ST LD49300PT08R, LD49300PT10R, LD49300PT12R User Manual

LD49300XX08 LD49300XX10, LD49300XX12

3 A very low drop-out voltage regulator

Features

■Input voltage range:

–VI = 1.4 V to 5.5 V

–VBIAS = 3 V to 6 V

■Stable with ceramic capacitor

■±1.5 % initial tolerance

■Maximum dropout voltage (VI - VO) of 400 mV over temperature

■Adjustable output voltage down to 0.8 V

■Ultra fast transient response (up to 10 MHz bandwidth)

■Excellent line and load regulation specifications

■Logic controlled shutdown option

■Thermal shutdown and current limit protection

■Junction temperature range: - 25 °C to 125 °C

Applications

■Graphics processors

■PC add-in cards

■Microprocessor core voltage supply

■Low voltage digital ICs

■High efficiency linear power supplies

■SMPS post regulators

PPAK

Description

The LD49300xx is a high-bandwidth, low dropout, 3.0 A voltage regulator, ideal for powering core voltages of low-power microprocessors. The LD49300xx implements a dual supply configuration allowing for very low output impedance and very fast transient response. The LD49300xx requires a bias input supply and a main input supply, allowing for ultra-low input voltages on the main supply rail. The input supply operates from 1.4 V to 5.5 V and the bias supply requires between 3 V and 6 V for proper operation. The LD49300xx offers fixed output voltages from 0.8 V to 1.8 V and adjustable output voltages down to 0.8 V. The LD49300xx requires a minimum output capacitance for stability, and works optimally with small ceramic capacitors.

Table 1.	Device summary
	Order codes	Package	Packaging
	LD49300PT08R (1)	PPAK (Tape and reel)	2500 parts per reel
	LD49300PT10R	PPAK (Tape and reel)	2500 parts per reel
	LD49300PT12R	PPAK (Tape and reel)	2500 parts per reel
1. Adjustable version.
June 2010		Doc ID 12861 Rev 3	1/20

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Contents	LD49300XX08, LD49300XX10, LD49300XX12

Contents

1	Typical application circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		. 3
2	Alternative application circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		4
3	Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		5
4	Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		6
5	Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		7
6	Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		8
7	Typical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		9
8	Application hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		13
	8.1	Input supply voltage (VIN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	13
	8.2	Bias supply voltage (VBIAS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	13
	8.3	External capacitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	13
	8.4	Output capacitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	13
	8.5	Minimum load current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	13
	8.6	Power sequencing recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . .	14
	8.7	Power dissipation/heatsinking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	14
	8.8	Heatsinking PPAK package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	15
	8.9	Adjustable regulator design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	15
	8.10	Enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	15
9	Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		16
10	Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		19

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LD49300XX08, LD49300XX10, LD49300XX12	Typical application circuits

1 Typical application circuits

Figure 1. Adjustable version

Figure 2. Fixed version with enable

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Alternative application circuits	LD49300XX08, LD49300XX10, LD49300XX12

2 Alternative application circuits

Figure 3. Single supply voltage solution

Figure 4. LD49300xx plus DC-DC pre-regulator to reduce power dissipation

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LD49300XX08, LD49300XX10, LD49300XX12	Pin configuration

3 Pin configuration

Figure 5. Pin connections (top view)

	Table 2.	Pin description
	Pin n°	Symbol	Note
	1	EN	Enable (Input): Logic High = Enable, Logic Low = Shutdown.
		ADJ	Adjustable regulator feedback input. Connect to resistor voltage divider.
	2	VIN	Input voltage which supplies current to the output power device.
	3	GND	Ground (TAB is connected to ground).
	4	VOUT	Regulator output.
	5	VBIAS	Input bias voltage for powering all circuitry on the regulator with the exception of the output
			power device.

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Diagram	LD49300XX08, LD49300XX10, LD49300XX12

4 Diagram

Figure 6. Block diagram

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