Headphone output power characteristics, Figure 2. headphone output test load, Figure 2 – Cirrus Logic CS42L52 User Manual
Page 18: For the, Note 9), Ters, Note 10)

18
DS680F2
CS42L52
3/1/13
9.
The PWM driver should be used in captive speaker systems only.
10. Optimal PWM performance is achieved when MCLK > 12 MHz.
HEADPHONE OUTPUT POWER CHARACTERISTICS
Test conditions (unless otherwise specified): Input test signal is a full-scale 997 Hz sine wave; Sample Frequency = 48 kHz;
Measurement Bandwidth is 20 Hz to 20 kHz; Test load R
L
= 16
C
L
= 10 pF (see
);
“Required Initialization Settings”
written on power up.
11. VHP settings lower than VA reduces the headroom of the headphone amplifier. As a result, the DAC
may not achieve the full THD+N performance at full-scale output voltage and power.
MOSFET On Resistance
R
DS(ON)
VP = 3.7V, I
d
= 0.5 A
-
640
-
m
MOSFET On Resistance
R
DS(ON)
VP = 2.5V, I
d
= 0.5 A
-
760
-
m
Efficiency
VP = 5.0 V, P
O
= 2 x 0.8 W, R
L
= 8
-
81
-
%
Output Operating Peak Current
I
PC
-
-
1.5
A
VP Input Current During Reset
I
VP
RESET, pin 32, is held low
-
0.8
5.0
µA
Parameters VA
=
2.5V
Min Typ Max
VA = 1.8V
Min Typ Max
Unit
AOUTx Power Into R
L
= 16
HP_GAIN[2:0] Analog
Gain
(G)
VHP
000
0.3959
1.8 V
-
14
-
-
7
-
mW
rms
2.5 V
-
14
-
-
7
-
mW
rms
001
0.4571
1.8 V
-
19
-
-
10
-
mW
rms
2.5 V
-
19
-
-
10
-
mW
rms
010
0.5111
1.8 V
-
23
-
-
12
-
mW
rms
2.5 V
-
23
-
-
12
-
mW
rms
011 (default)
0.6047
1.8 V
-
17
-
mW
rms
2.5 V
-
32
-
-
17
-
mW
rms
100
0.7099
1.8 V
-
23
-
mW
rms
2.5 V
-
44
-
-
23
-
mW
rms
101
0.8399
1.8 V
mW
rms
2.5 V
-
32
-
mW
rms
110
1.0000
1.8 V
(
) See
mW
rms
2.5 V
mW
rms
111
1.1430
1.8 V
mW
rms
2.5 V
mW
rms
Parameters
(Note 10)
Symbol Conditions
Min
Typ
Max Units
AOUTx
AGND
R
L
C
L
0.022
F
51
Figure 2. Headphone Output Test Load