1129-5) VIN = 3.75V (LT1129) DEVICE IS OPERATING IN DROPOUT TEMPERATURE (°C) –50 SHUTDOWN THRESHOLD (V) 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 50 75
1129 G27
–25 25 100 125 ILOAD = 1mA Shutdown Pin Threshold (On-to-Off) Shutdown Pin Threshold (Off-to-On) TEMPERATURE (°C) –50 SHUTDOWN THRESHOLD (V) 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 50 75
1129 G26
–25 25 100 125 ILOAD = 1mA ILOAD = 700mA INPUT VOLTAGE (V) GROUND PIN CURRENT (mA)
1129 G21
RLOAD = 6.6Ω ILOAD = 500mA* RLOAD = 11Ω ILOAD = 300mA* RLOAD = 4.7Ω ILOAD = 700mA* *For VOUT = 3.3V TJ = 25°C VOUT = VSENSE TYPICAL PERFOR A CE CHARACTERISTICSUW
LT1129/LT1129-3.3/LT1129-5 112935fc FREQUENCY (Hz) RIPPLE REJECTION (dB) 100 10 1k 10k 1M
1129 G01
IOUT = 500mA VIN = 6V + 50mVRMS RIPPLE COUT = 47µF SOLID TANTALUM COUT = 3.3µF SOLID TANTALUM Shutdown Pin Current SHUTDOWN PIN VOLTAGE (V) SHUTDOWN PIN INPUT CURRENT (mA) 2 4 59
1129 G24
Shutdown Pin Input Current Adjust Pin Bias Current Current Limit TEMPERATURE (°C) –50 SHORT-CIRCUIT CURRENT (A) 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 50 75
1129 G08
–25 25 100 125 VIN = 7V VOUT = 0V Current Limit INPUT VOLTAGE (V) SHORT-CIRCUIT CURRENT (A) 1.4 1.2 1.0 0.8 0.6 0.4 0.2 2 4 5
1129 G07
VOUT = 0V Reverse Output Current Reverse Output Current Ripple Rejection Ripple Rejection TEMPERATURE (°C) –50 RIPPLE REJECTION (dB) 0 50 75
1129 G03
–25 25 100 125 (VIN – VOUT)AVG = 1V VRIPPLE = 0.5VP-P IL = 0.7A TEMPERATURE (°C) –50 OUTPUT CURRENT (µA) 0 50 75
1129 G29
–25 25 100 125 VIN = 0V VOUT = VSENSE = 5V (LT1129-5) VOUT = VSENSE = 3.3V (LT1129-3.3) VOUT = VADJ = 3.75V (LT1129) TEMPERATURE (°C) –50 ADJUST PIN BIAS CURRENT (nA) 400 350 300 250 200 150 100 0 50 75
1129 G28
–25 25 100 125 VADJ = VOUT = 3.75V OUTPUT VOLTAGE (V) OUTPUT CURRENT (µA) 100
1129 G30
TJ = 25°C, VIN = 0V VOUT = VSENSE V OUT = VADJ (LT1129) CURRENT FLOWS INTO DEVICELT1129-3.3 LT1129 LT1129-5 TEMPERATURE (°C) –50 SHUTDOWN PIN CURRENT (µA) 0 50 75
1129 G25
–25 25 100 125 VSHDN = 0V TYPICAL PERFOR A CE CHARACTERISTICSUW
LT1129/LT1129-3.3/LT1129-5 112935fc LT1129-5 Transient ResponseLoad Regulation LT1129-5 Transient Response TYPICAL PERFOR A CE CHARACTERISTICSUW Input Pin: Power is supplied to the device through the input pin. The input pin should be bypassed to ground if the device is more than 6 inches away from the main input filter capacitor. In general, the output impedance of a battery rises with frequency so it is advisable to include a bypass capacitor in battery-powered circuits. A bypass capacitor in the range of 1 µF to 10 µF is sufficient. The LT1129 is designed to withstand reverse voltages on the input pin with respect to both ground and the output pin. In the case of a reversed input, which can happen if a battery is plugged in backwards, the LT1129 will act as if there is a diode in series with its input. There will be no reverse current flow into the LT1129 and no reverse voltage will appear at the load. The device will protect both itself and the load. Output Pin: The output pin supplies power to the load. An output capacitor is required to prevent oscillations. See the Applications Information section for recommended value of output capacitance and information on reverse output characteristics. Shutdown Pin (SHDN): This pin is used to put the device into shutdown. In shutdown the output of the device is turned off. This pin is active low. The device will be shut down if the shutdown pin is actively pulled low. The shutdown pin current