ADP1755 Analog Devices, ADP1755 Datasheet
ADP1755
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ADP1755 Summary of contents
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... OUT output allows power system monitors to check the health of the output voltage. The ADP1754/ADP1755 are available in a 16-lead × LFCSP, making them not only very compact solutions, but also providing excellent thermal performance for applications that require output current in a small, low profile footprint ...
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... Theory of Operation ...................................................................... 11 REVISION HISTORY 2/10—Rev Rev. B Changes to Table 4 ............................................................................ 5 Changes to Ordering Guide .......................................................... 19 4/09—Rev Rev. A Changes to Adjustable Output Voltage Accuracy (ADP1755) Parameter, Table 1 ............................................................................. 3 Changes to Table 3 ............................................................................ 5 10/08—Revision 0: Initial Version Soft Start Function (ADP1754/ADP1755) ............................. 11 Adjustable Output Voltage (ADP1755) ................................... 12 Enable Feature ............................................................................ 12 Power-Good Feature ...
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... Output Voltage Rising EN INPUT EN Input Logic High EN Input Logic Low EN Input Leakage Current UNDERVOLTAGE LOCKOUT Input Voltage Rising Input Voltage Falling Hysteresis SOFT START CURRENT ADJ INPUT BIAS CURRENT (ADP1755) SENSE INPUT BIAS CURRENT = 10 mA 4.7 μF, T OUT IN OUT Symbol Test Conditions/Comments ...
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... ADP1754/ADP1755 Parameter OUTPUT NOISE POWER SUPPLY REJECTION RATIO 1 Minimum output load current is 500 μA. 2 Accuracy when VOUT is connected directly to ADJ. When VOUT voltage is set by external feedback resistors, absolute accuracy in adjust mode depends on the tolerances of resistors used. 3 Based on an end-point calculation using 10 mA and 1.2 A loads. See 4 Dropout voltage is defined as the input to output voltage differential when the input voltage is set to the nominal output voltage ...
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... THERMAL DATA Absolute maximum ratings apply individually only, not in combination. The ADP1754/ADP1755 may be damaged if the junction temperature limits are exceeded. Monitoring ambient temperature does not guarantee that T J temperature limits. In applications with high power dissipation and poor thermal resistance, the maximum ambient temperature may need to be derated ...
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... GND inside the package recommended that the exposed pad be connected to the ground plane on the board. Rev Page PIN 1 INDICATOR 12 VOUT VIN 1 VIN 2 ADP1755 11 VOUT VIN 3 10 VOUT TOP VIEW (Not to Scale ADJ Figure 4. ADP1755 Pin Configuration ...
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... LOAD = 10mA LOAD = 100mA LOAD = 400mA 1000 LOAD = 800mA LOAD = 1.2A 3.0 3.2 3.4 3.6 Rev Page ADP1754/ADP1755 LOAD = 1.2A LOAD = 800mA 800 LOAD = 400mA 600 LOAD = 100mA 400 LOAD = 10mA 200 0 –40 – JUNCTION TEMPERATURE (°C) Figure 8. Ground Current vs. Junction Temperature ...
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... ADP1754/ADP1755 100 –40 – TEMPERATURE (°C) Figure 11. Shutdown Current vs. Temperature at Various Input Voltages 0.14 0.12 0.10 0.08 0.06 0.04 1.6V 0. 100 LOAD CURRENT (mA) Figure 12. Dropout Voltage vs. Load Current, V 2.60 2.55 2.50 2.45 2.40 2.35 2.30 2.25 2.20 2.3 2.4 2.5 2.6 INPUT VOLTAGE (V) Figure 13. Output Voltage vs. Input Voltage (in Dropout), V 4500 1.9V 2.0V 4000 2.4V 2.6V 3500 3.0V 3.6V 3000 2500 ...
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... LOAD Rev Page ADP1754/ADP1755 1.2A 800mA 400mA 100mA 10mA 100 1k 10k 100k 1M FREQUENCY (Hz) Figure 20. Power Supply Rejection Ratio vs. Frequency 0. 1.75 V OUT IN 1.2A 800mA 400mA 100mA ...
