LT1316 Micropower DC/DC Converter with Programmable Peak Current Limit U DESCRIPTION FEATURES ■ ■ ■ ■ ■ ■ ■ 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. 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 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. U APPLICATIONS ■ ■ Battery Backup LCD Bias Low Power – 48V to 5V/3.3V Converters The LT1316 is available in 8-lead MSOP and SO packages. , LTC and LT are registered trademarks of Linear Technology Corporation. U ■ TYPICAL APPLICATION 2-Cell to 5V Step-Up Converter L1 47µH 7 + 2 CELLS C1 47µF D1 5 SW VIN SHDN FB 5V 50mA R1 1M 1% 8 2 LBI RSET 3 R5 10k 1% D1: MOTOROLA MBR0520L L1: SUMIDA CD43-470 LBO + GND 4 1 3.3VIN 2.5VIN LT1316 NC 90 C2 47µF NC R2 324k 1% EFFICIENCY (%) 6 Efficiency vs Load Current 1.8VIN 80 70 60 1316 TA01 0.1 1 10 100 LOAD CURRENT (mA) 1316 TA02 1 LT1316 W U U W W W 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 U ABSOLUTE MAXIMUM RATINGS PACKAGE/ORDER INFORMATION ORDER PART NUMBER TOP VIEW LBO LBI RSET GND 8 7 6 5 1 2 3 4 FB SHDN VIN SW LT1316CMS8 MS8 PACKAGE 8-LEAD PLASTIC MSOP MS8 PART MARKING TJMAX = 125°C, θJA = 160°C/W LTCD ORDER PART NUMBER TOP VIEW LBO 1 8 FB LBI 2 7 SHDN RSET 3 6 VIN GND 4 5 SW LT1316CS8 LT1316IS8 S8 PART MARKING S8 PACKAGE 8-LEAD PLASTIC SO 1316 1316I 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 CONDITIONS MIN Minimum Operating Voltage TYP MAX UNITS 1.5 1.65 V Maximum Operating Voltage Quiescent Current 12 V 33 45 50 µA µA ● ● 3 7 5 10 µA µA ● 3 30 nA VSHDN = 2V, Not Switching ● Quiescent Current in Shutdown VSHDN = 0V, VIN = 2V VSHDN = 0V, VIN = 5V FB Pin Bias Current Line Regulation VIN = 1.8V to 12V ● LBI Input Threshold Falling Edge ● LBI Pin Bias Current 1.1 ● LBI Input Hysteresis 0.04 0.15 %/V 1.17 1.25 V 3 20 nA ● 35 65 mV LBO Output Voltage Low ISINK = 500µA ● 0.2 0.4 V LBO Output Leakage Current LBI = 1.7V, LBO = 5V ● 0.01 0.1 µA 0.4 V V 5 –3 µA µA SHDN Input Voltage High SHDN Input Voltage Low SHDN Pin Bias Current 2 ● ● VSHDN = 5V VSHDN = 0V ● ● 1.4 2 –1 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 CONDITIONS Switch OFF Time FB > 1V ● MIN TYP MAX UNITS 1.4 1.1 2.0 2.6 3.0 µs µs FB < 1V µs 3.4 Current Limit Not Asserted 1V < FB < 1.2V 4.4 3.4 6.3 ● 8.2 9.5 µs µs Current Limit Not Asserted 1V < FB < 1.2V 74 73 76 ● 90 90 % % Switch Saturation Voltage ISW = 0.5A ISW = 0.1A ● ● 0.30 0.06 0.4 0.15 V V Switch Leakage Switch Off, VSW = 5V ● 0.1 5 µA 1.21 1.23 1.25 V 90 90 70 100 100 90 110 115 110 mA mA mA ● 250 290 25 340 mA mA ● 1.205 1.23 1.255 ● ● 70 200 100 290 125 370 Switch ON Time Maximum Duty Cycle 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 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 The ● 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 V mA mA 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. U W TYPICAL PERFORMANCE CHARACTERISTICS Burst ModeTM Operation Load Transient Response VOUT 100mV/DIV AC COUPLED VOUT 100mV/DIV AC COUPLED 50mA VSW 5V/DIV ILOAD INDUCTOR CURRENT 200mA/DIV 0mA 1316 G01 1316 G02 Burst Mode IS A TRADEMARK OF LINEAR TECHNOLOGY CORPORATION. 