ISL54004IRTZ Intersil, ISL54004IRTZ Datasheet - Page 8

• Manufacturer Part Number: ISL54004IRTZ
• Description: IC AMP AUDIO PWR 1.23W AB 20TQFN
• Manufacturer: Intersil
• Type: Class ABr

Specifications of ISL54004IRTZ

• Output Type: 1-Channel (Mono) with Stereo Headphones
• Max Output Power X Channels @ Load: 1.23W x 1 @ 8 Ohm; 215mW x 2 @ 16 Ohm
• Voltage - Supply: 2.7 V ~ 5.5 V
• Features: Depop, Shutdown, Thermal Protection
• Mounting Type: Surface Mount
• Package / Case: 20-TQFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Low Power Shutdown
With a logic “1” at the SD control pin the device enters the
low power shutdown state. When in shutdown the BTL and
headphone amplifiers go into an high impedance state and
I
In shutdown mode before the amplifiers enter the high
impedance/low current drive state, the bias voltage of V
remains connected at the output of the amplifiers through a
100kΩ resistor.
This resistor is not present during active operation of the
drivers but gets switched in when the SD pin goes high. It
gets removed when the SD pin goes low.
Leaving the DC bias voltage connected through a 100kΩ
resistor while going into and out of shutdown reduces the
transient at the speakers to a small level preventing clicking
or popping in the speakers.
Note: When the SD pin is High it overrides all other logic
pins.
QFN Die Attach Paddle Considerations
The QFN package features an exposed thermal pad on its
underside. This pad lowers the package’s thermal resistance
by providing a direct heat conduction path from the die to the
PCB. Connect the exposed thermal pad to GND by using a
Typical Performance Curves
DD
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
supply current is reduced to 26µA (typ).
20
V
BTL
R
P
50
DD
O
L
FIGURE 1. THD+N vs FREQUENCY
= 8Ω
= 800mW
= 5V
100
200
FREQUENCY (Hz)
500
8
1k
2k
T
A
= +25°C, Unless Otherwise Specified
5k
10k
DD
20k
/2
ISL54004
large copper pad and multiple vias to the GND plane. The
vias should be plugged and tented with plating and solder
mask to ensure good thermal conductivity.
Best thermal performance is achieved with the largest
practical copper ground plane area.
PCB Layout Considerations and Power
Supply Bypassing
To maintain the highest load dissipation and widest output
voltage swing the power supply PCB traces and the traces
that connect the output of the drivers to the speaker loads
should be made as wide as possible to minimize losses due
to parasitic trace resistance.
Proper supply bypassing is necessary for high power supply
rejection and low noise performance. A filter network
consisting of a 10µF capacitor in parallel with a 0.1µF
capacitor is recommended at the voltage regulator that is
providing the power to the ISL54004 IC.
Local bypass capacitors of 0.1µF should be put at each V
pin of the ISL54004 device. They should be located as close
as possible to the pin, keeping the length of leads and traces
as short as possible.
A 1µF capacitor from the REF pin (pin 10) to GND is needed
for optimum PSRR and internal bias voltage stability.
0.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
20
V
BTL
R
P
DD
O
L
= 8Ω
= 200mW
50
= 3.6V
FIGURE 2. THD+N vs FREQUENCY
100
200
FREQUENCY (Hz)
500
1k
2k
5k
October 30, 2007
10k
FN6513.2
20k
DD