LT1316IS8

LT1316 Micropower DC/DC Converter with Programmable Peak Current Limit FEATURES s s DESCRIPTION The LT®1316 is a micropower step-up DC/DC converter that operates from an input voltage as low as 1.5V. A programmable input current limiting function allows precise control of peak switch current. Peak switch current can be set to any value between 30mA and 500mA by adjusting one resistor. This is particularly useful for DC/DC converters operating from high source impedance inputs such as lithium coin cells or telephone lines. The fixed off-time, variable on-time regulation scheme results in quiescent current of only 33µA in active mode. Quiescent current decreases to 3µA in shutdown with the low-battery detector still active. The LT1316 is available in 8-lead MSOP and SO packages. , LTC and LT are registered trademarks of Linear Technology Corporation. s s s s s Precise Control of Peak Switch Current Quiescent Current: 33µA in Active Mode 3µA in Shutdown Mode Low-Battery Detector Active in Shutdown Low Switch VCESAT: 300mV at 500mA 8-Lead MSOP and SO Packages Operates with VIN as Low as 1.5V Logic Level Shutdown Pin APPLICATIONS s s s Battery Backup LCD Bias Low Power – 48V to 5V/3.3V Converters TYPICAL APPLICATION 2-Cell to 5V Step-Up Converter L1 47µH 6 7 VIN SHDN LT1316 NC 2 LBI RSET 3 R5 10k 1% D1: MOTOROLA MBR0520L L1: SUMIDA CD43-470 LBO GND 4 1 NC R2 324k 1% 5 SW FB 8 D1 R1 1M 1% 5V 50mA 90 3.3VIN 2.5VIN 2 CELLS C1 47µF C2 47µF EFFICIENCY (%) + + 80 70 60 1316 TA01 0.1 U U U Efficiency vs Load Current 1.8VIN 1 10 100 1316 TA02 LOAD CURRENT (mA) 1 LT1316 ABSOLUTE MAXIMUM RATINGS VIN Voltage .............................................................. 12V SW Voltage ............................................... – 0.4V to 30V FB Voltage ..................................................... VIN + 0.3V RSET Voltage ............................................................. 5V SHDN Voltage ............................................................ 6V LBI Voltage ................................................................VIN LBO Voltage ............................................................. 12V Maximum Switch Current ................................... 750mA Maximum Junction Temperature ......................... 125°C Operating Temperature Range Commercial ............................................. 0°C to 70°C Extended Commercial (Note 1) .......... – 40°C to 85°C Industrial (Note 2) .............................. – 40°C to 85°C Storage Temperature Range ................. – 65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C PACKAGE/ORDER INFORMATION TOP VIEW LBO LBI RSET GND 1 2 3 4 8 7 6 5 FB SHDN VIN SW ORDER PART NUMBER LT1316CMS8 MS8 PART MARKING LTCD ORDER PART NUMBER MS8 PACKAGE 8-LEAD PLASTIC MSOP TJMAX = 125°C, θJA = 160°C/W TOP VIEW LBO 1 LBI 2 RSET 3 GND 4 8 7 6 5 FB SHDN VIN SW LT1316CS8 LT1316IS8 S8 PART MARKING 1316 1316I S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 125°C, θJA = 120°C/W Consult factory for Military grade parts. ELECTRICAL CHARACTERISTICS Commercial grade 0°C to 70°C, Industrial grade – 40°C to 85°C, VIN = 2V, VSHDN = VIN, TA = 25°C unless otherwise noted. (Notes 1, 2) PARAMETER Minimum Operating Voltage Maximum Operating Voltage Quiescent Current Quiescent Current in Shutdown FB Pin Bias Current