3 LT1316 U W TYPICAL PERFORMANCE CHARACTERISTICS Switch Saturation Voltage vs Switch Current LBI Pin Bias Current vs Temperature Off-Time vs Temperature 8 4 6 3 75°C 100°C 300 –40°C 200 25°C 100 0 0 OFF-TIME (µs) 400 LBI PIN CURRENT (nA) SWITCH SATURATION VOLTAGE (mV) 500 4 2 1 0 –50 100 200 300 400 500 600 700 800 SWITCH CURRENT (mA) –25 0 25 50 TEMPERATURE (°C) 75 Maximum On-Time vs Temperature –25 0 25 50 TEMPERATURE (°C) 75 34 32 30 28 26 –50 100 –25 0 25 50 TEMPERATURE (°C) 75 1316 G06 75 100 1316 G11 –25 0 25 50 TEMPERATURE (°C) 75 100 1316 G08 RSET = 4.84k PEAK SWITCH CURRENT (mA) FB PIN BIAS CURRENT (nA) SHUTDOWN PIN CURRENT (µA) 0 25 50 TEMPERATURE (°C) 1.220 –50 1000 3 2 1 0 –1 –25 1.225 Peak Switch Current vs Temperature 4 2 1 –50 100 1.230 Shutdown Pin Bias Current vs Shutdown Pin Voltage 4 100 1.235 1316 G07 FB Pin Bias Current vs Temperature 3 75 Feedback Voltage vs Temperature FEEDBACK VOLTAGE (V) QUIESCENT CURRENT (µA) MAXIMUM ON-TIME (µs) 6 0 25 50 TEMPERATURE (°C) 1.240 36 7 –25 1316 G05 Quiescent Current vs Temperature 8 4 0 –50 100 1316 G04 1316 G03 5 –50 2 0 1 2 3 4 5 SHUTDOWN PIN VOLTAGE (V) 6 1316 G09 RSET = 10k RSET = 27.4k 100 RSET = 97.3k 10 –50 –25 0 25 50 TEMPERATURE (°C) 75 100 1316 G10 LT1316 U U U PIN FUNCTIONS SW (Pin 5): Collector of NPN Power Transistor. Keep traces at this pin as short as possible. LBO (Pin 1): Low-Battery Detector Output. Open collector can sink up to 500µA. Low-battery detector remains active in shutdown mode. VIN (Pin 6): Input Supply. Must be bypassed close to the pin. LBI (Pin 2): Low-Battery Detector Input. When voltage at this pin drops below 1.17V, LBO goes low. 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). 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. 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). GND (Pin 4): Ground. Connect directly to ground plane. W BLOCK DIAGRA D1 L1 VOUT VIN C1 LB0 6 1 + A3 – 5 SW 1.5V UNDERVOLTAGE LOCKOUT R4 R3 = 10R4 – 1.17V – + 8 FB R2 A1 + LBI 2 VIN R1 A2 VREF 1.23V 0.5V + DRIVER A4 Q2 ×1 – 3 Q1 ×200 7 4 RSET OSCILLATOR 6.3µs ON 2µs OFF GND 1316 F01 SHDN R5 Figure 1. LT1316 Block Diagram 5 LT1316 U W U U 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. 