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... ADP1754/ADP1755 0 1.5V/1200mA 1.5V/10mA 2.5V/1200mA 2.5V/10mA –10 0.75V/1200mA 0.75V/10mA –20 –30 –40 –50 –60 –70 –80 –90 10 100 1k 10k FREQUENCY (Hz) Figure 23. Power Supply Rejection Ratio vs. Frequency and Output Voltage 100k 1M 10M Rev Page ...
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... the 0.5 V reference voltage. REF C is the soft start capacitance from SS to GND the current sourced from SS (0.9 μA). SS When the ADP1754/ADP1755 is disabled (using the EN pin), the soft start capacitor is discharged to GND through an internal 100 Ω VOUT resistor. 2.50 2.25 2.00 1.75 1.50 ADJ 1.25 1.00 0.9µ ...
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... Ramp-Up with Internal Soft Start OUT ADJUSTABLE OUTPUT VOLTAGE (ADP1755) The output voltage of the ADP1755 can be set over a 0. 3.0 V range. The output voltage is set by connecting a resistive voltage divider from VOUT to ADJ. The output voltage is calcu- lated using the following equation 0.5 V × ...
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... V Falling (V OUT IN REVERSE CURRENT PROTECTION FEATURE The ADP1754/ADP1755 have additional circuitry to protect against reverse current flow from VOUT to VIN. For a typical LDO with a PMOS pass device, there is an intrinsic body diode between VIN and VOUT. When V diode is reverse-biased diode becomes forward-biased and conducts current from VOUT to VIN, potentially causing destructive power dissipation ...
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... ADP1754/ADP1755. Transient response to changes in load current is also affected by output capacitance. Using a larger value of output capacitance improves the transient response of the ADP1754/ADP1755 to large changes in load current. Figure 33 and Figure 34 show the transient responses for output capacitance values of 4.7 μF and 22 μ ...
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... Consider the case where a hard short from VOUT to ground occurs. At first, the ADP1754/ADP1755 reach current limit so that only conducted into the short. If self-heating of the junction becomes great enough to cause its temperature to rise above 150° ...
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... ADP1754/ADP1755 140 MAX JUNCTION TEMPERATURE 120 LOAD = 1.2A 100 0.25 0.75 1.25 1.75 V – V (V) IN OUT 2 Figure 36. 6400 mm of PCB Copper, T 140 MAX JUNCTION TEMPERATURE 120 LOAD = 1.2A 100 LOAD = 800mA 0.25 0.75 1.25 1.75 V – V (V) IN OUT 2 Figure 37. 500 mm of PCB Copper, T 140 MAX JUNCTION ...
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... IN LOAD = 800mA 140 LOAD = 400mA 120 LOAD = 200mA 100 LOAD = 10mA 2.25 2.75 = 25°C, LFCSP B LOAD = 400mA LOAD = 200mA LOAD = 10mA 2.25 2.75 = 50°C, LFCSP B Rev Page ADP1754/ADP1755 MAX JUNCTION TEMPERATURE LOAD = 1.2A LOAD = 800mA 80 60 LOAD = 400mA LOAD = 200mA 40 LOAD = 10mA 20 LOAD = 100mA 0 0.25 0.75 1.25 1.75 2.25 V – V ...
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... PCB LAYOUT CONSIDERATIONS Heat dissipation from the package can be improved by increas- ing the amount of copper attached to the pins of the ADP1754/ ADP1755. However, as shown in Table 6, a point of diminishing returns is eventually reached, beyond which an increase in the copper size does not yield significant heat dissipation benefits. ...
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... Figure 49. 16-Lead Lead Frame Chip Scale Package [LFCSP_VQ × Body, Very Thin Quad (CP-16-4) Dimensions shown in millimeters Output Voltage (V) 0.75 1.0 1.1 1.2 1.5 1.8 2.5 Adjustable from 0.75 to 3.0 Adjustable from 0.75 to 3.0 1.5 Adjustable Rev Page ADP1754/ADP1755 0.60 MAX (BOTTOM VIEW) PIN 1 INDICATOR 0.25 MIN 1.95 BSC FOR PROPER CONNECTION OF THE EXPOSED PAD, REFER TO ...
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... ADP1754/ADP1755 NOTES ©2008–2010 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D07722-0-2/10(B) Rev Page ...