Line Regulation LBI Input Threshold LBI Pin Bias Current LBI Input Hysteresis LBO Output Voltage Low LBO Output Leakage Current SHDN Input Voltage High SHDN Input Voltage Low SHDN Pin Bias Current VSHDN = 5V VSHDN = 0V ISINK = 500µA LBI = 1.7V, LBO = 5V VIN = 1.8V to 12V Falling Edge VSHDN = 2V, Not Switching q CONDITIONS MIN TYP 1.5 33 MAX 1.65 12 45 50 5 10 30 0.15 1.25 20 65 0.4 0.1 0.4 UNITS V V µA µA µA µA nA %/V V nA mV V µA V V µA µA VSHDN = 0V, VIN = 2V VSHDN = 0V, VIN = 5V q q q q q q q q q q q q q 3 7 3 0.04 1.1 1.17 3 35 0.2 0.01 1.4 2 –1 5 –3 2 U W U U WW W LT1316 ELECTRICAL CHARACTERISTICS Commercial grade 0°C to 70°C, Industrial grade – 40°C to 85°C, VIN = 2V, VSHDN = VIN, TA = 25°C unless otherwise noted. (Notes 1, 2) PARAMETER Switch OFF Time CONDITIONS FB > 1V q MIN 1.4 1.1 4.4 3.4 74 73 TYP 2.0 3.4 6.3 76 0.30 0.06 0.1 MAX 2.6 3.0 8.2 9.5 90 90 0.4 0.15 5 UNITS µs µs µs µs µs % % V V µA FB < 1V Switch ON Time Maximum Duty Cycle Switch Saturation Voltage Switch Leakage Current Limit Not Asserted 1V < FB < 1.2V Current Limit Not Asserted 1V < FB < 1.2V ISW = 0.5A ISW = 0.1A Switch Off, VSW = 5V q q q q q Commercial grade 0°C to 70°C, VIN = 2V, VSHDN = VIN, TA = 25°C unless otherwise noted. FB Comparator Trip Point Peak Switch Current RSET = 27.4k, TA = 25°C RSET = 27.4k, TA =0°C RSET = 27.4k, TA = 70°C RSET = 10K RSET = 121k q q 1.21 90 90 70 250 1.23 100 100 90 290 25 1.25 110 115 110 340 V mA mA mA mA mA Industrial grade – 40°C to 85°C, VIN = 2V, VSHDN = VIN, TA = 25°C unless otherwise noted. FB Comparator Trip Point Peak Switch Current RSET = 27.4k, RSET = 10k q q q 1.205 70 200 1.23 100 290 1.255 125 370 V mA mA The q denotes specifications which apply over the specified temperature range. Note 1: C grade device specifications are guaranteed over the 0°C to 70°C temperature range. In addition, C grade device specifications are assured over the – 40°C to 85°C temperature range by design or correlation, but are not production tested. Note 2: I grade device specifications are guaranteed over the – 40°C to 85°C temperature range. TYPICAL PERFORMANCE CHARACTERISTICS Load Transient Response VOUT 100mV/DIV AC COUPLED 50mA ILOAD 0mA 1316 G01 UW Burst ModeTM Operation VOUT 100mV/DIV AC COUPLED VSW 5V/DIV INDUCTOR CURRENT 200mA/DIV 1316 G02 Burst Mode IS A TRADEMARK OF LINEAR TECHNOLOGY CORPORATION. 3 LT1316 TYPICAL PERFORMANCE CHARACTERISTICS Switch Saturation Voltage vs Switch Current 500 SWITCH SATURATION VOLTAGE (mV) 75°C 400 300 –40°C 200 25°C 4 OFF-TIME (µs) –25 0 25 50 TEMPERATURE (°C) 75 100 1316 G04 100°C LBI PIN CURRENT (nA) 100 0 0 100 200 300 400 500 600 700 800 SWITCH CURRENT (mA) 1316 G03 Maximum On-Time vs Temperature 8 36 QUIESCENT CURRENT (µA) MAXIMUM ON-TIME (µs) 7 32 FEEDBACK VOLTAGE (V) 6 5 –50 –25 0 25 50 TEMPERATURE (°C) FB Pin Bias Current vs Temperature 4 SHUTDOWN PIN CURRENT (µA) 4 FB PIN BIAS CURRENT (nA) 3 PEAK SWITCH CURRENT (mA) 3 2 1 –50 –25 0 25 50 TEMPERATURE (°C) 4 UW 75 1316 G06 LBI Pin Bias Current vs Temperature 8 4 Off-Time vs Temperature 6 3 2 2 1 0 –50 0 –50 –25 0 25 50 TEMPERATURE (°C) 75 100 1316 G05 Quiescent Current vs Temperature 1.240 Feedback Voltage vs Temperature 34 1.235 1.230 30 28 1.225 100 26 –50 –25 0 25 50 TEMPERATURE (°C) 75 100 1316 G07 1.220 –50 –25 0 25 50 TEMPERATURE (°C) 75 100 1316 G08 Shutdown Pin