User guide

MAX9700
1.2W, Low-EMI, Filterless,
Class D Audio Amplifier
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= PV
DD
= SHDN = 3.3V, GND = PGND = 0V, SYNC = GND (FFM), R
L
= 8Ω, R
L
connected between OUT+ and OUT-
(MAX9700B), 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
= 6Ω, L = 47µH.
For R
L
= 8Ω, L = 68µH. For R
L
= 16Ω, L = 136µH.
Note 3: PSRR is specified with the amplifier inputs connected to GND through C
IN
.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
FFM 89
BW = 22Hz
to 22kHz
SSM 87
FFM 92
Signal-to-Noise Ratio SNR V
OUT
= 2V
RMS
A-weighted
SSM 90
dB
SYNC = GND 980 1100 1220
SYNC = float 1280 1450 1620
Oscillator Frequency f
OSC
SYNC = V
DD
(SSM mode)
1220
±120
kHz
SYNC Frequency Lock Range 800 2000 kHz
Efficiency η P
OUT
= 500mW, f
IN
= 1kHz 94 %
DIGITAL INPUTS (SHDN, SYNC)
V
IH
2
Input Thresholds
V
IL
0.8
V
SHDN Input Leakage Current ±1µA
SYNC Input Current ±5µA
ELECTRICAL CHARACTERISTICS
(V
DD
= PV
DD
= SHDN = 5V, GND = PGND = 0V, SYNC = GND (FFM), R
L
= 8Ω, R
L
connected between OUT+ and OUT-
(MAX9700B), 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
5.2 mA
Shutdown Current I
SHDN
0.1 µA
Common-Mode Rejection Ratio CMRR f = 1kHz, input referred 72 dB
f = 217Hz 72
Power-Supply Rejection Ratio PSRR 200mV
P-P
ripple
f = 20kHz 55
dB
R
L
= 16Ω 700
R
L
= 8Ω 1200Output Power P
OUT
THD+N = 1%
R
L
= 6Ω 1600
mW
R
L
= 8Ω, P
OUT
= 125mW 0.015
Total Harmonic Distortion
Plus Noise
THD+N
f = 1kHz, either
FFM or SSM
R
L
= 4Ω, P
OUT
= 125mW 0.02
%
FFM 92.5
BW = 22Hz to
22kHz
SSM 90.5
FFM 95.5
Signal-to-Noise Ratio SNR
V
OUT
=
3V
RMS
A-weighted
SSM 93.5
dB