LM4991

SNAS217A – MAY 2004 – REVISED APRIL 2013

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Electrical Characteristics VDD = 3V

(1) (2) (continued)

The following specifications apply for VDD = 3V and RL = 8Ω unless otherwise specified. Limits apply for TA = 25°C.

LM4991

Parameter

Test Conditions

Units

Typ(3)

Limit(4)

(Limits)

PSRR

Power Supply Rejection Ratio VRIPPLE = 200mV sine p-p,

Input terminated with 10

Ω,

68

dB

f = 1kHz

Electrical Characteristics VDD = 2.6V

(1) (2)

The following specifications apply for VDD = 2.6V and RL = 8Ω unless otherwise specified. Limits apply for TA = 25°C.

LM4991

Parameter

Test Conditions

Units

Typ(3)

Limits(4)

(Limits)

Quiescent Power Supply Current VIN = 0V, no Load

2

IDD

mA (max)

VIN = 0V, RL = 8Ω

3

ISD

Shutdown Current

VSHUTDOWN = VDD

0.1

µA(max)

VSDIH

Shutdown Voltage Input High

1

V

VSDIL

Shutdown Voltage Input Low

0.9

V

VOS

Output Offset Voltage

5

35

mV (max)

THD = 1% (max), f = 1kHz

RL = 4Ω

400

mW

Po

Output Power

RL = 8Ω

300

%

THD+N

Total Harmonic Distortion+Noise

PO = 0.15W, f = 1kHz

0.1

PSRR

Power Supply Rejection Ratio

VRIPPLE = 200mV sine p-p,

Input terminated with 10

Ω,

51

dB

f = 1kHz

(1)

Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for

which the device is functional, but do not ensure specific performance limits. Electrical Characteristics VDD= 5V state DC and AC

electrical specifications under particular test conditions which ensure specific performance limits. This assumes that the device is within

the Operating Ratings. Specifications are not ensure for parameters where no limit is given, however, the typical value is a good

indication of device performance.

(2)

All voltages are measured with respect to the ground pin, unless otherwise specified.

(3)

Typicals are specified at 25°C and represent the parametric norm.

(4)

Limits are ensured to AOQL (Average Outgoing Quality Level).

External Components Description

(Figure 3)

Components

Functional Description

1.

Ri

Inverting input resistance that sets the closed-loop gain in conjunction with Rf. This resistor also forms a high pass filter

with Ci at fC= 1/(2π RiCi).

2.

Ci

Input coupling capacitor that blocks the DC voltage at the amplifiers input terminals. Also creates a highpass filter with

Ri at fc = 1/(2π RiCi). Refer to the section, PROPER SELECTION OF EXTERNAL COMPONENTS, for an explanation

of how to determine the value of Ci.

3.

Rf

Feedback resistance that sets the closed-loop gain in conjunction with Ri.

4.

CS

Supply bypass capacitor that provides power supply filtering. Refer to the POWER SUPPLY BYPASSING section for

information concerning proper placement and selection of the supply bypass capacitor.

5.

CB

Bypass pin capacitor that provides half-supply filtering. Refer to the section, PROPER SELECTION OF EXTERNAL

COMPONENTS, for information concerning proper placement and selection of CB.

4

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