Bias Current vs Shutdown Pin Voltage 1000 Peak Switch Current vs Temperature RSET = 4.84k RSET = 10k 2 100 RSET = 27.4k 1 RSET = 97.3k 0 –1 75 100 1316 G11 0 1 2 3 4 5 SHUTDOWN PIN VOLTAGE (V) 6 1316 G09 10 –50 –25 0 25 50 TEMPERATURE (°C) 75 100 1316 G10 LT1316 PIN FUNCTIONS LBO (Pin 1): Low-Battery Detector Output. Open collector can sink up to 500µA. Low-battery detector remains active in shutdown mode. LBI (Pin 2): Low-Battery Detector Input. When voltage at this pin drops below 1.17V, LBO goes low. RSET (Pin 3): A resistor between RSET and GND programs peak switch current. The resistor value should be between 3k and 150k. Do not float or short to ground. This is a high impedance node. Keep traces at this pin as short as possible. Do not put capacitance at this pin. GND (Pin 4): Ground. Connect directly to ground plane. SW (Pin 5): Collector of NPN Power Transistor. Keep traces at this pin as short as possible. VIN (Pin 6): Input Supply. Must be bypassed close to the pin. SHDN (Pin 7): Shutdown. Ground this pin to place the part in shutdown mode (only the low-battery detector remains active). Tie to a voltage between 1.4V and 6V to enable the device. SHDN pin is logic level and need only meet the logic specification (1.4V for high, 0.4V for low). FB (Pin 8): Feedback Pin. Reference voltage is 1.23V. Connect resistive divider tap here. Minimize trace area at FB. Set VOUT according to: VOUT = 1.23V(1 + R1/R2). BLOCK DIAGRA LB0 1 6 LBI 2 + A3 – 1.17V 1.5V UNDERVOLTAGE LOCKOUT R3 = 10R4 R4 8 FB R2 A1 A2 0.5V + A4 DRIVER Q2 ×1 Q1 ×200 4 RSET R5 GND OSCILLATOR 6.3µs ON 2µs OFF – 3 7 1316 F01 SHDN Figure 1. LT1316 Block Diagram – + – + W U U U L1 VIN D1 VOUT C1 R1 VIN 5 SW VREF 1.23V 5 LT1316 APPLICATIONS INFORMATION Table 1 simplifies component selection for commonly used input and output voltages. The methods used in determining these values are discussed in more detail later in this data sheet. VOUT can be set using the equation: VOUT R2 + R1 VOUT = 1.23 R2 ) ) R1 FB R2 1316 EQF01 Table 1. RSET Resistor and Inductor Values VIN 2 2 2 2 5 5 5 5 VOUT 5 5 5 5 12 28 28 28 LOAD CURRENT 10mA 25mA 50mA 75mA 100mA 1mA 5mA 10mA RSET RESISTOR 36.8k 18.2k 10k 6.81k 6.81k 75k 22.1k 10k INDUCTOR 100µH 68µH 47µH 33µH 82µH 100µH 100µH 100µH PEAK SWITCH CURRENT 80mA 165mA 320mA 500mA 490mA 56mA 140mA 270mA Operation To understand operation of the LT1316, first examine Figure 1. Comparator A1 monitors FB voltage which is VOUT divided down by resistor divider network R1/R2. When voltage at the FB pin drops below the reference voltage (1.23V), A1’s output goes high and the oscillator is enabled. The oscillator has an off-time fixed at 2µs and an on-time limited to 6.3µs. Power transistor Q1 is cycled on and off by the oscillator forcing current through the inductor to alternately ramp up and down (see Figure 2). VOUT AC COUPLED 200mV/DIV VSW 5V/DIV INDUCTOR CURRENT 100mA/DIV DC CURRENT LIMIT (mA) 10µs/DIV 1316 F02 Figure 2. Switching Waveforms 6 U W U U During the portion of the switch cycle when Q1 is turned off, current is forced through D1 to C1 causing output voltage to rise. This switching action continues until output voltage rises enough to overcome A1’s hysteresis. Peak switch current is set by a resistor from the RSET pin to ground. Voltage at the RSET pin is forced to 0.5V by