sc172mltrt Semtech Corporation, sc172mltrt Datasheet
sc172mltrt
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sc172mltrt Summary of contents
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... Standby current is less than 10μA when disabled. The device is available in a low profile, thermally en- hanced MLPD-3x3mm 10-pin package. VIN BST LX SC172 VDD FB PGOOD Power Good EN/PSV TON PGND AGND © 2010 Semtech Corporation Synchronous Step-Down TM internal switch- DS(ON) VOUT = 0.75V to 95% VIN TM 1 ...
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... Date Code(Example: 0952) xxxx = Semtech Lot Number(Example: 3901) © 2010 Semtech Corporation Ordering Information Device SC172MLTRT SC172EVB VDD Notes: AGND 1) Available in tape and reel packaging only. A reel contains 3000 devices. TON 2) Available in lead-free packaging only. WEEE compliant and Halogen EN/PSV free ...
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... FB On-Time Threshold Frequency Programming Range FB Input Bias Current © 2010 Semtech Corporation Recommended Operating Conditions Supply Input Voltage……………………………… 5.5V Maximum Continuous Output Current …………………… 2A Thermal Information -0 ...
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... Noise Immunity Delay Time Leakage Power Good On-Resistance Fault Protection Output Under-Voltage Fault Output Over-Voltage Fault Smart PowerSave Protection Threshold OV, UV Fault Noise Immunity Delay Over-Temperature Shutdown © 2010 Semtech Corporation < 125°C J Symbol Conditions Continuous Mode V =5V, V =3V, R =66.7kΩ IN OUT ...
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... BST Switch On resistance Internal Power MOSFETs Current Limit LX Leakage Current Switch Resistance Non-overlap time (1) Note: (1) Typical value from EVB, not ATE tested. © 2010 Semtech Corporation < 125°C J Symbol Conditions EN/PSV = VDD or 0V EN/PSV floating Valley Current Limit, VDD=5V Valley Current Limit, VDD=3V VIN=5 ...
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... On-time set input. Set the on-time by a series resistor to AGND 9 AGND Analog Ground. 10 VDD Input power for internal control circuit. Needs 1mF decoupling capacitor from this pin to AGND. Thermal pad for heatsinking purposes. Connect to ground plane using multiple vias. Not con- PAD nected internally. © 2010 Semtech Corporation SC172 . 6 ...
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... Block Diagram 10 VDD AGND Reference 9 Soft Start TON © 2010 Semtech Corporation PGOOD Control Gate Drive Control On-Time Generator Zero-Cross Valley Current Limit 1 VDD BST VIN VDD PGND ...
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... Vo=1.2V, R 75.0 TON L : DS86C-B992AS-2R0N OUT 70.0 C :22 m F+0 OUT Forced Continuous Mode 65.0 Red:Vin = 3.5V Green: Vin = 4.0V 60.0 Blue: Vin = 5.0V 55.0 50.0 0 0.5 1 Output Current (A) © 2010 Semtech Corporation 3.350 3.344 3.338 3.332 3.326 3.320 1.5 2 1.224 1.223 1.222 1.221 1.220 1.219 1.218 1.217 1.216 1.5 2 1.225 1.223 1.220 = 24.9kOhm 1 ...
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... V =V BST IN -0.0140 -0.0160 -0.0180 -0.0200 -40 - Temperature (°C) © 2010 Semtech Corporation Start up waveform ( Channel 1: 500mV/Div, Channel 4: 1A/Div, Time: 0.5ms/Div 60 80 100 120 Load Transient Test ( Forced Continuous Conduction Mode OUT 2:5V/Div,Channel 4: 1A/Div, Time:10µs/Div) 85 110 135 ...
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... Temperature (°C) © 2010 Semtech Corporation Load Transient Test ( PSAVE Mode Enabled, L 50mV/Div, Channel 2:5V/Div,Channel 4:1A/Div,Time:10µs/Div) 85 110 135 Load Transient Test ( PSAVE Mode Enabled, L 50mV/Div,Channel 2:5V/Div,Channel 4:1A/Div, Time:10µs/Div) Blue: VDD=3.0V Black: VDD=5.0V ...
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... C OUT Figure 1 — PWM Control Method, V © 2010 Semtech Corporation The adaptive on-time is determined by an internal one- shot timer. When the one-shot is triggered by the out- put ripple, the device sends a single on-time pulse to the high-side MOSFET. The pulse period is determined by ...
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... OUT R 2 © 2010 Semtech Corporation Enable and Power-save Inputs The EN/PSV input is used to enable or disable the switch- V ing regulator. When EN/PSV is low (grounded), the switch LPF OUT ing regulator is off and in its lowest power state. When ...
