Preliminary
RT9131
DS9131-01 November 2002
www.richtek.com.tw
1
Class AB Stereo Headphone Drive with Mute
General Description
The RT9131 is an integrated class AB stereo
headphone driver contained in a SOP-8 or DIP-8
plastic package with Mute feature. A class AB output
stage bias control circuit is employed to maintain low
audio signal distortion and power consumption. The
RT9131 further integrates a voltage divider inside
the chip. Thus, the external resistors can be
eliminated. The device is fabricated in a CMOS
process and has been primarily developed for
portable digital audio applications.
Ordering Information
RT9131
Marking Information
Part Number
Marking
RT9131CN RT9131CN
RT9131CS
RT9131CS
Typical Application Circuit
Features
High Signal-to-Noise Ratio
High Slew Rate
Low Distortion
Large Output Voltage Swing
Flexible Mute Function
Excellent Power Supply Ripple Rejection
Low Power Consumption
Short-circuit Elimination
Wide Temperature Range
No Switch ON/OFF Clicks
Integrated Voltage Divider (V
DD
/2) to Eliminate
External Resistors
Applications
Portable Digital Audio
Pin Configurations
Part Number
Pin Configurations
RT9131CN
(Plastic DIP-8)
RT9131CS
(Plastic SOP-8)
TOP VIEW
Operating Tmperature Rnge
C: Commercial Standard
PackageType
N : DIP-8
S : SOP-8
OUTA
MUTE
INA
GND
1
2
3
4
8
7
6
5
VDD
OUTB
BIAS
INB
OUTA
MUTE
INA
GND
VDD
OUTB
BIAS
INB
1
2
3
4
8
7
6
5
RT9131
V
INA
C2
2.2
F
+
C7 220
F
+
C6 220
F
+
V
DD
C1
100
F
+C5
4.7
F
V
INB
C3 2.2
F
V
MUTE
R1
100K
C4
1
F
H: Speaker Action
L: Mute On
RT9131
Preliminary
www.richtek.com.tw
DS9131-01 November 2002
2
Absolute Maximum Ratings
Supply Voltage
7V
Operating Ambient Temperature Range
-40
C to 85C
Maximum Junction Temperature
150
C
Storage Temperature Range
-60
C to 150C
Power Dissipation, P
D
@ T
A
= 25
C
DIP-8
1.25W
SOP-8
0.625W
Package Thermal Resistance
DIP-8,
JA
100
C/W
SOP-8,
JA
160
C/W
Electrostatic Discharge
-3000 to 3000V
(1)
-200 to 200V
(2)
Notes: (1) Human body mode: C = 100pF, R = 1500
, 3 positive pulses plus 3 negative pulses
(2) Machine mode: C = 200pF, L = 0.5mH, R = 0
, 3 positive pulses plus 3 negative pulses
Electrical Characteristics
(V
IN
= 0dbV, V
CC
= 5V, T
A
= 25
C, f = 1kHz, R
L
= 32
, unless otherwise specified)
Parameter Symbol
Test
Conditions
Min
Typ
Max
Units
Operating V
DD
Range
V
DD
3 -- 6 V
Quiescent Current
I
Q
V
IN
= 0Vms
-- 3.6 6 mA
Mute Terminal Voltage
V
MUTE
0.3
0.7
1.6
V
Voltage Gain
A
V
-2
--
2
dB
Differential Channel Voltage Gain
A
V
-0.5
--
0.5
dB
Total Harmonic Channel Distortion Factor THD
RW = 20 ~ 20kHz
--
0.02
0.1
%
Rated Output Power 1
P
O
R
L
= 32
, THD < 0.1%
25 31 -- mW
Rated Output Power 2
P
O
R
L
= 16
, THD < 0.1%
50 62 -- mW
Output Noise Voltage
BW = 20 ~ 20kHz, R
G
= 0
-- -93 -- dBv
Channel Separation
R
G
= 0
-- 75 -- dB
Mute Attenuation
R
G
= 0
-- 60 -- dB
Ripple Rejection
PSRR
f
RR
= 100Hz, f
RR
= -20dBv
-- -57 -- dB
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