A4 and is used to set up a constant current through R5. This current also flows through R3 which sets the voltage at the positive input of comparator A2. When Q1 turns on, the SW pin goes low and current ramps up at the rate VIN/L. Current through Q2 is equal to Q1’s current divided by 200. When current through Q2 causes the voltage drop across R4 and R3 to be equal, A2 changes state and resets the oscillator, causing Q1 to turn off. Shutdown is accomplished by grounding the SHDN pin. The low-battery detector A3 has its own 1.17V reference and is always on. The open collector output device can sink up to 500µA. Approximately 35mV of hysteresis is built into A3 to reduce “buzzing” as the battery voltage reaches the trip level. Current Limit During active mode when the part is switching, current in the inductor ramps up each switch cycle until reaching a preprogrammed current limit. This current limit value must be set by placing the appropriate resistor from the RSET pin to ground. This resistance value can be found by using Figure 3 to locate the desired DC current limit and 1000 100 10 10 RSET (kΩ) 1316 F03 100 Figure 3. DC Current Limit vs RSET Resistor Note: DC Current is the Peak Switch Current if the Power Transistor had Zero Turn-Off Delay LT1316 APPLICATIONS INFORMATION then adding in the amount of overshoot that will occur due to turn-off delay of the power transistor. This turn-off delay is approximately 300ns. Peak switch current = DC current limit from graph + VIN/L(turn-off delay) Example: Set peak switch current to 100mA for: VIN = 2V, L = 33µH Overshoot = VIN/L(turn-off delay) = (2/33µH)(300ns) = 18.2mA Refer to RSET graph and locate (100mA – 18.2mA) ≈ 82mA RSET ≈ 33k Calculating Duty Cycle For a boost converter running in continuous conduction mode, duty cycle is constrained by VIN and VOUT according to the equation: DC = VOUT – VIN + VD VOUT – VSAT + VD where VD = diode voltage drop ≈ 0.4V and VSAT = switch saturation voltage ≈ 0.2V. If the duty cycle exceeds the LT1316’s minimum specified duty cycle of 0.73, the converter cannot operate in continuous conduction mode and must be designed for discontinuous mode operation. Inductor Selection and Peak Current Limit for Continuous Conduction Mode Peak current and inductance determine available output power. Both must be chosen properly. If peak current or inductance is increased, output power increases. Once output power or current and duty cycle are known, peak current can be set by the following equation, assuming continuous mode operation: MINIMUM INDUCTANCE FOR CONTINOUS MODE OPERATION (µH) IPEAK = 2(IOUT) 1 – DC Inductance can now be calculated using the peak current: U W U U L= VOUT – VIN + VD (tOFF) 0.4(IPEAK) (2) where tOFF = 2µs and VD = 0.4V. As a result of equations 1 and 2, ripple current during switching will be 40% of the peak current (see Figure 2). Using these equations at the specified IOUT, the part is delivering approximately 60% of its maximum output power. In other words, the part is operating on a 40% reserve. This is a safe margin to use and can be decreased if input voltage and output current are tightly controlled. For some applications, this recommended inductor size may be too large. Inductance can be reduced but available output power will decrease. Also, ripple current during