LD2982Axx LD2982Bxx
Very low drop and low noise voltage regulator with inhibit function, low ESR capacitors compatible
Features
■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■
Very low dropout voltage (120 mV at 50 mA and 7 mV at 1 mA load) Very low quiescent current (375 mA typ. at 50 mA load and 75 mA at 1 mA) Output current up to 50 mA Logic controlled electronic shutdown Output voltage of 1.8, 2.7, 3.2, 3.3 V Internal current and thermal limit Available in ± 1 % tolerance (at 25 °C, A version) Supply voltage rejection: 45 dB (typ) Only 1 µF for stability Low output noise voltage 30 µVrms Smallest package SOT23-5L Temperature range: -40 °C to 125 °C An external capacitor CBYP = 10 nF connected between bypass pin and GND reduce the noise to 30 µVrms. Typical application are in cellular phone, palmtop/laptop computer, personal digital assistant (PDA), personal stereo, camcorder and camera.
SOT23-5L
Description
The LD2982A/Bxx is a 50 mA fixed output voltage regulator. The ultra low drop voltage and the low quiescent current make them particularly suitable for low noise, low power applications, and in battery powered systems. In sleep mode quiescent current is less than 1 µA when INHIBIT pin is pulled low. Shutdown logic control function is available on pin 3 (TTL compatible). This means that when the device is used as local regulator, it is possible to put a part of the board in standby, decreasing the total power consumption. Table 1. Device summary
Part numbers A Version LD2982AXX18 LD2982AXX27 LD2982AXX32 B Version LD2982BXX18 LD2982BXX27 LD2982BXX32 Output voltage 1.8 V 2.7 V 3.2 V
July 2008
Rev 6
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LD2982Axx - LD2982Bxx
Contents
1 2 3 4 5 6 Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Typical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Application notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
6.1 6.2 6.3 6.4 6.5 6.6 External capacitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Input capacitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Output capacitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Important . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Inhibit input operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Reverse current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
7 8 9
Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Order codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
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LD2982Axx - LD2982Bxx
Diagram
1
Figure 1.
Diagram
Schematic diagram
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Pin configuration
LD2982Axx - LD2982Bxx
2
Figure 2.
Pin configuration
Pin connections (top view)
Table 2.
Pin n° 1 2 3 4 5
Pin description
Symbol IN GND INHIBIT Bypass OUT Input port Ground pin Control switch ON/OFF. Inhibit is not internally pulled-up; it cannot be left floating. Disable the device when connected to GND or to a positive voltage less than 0.18V Bypass Pin: Capacitor to be connected to GND in order to improve the thermal noise performances Output port Name and function
Table 3.
Symbol RthJC RthJA
Thermal data
Parameter Thermal resistance junction-case Thermal resistance junction-ambient SOT23-5L 81 255 Unit °C/W °C/W
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LD2982Axx - LD2982Bxx
Maximum ratings
3
Table 4.
Maximum ratings
Absolute maximum ratings
Parameter DC input voltage INHIBIT input voltage Output current Power dissipation Storage temperature range Operating junction temperature range Value 16 16 Internally limited Internally limited -65 to 150 -40 to 125 °C °C Unit V V
Symbol VI VINH IO PD TSTG TOP
Note:
Absolute maximum ratings are those values beyond which damage to the device may occur. Functional operation under these condition is not implied.
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Electrical characteristics
LD2982Axx - LD2982Bxx
4
Table 5.
Symbol VOP VO
Electrical characteristics
Electrical characteristics for LD2982A (TJ = 25 °C, VI = VO + 1 V, IO =1 mA, VSHDN = 2V, CI = CO = 1 µF, unless otherwise specified).
