ST LD2979M30TR, LD2979M33TR, LD2979M38TR, LD2979M50TR User Manual

LD2979xx

Very low drop voltage regulators with inhibit

Features

■Very low dropout voltage (0.2 V typ. at 50 mA load)

■ Very low quiescent current (typ. 500 µA at 50 mA load)

■Output current up to 50 mA

■Logic-controlled electronic shutdown

SOT23-5L

■Output voltages of 3.0; 3.3; 3.8; 5.0 V

■Internal current and thermal limit

■Supply voltage rejection: 63 dB (typ)

■Only 1 µF for stability

■Selection at 25 °C

■Temperature range: -25 °C to 125 °C

■Package available: SOT23-5L

Description

The LD2979 series are very low drop regulators available in SOT23-5L.

The very low drop-voltage and the very low quiescent current make them particularly suitable for low noise, low power applications and in battery powered systems.

Shutdown logic control function is available on five pin version (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	Order codes	Output voltages
	LD2979XX30	LD2979M30TR	3.0 V
	LD2979XX33	LD2979M33TR	3.3 V
	LD2979XX38	LD2979M38TR	3.8 V
	LD2979XX50	LD2979M50TR	5.0 V
April 2008		Rev 14	1/15
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Contents	LD2979xx

Contents

1	Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 3
2	Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 4
3	Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	5
4	Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	6
5	Typical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	8
6	Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	11
7	Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	14

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LD2979xx	Diagram

1 Diagram

Figure 1. Schematic diagram

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Pin configuration	LD2979xx

2 Pin configuration

Figure 2. Pin connections (top view)

SOT23-5L

Table 2.	Pin description
Symbol		Name and function	Pin number
	VI	Input voltage	1
	GND	Ground	2
INHIBIT		Control switch ON/OFF (1)	3
	NC	Not to be connected	4
	VO	Output voltage	5

1.Inhibit pin is not internally pulled-up then it must not be left floating. Connect to a positive voltage higher than 2 V to able the device.

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LD2979xx			Maximum ratings
3	Maximum ratings
Table 3.	Absolute maximum ratings
Symbol		Parameter	Value	Unit
VI		DC input voltage	16	V
VINH		DC inhibit input voltage	VIN	V
IO		Output current	Internally limited
PD		Power dissipation	Internally limited
TSTG		Storage temperature range	-40 to 150	°C
TOP		Operating junction temperature range	-25 to 125	°C
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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