switching will increase and may cause discontinuous operation. Discontinuous operation occurs when inductor current ramps down to zero at the end of each switch cycle (see Figure 4). Shown in Figure 5 is minimum inductance vs peak current for the part to remain in continuous mode. 0mA INDUCTOR CURRENT 100mA/DIV SW PIN 5V/DIV 2µs/DIV 1316 F04 Figure 4. Discontinuous Mode Operation 1000 5V TO 18V 5V TO 12V 2V TO 5V 100 (1) 10 10 100 PEAK CURRENT (mA) 1000 1316 F05 Figure 5. Minimum Inductance vs Peak Current for Continuous Mode Operation 7 LT1316 APPLICATIONS INFORMATION Discontinuous Mode Operation A boost converter with a high VOUT:VIN ratio operates with a high duty cycle in continuous mode. For duty cycles exceeding the LT1316’s guaranteed minimum specification of 0.73, the circuit will need to be designed for discontinuous operation. Additionally, very low peak current limiting below 50mA may necessitate operating in this mode unless high inductance values are acceptable. When operating in discontinuous mode, a different equation governs available output power. For each switch cycle, the inductor current ramps down to zero, completely releasing the stored energy. Energy stored in the inductor at any time is equal to 1/2 LI2. Because this energy is released each cycle, the equation for maximum power out is: 2. IPEAK = 3. Find L L= 2(IOUT) 2(10mA) = = 58mA 1 – DC 1 – 0.654 POUT(MAX) = 1/2L(IPEAK2)f 1 Where f = IPEAK(L) +t VIN – VSAT OFF ) ) When designing for very low peak currents (< 50mA), the inductor size needs to be large enough so that on-time is a least 1µs. On-time can be calculated by the equation: On-Time = ) IPEAK • L (VIN – VSAT) ) where VSAT = 0.2V. Also, at these low current levels, current overshoot due to power transistor turn-off delay will be a significant portion of peak current. Increasing inductor size will keep this to a minimum. Design Example 1 Requirements: VIN = 2V, VOUT = 5V and ILOAD = 10mA. 1. Find duty cycle DC = ) VOUT – VIN + VD = 5 – 2 + 0.4 = 0.654 VOUT – VSAT + VD 5 – 0.2 + 0.4 )) ) Because duty cycle is less than the LT1316 minimum specification (0.73), the circuit can be designed for continuous operation. 8 U W U U = 5 – 2 + 0.4 2µs 0.4(58mA) = 293µH ) ) VOUT – VIN + VD tOFF 0.4(IPEAK) ) ) 4. Find RSET resistor Overshoot = = )) )) VIN 300ns L 2 = 1.8mA 330µH Find RSET from Figure 3 for 58mA – 1.8mA = 56.2mA RSET ≈ 47k Design Example 2 Requirements: VIN = 3.3V, VOUT = 28V and ILOAD = 5mA. 1. Find duty cycle: DC = ) VOUT – VIN + VD = 28 – 3.3 + 0.4 = 0.89 VOUT – VSAT + VD 28 – 0.2 + 0.4 )) ) Because duty cycle exceeds LT1316 minimum specification of 73%, the circuit must be designed for discontinuous operation. 2. Find POUT(MAX) Multiply POUT by 1.4 to give a safe operating margin POUT(MAX) = POUT(1.4) = (5mA)(28V)(1.4) = 0.196W 3. Set the on-time to the data sheet minimum of 3.4µs and find L L= = (tON2)(VIN – VSAT)2 2POUT(MAX)(tON + tOFF) (3.4µs2)(3.3 – 0.2)2 = 52µH 2(0.196W)(3.4µs + 2µs) LT1316 APPLICATIONS INFORMATION 4. Find IPEAK for 3.4µs on-time t (V – VSAT) 3.4µs(3.3 – 0.2) IPEAK = ON IN = L 52µH = 0.202A 5. Find RSET resistor For through-hole applications Sanyo OS-CON capacitors offer extremely low ESR in a small package size. If peak switch current is reduced using the RSET pin, capacitor requirements can be eased and smaller, higher