MAX9770ETI+T Maxim Integrated Products, MAX9770ETI+T Datasheet - Page 11

• Manufacturer Part Number: MAX9770ETI+T
• Description: IC AMP AUDIO 1.2W MONO D 28TQFN
• Manufacturer: Maxim Integrated Products
• Type: Class Dr

Specifications of MAX9770ETI+T

• Output Type: 1-Channel (Mono) with Stereo Headphones
• Max Output Power X Channels @ Load: 1.2W x 1 @ 8 Ohm; 80mW x 2 @ 16 Ohm
• Voltage - Supply: 2.5 V ~ 5.5 V
• Features: Depop, Input Multiplexer, Mute, Short-Circuit and Thermal Protection, Shutdown
• Mounting Type: Surface Mount
• Package / Case: 28-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The MAX9770 combines a mono 1.2W Class D speaker
amplifiers and stereo 80mW DirectDrive headphone
amplifiers with integrated headphone sensing and
comprehensive click-and-pop suppression. A
mixer/multiplexer allows for selection and mixing
between two stereo input sources and a single mono
source. The MAX9770 features PSRR as high as 85dB,
THD as low as 0.015%, industry-leading click-and-pop
suppression, and a low-power shutdown mode.
The MAX9770 Class D amplifier features true filterless,
low-EMI, switch-mode architecture that provides Class
AB-like performance with Class D efficiency.
Comparators monitor the MAX9770 input and compare
the input voltage to a sawtooth waveform. The com-
parators trip when the input magnitude of the sawtooth
exceeds the corresponding input voltage. The com-
parator resets at a fixed time after the rising edge of the
Figure 1. MAX9770 Outputs with an Input Signal Applied
1.2W, Low-EMI, Filterless, Mono Class D Amplifier
with Stereo DirectDrive Headphone Amplifiers
V
V
V
IN+
OUT+
IN-
- V
______________________________________________________________________________________
OUT-
OUT+
OUT-
Class D Speaker Amplifier
Detailed Description
t
ON(MIN)
t
SW
second comparator trip point, generating a minimum-
width pulse t
parator (Figure 1). As the input voltage increases or
decreases, the duration of the pulse at one output
increases (the first comparator trip point) while the
other output pulse duration remains at t
causes the net voltage across the speaker (V
V
Table 1. Operating Modes
OUT-
SYNC INPUT
Unconnected
Clocked
) to change.
GND
V
DD
ON(MIN)
FFPWM with f
FFPWM with f
SSPWM with f
FFPWM with f
at the output of the second com-
S
S
S
S
= 1100kHz
= 1450kHz
= external clock frequency
= 1220kHz ±120kHz
MODE
ON(MIN)
OUT+
. This
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