Ver: 1.6

Aug 04, 2005

TEL: 886-3-5788833

http://www.gmt.com.tw

1

G1421

Global Mixed-mode Technology Inc.

2W Stereo Audio Amplifier with No Headphone

Coupling Capacitor Function

Features

Depop Circuitry Integrated

Output Power at 1% THD+N, VDD=5V

--1.8W/CH (typical) into a 4

Ω Load

--1.2W/CH (typical) into a 8

Ω Load

Eliminates Headphone Amplifier Output Cou-

pling Capacitors

Maximum Output Power Clamping Circuitry

Integrated

Bridge-Tied Load (BTL), Single-Ended (SE),

and Stereo Headphone Amplifier (HP-IN) modes

Supported

Stereo Input MUX

Mute and Shutdown Control Available

Surface-Mount Power Package

24-Pin TSSOP-P

Applications

Stereo Power Amplifiers for Notebooks or

Desktop Computers

Multimedia Monitors

Stereo Power Amplifiers for Portable Audio

Systems

General Description

G1421 is a stereo audio power amplifier in 24pin

TSSOP thermal pad package. It can drive 1.8W con-

tinuous RMS power into 4

Ω load per channel in

Bridge-Tied Load (BTL) mode at 5V supply voltage. Its

THD is smaller than 1% under the above operation

condition. To simplify the audio system design in the

notebook application, G1421 supports the Bridge-Tied

Load (BTL) mode for driving the speakers, Single-End

(SE) mode for driving the headphone. In the HP-IN

mode, it can support a DC value to the phone-jacket

and drive the headphone without the audio amplifier

outputs coupling capacitors. G1421 can mute the out-

put when Mute-In is activated. For the low current

consumption applications, the SHDN mode is sup-

ported to disable G1421 when it is idle. The current

consumption can be further reduced to below 5µA.

G1421 also supports two input paths, that means two

different gain loops can be set in the same PCB and

choosing either one by setting HP/

LINE pin. It en-

hances the hardware designing flexibility. G1421 also

supports an extra function -- the maximum output

power clamping function to protect the speakers or

headphones from burned-out.

Ordering Information

ORDER

NUMBER

ORDER NUMBER

(Pb free)

TEMP.

RANGE

PACKAGE

G1421

G1421f

-40°C to +85°C

TSSOP-24 (FD)

Note: U: Tape & Reel

(FD): Thermal Pad

Pin Configuration

ROUT+

RLINEIN

RHPIN

RBYPASS

RVDD

HP-IN

HP/LINE

ROUT-

SE/BTL

GND/HS

LOUT+

LLINEIN

LHPIN

LBYPASS

LVDD

SHUTDOWN

MUTE OUT

LOUT-

MUTE IN

G1421

GND/HS

TSSOP-24 (FD)

13

24

23

22

21

20

19

18

17

16

15

5

6

7

8

9

10

11

12

1

4

3

2

14

TJ

VOL

14

Thermal

Pad

Top View

Bottom View

GND/HS

GND/HS

Note: Recommend connecting the Thermal Pad to the GND for excellent power dissipation.

ROUT+

RLINEIN

RHPIN

RBYPASS

RVDD

HP-IN

HP/LINE

ROUT-

SE/BTL

GND/HS

LOUT+

LLINEIN

LHPIN

LBYPASS

LVDD

SHUTDOWN

MUTE OUT

LOUT-

MUTE IN

G1421

GND/HS

TSSOP-24 (FD)

13

24

23

22

21

20

19

18

17

16

15

5

6

7

8

9

10

11

12

1

4

3

2

14

TJ

VOL

14

Thermal

Pad

Top View

Bottom View

GND/HS

GND/HS

Note: Recommend connecting the Thermal Pad to the GND for excellent power dissipation.