ESR units can be used. Ordinary generic capacitors can generally be used when peak switch current is less than 100mA, although output voltage ripple may increase. Diodes Most of the application circuits on this data sheet specify the Motorola MBR0520L surface mount Schottky diode. This 0.5A, low drop diode suits the LT1316 well. In lower current applications, a 1N4148 can be used although efficiency will suffer due to the higher forward drop. This effect is particularly noticeable at low output voltages. For higher output voltage applications, such as LCD bias generators, the extra drop is a small percentage of the output voltage so the efficiency penalty is small. The low cost of the 1N4148 makes it attractive wherever it can be used. In through-hole applications the 1N5818 is the all around best choice. Lowering Output Ripple Voltage To obtain lower output ripple voltage, a small feedforward capacitor of about 50pF to 100pF may be placed from VOUT to FB as detailed in Figure 6. Ripple voltages with and without the added capacitor are pictured in Figures 7 and 8. Overshoot = 3.3 = 300ns = 19mA 52µH Find RSET from Figure 3 for 0.202A – 19mA = 0.183A RSET ≈ 13k These discontinuous mode equations are designed to minimize peak current at the expense of inductor size. If smaller inductors are desired peak current must be increased. Capacitor Selection Low ESR (Equivalent Series Resistance) capacitors should be used at the output of the LT1316 to minimize output ripple voltage. High quality input bypassing is also required. For surface mount applications AVX TPS series tantalum capacitors are recommended. These have been specifically designed for switch mode power supplies and have low ESR along with high surge current ratings. SHUTDOWN L1 47µH )) )) VIN 300ns L 2 CELLS + 47µF RSET Figure 6. 2-Cell to 5V Step-Up Converter with Reduced Output Ripple Voltage U W U U D1 R1 1M 1% FB R2 324k 1% GND VIN SHDN LT1316 SW C1 100pF + VOUT 47µF 10k 1316 F06 9 LT1316 APPLICATIONS INFORMATION VOUT 100mV/DIV AC COUPLED VOUT 100mV/DIV AC COUPLED IL 100mA/DIV 100µs/DIV 1316 F07 Figure 7. Switching Waveforms for the Circuit Shown in Figure 7 Without C1. The Output Ripple Voltage is Approximately 140mVP-P Layout/Input Bypassing The LT1316’s high speed switching mandates careful attention to PC board layout. Suggested component placement is shown in Figure 9. The input supply must have low impedance at AC and the input capacitor should be placed as indicated in the figure. The value of this capacitor depends on how close the input supply is to the IC. In situations where the input supply is more than a few inches away from the IC, a 47µF to 100µF solid tantalum bypass capacitor is required. If the input supply is close to the IC, a 1µF ceramic capacitor can be used instead. The LT1316 switches current in pulses up to 0.5A, so a low impedance supply must be available. If the power source (for example, a 2 AA cell battery) is within 1 or 2 inches of the IC, the battery itself provides bulk capacitance and the RSET Figure 9. Suggested PC Layout 10 + U W U U IL 100mA/DIV 50µs/DIV 1316 F08 Figure 8. By Adding C1, Output Ripple Voltage is Reduced to Less Than 80mVP-P 1µF ceramic capacitor acts to smooth voltage spikes at switch turn-on and turn-off. If the power source is far away from the