with the pin pulled to ground will be 6µA. The shutdown pin is internally clamped to 7V and – 0.6V (one V BE). This allows the shutdown pin to be driven directly by 5V logic or by open collector logic with a pull- up resistor. The pull-up resistor is only required to supply the leakage current of the open collector gate, normally several microamperes. Pull-up current must be limited to a maximum of 20mA. A curve of shutdown pin input current as a function of voltage appears in the Typical Performance Characteristics. If the shutdown pin is not used it can be left open circuit. The device will be active, output on, if the shutdown pin is not connected. Sense Pin: For fixed voltage versions of the LT1129 (LT1129-3.3, LT1129-5) the sense pin is the input to the error amplifier. Optimum regulation will be obtained at the point where the sense pin is connected to the output pin. For most applications the sense pin is connected directly to the output pin at the regulator. In critical applications small voltage drops caused by the resistance (R P) of PC traces between the regulator and the load, which would normally degrade regulation, may be eliminated by con- necting the sense pin to the output pin at the load as shown in Figure 1 (Kelvin Sense Connection). Note that the voltage drop across the external PC traces will add to the dropout voltage of the regulator. The sense pin bias current is 15µA at the nominal regulated output voltage. This pin is internally clamped to – 0.6V (one V BE). TEMPERATURE (°C) –50 LOAD REGULATION (mV) –10 –15 –20 –25 –30 0 50 75
1129 G09
–25 25 100 125 LT1129* LT1129-3.3 LT1129-5 VIN = VOUT(NOMINAL) + 1V ∆ILOAD = 1mA to 700mA *VADJ = VOUT TIME (µs) OUTPUT VOLTAGE DEVIATION (V) 0.10 0.05 –0.05 –0.10 400
1129 G31
0.6 0.5 LOAD CURRENT (A) 100 150 250 350 450 VIN = 6V CIN = 3.3µF COUT = 3.3µF TIME (ms) OUTPUT VOLTAGE DEVIATION (V) 0.2 0.1 –0.1 –0.2 1.6
1129 G32
0.2 0.8 1.2 2.0 0.7 0.5 0.3 0.1 LOAD CURRENT (A) VIN = 6V CIN = 3.3µF COUT = 47µF PI FU CTIO S UU U
- Output current multiplied by the input/output voltage
- Ground pin current multiplied by the input voltage:
of the two components listed above. all sources of thermal resistance from junction to ambient. heat generated by power devices. with other components as well as board size and shape. Table 1. Q Package, 5-Lead DD Table 2. ST Package, 3-Lead SOT-223 Table 3. S8 Package, 8-Lead Plastic SOIC
LT1129/LT1129-3.3/LT1129-5 112935fc Calculating Junction Temperature Example: Given an output voltage of 3.3V, an input voltage range of 4.5V to 5.5V, an output current range of 0mA to 500mA, and a maximum ambient temperature of 50 °C, what will the maximum junction temperature be? The power dissipated by the device will be equal to: IOUT MAX • (VIN MAX – VOUT) + (IGND • VIN MAX) where, I OUT MAX = 500mA VIN MAX = 5.5V IGND at (IOUT = 500mA, VIN = 5.5V) = 25mA = 1.24W If we use a DD package, then the thermal resistance will be in the range of 25°C/W to 35°C/W depending on copper area. So the junction temperature rise above ambient will be approximately equal to: The maximum junction temperature will then be equal to the maximum junction temperature rise above ambient plus the maximum ambient temperature or: T Output Capacitance and Transient Performance The LT1129 is designed to be stable with a wide range of output capacitors. The minimum recommended value is 3.3µF with an ESR of 2 Ω or less. The LT1129 is a micropower device and output transient response will be a