LP3891

SNVS235D – SEPTEMBER 2003 – REVISED APRIL 2013

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ELECTRICAL CHARACTERISTICS

Limits in standard typeface are for TJ = 25°C, and limits in boldface type apply over the full operating temperature range.

Unless otherwise specified: VIN = VO(NOM) + 1V, VBIAS = 4.5V, IL = 10 mA, CIN = COUT = 10 µF, VS/D = VBIAS.

Typical

Symbol

Parameter

Conditions

MIN (1)

MAX (1)

Units

(2)

VO

Output Voltage Tolerance

10 mA

≤ IL ≤ 0.8A, VO(NOM) + 1V ≤ VIN ≤

1.198

1.234

1.216

5.5V,

1.186

1.246

4.5V

≤ VBIAS ≤ 6V

1.478

1.522

1.5

V

1.455

1.545

1.773

1.827

1.8

1.746

1.854

ΔVO/ΔVIN

Output Voltage Line Regulation (3)

VO(NOM) + 1V ≤ VIN ≤ 5.5V

0.01

%/V

ΔVO/ΔIL

Output Voltage Load Regulation(4)

10 mA

≤ IL ≤ 0.8A

0.04

%/A

(5)

0.06

VDO

Dropout Voltage (6)

IL = 0.8A (TO220 and TO263 only)

300

100

400

mV

IL = 0.8A (SO PowerPAD only)

320

115

430

IQ(VIN)

Quiescent Current Drawn from VIN 10 mA ≤ IL ≤ 0.8A

7

3

mA

Supply

8

VS/D ≤ 0.3V

1

0.03

µA

30

IQ(VBIAS)

Quiescent Current Drawn from

10 mA

≤ IL ≤ 0.8A

2

1

mA

VBIAS Supply

3

VS/D ≤ 0.3V

1

0.03

µA

30

ISC

Short-Circuit Current

VOUT = 0V

2.5

A

Shutdown Input

VSDT

Output Turn-off Threshold

Output = ON

1.3

0.7

V

Output = OFF

0.7

0.3

Td (OFF)

Turn-OFF Delay

RLOAD X COUT << Td (OFF)

20

µs

Td (ON)

Turn-ON Delay

RLOAD X COUT << Td (ON)

15

IS/D

S/D Input Current

VS/D =1.3V

1

µA

VS/D ≤ 0.3V

−1

AC Parameters

PSRR (VIN)

Ripple Rejection for VIN Input

VIN = VOUT +1V, f = 120 Hz

80

Voltage

VIN = VOUT + 1V, f = 1 kHz

65

dB

PSRR

Ripple Rejection for VBIAS Voltage

VBIAS = VOUT + 3V, f = 120 Hz

70

(VBIAS)

VBIAS = VOUT + 3V, f = 1 kHz

65

Output Noise Density

f = 120 Hz

µV/root

−

1

Hz

en

Output Noise Voltage

BW = 10 Hz

− 100 kHz, VOUT = 1.8V

150

µV (rms)

BW = 300 Hz

− 300 kHz, VOUT = 1.8V

90

(1)

Limits are specified through testing, statistical correlation, or design.

(2)

Typical numbers represent the most likely parametric norm for 25°C operation.

(3)

Output voltage line regulation is defined as the change in output voltage from nominal value resulting from a change in input voltage.

(4)

If used in a dual-supply system where the regulator load is returned to a negative supply, the output pin must be diode clamped to

ground.

(5)

Output voltage load regulation is defined as the change in output voltage from nominal value as the load current increases from no load

to full load.

(6)

Dropout voltage is defined as the minimum input to output differential required to maintain the output with 2% of nominal value. The SO

PowerPAD-8 package devices have a slightly higher dropout voltage due to increased band wire resistance.

4

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