IC, inductance in the power source leads results in high impedance at high frequency. A local high capacitance bypass is then required to restore low impedance at the IC. Low-Battery Detector The LT1316 contains an independent low-battery detector that remains active when the device is shut down. This detector, actually a hysteretic comparator, has an open collector output that can sink up to 500µA. The comparator also operates below the switcher’s undervoltage lockout threshold, operating until VIN reaches approximately 1.4V. 1 2 3 4 LT1316 8 7 6 5 L VIN CIN D COUT + GND 1316 F09 VOUT LT1316 TYPICAL APPLICATIONS N Nonisolated – 48V to 5V Flyback Converter D1 1N5817 2 L3 1 D2 1N4148 7 L2 C2 0.022µF R1 1.3M Q1 R4 2M C1 0.1µF R2 1.30M 1% 7 1 2 SHDN LB0 LBI RSET R3 604k 1% – 48V 3 R5 69.8k 1% GND 4 LT1316 FB 8 6 VIN 5 SW 6 D3 1N4148 VA VOUT 5V 50mA Q3 2N3904 EFFICIENCY (%) U T1 10:1:1 3 L1 4 + C3 47µF + C4 R7 Q2 MPSA92 432k, 1% 47µF R6 121k 1% T1 = DALE LPE-4841-A313 (605-665-9301) L PRI: 2mH R DS(ON): 4.3Ω AT VGS = 2.5V R6, Q2,R7 MUST BE PLACED NEXT TO THE FB PIN IIN = 190µA WHEN VIN = 48V, ILOAD = 1mA 1316 • TA03 Efficiency vs Load Current 90 80 36VIN 70 48VIN 72VIN 60 50 40 1 10 LOAD CURRENT (mA) 100 1316 TA04 11 LT1316 TYPICAL APPLICATIONS N Positive-to-Negative Converter for LCD Bias SHUTDOWN VIN 6 VIN 7 SHDN LT1316 5 SW FB 8 L1 33µH D1 MMBD914 C2 0.01µF 50V C3 100pF 50V R1 3.3M 2.2M R2 210k CONTRAST ADJUST + 2 CELLS C1 33µF 10V RSET 3 C4: SPRAGUE 293D105X9035B2T C5: SPRAGUE 293D225X0035B2T L1: SUMIDA CD43-330 VIN 470k 1 LBO LT1316 7 SHDN RSET 3 20k 1316 TA08 + 2 CELLS C1 47µF 16V C1: AVX TPS 47µF, 16V C2: SANYO 50MV470GX L1: SUMIDA CD43-470 CAP SHUTDOWN GOOD When Solenoid Is Energized (VENERGIZE High) Peak Input Current Remains Low and Controlled, Maximizing Battery Life VENERGIZE 5V/DIV IL1 200mA/DIV VCAP 10V/DIV CAP GOOD 5V/DIV 500ms/DIV 1316 TA09 12 U + GND 4 R3 15k C4 1µF 35V D2 MMBD914 + C5 2.2µF 35V C6 0.33µF 50V D3 MBR0530L VOUT –20V 6mA 1316 TA06 Battery-Powered Solenoid Driver L1 47µH BAT-85 VCAP ZTX949 47k 6.8M 2 5k FB GND 4 8 324K 1N4148 6 VIN 5 SW LBI + C2 470µF 50V 1.3k SOLENOID 50k 2N3904 VENERGIZE LT1316 TYPICAL APPLICATIONS N Super Cap Backup Supply R1 10k READY 1M D1 0.5A 5 SW + CSUP + 0.1F 5.5V 75Ω RUN CIN, COUT: TAJB330M010R CSUP: PANASONIC EEC-S5R5V104 +VIN 25V TO 50V 0.022µF 100V CERAMIC 0.1µF 1.30M 1% 2N3904 604k 1% U L1 47µH 6 VIN CONNECT TO MAIN SUPPLY 5V 6mA 1.00M 1 LBO CIN 33µF 10V 2 357k 7 LBI SHDN RSET 3 RSET 33k LT1316 FB GND 4 8 324k 1.00M 100pF + COUT 33µF 10V 1316 TA10 D1: MBR0520LT3 L1: SUMIDA CD43-470 50V to 6V Isolated Flyback Converter T1 LPRI: 2mH 1N5817 10:1:1 3 2 + + C1 100µF 16V VOUT 6V/20mA 75% EFFICIENCY 4 1 7 – 1N4148 510k Q1 1N4148 2M 6 VIN SHDN LB0 LBI RSET 3 69.8k 1% GND 4 LT1316 FB 8 12.7k 5 SW 50k 6 7 1 2 1µF 16V CERAMIC C1 = SANYO OS-CON 100µF, 16V Q1 = ZETEX ZVN 4424A T1 = DALE LPE-4841-A313 (605-665-9301) 1316 TA11 13 LT1316 TYPICAL APPLICATIONS N LCD Bias Generator with Output Disconnect in Shutdown VBAT 1.6V TO 3.5V OPTIONAL CONNECTION L1 22µH VIN 3.3V 6 150k + C1 22µF 6.3V 7 SHUTDOWN C1: AVX TAJA226M006R C2: AVX TAJB335M035R L1: MURATA LQH3C220K04 Q1: MMBT3906LT3 Universal Serial Bus (USB) to 5V/100mA DC/DC Converter RB 100Ω L1 33µH 6 VIN SHDN LT1316 3 RSET GND R3 10k 4 FB 8 R1 324k 5 SW VIN 4V TO 7V 7 + C1 10µF 10V