IS31AP4990D datasheet(7/10 Pages) ISSI

Part #	IS31AP4990D

Description	1.2W AUDIO POWER AMPLIFIER WITH ACTIVE-LOW SHUTDOWN MODE

Download	10 Pages

Scroll/Zoom	100%

Manufacturer	ISSI [Integrated Silicon Solution, Inc]

Direct Link	http://www.issi.com

Logo

7 / 10 page

IS31AP4990D

Integrated Silicon Solution, Inc. – www.issi.com

7

Rev.A, 11/22/2011

APPLICATION INFORMATION

BTL CONFIGURATION PRINCIPLE

The IS31AP4990D is a monolithic power amplifier with

a BTL output type. BTL (bridge tied load) means that

each end of the load is connected to two single-ended

output amplifiers. Thus, we have:

Single-ended output 1 = VOUT+ = VOUT (V)

Single ended output 2 = VOUT- = -VOUT (V)

and VOUT+ - VOUT- = 2VOUT (V)

The output power is:

L

OUT

R

V

P

RMS

2

)

2

(



For the same power supply voltage, the output power

in BTL configuration is four times higher than the

output power in single ended configuration.

GAIN IN A TYPICAL APPLICATION SCHEMATIC

The typical application schematic is shown in Figure 1

on page 1.

In the flat region (no CIN effect), the output voltage of

the first stage is (in Volts):

IN

F

IN

OUT

R

V

)

(







For the second stage: VOUT+ = -VOUT- (V)

The differential output voltage is (in Volts):

IN

F

IN

OUT

R

V

2







The differential gain, Gv, in shourt, is given by:

IN

F

IN

OUT

v

R

V

G

2











VOUT+ is in phase with VIN and VOUT- is phased 180°

with VIN. This means that the positive terminal of the

loudspeaker should be connected to VOUT+ and the

negative to VOUT-.

LOW AND HIGH FREQUENCY RESPONSE

In the low frequency region, CIN starts to have an effect.

CIN forms with RIN a high-pass filter with a -3dB cut-off

frequency. FCL is in Hz.

IN

CL

C

R

F



2

1



In the high frequency region, you can limit the

bandwidth by adding a capacitor (CF) in parallel with RF.

It forms a low-pass filter with a -3dB cut-off frequency.

FCH is in Hz.

F

CH

C

R

F



2

1



DECOUPLING OF THE CIRCUIT

Two capacitors are needed to correctly bypass the

IS31AP4990D: a power supply bypass capacitor CS

and a bias voltage bypass capacitor CBYPASS.

CS has particular influence on the THD+N in the high

frequency region (above 7kHz) and an indirect

influence on power supply disturbances. With a value

for CS of 1μF, you can expect THD+N levels similar to

those shown in the datasheet.

In the high frequency region, if CS is lower than 1μF, it

increases THD+N and disturbances on the power

supply rail are less filtered.

On the other hand, if CS is higher than 1μF, those

disturbances on the power supply rail are more filtered.

CBYPASS has an influence on THD+N at lower

frequencies, but its function is critical to the final result

of PSRR (with input grounded and in the lower

frequency region).

If CBYPASS is lower than 1μF, THD+N increases at lower

frequencies and PSRR worsens.

If CBYPASS is higher than 1μF, the benefit on THD+N at

lower frequencies is small, but the benefit to PSRR is

substantial.

Note that CIN has a non-negligible effect on PSRR at

lower frequencies. The lower the value of CIN, the

higher the PSRR is.

WAKE-UP TIME (tWU)

When the SDB pin is released to put the device ON,

the bypass capacitor CBYPASS will not be charged

immediately. As CBYPASS is directly linked to the bias of

the amplifier, the bias will not work properly until the

CBYPASS voltage is correct. The time to reach this

voltage is called wake-up time or tWU and specified in

the electrical characteristics table with CBYPASS = 1μF.

POP PERFORMANCE

Pop performance is intimately linked with the size of

the input capacitor CIN and the bias voltage bypass

capacitor CBYPASS.

The size of CIN is dependent on the lower cut-off

frequency and PSRR values requested. The size of

CBYPASS is dependent on THD+N and PSRR values

requested at lower frequencies.

Moreover, CBYPASS determines the speed with which

the amplifier turns ON.

Similar Part No. - IS31AP4990D

Manufacturer	Part #	Datasheet	Description
Integrated Silicon Solu...	IS31AP4990D-UTLS2-TR	293Kb / 10P	1.2W AUDIO POWER AMPLIFIER WITH ACTIVE-LOW SHUTDOWN MODE

More results

Similar Description - IS31AP4990D

Manufacturer	Part #	Datasheet	Description
Unisonic Technologies	TBA820M	178Kb / 6P	1.2W AUDIO POWER AMPLIFIER WITH ACTIVE-LOW SHUTDOWN MODE
Integrated Silicon Solu...	IS31AP4990D-UTLS2-TR	293Kb / 10P	1.2W AUDIO POWER AMPLIFIER WITH ACTIVE-LOW SHUTDOWN MODE
Unisonic Technologies	PA4990	259Kb / 8P	1.2W AUDIO POWER AMPLIFIER WITH ACTIVE-LOW SHUTDOWN MODE
	PA4990	289Kb / 8P	1.2W AUDIO POWER AMPLIFIER WITH ACTIVE-LOW SHUTDOWN MODE
	PA4990	221Kb / 9P	1.2W AUDIO POWER AMPLIFIER WITH ACTIVE-LOW SHUTDOWN MODE
Integrated Silicon Solu...	IS31AP4991	427Kb / 12P	1.2W AUDIO POWER AMPLIFIER WITH ACTIVE-LOW STANDBY MODE
List of Unclassifed Man...	IS31AP4991-SLS2-TR	418Kb / 11P	1.2W AUDIO POWER AMPLIFIER WITH ACTIVE-LOW STANDBY MODE
STMicroelectronics	TS4984FC	1Mb / 30P	1.2W Stereo Audio Power Amplifier with Active Low Standby Mode
Integrated Silicon Solu...	IS31AP4991A	373Kb / 11P	1.1W AUDIO POWER AMPLIFIER WITH ACTIVE-LOW SHUTDOWN MODE
Integrated Silicon Solu...	IS31AP4991A-GRLS2-TR	373Kb / 11P	1.1W AUDIO POWER AMPLIFIER WITH ACTIVE-LOW SHUTDOWN MODE

More results

IS31AP4990D Datasheet(PDF) 7 Page - Integrated Silicon Solution, Inc

IS31AP4990D Datasheet(HTML) 7 Page - Integrated Silicon Solution, Inc

Similar Part No. - IS31AP4990D

Similar Description - IS31AP4990D

Html Pages

1 2 3 4 5 6 7 8 9 10

Datasheet Download

Link URL