MAX9720, MAX9720A, MAX9720B 50mW, DirectDrive, Stereo Headphone Amplifier with SmartSense and Shutdown

Description

The MAX9720 stereo headphone amplifier combines Maxim's patented DirectDrive architecture and SmartSense™, an automatic mono/stereo detection feature. Conventional headphone amplifiers require a bulky DC-blocking capacitor between the headphone and the amplifier. DirectDrive produces a ground-referenced output from a single supply, eliminating the need for large DC-blocking capacitors, saving cost, board space, and component height.

SmartSense automatically detects the presence of a short at either the left or right amplifier output. Under a fault condition, the shorted output is automatically disabled and the stereo input signal is automatically mixed and routed to the remaining active channel. This feature is useful in cell phone and PDA applications where a variety of headphone jacks with unknown loads can be inserted into the headphone jack socket. SmartSense prevents both damage to the amplifier and eliminates battery drain into a shorted load.

The MAX9720 delivers up to 50mW per channel into a 16Ω load and has an ultra-low 0.003% THD+N. A high (92dB at 217kHz) power-supply rejection ratio (PSRR) allows the device to operate from noisy digital supplies without additional power conditioning. The gain of the MAX9720 is set internally, further reducing component count. Two gain options are available (-1V/V, MAX9720A and -1.41V/V, MAX9720B). The headphone outputs include a comprehensive click-and-pop circuitry that eliminates audible glitches on startup and shutdown. A shutdown mode provides a fast 250µs turn-on time.

The MAX9720 operates from a single 1.8V to 3.6V supply and consumes only 5mA of supply current. The MAX9720 also features thermal overload protection, and is specified over the extended -40°C to +85°C temperature range. The MAX9720 is available in a tiny (2mm x 2mm x 0.6mm) 16-bump chip-scale package (UCSP™) and a 16-pin TSSOP package.

Key Features

Applications/Uses

DirectDrive Eliminates Bulky DC-Blocking Capacitors
SmartSense Automatic Short Detection
Low 5mA Quiescent Current
Fixed Gain Eliminates External Feedback Network
- MAX9720A: -1V/V
- MAX9720B: -1.41V/V
50mW per Channel Output Power
Ultra-Low 0.003% THD+N
High PSRR (92dB at 217Hz)
Integrated Click-and-Pop Suppression
1.8V to 3.6V Single-Supply Operation
Thermal Overload Protection
Available in Space-Saving Packages
- 16-Bump UCSP (2mm x 2mm x 0.6mm)
- 16-Pin TSSOP

	Cell Phones
	MP3 Players
	Notebook Computers
	PDAs
	Portable Audio Equipment
	Smartphones
	Tablet PCs

Key Specifications: Headphone Amplifiers

Part Number

Headphone Amp. V_CC (min) (V)

Headphone Amp. V_CC (max) (V)

Headphone Amp. I_CC (typ) (mA)

Headph. Amp. P_OUT into 32Ω @1% THD+N (W)

Headphone Amp. Half Pwr. THD+N (%)

SNR, A-weighted (dB)

PSRR (db)

Headphone Amp. External Gain

Headphone Amp. Fixed Gain (min) (|V/V|)

Headphone Amp. Fixed Gain (max) (|V/V|)

Features

RoHS Available

Package

Smallest Available Package (max w/pins) (mm²)

Price^**

MAX9720

1.8

3.6

0.006

100

1.41

•	SmartSense Automatic Short Circuit Detection

Yes

UCSP/16

$0.65 @ 1k

See All Headphone Amplifiers (11)

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 prices and delivery, please see the price and availability page or contact an authorized distributor.

Ordering Information

Notes:

Other options and links for purchasing parts are listed at: http://www.maxim-ic.com/sales.
Didn't Find What You Need? Ask our applications engineers. Expert assistance in finding parts, usually within one business day.
Part number suffixes: T or T&R = tape and reel; + = RoHS/lead-free; # = RoHS/lead-exempt. More: SeeFull Data Sheet or Part Naming Conventions.
* Some packages have variations, listed on the drawing. "PkgCode/Variation" tells which variation the product uses. Note that "+", "#", "-" in the part number suffix describes RoHS status. Package drawings may show a different suffix character.

Devices: 1-8 of 8

MAX9720A

Free
Sample

Buy

Package:	TYPE PINS FOOTPRINT
	DRAWING CODE/VAR *

Temp

RoHS/Lead-Free?
Materials Analysis

MAX9720AEBE+

UCSP;16 pin;4 mm²
Dwg: 21-0101H (PDF)
Use pkgcode/variation: B16+1*

0°C to +70°C

RoHS/Lead-Free: Lead Free
Materials Analysis

MAX9720AEBE

UCSP;16 pin;4 mm²
Dwg: 21-0101H (PDF)
Use pkgcode/variation: B16-1*

0°C to +70°C

RoHS/Lead-Free: No
Materials Analysis

MAX9720AEBE-T

UCSP;16 pin;4 mm²
Dwg: 21-0101H (PDF)
Use pkgcode/variation: B16-1*

0°C to +70°C

RoHS/Lead-Free: No
Materials Analysis

MAX9720AEBE+T

UCSP;16 pin;4 mm²
Dwg: 21-0101H (PDF)
Use pkgcode/variation: B16+1*

0°C to +70°C

RoHS/Lead-Free: Lead Free
Materials Analysis

MAX9720B

Free
Sample

Buy

Package:	TYPE PINS FOOTPRINT
	DRAWING CODE/VAR *

Temp

RoHS/Lead-Free?
Materials Analysis

MAX9720BEBE+

UCSP;16 pin;4 mm²
Dwg: 21-0101H (PDF)
Use pkgcode/variation: B16+1*

0°C to +70°C

RoHS/Lead-Free: Lead Free
Materials Analysis

MAX9720BEBE

UCSP;16 pin;4 mm²
Dwg: 21-0101H (PDF)
Use pkgcode/variation: B16-1*

0°C to +70°C

RoHS/Lead-Free: No
Materials Analysis

MAX9720BEBE-T

UCSP;16 pin;4 mm²
Dwg: 21-0101H (PDF)
Use pkgcode/variation: B16-1*

0°C to +70°C

RoHS/Lead-Free: No
Materials Analysis

MAX9720BEBE+T

UCSP;16 pin;4 mm²
Dwg: 21-0101H (PDF)
Use pkgcode/variation: B16+1*

0°C to +70°C

RoHS/Lead-Free: Lead Free
Materials Analysis

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