C1: 10µF 10V AVX TAJB106M010 C2: 33µF 10V AVX TPSC336M010 C3: 10µF ALUMINUM ELECTROLYTIC D1: MBR0520LT1 L1: 33µH SUMIDA CD43 (OR COILCRAFT DO1608) Q1: MPS1907A 14 U MBR0540LT1 100pF 50V CERAMIC Q1 VIN 5 SW FB LT1316 8 3.32M 1% VOUT 17.1V TO 19.8V 4mA SHDN RSET 3 11k 1% GND 4 4.7M 232k 1% + C2 3.3µF 35V 0.33µF 50V CERAMIC 1316 TA12 VADJ (VOUT ADJUST) 0V TO 3.3V D1 Q1 VOUT 5V 100mA + C2 33µF 10V 100pF R2 1.00M + C3 10µF 10V 1316 TA13 LT1316 PACKAGE DESCRIPTION 0.007 (0.18) 0.021 ± 0.006 (0.53 ± 0.015) * DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE ** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 0°– 8° TYP 0.016 – 0.050 0.406 – 1.270 *DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE **DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE 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 circuits as described herein will not infringe on existing patent rights. U Dimensions in inches (millimeter) unless otherwise noted. MS8 Package 8-Lead Plastic MSOP (LTC DWG # 05-08-1660) 0.118 ± 0.004* (3.00 ± 0.102) 8 76 5 0.192 ± 0.004 (4.88 ± 0.10) 0.118 ± 0.004** (3.00 ± 0.102) 1 0.040 ± 0.006 (1.02 ± 0.15) 0° – 6° TYP SEATING PLANE 0.012 (0.30) 0.0256 REF (0.65) TYP 23 4 0.034 ± 0.004 (0.86 ± 0.102) 0.006 ± 0.004 (0.15 ± 0.102) MSOP (MS8) 1197 S8 Package 8-Lead Plastic Small Outline (Narrow 0.150) (LTC DWG # 05-08-1610) 0.189 – 0.197* (4.801 – 5.004) 8 7 6 5 0.228 – 0.244 (5.791 – 6.197) 0.150 – 0.157** (3.810 – 3.988) 1 2 3 4 0.053 – 0.069 (1.346 – 1.752) 0.004 – 0.010 (0.101 – 0.254) 0.014 – 0.019 (0.355 – 0.483) 0.050 (1.270) TYP SO8 0996 15 LT1316 TYPICAL APPLICATIONS N Low Profile 2 Cell-to-28V Converter for LCD Bias VIN 6 VIN SHDN LBI LBO RSET 3 10k 1316 TA05 SHUTDOWN 2 CELLS C1 10µF C1: MURATA GRM235Y5V106Z010 C2: SPRAGUE 293D105X9035B2T C3: 0.33µF CERAMIC, 50V C4: 100pF CERAMIC, 50V D1: BAT-54 L1: MURATA LQH3C220K04 VIN 3.3V TO 4.2V + 7 C1 22µF 16V C1: AVX TAJB226M016R C2, C3: AVX TAJA105K035R C4: AVX TAJB335M035R L1: MURATA LQH3C470 RELATED PARTS PART NUMBER LTC 1163 LTC1174 LT1302 LT1304 LT1307 LTC1440/1/2 LTC1516 LT1521 ® DESCRIPTION Triple High Side Driver for 2-Cell Inputs Micropower Step-Down DC/DC Converter High Output Current Micropower DC/DC Converter 2-Cell Micropower DC/DC Converter Single Cell Micropower 600kHz PWM DC/DC Converter 2-Cell to 5V Regulated Charge Pump Micropower Low Dropout Linear Regulator Ultralow Power Single/Dual Comparators with Reference 2.8µA IQ, Adjustable Hysteresis 12µA IQ, No Inductors, 5V at 50mA from 3V Input 500mV Dropout, 300mA Current, 12µA IQ 16 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 q (408) 432-1900 FAX: (408) 434-0507q TELEX: 499-3977 q www.linear-tech.com U L1 22µH D1 VOUT 28V 5mA C4 100pF 50V C3 0.33µF 50V C2 1µF 35V 5 SW 4.32M LT1316 FB 8 204k GND 4 7 1 2 + Bipolar LCD Bias Supply L1 47µH 6 VIN 5 SW 100pF SHDN LT1316 FB 8 1N914 C2 1µF 35V 1.00M 2N3904 13V 0.5mA + 22k 10k + RSET 3 47k GND 4 C3 1µF 35V 88.7k + C4 3.3µF 35V –15V 1.5mA BAT54 ×2 (BAT54 = TWO DIODES IN SOT23) 1316 TA14 COMMENTS 1.8V Minimum Input, Drives N-Channel MOSFETs 94% Efficiency, 130µA IQ, 9V to 5V at 300mA 5V/600mA from 2V, 2A Internal Switch, 200µA IQ Low-Battery Detector Active in Shutdown, 5V at 200mA for 2 Cells 3.3V at 75mA from 1 Cell 1316f LT/TP 0298 4K • PRINTED IN USA © LINEAR TECHNOLOGY CORPORATION 1997