Global Mixed-mode Technology Inc.
G1421
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 4Ω Load
--1.2W/CH (typical) into a 8Ω 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
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 4Ω 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.
Applications
Stereo Power Amplifiers for Notebooks or
Desktop Computers
Multimedia Monitors
Stereo Power Amplifiers for Portable Audio
Systems
Ordering Information
ORDER
NUMBER
G1421
Note: U: Tape & Reel
(FD): Thermal Pad
ORDER NUMBER
(Pb free)
G1421f
TEMP.
RANGE
-40°C to +85°C
PACKAGE
TSSOP-24 (FD)
Pin Configuration
G1421
GND/HS
TJ
LOUT+
LLINEIN
LHPIN
LBYPASS
LVDD
SHUTDOWN
MUTE OUT
1
2
3
4
5
6
7
8
9
24
23
22
21
20
19
18
17
16
15
14
13
GND/HS
VOL
ROUT+
RLINEIN
RHPIN
RBYPASS
RVDD
HP-IN
HP/LINE
ROUT-
SE/BTL
GND/HS
14
Thermal
Pad
LOUT- 10
MUTE IN 11
GND/HS 12
Top View
TSSOP-24 (FD)
Bottom View
Note: Recommend connecting the Thermal Pad to the GND for excellent power dissipation.
Ver: 1.6
Aug 04, 2005
TEL: 886-3-5788833
http://www.gmt.com.tw
1
GMT [ GLOBAL MIXED-MODE TECHNOLOGY INC ]
