Datasheet

MAX9705
2.3W, Ultra-Low-EMI, Filterless,
Class D Audio Amplifier
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= PV
DD
= V
SHDN
= 3.3V, V
GND
= V
PGND
= 0, SYNC = GND (FFM), R
L
= ∞, R
L
connected between OUT+ and OUT-,
T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.) (Notes 1, 2)
Note 1: All devices are 100% production tested at +25°C. All temperature limits are guaranteed by design.
Note 2: Testing performed with a resistive load in series with an inductor to simulate an actual speaker load. For R
L
= 4Ω, L = 33µH.
For R
L
= 8Ω, L = 68µH. For R
L
= 16Ω, L = 136µH.
Note 3: Inputs AC-coupled to GND.
Note 4: Testing performed with 8Ω resistive load in series with 68µH inductive load connected across BTL output. Mode transitions
are controlled by SHDN pin. K
CP
level is calculated as 20 x log[(peak voltage under normal operation at rated power
level)/(peak voltage during mode transition, no input signal)]. Units are expressed in dB.
Note 5: SYNC has a 1MΩ resistor to V
REF
= 1.25V.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Rise/Fall Time t
RISE
, t
FALL
10% to 90% 15 ns
FFM 91
BW = 22Hz
to 22kHz
SSM 89
FFM 93
Signal-to-Noise Ratio SNR V
OUT
= 2V
RMS
A-weighted
SSM 91
dB
SYNC = GND 980 1100 1220
Oscillator Frequency f
OSC
SYNC = V
DD
(SSM mode)
1220
±120
kHz
SYNC Frequency Lock Range 800 2000 kHz
Efficiency η P
OUT
= 800mW, f
IN
= 1kHz, R
L
= 8Ω 89 %
DIGITAL INPUTS (SHDN, SYNC)
V
IH
2
Input Thresholds
V
IL
0.8
V
SHDN Input Leakage Current 0.1 ±10 µA
SYNC Input Current (Note 5) -1.25 ±10 µA
ELECTRICAL CHARACTERISTICS
(V
DD
= PV
DD
= V
SHDN
= 5V, V
GND
= V
PGND
= 0, SYNC = GND (FFM), R
L
= ∞, R
L
connected between OUT+ and OUT-,
T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.) (Notes 1, 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Quiescent Current I
DD
7mA
Shutdown Current I
SHDN
0.55 µA
f = 217Hz 75
Power-Supply Rejection Ratio PSRR 200mV
P-P
ripple
f = 20kHz 60
dB
R
L
= 16Ω 750
R
L
= 8Ω 1400
Output Power P
OUT
THD+N = 1%,
f = 1kHz
R
L
= 4Ω
MAX9705_ETB+T and
MAX9705_EUB+ only
2300
mW
R
L
= 8Ω, P
OUT
= 1.0W 0.02
Total Harmonic Distortion
Plus Noise
THD+N
f = 1kHz, either
FFM or SSM
R
L
= 4Ω, P
OUT
= 1.75W 0.05
%
FFM 94
BW = 22Hz to
22kHz
SSM 91
FFM 97
Signal-to-Noise Ratio SNR
V
OUT
=
3V
RMS
A-weighted
SSM 93
dB