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. VOUT can be set using the equation: 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. ) ) R2 + R1 VOUT = 1.23 R2 R1 FB R2 1316 EQF01 Table 1. RSET Resistor and Inductor Values VIN VOUT LOAD CURRENT RSET RESISTOR INDUCTOR PEAK SWITCH CURRENT 2 5 10mA 36.8k 100µH 80mA 2 5 25mA 18.2k 68µH 165mA 2 5 50mA 10k 47µH 320mA 2 5 75mA 6.81k 33µH 500mA 5 12 100mA 6.81k 82µH 490mA 5 28 1mA 75k 100µH 56mA 5 28 5mA 22.1k 100µH 140mA 5 28 10mA 10k 100µH 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 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 DC CURRENT LIMIT (mA) VOUT 100 VSW 5V/DIV 10 INDUCTOR CURRENT 100mA/DIV 10 100 RSET (kΩ) 1316 F03 10µs/DIV Figure 2. Switching Waveforms 6 1316 F02 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 U W U U 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: VOUT – VIN + VD VOUT – VSAT + VD 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. 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. SW PIN 5V/DIV 2µs/DIV 1316 F04 Figure 4. Discontinuous Mode Operation 1000 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: 2(IOUT) 1 – DC (2) 0mA INDUCTOR CURRENT 100mA/DIV where VD = diode voltage drop ≈ 0.4V and VSAT = switch saturation voltage ≈ 0.2V. IPEAK = VOUT – VIN + VD (tOFF) 0.4(IPEAK) (1) Inductance can now be calculated using the peak current: MINIMUM INDUCTANCE FOR CONTINOUS MODE OPERATION (µH) DC = L= 5V TO 12V 5V TO 18V 2V TO 5V 100 10 10 100 PEAK CURRENT (mA) 1000 1316 F05 Figure 5. Minimum Inductance vs Peak Current for Continuous Mode Operation 7 LT1316 U U W U 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: POUT(MAX) = 1/2L(IPEAK2)f ) 1 Where f = IPEAK(L) +t VIN – VSAT OFF ) ) IPEAK • L (VIN – VSAT) 2(IOUT) 2(10mA) = = 58mA 1 – DC 1 – 0.654 3. Find L L= ) ) ) VOUT – VIN + VD tOFF 0.4(IPEAK) ) = 5 – 2 + 0.4 2µs 0.4(58mA) = 293µH 4. Find RSET resistor Overshoot = = ) ) ) ) VIN 300ns L 2 = 1.8mA 330µH Find RSET from Figure 3 for 58mA – 1.8mA = 56.2mA 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 = 2. IPEAK = ) RSET ≈ 47k Design Example 2 Requirements: VIN = 3.3V, VOUT = 28V and ILOAD = 5mA. 1. Find duty cycle: DC = 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. ) )) ) 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) Design Example 1 Multiply POUT by 1.4 to give a safe operating margin Requirements: VIN = 2V, VOUT = 5V and ILOAD = 10mA. POUT(MAX) = POUT(1.4) = (5mA)(28V)(1.4) = 0.196W 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 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 U W U U APPLICATIONS INFORMATION 4. Find IPEAK for 3.4µs on-time 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. t (V – VSAT) 3.4µs(3.3 – 0.2) IPEAK = ON IN = L 52µH = 0.202A 5. Find RSET resistor Overshoot = ) ) ) ) VIN 300ns L Diodes 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. VIN 2 CELLS 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. L1 47µH SHUTDOWN D1 R1 1M 1% SW SHDN + 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. + VOUT 47µF FB R2 324k 1% LT1316 47µF C1 100pF RSET GND 10k 1316 F06 Figure 6. 