MAX13330GEE/V+T Maxim Integrated Products, MAX13330GEE/V+T Datasheet - Page 11

• Manufacturer Part Number: MAX13330GEE/V+T
• Description: IC AMP STEREO HEADPHONE 16-QSOP
• Manufacturer: Maxim Integrated Products
• Series: DirectDrive™r
• Type: Class ABr

Specifications of MAX13330GEE/V+T

• Output Type: Headphones, 2-Channel (Stereo)
• Max Output Power X Channels @ Load: 135mW x 2 @ 32 Ohm
• Voltage - Supply: 4 V ~ 5.5 V
• Features: Depop, Short-Circuit Protection, Shutdown
• Mounting Type: Surface Mount
• Package / Case: 16-QSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Thermal-overload protection limits total power dissipa-
tion in the MAX13330/MAX13331. When the junction
temperature exceeds +145°C (typ), the thermal-protec-
tion circuitry disables the amplifier output stage. The
amplifiers are enabled once the junction temperature
cools by 5°C. This results in a pulsing output under
continuous thermal-overload conditions.
The device has been specified for the worst-case sce-
nario, when both inputs are in-phase. Under this condi-
tion, the amplifiers simultaneously draw current from the
charge pump, leading to a proportional reduction in
V
left and right signals have differences in both magni-
tude and phase, subsequently leading to an increase in
the maximum attainable output power. Figure 4 shows
the two extreme cases for in- and out-of-phase. In reali-
ty, the available power lies between these extremes.
The MAX13330/MAX13331 feature a UVLO function that
prevents the device from operating if the supply voltage
is less than 3.6V (typ). This feature ensures proper
operation during brownout conditions and prevents
deep battery discharge. Once the supply voltage
reaches the UVLO threshold, the charge-pump is
turned on and the amplifiers are powered.
Figure 4. Output Power vs. Supply Voltage
SS
Automotive DirectDrive Headphone Amplifiers
headroom. In typical stereo audio applications, the
250
200
150
100
50
0
4.00
OUTPUT POWER vs. SUPPLY VOLTAGE
f
R
THD+N = 10%
IN
L
= 1kHz
= 32Ω
4.25
______________________________________________________________________________________
with Output Protection and Diagnostics
SUPPLY VOLTAGE (V)
4.50
OUT OF PHASE
INPUTS 180°
4.75
5.00
IN PHASE
INPUTS
5.25
Output Power
5.50
UVLO
The gain of the MAX13330 is internally set at -1.5V/V.
All gain-setting resistors are integrated into the device,
reducing external component count. The internally set
gain, in combination with DirectDrive, results in a head-
phone amplifier that requires only five tiny 1µF capaci-
tors to complete the amplifier circuit: two for the
charge-pump, two for audio input coupling, and one for
power-supply bypassing (see the Typical Application
Circuits ). The gain of the MAX13331 amplifier is set
externally as shown in the Typical Application Circuits ,
the gain is:
Choose feedback resistor values of 10kΩ. Values other
than 10kΩ increase output offset voltage due to the
input bias current, which in turn, increases the amount
of DC current flow to the load.
The input capacitor (C
resistor (R
DC bias from an incoming signal (see the Typical
Application Circuits ). The AC-coupling capacitor allows
the device to bias the signal to an optimum DC level.
Assuming zero source impedance, the -3dB point of
the highpass filter is given by:
Choose C
of interest. For the MAX13330, use the value of R
given in the Electrical Characteristics table. Setting
f
response. Use capacitors whose dielectrics have low-
voltage coefficients, such as tantalum or aluminum
electrolytic. Capacitors with high-voltage coefficients,
such as ceramics, can result in increased distortion at
low frequencies.
Use capacitors with an ESR less than 100mΩ for opti-
mum performance. Low-ESR ceramic capacitors mini-
mize the output resistance of the charge pump. For
best performance over the extended temperature
range, select capacitors with an X7R dielectric.
-3dB
Gain-Setting Resistors (MAX13331 Only)
too high affects the device’s low-frequency
IN
IN
Charge-Pump Capacitor Selection
), forms a highpass filter that removes the
so f
f
−
3
-3dB
dB
A
=
V
Component Selection
is well below the lowest frequency
2π
= −
IN
), in conjunction with the input
×
R
R
R
IN
F
IN
1
( / )
V V
×
C
IN
(
Hz
Input Filtering
)
IN
11
as