Parameter Operating input voltage VI = 2.5V Output voltage IO = 1 to 50mA IO = 1 to 50mA, TJ= -40 to 125°C VI = 2.8V VO Output voltage IO = 1 to 50mA IO = 1 to 50mA, TJ= -40 to 125°C VI = 3.5V VO Output voltage IO = 1 to 50mA IO = 1 to 50mA, TJ= -40 to 125°C VI = 3.8V VO Output voltage IO = 1 to 50mA IO = 1 to 50mA, TJ= -40 to 125°C VI = 3.85V VO Output voltage IO = 1 to 50mA IO = 1 to 50mA, TJ= -40 to 125°C VI = 4.0V VO Output voltage IO = 1 to 50mA IO = 1 to 50mA, TJ= -40 to 125°C VI = 4.1V VO Output voltage IO = 1 to 50mA IO = 1 to 50mA, TJ= -40 to 125°C VI = 4.2V VO Output voltage IO = 1 to 50mA IO = 1 to 50mA, TJ= -40 to 125°C VI = 4.3V VO Output voltage IO = 1 to 50mA IO = 1 to 50mA, TJ= -40 to 125°C VI = 4.5V VO Output voltage IO = 1 to 50mA IO = 1 to 50mA, TJ= -40 to 125°C VI = 4.6V VO Output voltage IO = 1 to 50mA IO = 1 to 50mA, TJ= -40 to 125°C VI = 4.8V VO Output voltage IO = 1 to 50mA IO = 1 to 50mA, TJ= -40 to 125°C Test conditions Min. 2.5 1.485 1.477 1.470 1.782 1.773 1.764 2.475 2.462 2.45 2.772 2.758 2.744 2.821 2.807 2.793 2.970 2.955 2.94 3.069 3.053 3.038 3.168 3.152 3.136 3.267 3.250 3.234 3.465 3.447 3.43 3.564 3.546 3.528 3.762 3.743 3.724 3.8 3.6 3.5 3.3 3.2 3.1 3.0 2.85 2.8 2.5 1.8 1.5 Typ. Max. 16 1.515 1.523 1.530 1.818 1.827 1.836 2.525 2.537 2.55 2.828 2.842 2.856 2.879 2.893 2.907 3.030 3.045 3.06 3.131 3.146 3.162 3.232 3.248 3.264 3.333 3.349 3.366 3.535 3.552 3.57 3.636 3.654 3.672 3.838 3.857 3.876 V V V V V V V V V V V V Unit V
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LD2982Axx - LD2982Bxx Table 5.
Symbol
Electrical characteristics
Electrical characteristics for LD2982A (continued) (TJ = 25 °C, VI = VO + 1 V, IO =1 mA, VSHDN = 2V, CI = CO = 1 µF, unless otherwise specified).
Parameter VI = 5.0V Test conditions Min. 3.96 3.94 3.92 4.653 4.629 4.606 4.95 4.925 4.9 150 0.003 0.014 0.032 1 7 40 120 80 100 200 600 0 1 45 0.15 2 5 0 30 15 -1 dB V V µA µV 3 5 10 15 60 90 150 225 100 150 150 200 300 400 900 1200 µA mV %/VI 5 4.7 Typ. 4 Max. 4.04 4.06 4.08 4.747 4.77 4.794 5.05 5.075 5.1 mA V V V Unit
VO
Output voltage
IO = 1 to 50mA IO = 1 to 50mA, TJ= -40 to 125°C VI = 5.7V
VO
Output voltage
IO = 1 to 50mA IO = 1 to 50mA, TJ= -40 to 125°C VI = 6.0V
VO ISC ΔVO/ΔVI
Output voltage Short circuit current Line regulation
IO = 1 to 50mA IO = 1 to 100 mA, TJ= -40 to 125°C RL = 0 VI = VO + 1V to 16V, IO = 1 mA VI = VO + 1V to 16V, IO = 1 mA, TJ= -40 to 125°C IO = 0 IO = 0, TJ= -40 to 125°C IO = 1mA IO = 1mA, TJ= -40 to 125°C IO = 10mA IO = 10mA, TJ= -40 to 125°C IO = 50mA IO = 50mA, TJ= -40 to 125°C IO = 0 IO = 0, TJ= -40 to 125°C IO = 1mA
VDROP
Dropout voltage
Quiescent current ON MODE IQ
IO = 1mA, TJ= -40 to 125°C IO = 10mA IO = 10mA, TJ= -40 to 125°C IO = 50mA IO = 50mA, TJ= -40 to 125°C VINH