2-Cell to 5V Step-Up Converter with Reduced Output Ripple Voltage 9 LT1316 U W U U APPLICATIONS INFORMATION VOUT 100mV/DIV AC COUPLED VOUT 100mV/DIV AC COUPLED IL 100mA/DIV IL 100mA/DIV 1316 F07 100µs/DIV 50µs/DIV Figure 7. Switching Waveforms for the Circuit Shown in Figure 7 Without C1. The Output Ripple Voltage is Approximately 140mVP-P Figure 8. By Adding C1, Output Ripple Voltage is Reduced to Less Than 80mVP-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 1 RSET 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. 8 2 LT1316 7 3 6 4 5 VIN L + CIN D GND COUT + 1316 F09 VOUT Figure 9. Suggested PC Layout 10 1316 F08 LT1316 U TYPICAL APPLICATIONS N Nonisolated – 48V to 5V Flyback Converter VOUT 5V 50mA D1 1N5817 T1 10:1:1 3 2 L1 L3 4 1 + C3 47µF D2 1N4148 7 L2 6 R1 1.3M C2 0.022µF D3 1N4148 VA Q1 R4 2M 7 C1 0.1µF Q3 2N3904 R2 1.30M 1% 1 2 + C4 5 SW 6 VIN 47µF SHDN LB0 LT1316 FB R6 121k 1% LBI GND RSET 3 R5 69.8k 1% R3 604k 1% R7 Q2 MPSA92 432k, 1% 8 4 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 – 48V Efficiency vs Load Current 90 80 EFFICIENCY (%) 36VIN 70 48VIN 60 72VIN 50 40 1 10 LOAD CURRENT (mA) 100 1316 TA04 11 LT1316 U TYPICAL APPLICATIONS N Positive-to-Negative Converter for LCD Bias D1 MMBD914 L1 33µH SHUTDOWN VIN 6 VIN 7 + SHDN C1 33µF 10V 2 CELLS FB C3 100pF 50V C2 0.01µF 50V 5 SW R1 3.3M 2.2M 8 CONTRAST ADJUST R2 210k LT1316 + RSET GND 3 4 C4 1µF 35V + C6 0.33µF 50V C5 2.2µF 35V D2 MMBD914 R3 15k VOUT –20V 6mA D3 MBR0530L C4: SPRAGUE 293D105X9035B2T C5: SPRAGUE 293D225X0035B2T L1: SUMIDA CD43-330 1316 TA06 Battery-Powered Solenoid Driver L1 47µH VCAP BAT-85 ZTX949 VIN 6 470k VIN 1 + 2 CELLS C1 47µF 16V 47k 5 SW LBO LBI 2 LT1316 7 SHDN RSET 3 + 5k FB GND 1N4148 6.8M 8 4 324K C2 470µF 50V 1.3k SOLENOID 50k 2N3904 VENERGIZE 20k 1316 TA08 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 12 1316 TA09 LT1316 U TYPICAL APPLICATIONS N Super Cap Backup Supply R1 10k READY 1M D1 0.5A L1 47µH 6 VIN + CSUP + 0.1F 5.5V 75Ω CONNECT TO MAIN SUPPLY 5V 6mA 5 SW 1.00M 1 LBO CIN 33µF 10V 2 357k 7 + LT1316 LBI 100pF 1.00M FB SHDN RSET GND 3 4 8 COUT 33µF 10V 324k RSET 33k RUN CIN, COUT: TAJB330M010R CSUP: PANASONIC EEC-S5R5V104 1316 TA10 D1: MBR0520LT3 L1: SUMIDA CD43-470 50V to 6V Isolated Flyback Converter T1 LPRI: 2mH 1N5817 10:1:1 +VIN 25V TO 50V 3 4 2 C1 100µF 16V 1 7 510k 0.022µF 100V CERAMIC + + VOUT 6V/20mA 75% EFFICIENCY – 1N4148 Q1 1N4148 6 2M 7 0.1µF 1.30M 1% 1 2 2N3904 604k 1% 6 VIN 5 SW SHDN LB0 50k LT1316 FB 8 12.7k LBI RSET GND 3 4 69.8k 1% 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 U TYPICAL APPLICATIONS N LCD Bias Generator with Output Disconnect in Shutdown VBAT 1.6V TO 3.5V 150k OPTIONAL CONNECTION L1 22µH MBR0540LT1 VIN 3.3V 6 + 5 SW VIN C1 22µF 6.3V 100pF 50V CERAMIC 3.32M 1% FB Q1 8 VOUT 17.1V TO 19.8V 4mA LT1316 7 SHUTDOWN SHDN RSET GND 3 4 4.7M + 232k 1% 0.33µF 50V CERAMIC C2 3.3µF 35V 11k 1% 1316 TA12 VADJ (VOUT ADJUST) 0V TO 3.3V 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 VIN 4V TO 7V D1 VOUT 5V 100mA Q1 7 + C1 10µF 10V 6 VIN 5 SW + SHDN LT1316 3 RSET FB 100pF R2 1.00M + C3 10µF 10V 8 GND R3 10k C2 33µF 10V 4 R1 324k 1316 TA13 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 LT1316 U PACKAGE DESCRIPTION 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 7 6 5 0.118 ± 0.004** (3.00 ± 0.102) 0.192 ± 0.004 (4.88 ± 0.10) 1 2 3 4 0.040 ± 0.006 (1.02 ± 0.15) 0.007 (0.18) 0.034 ± 0.004 (0.86 ± 0.102) 0° – 6° TYP SEATING PLANE 0.012 (0.30) 0.0256 REF (0.65) TYP 0.021 ± 0.006 (0.53 ± 0.015) 0.006 ± 0.004 (0.15 ± 0.102) * 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 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 0.150 – 0.157** (3.810 – 3.988) 0.228 – 0.244 (5.791 – 6.197) 1 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 2 3 0.053 – 0.069 (1.346 – 1.752) 0°– 8° TYP 0.016 – 0.050 0.406 – 1.270 0.014 – 0.019 (0.355 – 0.483) *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. 4 0.004 – 0.010 (0.101 – 0.254) 0.050 (1.270) TYP SO8 0996 15 LT1316 U TYPICAL APPLICATIONS N Low Profile 2 Cell-to-28V Converter for LCD Bias L1 22µH VIN 7 SHUTDOWN 1 C1 10µF 2 CELLS 2 6 VIN D1 5 SW C4 100pF 50V 4.32M SHDN LT1316 LBI VOUT 28V 5mA FB LBO + 8 C3 0.33µF 50V C2 1µF 35V 204k RSET GND 3 4 10k 1316 TA05 C1: MURATA GRM235Y5V106Z010 C2: SPRAGUE 293D105X9035B2T C3: 0.33µF CERAMIC, 50V C4: 100pF CERAMIC, 50V D1: BAT-54 L1: MURATA LQH3C220K04 Bipolar LCD Bias Supply L1 47µH VIN 3.3V TO 4.2V 1N914 6 VIN 7 + C1 22µF 16V 2N3904 C2 1µF 35V 5 SW SHDN LT1316 FB RSET GND 3 4 100pF 1.00M C3 1µF 35V 88.7k + 22k 13V 0.5mA 10k 8 + 47k BAT54 ×2 + C4 3.3µF 35V –15V 1.5mA (BAT54 = TWO DIODES IN SOT23) 1316 TA14 C1: AVX TAJB226M016R C2, C3: AVX TAJA105K035R C4: AVX TAJB335M035R L1: MURATA LQH3C470 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LTC 1163 Triple High Side Driver for 2-Cell Inputs 1.8V Minimum Input, Drives N-Channel MOSFETs LTC1174 Micropower Step-Down DC/DC Converter 94% Efficiency, 130µA IQ, 9V to 5V at 300mA LT1302 High Output Current Micropower DC/DC Converter 5V/600mA from 2V, 2A Internal Switch, 200µA IQ LT1304 2-Cell Micropower DC/DC Converter Low-Battery Detector Active in Shutdown, 5V at 200mA for 2 Cells LT1307 Single Cell Micropower 600kHz PWM DC/DC Converter 3.3V at 75mA from 1 Cell LTC1440/1/2 LTC1516 Ultralow Power Single/Dual Comparators with Reference 2.8µA IQ, Adjustable Hysteresis 2-Cell to 5V Regulated Charge Pump 12µA IQ, No Inductors, 5V at 50mA from 3V Input LT1521 Micropower Low Dropout Linear Regulator ® 16 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 ● (408) 432-1900 FAX: (408) 434-0507● TELEX: 499-3977 ● www.linear-tech.com 500mV Dropout, 300mA Current, 12µA IQ 1316f LT/TP 0298 4K • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 1997