ST L4949ED-E, L4949EP-E User Manual

L4949ED-E

L4949EP-E

Multifunction very low drop voltage regulator

Features

■ECOPACK®: lead free and RoHS compliant

■Automotive Grade: compliance with AEC guidelines

■Operating DC supply voltage range 5 V - 28 V

■Transient supply voltage up to 40V

■Extremely low quiescent current in standby mode

■High precision standby output voltage 5V±1%

■Output current capability up to 100mA

■Very low dropout voltage less than 0.5V

■Reset circuit sensing the output voltage

■Programmable reset pulse delay with external capacitor

■Voltage sense comparator

■Thermal shutdown and short circuit protections

SO-8

SO-20W (12+4+4)

Description

The L4949ED-E and L4949EP-E are monolithic integrated 5V voltage regulators with a very low dropout output and additional functions as poweron reset and input voltage sense. They are designed for supplying the microcomputer controlled systems especially in automotive applications.

Table 1.	Device summary
	Package		Order codes
		Tube		Tape and reel
	SO-8	L4949ED-E		L4949EDTR-E
	SO-20W	L4949EP-E		L4949EPTR-E
November 2009		Doc ID 16823 Rev 1	1/19

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Contents	L4949ED-E, L4949EP-E

Contents

1	Block diagram and pin description . . . . . . . . . . . . . . . . . . . . . . . . . . .		. 5
2	Electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		7
	2.1	Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	7
	2.2	Thermal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	7
	2.3	Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	8
3	Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		10
	3.1	Supply voltage transient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	10
	3.2	Functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	10
	3.3	Voltage regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	11
	3.4	Preregulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	12
	3.5	Reset circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	13
	3.6	Sense comparator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	13
4	Package and packing information . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		15
	4.1	ECOPACK® packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	15
	4.2	SO-8 TP package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	15
	4.3	SO-20 TP package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	16
5	Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		18

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L4949ED-E, L4949EP-E	List of tables

List of tables

Table 1. Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Table 2. Pin definitions and functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Table 3. Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Table 4. Thermal data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Table 5. Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Table 6. Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Table 7. Sense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Table 8. Preregulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Table 9. SO-8 TP mechanical data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Table 10. SO-20 TP mechanical data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Table 11. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

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List of figures	L4949ED-E, L4949EP-E

List of figures

Figure 1. Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Figure 2. Configuration diagram (top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Figure 3. Application circuit(1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Figure 4. Foldback characteristic of VO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Figure 5. Output voltage vs input voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Figure 6. Quiescent current vs supply voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Figure 7. Block circuit of reset circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Figure 8. Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Figure 9. SO-8 TP package dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Figure 10. SO20 TP package dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

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L4949ED-E, L4949EP-E	Block diagram and pin description

1 Block diagram and pin description

Figure 1. Block diagram

Note:	The block diagram illustrates only a major internal device functionality and it is not intended
	to mimic any details of hardware design
Figure 2.	Configuration diagram (top view)

SO-8

SO-20

Doc ID 16823 Rev 1

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Block diagram and pin description						L4949ED-E, L4949EP-E
	Table 2.		Pin definitions and functions
			Pin N°		Symbol	Function
	SO-8		SO-20
	1		19		VS	Input supply voltage. Block to GND via an external
						capacitor (see Figure 3).
	2		20		SI	Sense input pin to supervise input voltage. Connect via an
						external voltage divider connected to VS and to GND.
	3		1		VZ	Preregulator output voltage. For details, see Section 3.4:
						Preregulator.
	4		2		CT	Reset pulse delay adjustment. Connecting this pin via a
						capacitor to GND
	5		4, 5, 6, 7, 14,		GND	Ground reference
			15, 16, 17
	6		10		RES	Reset output. It is pulled down when the output voltage
						goes below VRT.
						Sense output. This open collector pin must be connected to
	7		11		SO	VOUT via an external resistor. It is pulled down whenever
						the SI voltage becomes lower than an internal voltage.
	8		12		VOUT	Output voltage. Block to GND via an external capacitor (see
						Figure 3)
	-		3, 8, 9, 13, 18		NC	Not connected pins

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