Mono 7W Class D Amplifier

Direct-from-Battery 7W Class D Amplifier Slashes Notebook 2.1 Solution Cost


The MAX9737 mono 7W Class D amplifier provides a high-performance, thermally efficient amplifier solution that offers up to 88% efficiency at a 12V supply. The device operates from 8V to 28V and provides a high 80dB PSRR, eliminating the need for a regulated power supply.

Filterless modulation allows the MAX9737 to pass CE EMI limits with 1m cables using only a low-cost ferrite bead and small-value capacitor on each output.

Comprehensive click-and-pop suppression circuitry reduces noise on power-up/down or into and out of shutdown or mute.

An input op amp allows the user to create a lowpass or highpass filter, and select an optimal gain. The internal precharge circuit ensures clickless/popless turn-on within 10ms.

The MAX9737 is available in the 24-pin, TQFN-EP package and is specified over the -40°C to +85°C temperature range.
MAX9737: Typical Application Circuit MAX9737: Typical Application Circuit Enlarge+

Key Features

  • 8V to 28V Supply Voltage Range
  • Spread-Spectrum Modulation Enables Low-EMI Solution
  • Passes EMI Limit with Up to 1m of Speaker Cable
  • High 80dB PSRR
  • Up to 88% Efficiency Eliminates Heatsink
  • Thermal and Output Current Protection
  • < 1µA Shutdown Mode
  • Click-and-Pop Suppression
  • < 10ms Turn-On Time
  • Space-Saving, 4mm x 4mm x 0.8mm, 24-Pin TQFN Package


  • 2.1 Notebook PCs
  • LCD/PDP/CRT Monitors
  • MP3 Docking Stations
  • PC Surround Speakers
Part Number Class Spkr. Amp. VCC
Spkr. Amp. VCC
Spkr. Amp. ICC
POUT into 4Ω @ 1% THD+N
POUT into 4Ω @ 10% THD+N
POUT into 8Ω @ 1% THD+N
POUT into 8Ω @ 10% THD+N
Spkr. Amp. Half Pwr. THD+N
Package/Pins Budgetary
min max typ min min min min A- Weighted min See Notes
MAX9737  D 8 28 15 12 14 6 7.5 0.06 97 80
$1.09 @1k
See All Speaker Amplifiers (34)
Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

MAX9737EVKIT: Evaluation Kit for the MAX9737

Quality and Environmental Data

Product Reliability Reports: MAX9737.pdf 
Lead-Free Package Tin (Sn) Whisker Reports

Related Resources