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... Smart Power Save Protection Active loads may leak current from a higher voltage into the switcher output. Under light load conditions with © 2010 Semtech Corporation power save enabled, this can force V and reach the over-voltage threshold, resulting in a hard shutdown. Smart power save prevents this condition. ...
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... This soft start operation is implemented even if FCM is selected. FCM operation is allowed only after PGOOD is high. © 2010 Semtech Corporation Power Good Output The power good (PGOOD) output is an open-drain output I PEAK which requires a pull-up resistor ...
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... A resistor ( used to program the on-time (indirectly TON setting the frequency) using the following equation un- © 2010 Semtech Corporation der zero load condition. Since the f R should be programmed at 600kHz under zero load TON to achieve 800kHz at full load ...
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... Since this 2% error comes from 1/2 of the ripple voltage, the allowable ripple is 4%, or 40mV for a 1V out- put. © 2010 Semtech Corporation The maximum ripple current of 0.511A creates a ripple voltage across the ESR. The maximum ESR value allowed is shown by the following equations. ...
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... This form of instability can usually be avoided by providing the FB pin with a smooth, clean ripple signal that is at least 10mVp-p, which may dictate the need to © 2010 Semtech Corporation increase the ESR of the output capacitors also im- perative to provide a proper PCB layout as discussed in the Layout Guidelines section ...
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... C =39pF can be used for many output volt ages and loads. © 2010 Semtech Corporation Output Voltage Dropout The output voltage adjustable range for continuous- conduction operation is limited by the fixed 320ns (typi- cal) minimum off-time. When working with low input voltages, the duty-factor limit must be calculated using worst-case values for on and off times ...
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... PVIN pin, the device is designed and guaranteed to tolerate the short transient voltages, of maximum 20ns duration, that will appear on the LX pin due to the © 2010 Semtech Corporation deadtime diode conduction, as long as the transient volt- age on PVIN is less than 6.0V. The time duration of the transient LX pin voltage is measured on the voltage por- tion which is either over 6 ...
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... It is recommended to get the power from VIN through an RC filtering network consisted of R1, C6 and C10. The value of R1 can be between 3.01W and 10W and the capacitance of C10 should be above 1mF. C6, with a value of 1nF, is the high frequency filtering capacitor. The © 2010 Semtech Corporation ...
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... R6 in series with C9 is connected to the LX pin (through the via) to the power ground the coupling capacitor which injects the ramp signal generated the FB pin of the SC172 the pull up resistor for the PGOOD pin. © 2010 Semtech Corporation 21 ...
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... VIN © 2010 Semtech Corporation V IN C11 C1 PGND AGND PGND AGND Top Layer C6 R1 AGND C10 R2 EN/PSV Inner Layer 1 22 ...
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... VIN PGND © 2010 Semtech Corporation PGND 5 6 AGND AGND SC172 Inner Layer 2 Bottom Layer 23 ...
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... Application Circuit: Buck Converter with 1.2V out and load current (Vin= 5V) VIN+ C101 C1 10uF/6.3V VIN- 0.1uF/6.3V VOUT 22uF/6.3v 22uF/6.3v VOUT- 38p FB Application Circuit: Buck Converter with 3.3V out and load current (Vin=5V) © 2010 Semtech Corporation 1uF/6. 2.0uH R6 R4 100k 9.09k R5 C10 2.49k C18 68pF C19 R2 ...
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... Outline Drawing - MLPD-10 3x3 A PIN 1 INDICATOR (LASER MARK) aaa C 1 LxN E D/2 NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS TERMINALS. © 2010 Semtech Corporation D B DIM aaa bbb A SEATING ...
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... SHALL BE CONNECTED TO A SYSTEM GROUND PLANE. SHALL BE CONNECTED TO A SYSTEM GROUND PLANE. FAILURE MAY COMPROMISE THE THERMAL AND/OR FAILURE MAY COMPROMISE THE THERMAL AND/OR FUNCTIONAL PERFORMANCE OF THE DEVICE. FUNCTIONAL PERFORMANCE OF THE DEVICE. © 2010 Semtech Corporation K DIM C K DIMENSIONS ...
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... Semtech products for any such unauthorized application, the customer shall indemnify and hold Semtech and its officers, em- ployees, subsidiaries, affiliates, and distributors harmless against all claims, costs damages and attorney fees which could arise. Contact Information © 2010 Semtech Corporation Semtech Corporation Power Mangement Products Division ...