G1421 Datasheet, PDF (16/24 Pages) Global Mixed-mode Technology Inc – 2W Stereo Audio Amplifier with No Headphone Coupling Capacitor Function

Global Mixed-mode Technology Inc.
Pin Description
G1421
PIN
1,12,13,24
2
3
4
5
NAME
GND/HS
TJ
LOUT+
LLINE IN
LHP IN
I/O
FUNCTION
Ground connection for circuitry, directly connected to thermal pad.
O Source a current inversely to the junction temperature. This pin should be left uncon-
nected during normal operation. For more information, see the junction temperature
measurement section of this document.
O Left channel + output in BTL mode, + output in SE mode.
I Left channel line input, selected when HP/ pin is held low.
I Left channel headphone input, selected when HP/pin is held high.
6
LBYPASS
Connect to voltage divider for left channel internal mid-supply bias.
7
LVDD
I Supply voltage input for left channel and for primary bias circuits.
8
SHUTDOWN I Shutdown mode control signal input, places entire IC in shutdown mode when held
high, I_DD = 5µA.
9
MUTE OUT O Follows MUTE IN pin, provides buffered output.
10
LOUT-
O Left channel - output in BTL mode, high impedance state in SE mode. Supply VDD/2 to
the phone jacket in HP-IN mode.
11
MUTE IN
I Mute control signal input, hold low for normal operation, hold high to mute.
14
SE/
I Mode control signal input, hold low for BTL mode, hold high for SE mode.
15
ROUT-
O Right channel - output in BTL mode, high impedance state in SE mode.
16
HP/
I MUX control input, hold high to select headphone inputs (5,20), hold low to select line
inputs (4,21).
17
HP-IN
This pin can activate the HP-IN mode to supplied the VDD/2 at LOUT- onto the phone
jacket. So the DC blocking capacitors can be removed in HP-IN type (like SE mode
except no DC blocking capacitors). Hold high to activate this function. If this function is
not used, it should be strongly tied to low.
18
RVDD
I Supply voltage input for right channel.
19
RBYPASS
Connect to voltage divider for right channel internal mid-supply bias.
20
RHP IN
I Right channel headphone input, selected when HP/pin is held high.
21
RLINE IN
I Right channel line input, selected when HP/pin is held low.
22
ROUT+
O Right channel + output in BTL mode, + output in SE mode.
23
VOL
I The output power can be clamped by setting a low bound voltage to this pin. The high
bound voltage will be generated internally. The output voltage will be clamped between
high/low bound voltages. Then the output power is limited. It is weakly pull-low inter-
nally, let this pin floating or tied to GND can deactivate this function.
Thermal Pad
Recommend connecting the Thermal Pad to the GND for excellent power dissipation.
Ver: 1.6
Aug 04, 2005
TEL: [phone]
http://www.gmt.com.tw
16