function of output capacitance. See the Transient Re- sponse curves in the Typical Performance Characteristics. Larger values of output capacitance will decrease the peak deviations and provide improved output transient re- sponse. Bypass capacitors, used to decouple individual components powered by the LT1129, will increase the effective value of the output capacitor. Protection Features The LT1129 incorporates several protection features which make it ideal for use in battery-powered circuits. In addi- tion to the normal protection features associated with monolithic regulators, such as current limiting and ther- mal limiting, the device is protected against reverse input voltages, and reverse voltages from output to input. For fixed voltage devices the output and sense pins are tied together at the output. Current limit protection and thermal overload protection are intended to protect the device against current overload conditions at the output of the device. For normal opera- tion, the junction temperature should not exceed 125°C. The input of the device will withstand reverse voltages of 30V. Current flow into the device will be limited to less than 1mA (typically less than 100µA) and no negative voltage will appear at the output. The device will protect both itself and the load. This provides protection against batteries that can be plugged in backwards. For fixed voltage versions of the device, the sense pin is internally clamped to one diode drop below ground. For the adjustable version of the device, the output pin is internally clamped at one diode drop below ground. If the output pin of an adjustable device, or the sense pin of a fixed voltage device, is pulled below ground, with the input open or grounded, current must be limited to less than 5mA. In circuits where a backup battery is required, several different input/output conditions can occur. The output voltage may be held up while the input is either pulled to ground, pulled to some intermediate voltage, or is left open circuit. Current flow back into the output will vary depending on the conditions. Many battery-powered cir- cuits incorporate some form of power management. The following information will help optimize battery life. Table 3 summarizes the following information. The reverse output current will follow the curve in Figure 3 when the input pin is pulled to ground. This current flows through the output pin to ground. The state of the shut- down pin will have no effect on output current when the input pin is pulled to ground. APPLICATIO S I FOR ATIOWU UU
1129 F03
Figure 3. Reverse Output Current
1129 F04
Figure 4. Input Current to the LT1129 unconnected when the output is held high. Figure 3. This can happen if the input of the LT1129 is output current when the output is pulled above the input. Table 4. Fault Conditions
LT1129/LT1129-3.3/LT1129-5 112935fc PACKAGE DESCRIPTIO U F Package 20-Lead Plastic TSSOP (4.4mm) (LTC DWG # 05-08-1650) OBSOLETE PACKAGE F20 TSSOP 0204 0.09 – 0.20 (.0035 – .0079) 0° – 8° 0.25 REF 0.50 – 0.75 (.020 – .030) 4.30 – 4.50** (.169 – .177) 13 4 5 6 7 89 1 0 111214 13 6.40 – 6.60* (.252 – .260) 20 19 18 17 16 15 1.10 (.0433) MAX 0.05 – 0.15 (.002 – .006) 0.65 (.0256) BSC 6.40 (.252) BSC 0.19 – 0.30 (.0075 – .0118) TYP MILLIMETERS (INCHES) DIMENSIONS DO NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED .152mm (.006") PER SIDE NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS 2. DIMENSIONS ARE IN 3. DRAWING NOT TO SCALE RECOMMENDED SOLDER PAD LAYOUT 0.45 ±0.05 0.65 BSC 1.05 ±0.10
LT1129/LT1129-3.3/LT1129-5 112935fc Q(DD5) 0502 .028 – .038 (0.711 – 0.965) TYP .143 +.012 –.020 ()3.632+0.305 –0.508 .067 (1.702) BSC .013 – .023 (0.330 – 0.584) .095 – .115 (2.413 – 2.921) .004 +.008 –.004 ()0.102 +0.203 –0.102 .050 ± .012 (1.270 ± 0.305) .059 (1.499) TYP .045 – .055 (1.143 – 1.397) .165 – .180 (4.191 – 4.572) .330 – .370 (8.382 – 9.398) .060 (1.524) TYP .390 – .415 (9.906 – 10.541) 15° TYP .420 .350 .565 .090 .042.067 RECOMMENDED SOLDER PAD LAYOUT .325 .205 .080 .565 .090 RECOMMENDED SOLDER PAD LAYOUT FOR THICKER SOLDER PASTE APPLICATIONS .042.067 .420 .276 .320 NOTE: 1. DIMENSIONS IN INCH/(MILLIMETER) 2. DRAWING NOT TO SCALE .300 (7.620) .075 (1.905) .183 (4.648) .060 (1.524) .060 (1.524) .256 (6.502) BOTTOM VIEW OF DD PAK HATCHED AREA IS SOLDER PLATED COPPER HEAT SINK PACKAGE DESCRIPTIO U Q Package 5-Lead Plastic DD Pak (LTC DWG # 05-08-1461)
LT1129/LT1129-3.3/LT1129-5 112935fc 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 represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. PACKAGE DESCRIPTIO U 3-Lead Plastic SOT-223 (LTC DWG # 05-08-1630) 8-Lead Plastic Small Outline (Narrow 0.150) (LTC DWG # 05-08-1610) .114 – .124 (2.90 – 3.15) .248 – .264 (6.30 – 6.71) .130 – .146 (3.30 – 3.71) .264 – .287 (6.70 – 7.30) .0905 (2.30) BSC .033 – .041 (0.84 – 1.04) .181 (4.60) BSC .024 – .033 (0.60 – 0.84) .071 (1.80) MAX 10° MAX .012 (0.31) MIN .0008 – .0040 (0.0203 – 0.1016) 10° – 16° .010 – .014 (0.25 – 0.36) 10° – 16° RECOMMENDED SOLDER PAD LAYOUT ST3 (SOT-233) 0502 .129 MAX .059 MAX .059 MAX .181 MAX .039 MAX .248 BSC .090 BSC .016 – .050 (0.406 – 1.270) .010 – .020 0°– 8° TYP .008 – .010 (0.203 – 0.254) SO8 0303 .053 – .069 (1.346 – 1.752) .014 – .019 (0.355 – 0.483) TYP .004 – .010 (0.101 – 0.254) .050 (1.270) BSC 1 2 3 4 .150 – .157 (3.810 – 3.988) NOTE 3 8 7 6 5 .189 – .197 (4.801 – 5.004) NOTE 3 .228 – .244 (5.791 – 6.197) .245 MIN .160 ±.005 RECOMMENDED SOLDER PAD LAYOUT .045 ±.005 .050 BSC .030 ±.005 TYP INCHES (MILLIMETERS) NOTE: 1. DIMENSIONS IN 2. DRAWING NOT TO SCALE 3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
LT1129/LT1129-3.3/LT1129-5 112935fc © LINEAR TECHNOLOGY CORPORATION 1 994 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1121 150mA LDO Micropower Regulator 30 µA IQ, SOT-223 Package LT1761 100mA Low Noise, LDO Micropower Regulator 20 µA IQ, 20µVRMS Noise LT1762 150mA Low Noise, LDO Micropower Regulator 25 µA IQ, 20µVRMS Noise LT1962 300mA Low Noise, LDO Micropower Regulator 30 µA IQ, 20µVRMS Noise LT1763 500mA Low Noise, LDO Micropower Regulator 30 µA IQ, 20µVRMS Noise LT1963 1.5A Low Noise, Fast Transient, LDO Regulator 340mV Dropout Voltage, 40 µVRMS Noise LT1764 3A Low Noise, Fast Transient, LDO Regulator 340mV Dropout Voltage, 40 µVRMS Noise TYPICAL APPLICATIO U T Package 5-Lead Plastic TO-220 (Standard) (LTC DWG # 05-08-1421) T5 (TO-220) 0801 .028 – .038 (0.711 – 0.965) .067 (1.70) .135 – .165 (3.429 – 4.191) .700 – .728 (17.78 – 18.491) .045 – .055 (1.143 – 1.397) .095 – .115 (2.413 – 2.921) .013 – .023 (0.330 – 0.584) .620 (15.75) TYP .155 – .195* (3.937 – 4.953) .152 – .202 (6.60 – 8.13) .165 – .180 (4.191 – 4.572) .147 – .155 (3.734 – 3.937) DIA .390 – .415 (9.906 – 10.541) .330 – .370 (8.382 – 9.398) .460 – .500 (11.684 – 12.700) .570 – .620 (14.478 – 15.748) .230 – .270 (5.842 – 6.858) BSC SEATING PLANE * MEASURED AT THE SEATING PLANE Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LT/TP 0205 1K REV C • PRINTED IN USA